Add decimal module and operator interop registry

Use canonical class identity for delegate checks
Fix lazy delegate type resolution across modules
2026-03-27 21:31:37 +03:00 · 2026-03-27 19:19:38 +03:00 · 2026-03-27 18:57:27 +03:00 · 2026-03-27 18:46:53 +03:00 · 2026-03-27 16:10:49 +03:00 · 2026-03-27 15:53:12 +03:00
491 changed files with 69439 additions and 12568 deletions
@@ -17,3 +17,13 @@ xcuserdata
 /sample_texts/1.txt.gz
 /kotlin-js-store/wasm/yarn.lock
 /distributables
 .output*.txt
 debug.log
 /build.log
 /test.md
 /build_output.txt
 /build_output_full.txt
 /check_output.txt
 /compile_jvm_output.txt
 /compile_metadata_output.txt
 test_output*.txt
@@ -0,0 +1,11 @@
 # Lyng Project Guidelines
 This project uses the Lyng scripting language for multiplatform scripting.
 ## Coding in Lyng
 When writing, refactoring, or analyzing Lyng code:
 - **Reference**: Always use `LYNG_AI_SPEC.md` in the project root as the primary source of truth for syntax and idioms.
 - **File Extensions**: Use `.lyng` for all script files.
 - **Implicit Coroutines**: Remember that all Lyng functions are implicitly coroutines; do not look for `async/await`.
 - **Everything is an Expression**: Leverage the fact that blocks, if-statements, and loops return values.
 - **Maps vs Blocks**: Be careful: `{}` is a block/lambda, use `Map()` for an empty map.
@@ -0,0 +1,28 @@
 <component name="ProjectRunConfigurationManager">
  <configuration default="false" name="Tests in 'lyng.lynglib.jvmTest'" type="GradleRunConfiguration" factoryName="Gradle">
    <ExternalSystemSettings>
      <option name="executionName" />
      <option name="externalProjectPath" value="$PROJECT_DIR$" />
      <option name="externalSystemIdString" value="GRADLE" />
      <option name="scriptParameters" value="" />
      <option name="taskDescriptions">
        <list />
      </option>
      <option name="taskNames">
        <list>
          <option value=":lynglib:cleanJvmTest" />
          <option value=":lynglib:jvmTest" />
        </list>
      </option>
      <option name="vmOptions" />
    </ExternalSystemSettings>
    <ExternalSystemDebugServerProcess>false</ExternalSystemDebugServerProcess>
    <ExternalSystemReattachDebugProcess>true</ExternalSystemReattachDebugProcess>
    <ExternalSystemDebugDisabled>false</ExternalSystemDebugDisabled>
    <DebugAllEnabled>false</DebugAllEnabled>
    <RunAsTest>true</RunAsTest>
    <GradleProfilingDisabled>false</GradleProfilingDisabled>
    <GradleCoverageDisabled>false</GradleCoverageDisabled>
    <method v="2" />
  </configuration>
 </component>
@@ -1,3 +1,20 @@
 <!--
  ~ Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~     http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  ~
  -->
 <component name="ProjectRunConfigurationManager">
  <configuration default="false" name="lyng:site [jsBrowserDevelopmentRun]" type="GradleRunConfiguration" factoryName="Gradle">
    <ExternalSystemSettings>
@@ -17,8 +34,11 @@
    </ExternalSystemSettings>
    <ExternalSystemDebugServerProcess>true</ExternalSystemDebugServerProcess>
    <ExternalSystemReattachDebugProcess>true</ExternalSystemReattachDebugProcess>
    <ExternalSystemDebugDisabled>false</ExternalSystemDebugDisabled>
    <DebugAllEnabled>false</DebugAllEnabled>
    <RunAsTest>false</RunAsTest>
    <GradleProfilingDisabled>true</GradleProfilingDisabled>
    <GradleCoverageDisabled>true</GradleCoverageDisabled>
    <method v="2" />
  </configuration>
 </component>
@@ -0,0 +1,41 @@
 # AI Agent Notes
 ## Canonical AI References
 - Use `docs/ai_language_reference.md` as the primary, compiler-verified Lyng language reference for code generation.
 - For generics-heavy code generation, follow `docs/ai_language_reference.md` section `7.1 Generics Runtime Model and Bounds` and `7.2 Differences vs Java / Kotlin / Scala`.
 - Use `docs/ai_stdlib_reference.md` for default runtime/module APIs and stdlib surface.
 - Treat `LYNG_AI_SPEC.md` and older docs as secondary if they conflict with the two files above.
 - Prefer the shortest clear loop: use `for` for straightforward iteration/ranges; use `while` only when loop state/condition is irregular or changes in ways `for` cannot express cleanly.
 - In Lyng code, slice strings with range indexing (`text[a..<b]`, `text[..<n]`, `text[n..]`) and avoid Java/Kotlin-style `substring(...)`.
 ## Lyng-First API Declarations
 - Use `.lyng` declarations as the single source of truth for Lyng-facing API docs and types (especially module extern declarations).
 - Prefer defining Lyng entities (enums/classes/type shapes) in `.lyng` files; only define them in Kotlin when there is Kotlin/platform-specific implementation detail that cannot be expressed in Lyng.
 - Avoid hardcoding Lyng API documentation in Kotlin registrars when it can be declared in `.lyng`; Kotlin-side docs should be fallback/bridge only.
 - For mixed pluggable modules (Lyng + Kotlin), embed module `.lyng` sources as generated Kotlin string literals, evaluate them into module scope during registration, then attach Kotlin implementations/bindings.
 ## Kotlin/Wasm generation guardrails
 - Avoid creating suspend lambdas for compiler runtime statements. Prefer explicit `object : Statement()` with `override suspend fun execute(...)`.
 - Do not use `statement { ... }` or other inline suspend lambdas in compiler hot paths (e.g., parsing/var declarations, initializer thunks).
 - If you need a wrapper for delegated properties, check for `getValue` explicitly and return a concrete `Statement` object when missing; avoid `onNotFoundResult` lambdas.
 - If wasmJs browser tests hang, first run `:lynglib:wasmJsNodeTest` and look for wasm compilation errors; hangs usually mean module instantiation failed.
 - Do not increase test timeouts to mask wasm generation errors; fix the invalid IR instead.
 ## Type inference notes (notes/new_lyng_type_system_spec.md)
 - Nullability is Kotlin-style: `T` non-null, `T?` nullable, `!!` asserts non-null.
 - `void` is a singleton of class `Void` (syntax sugar for return type).
 - Object members are always allowed even on unknown types; non-Object members require explicit casts. Remove `inspect` from Object and use `toInspectString()` instead.
 - Type expression checks: `x is T` is value instance check; `T1 is T2` is type-subset; `A in T` means `A` is subset of `T`; `==` is structural type equality.
 - Type aliases: `type Name = TypeExpr` (generic allowed) expand to their underlying type expressions; no nominal distinctness.
 - Bounds and variance: `T: A & B` / `T: A | B` for bounds; declaration-site variance with `out` / `in`.
 - Do not reintroduce bytecode fallback opcodes (e.g., `GET_NAME`, `EVAL_*`, `CALL_FALLBACK`) or runtime name-resolution fallbacks; all symbol resolution must stay compile-time only.
 ## Bytecode frame-first migration plan
 - Treat frame slots as the only storage for locals/temps by default; avoid pre-creating scope slot mappings for compiled functions.
 - Create closure references only when a capture is detected; use a direct frame+slot reference (foreign slot ref) instead of scope slots.
 - Keep Scope as a lazy reflection facade: resolve name -> slot only on demand for Kotlin interop (no eager name mapping on every call).
 - Avoid PUSH_SCOPE/POP_SCOPE in bytecode for loops/functions unless dynamic name access or Kotlin reflection is requested.
 ## ABI proposal notes
 - Runtime generic metadata for generic extern classes is tracked in `proposals/extern_generic_runtime_abi.md`.
 - Keep this design `Obj`-centric: do not assume extern-class values are `ObjInstance`; collection must be enabled on `ObjClass`.
@@ -1,83 +1,88 @@
 ## Changelog
 ### Unreleased
 - Docs: Scopes and Closures guidance
  - New page: `docs/scopes_and_closures.md` detailing `ClosureScope` resolution order, recursion‑safe helpers (`chainLookupIgnoreClosure`, `chainLookupWithMembers`, `baseGetIgnoreClosure`), cycle prevention, and capturing lexical environments for callbacks (`snapshotForClosure`).
  - Updated: `docs/advanced_topics.md` (link to the new page), `docs/parallelism.md` (closures in `launch`/`flow`), `docs/OOP.md` (visibility from closures with preserved `currentClassCtx`), `docs/exceptions_handling.md` (compatibility alias `SymbolNotFound`).
  - Tutorial: added quick link to Scopes and Closures.
 - IDEA plugin: Lightweight autocompletion (experimental)
  - Global completion: local declarations, in‑scope parameters, imported modules, and stdlib symbols.
  - Member completion: after a dot, suggests only members of the inferred receiver type (incl. chained calls like `Path(".." ).lines().` → `Iterator` methods). No global identifiers appear after a dot.
  - Inheritance-aware: direct class members first, then inherited (e.g., `List` includes `Collection`/`Iterable` methods).
  - Heuristics: handles literals (`"…"` → `String`, numbers → `Int/Real`, `[...]` → `List`, `{...}` → `Dict`) and static `Namespace.` members.
  - Performance: capped results, early prefix filtering, per‑document MiniAst cache, cancellation checks.
  - Toggle: Settings | Lyng Formatter → "Enable Lyng autocompletion (experimental)" (default ON).
  - Stabilization: DEBUG completion/Quick Doc logs are OFF by default; behavior aligned between IDE and isolated engine tests.
 - Language: Named arguments and named splats
  - New call-site syntax for named arguments using colon: `name: value`.
    - Positional arguments must come before named; positionals after a named argument inside parentheses are rejected.
    - Trailing-lambda interaction: if the last parameter is already assigned by name (or via a named splat), a trailing `{ ... }` block is illegal.
  - Named splats: `...` can now expand a Map into named arguments.
    - Only string keys are allowed; non-string keys raise a clear error.
    - Duplicate assignment across named args and named splats is an error.
    - Ellipsis (variadic) parameters remain positional-only and cannot be named.
  - Rationale: `=` is assignment and an expression in Lyng; `:` at call sites avoids ambiguity. Declarations keep `name: Type`; call-site casts continue to use `as` / `as?`.
  - Documentation updated: proposals and declaring-arguments sections now cover named args/splats and error cases.
  - Tests added covering success cases and errors for named args/splats and trailing-lambda interactions.
 - Tooling: Highlighters and TextMate bundle updated for named args
  - Website/editor highlighter (lyngweb + site) works with `name: value` and `...Map("k" => v)`; added JS tests covering punctuation/operator spans for `:` and `...`.
  - TextMate grammar updated to recognize named call arguments: `name: value` after `(` or `,` with `name` highlighted as `variable.parameter.named.lyng` and `:` as punctuation; excludes `::`.
  - TextMate bundle version bumped to 0.0.3; README updated with details and guidance.
 - Multiple Inheritance (MI) completed and enabled by default:
  - Active C3 Method Resolution Order (MRO) for deterministic, monotonic lookup across complex hierarchies and diamonds.
  - Qualified dispatch:
    - `this@Type.member(...)` inside class bodies starts lookup at the specified ancestor.
    - Cast-based disambiguation: `(expr as Type).member(...)`, `(expr as? Type)?.member(...)` (works with existing safe-call `?.`).
  - Field inheritance (`val`/`var`) under MI:
    - Instance storage is disambiguated per declaring class; unqualified read/write resolves to the first match in MRO.
    - Qualified read/write targets the chosen ancestor’s storage.
  - Constructors and initialization:
    - Direct bases are initialized left-to-right; each ancestor is initialized at most once (diamond-safe de-duplication).
    - Header-specified constructor arguments are passed to direct bases.
  - Visibility enforcement under MI:
    - `private` visible only inside the declaring class body.
    - `protected` visible inside the declaring class and any of its transitive subclasses; unrelated contexts cannot access it (qualification/casts do not bypass).
  - Diagnostics improvements:
    - Missing member/field messages include receiver class and linearization order; hints for `this@Type` or casts when helpful.
    - Invalid `this@Type` reports that the qualifier is not an ancestor and shows the receiver lineage.
    - `as`/`as?` cast errors include actual and target type names.
 - Documentation updated (docs/OOP.md and tutorial quick-start) to reflect MI with active C3 MRO.
 Notes:
 - Existing single-inheritance code continues to work; resolution reduces to the single base.
 - If code previously relied on non-deterministic parent set iteration, C3 MRO provides a predictable order; disambiguate explicitly if needed using `this@Type`/casts.
 # Changelog
-All notable changes to this project will be documented in this file.
+This file tracks user-visible Lyng language/runtime/tooling changes.
-## Unreleased
+History note:
 - The project had periods where changelog maintenance lagged behind commits.
 - Entries below are synchronized and curated for `1.5.x`.
 - Earlier history may be incomplete and should be cross-checked with git tags/commits when needed.
- CLI: Added `fmt` as a first-class Clikt subcommand.
+## 1.5.1 (2026-03-25)
  - Default behavior: formats files to stdout (no in-place edits by default).
  - Options:
    - `--check`: check only; print files that would change; exit with code 2 if any changes are needed.
    - `-i, --in-place`: write formatted result back to files.
    - `--spacing`: apply spacing normalization.
    - `--wrap`, `--wrapping`: enable line wrapping.
  - Mutually exclusive: `--check` and `--in-place` together now produce an error and exit with code 1.
  - Multi-file stdout prints headers `--- <path> ---` per file.
  - `lyng --help` shows `fmt`; `lyng fmt --help` displays dedicated help.
- CLI: Preserved legacy script invocation fast-paths:
+### Language
-  - `lyng script.lyng [args...]` executes the script directly.
+- Added string interpolation:
-  - `lyng -- -file.lyng [args...]` executes a script whose name begins with `-`.
+  - `"$name"` identifier interpolation.
  - `"${expr}"` expression interpolation.
 - Added literal-dollar forms in strings:
  - `"\$"` -> `$`
  - `"$$"` -> `$`
  - `\\$x` is parsed as backslash + interpolation of `x`.
 - Added per-file interpolation opt-out via leading directive comment:
  - `// feature: interpolation: off`
- CLI: Fixed a regression where the root help banner could print before subcommands.
+### Docs and AI references
-  - Root command no longer prints help when a subcommand (e.g., `fmt`) is invoked.
+- Updated compiler-accurate AI language docs:
  - interpolation syntax and escaping
  - per-file feature switch behavior
 - Refreshed tutorial examples and doctests to reflect new interpolation semantics.
 - Added/reworked current proposal/reference materials for Lyng common-platform guidance.
 ### Compatibility notes
 - Interpolation is enabled by default for normal string literals.
 - Existing code that intentionally used `$name` as literal text should use `\$name`, `$$name`, or the file directive `// feature: interpolation: off`.
 ## 1.5.0 (2026-03-22)
 ### Major runtime/compiler direction
 - Completed migration to bytecode-first/bytecode-only execution paths.
 - Removed interpreter fallback behavior in core execution hot paths.
 - Continued frame-slot-first local/capture model improvements and related diagnostics.
 ### Language features and semantics
 - Added/finished `return` semantics including labeled non-local forms (`return@label`).
 - Added abstract classes/members and `interface` support (as abstract-class-style construct).
 - Completed and enabled multiple inheritance with C3 MRO by default.
 - Added class properties with accessors (`get`/`set`) and restricted setter visibility (`private set`, `protected set`).
 - Added late-initialized class `val` support with `Unset` protection rules.
 - Added named arguments (`name: value`) and named splats (`...map`) with stricter validation.
 - Added assign-if-null operator `?=`.
 - Improved nullable/type-checking behavior (including `T is nullable` and related type checks).
 - Added variadic function types (`...` in function type declarations) and tighter lambda type checks.
 ### Type system and collections
 - Added immutable collections hierarchy (`ImmutableList`, `ImmutableSet`, `ImmutableMap`).
 - Improved generic runtime binding/checking for explicit type arguments and bounds.
 - Added smarter type-aware collection ops (`+=`, `-=`) and stronger declared-member type checks.
 ### Extern/Kotlin bridge
 - Tightened extern declaration rules:
  - explicit extern members are required for extern class/object declarations.
 - Improved extern generic class behavior and diagnostics.
 - Extended bridge APIs for binding global functions/variables and object/member interop scenarios.
 ### Standard library and modules
 - Added `lyng.observable` improvements (`ObservableList` hooks/events).
 - Added `Random` stdlib API used by updated samples.
 - Added/extended `lyngio.console` support and CLI integration for console interaction.
 - Migrated time APIs to `kotlin.time` (`Instant` migration and related docs/tests).
 ### CLI, IDE, and docs/tooling
 - CLI:
  - added first-class `fmt` command
  - preserved direct script fast-path invocation
  - improved command help/dispatch behavior
 - IntelliJ plugin:
  - improved lightweight completion and documentation/inspection behavior
  - continued highlighter and Grazie/spellchecking integration work
 - Docs:
  - substantial updates across tutorial/OOP/type/runtime references
  - expanded bytecode and advanced topics coverage
 ## Migration checklist for 1.5.x
 - If you rely on literal `$...` strings:
  - replace with `\$...` or `$$...`, or
  - add `// feature: interpolation: off` at file top.
 - Review any code relying on interpreter-era fallback behavior; 1.5.x assumes bytecode-first execution.
 - For extern declarations, ensure members are explicitly declared where required.
 - For named arguments/splats, verify call sites follow stricter ordering/duplication rules.
@@ -0,0 +1,130 @@
 # Lyng Language AI Specification (V1.5.0-SNAPSHOT)
 High-density specification for LLMs. Reference this for all Lyng code generation.
 ## 1. Core Philosophy & Syntax
 - **Everything is an Expression**: Blocks, `if`, `when`, `for`, `while`, `do-while` return their last expression (or `void`).
 - **Static Types + Inference**: Every declaration has a compile-time type (explicit or inferred). Types are Kotlin‑style: non‑null by default, nullable with `?`.
 - **Loops with `else`**: `for`, `while`, and `do-while` support an optional `else` block.
    - `else` executes **only if** the loop finishes normally (without a `break`).
    - `break <value>` exits the loop and sets its return value.
    - Loop Return Value:
        1. Value from `break <value>`.
        2. Result of `else` block (if loop finished normally and `else` exists).
        3. Result of the last iteration (if loop finished normally and no `else`).
        4. `void` (if loop body never executed and no `else`).
 - **Implicit Coroutines**: All functions are coroutines. No `async/await`. Use `launch { ... }` (returns `Deferred`) or `flow { ... }`.
 - **Functions**: Use `fun` or the short form `fn`. Function declarations are expressions returning a callable.
 - **Variables**: `val` (read-only), `var` (mutable). Supports late-init `val` in classes (must be assigned in `init` or body).
 - **Serialization**: Use `@Transient` attribute before `val`/`var` or constructor parameters to exclude them from Lynon/JSON serialization. Transient fields are also ignored during `==` structural equality checks.
 - **Null Safety**: `?` (nullable type), `?.` (safe access), `?( )` (safe invoke), `?{ }` (safe block invoke), `?[ ]` (safe index), `?:` or `??` (elvis), `?=` (assign-if-null).
 - **Equality**: `==` (equals), `!=` (not equals), `===` (ref identity), `!==` (ref not identity).
 - **Comparison**: `<`, `>`, `<=`, `>=`, `<=>` (shuttle/spaceship, returns -1, 0, 1).
 - **Destructuring**: `val [a, b, rest...] = list`. Supports nested `[a, [b, c]]` and splats.
 - **Compile-Time Resolution Only**: All names/members must resolve at compile time. No runtime name lookup or fallback opcodes.
 ## 2. Object-Oriented Programming (OOP)
 - **Multiple Inheritance**: Supported with **C3 MRO** (Python-style). Diamond-safe.
 - **Header Arguments**: `class Foo(a, b) : Base(a)` defines fields `a`, `b` and passes `a` to `Base`.
 - **Members**: `fun name(args) { ... }`, `val`, `var`, `static val`, `static fun`.
 - **Properties (Get/Set)**: Pure accessors, no auto-backing fields.
    ```lyng
    var age
        get() = _age
        private set(v) { if(v >= 0) _age = v }
    // Laconic syntax:
    val area get = π * r * r
    ```
 - **Mandatory `override`**: Required for all members existing in the ancestor chain.
 - **Visibility**: `public` (default), `protected` (subclasses and ancestors for overrides), `private` (this class instance only). `private set` / `protected set` allowed on properties.
 - **Disambiguation**: `this@Base.member()` or `(obj as Base).member()`. `as` returns a qualified view.
 - **Abstract/Interface**: `interface` is a synonym for `abstract class`. Both support state and constructors.
 - **Extensions**: `fun Class.ext()` or `val Class.ext get = ...`. Scope-isolated.
 - **Member Access**: Object members (`toString`, `toInspectString`, `let`, `also`, `apply`, `run`) are allowed on unknown types; all other members require a statically known receiver type or explicit cast.
 ## 2.1 Type System (2026)
 - **Root Type**: Everything is an `Object` (root of the hierarchy).
 - **Nullability**: Non-null by default (`T`), nullable with `T?`, `!!` asserts non-null.
 - **Untyped params**: `fun foo(x)` -> `x: Object`, `fun foo(x?)` -> `x: Object?`.
 - **Untyped vars**: `var x` is `Unset` until first assignment locks the type (including nullability).
  - `val x = null` -> type `Null`; `var x = null` -> type `Object?`.
 - **Inference**:
  - List literals infer union element types; empty list defaults to `List<Object>` unless constrained.
  - Map literals infer key/value types; empty map defaults to `Map<Object, Object>` unless constrained.
  - Mixed numeric ops promote `Int` + `Real` to `Real`.
 - **Type aliases**: `type Name = TypeExpr` (generic allowed). Aliases expand to their underlying type expressions (no nominal distinctness).
 - **Generics**: Bounds with `T: A & B` or `T: A | B`; variance uses `out`/`in` (declaration‑site only).
 - **Casts**: `as` is a runtime-checked cast; `as?` is safe-cast returning `null`. If the value is nullable, `as T` implies `!!`.
 ## 2.2 Type Expressions and Checks
 - **Value checks**: `x is T` (runtime instance check).
 - **Type checks**: `T1 is T2` and `A in T` are subset checks between type expressions (compile-time where possible).
 - **Type equality**: `T1 == T2` is structural (unions/intersections are order‑insensitive).
 - **Compile-time enforcement**: Bounds are checked at call sites; runtime checks only appear when the compile‑time type is too general.
 ## 3. Delegation (`by`)
 Unified model for `val`, `var`, and `fun`.
 ```lyng
 val x by MyDelegate()
 var y by Map() // Uses "y" as key in map
 fn f(a, b) by RemoteProxy() // Calls Proxy.invoke(thisRef, "f", a, b)
 ```
 Delegate Methods:
 - `getValue(thisRef, name)`: for `val`/`var`.
 - `setValue(thisRef, name, val)`: for `var`.
 - `invoke(thisRef, name, args...)`: for `fn` (called if `getValue` is absent).
 - `bind(name, access, thisRef)`: optional hook called at declaration/binding time. `access` is `DelegateAccess.Val`, `Var`, or `Callable`.
 ## 4. Standard Library & Functional Built-ins
 - **Scope Functions**:
    - `obj.let { it... }`: result of block. `it` is `obj`.
    - `obj.apply { this... }`: returns `obj`. `this` is `obj`.
    - `obj.also { it... }`: returns `obj`. `it` is `obj`.
    - `obj.run { this... }`: result of block. `this` is `obj`.
    - `with(obj, { ... })`: result of block. `this` is `obj`.
 - **Functional**: `forEach`, `map`, `filter`, `any`, `all`, `sum`, `count`, `sortedBy`, `flatten`, `flatMap`, `associateBy`.
 - **Lazy**: `val x = cached { expensive() }` (call as `x()`) or `val x by lazy { ... }`.
 - **Collections**: `List` ( `[a, b]` ), `Map` ( `Map(k => v)` ), `Set` ( `Set(a, b)` ). `MapEntry` ( `k => v` ).
 ## 5. Patterns & Shorthands
 - **Map Literals**: `{ key: value, identifier: }` (identifier shorthand `x:` is `x: x`). Empty map is `{:}`.
 - **Named Arguments**: `fun(y: 10, x: 5)`. Shorthand: `Point(x:, y:)`.
 - **Varargs & Splats**: `fun f(args...)`, `f(...otherList)`.
 - **Labels**: `loop@ for(x in list) { if(x == 0) break@loop }`.
 - **Dynamic**: `val d = dynamic { get { name -> ... } }` allows `d.anyName` via explicit dynamic handler (not implicit fallback).
 ## 6. Operators & Methods to Overload
 | Op | Method | Op | Method |
 | :--- | :--- | :--- | :--- |
 | `+` | `plus` | `==` | `equals` |
 | `-` | `minus` | `<=>` | `compareTo` |
 | `*` | `mul` | `[]` | `getAt` / `putAt` |
 | `/` | `div` | `!` | `logicalNot` |
 | `%` | `mod` | `-` | `negate` (unary) |
 | `=~` | `operatorMatch` | `+=` | `plusAssign` |
 ## 7. Common Snippets
 ```lyng
 // Multiple Inheritance and Properties
 class Warrior(id, hp) : Character(id), HealthPool(hp) {
    override fun toString() = "Warrior #%s (%s HP)"(id, hp)
 }
 // Map entry and merging
 val m = Map("a" => 1) + ("b" => 2)
 m += "c" => 3
 // Destructuring with splat
 val [first, middle..., last] = [1, 2, 3, 4, 5]
 // Safe Navigation and Elvis
 val companyName = person?.job?.company?.name ?: "Freelancer"
 ```
 ## 8. Standard Library Discovery
 To collect data on the standard library and available APIs, AI should inspect:
 - **Global Symbols**: `lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt` (root functions like `println`, `sqrt`, `assert`).
 - **Core Type Members**: `lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/*.kt` (e.g., `ObjList.kt`, `ObjString.kt`, `ObjMap.kt`) for methods on built-in types.
 - **Lyng-side Extensions**: `lynglib/stdlib/lyng/root.lyng` for high-level functional APIs (e.g., `map`, `filter`, `any`, `lazy`).
 - **I/O & Processes**: `lyngio/src/commonMain/kotlin/net/sergeych/lyng/io/` for `fs` and `process` modules.
 - **Documentation**: `docs/*.md` (e.g., `tutorial.md`, `lyngio.md`) for high-level usage and module overviews.
@@ -1,47 +1,62 @@
-# Lyng: modern scripting for kotlin multiplatform
+# Lyng: ideal scripting for kotlin multiplatform
 __Please visit the project homepage: [https://lynglang.com](https://lynglang.com) and a [telegram channel](https://t.me/lynglang).__
 __Main development site:__ [https://gitea.sergeych.net/SergeychWorks/lyng](https://gitea.sergeych.net/SergeychWorks/lyng)
 __github mirror__: [https://github.com/sergeych/lyng](https://github.com/sergeych/lyng)
 We keep github as a mirror and backup for the project, while the main development site is hosted on gitea.sergeych.net. We use gitea for issues and pull requests, and as a main point of trust, as github access now is a thing that can momentarily be revoked for no apparent reason.
 We encourage using the github if the main site is not accessible from your country and vice versa. We recommend to `publishToMavenLocal` and not depend on politics.
 Please visit the project homepage: [https://lynglang.com](https://lynglang.com) and a [telegram channel](https://t.me/lynglang) for updates.
 - simple, compact, intuitive and elegant modern code:
-```
+```lyng
-class Point(x,y) {
+class Point(x, y) {
   fun dist() { sqrt(x*x + y*y) } 
 }
-Point(3,4).dist() //< 5
+
 // Auto-named arguments shorthand (x: is x: x):
 val x = 3
 val y = 4
 Point(x:, y:).dist() //< 5
 fun swapEnds(first, args..., last, f) {
    f( last, ...args, first)
 } 
 class A {
    class B(x?)
    object Inner { val foo = "bar" }
    enum E* { One, Two }
 }
 val ab = A.B()
 assertEquals(null, ab.x)
 assertEquals("bar", A.Inner.foo)
 assertEquals(A.E.One, A.One)
 ```
 - extremely simple Kotlin integration on any platform (JVM, JS, WasmJS, Lunux, MacOS, iOS, Windows)
 - 100% secure: no access to any API you didn't explicitly provide
- 100% coroutines! Every function/script is a coroutine, it does not block the thread, no async/await/suspend keyword garbage, see [parallelism]
+- 100% coroutines! Every function/script is a coroutine, it does not block the thread, no async/await/suspend keyword garbage, see [parallelism]. it is multithreaded on platforms supporting it (automatically, no code changes required, just `launch` more coroutines and they will be executed concurrently if possible). See [parallelism]
-
+- functional style and OOP together: multiple inheritance (so you got it all - mixins, interfaces, etc.), delegation, sigletons, anonymous classes,extensions.
-```
+- nice literals for maps and arrays, destructuring assignment, ranges.
  val deferred = launch {
    delay(1.5) // coroutine is delayed for 1.5s, thread is not blocked!
    "done"
  }
  // ...
  // suspend current coroutine, no thread is blocked again,
  // and wait for deferred to return something:
  assertEquals("donw", deferred.await())
 ```
 and it is multithreaded on platforms supporting it (automatically, no code changes required, just
 `launch` more coroutines and they will be executed concurrently if possible). See [parallelism]
 - functional style and OOP together, multiple inheritance, implementing interfaces for existing classes, writing extensions.
 - Any Unicode letters can be used as identifiers: `assert( sin(π/2) == 1 )`.
 ## Resources: 
 - [Language home](https://lynglang.com)
 - [introduction and tutorial](docs/tutorial.md) - start here please
 - [What's New in 1.5](docs/whats_new_1_5.md)
 - [Testing and Assertions](docs/Testing.md)
 - [Filesystem and Processes (lyngio)](docs/lyngio.md)
 - [Return Statement](docs/return_statement.md)
 - [Efficient Iterables in Kotlin Interop](docs/EfficientIterables.md)
 - [Samples directory](docs/samples)
 - [Formatter (core + CLI + IDE)](docs/formatter.md)
 - [Books directory](docs)
 - [AI agent guidance](AGENTS.md)
 ## Integration in Kotlin multiplatform
@@ -49,7 +64,7 @@ and it is multithreaded on platforms supporting it (automatically, no code chang
 ```kotlin
 // update to current please:
-val lyngVersion = "0.6.1-SNAPSHOT"
+val lyngVersion = "1.5.0-SNAPSHOT"
 repositories {
    // ...
@@ -73,7 +88,7 @@ Now you can import lyng and use it:
 ### Execute script:
 ```kotlin
-import net.sergeyh.lyng.*
+import net.sergeych.lyng.*
 // we need a coroutine to start, as Lyng
 // is a coroutine based language, async topdown
@@ -89,9 +104,7 @@ Script is executed over some `Scope`. Create instance,
 add your specific vars and functions to it, and call:
 ```kotlin
-
+import net.sergeych.lyng.*
 import com.sun.source.tree.Scope
 import new.sergeych.lyng.*
 // simple function
 val scope = Script.newScope().apply {
@@ -139,6 +152,12 @@ Tips:
 - After a dot, globals are intentionally suppressed (e.g., `lines().Path` is not valid), only the receiver’s members are suggested.
 - If completion seems sparse, make sure related modules are imported (e.g., `import lyng.io.fs` so that `Path` and its methods are known).
 ## AI Assistant Support
 To help AI assistants (like Cursor, Windsurf, or GitHub Copilot) understand Lyng with minimal effort, we provide a high-density language specification:
 - **[LYNG_AI_SPEC.md](LYNG_AI_SPEC.md)**: A concise guide for AI models to learn Lyng syntax, idioms, and core philosophy. We recommend pointing your AI tool to this file or including it in your project's custom instructions.
 ## Why? 
 Designed to add scripting to kotlin multiplatform application in easy and efficient way. This is attempt to achieve what Lua is for C/++.
@@ -158,7 +177,7 @@ Designed to add scripting to kotlin multiplatform application in easy and effici
 # Language Roadmap
-We are now at **v1.0**: basic optimization performed, battery included: standard library is 90% here, initial
+We are now at **v1.5.0-SNAPSHOT** (stable development cycle): basic optimization performed, battery included: standard library is 90% here, initial
 support in HTML, popular editors, and IDEA; tools to syntax highlight and format code are ready. It was released closed to schedule.
 Ready features:
@@ -170,6 +189,7 @@ Ready features:
 - [x] ranges, lists, strings, interfaces: Iterable, Iterator, Collection, Array
 - [x] when(value), if-then-else
 - [x] exception handling: throw, try-catch-finally, exception classes.
 - [x] user-defined exception classes
 - [x] multiplatform maven publication
 - [x] documentation for the current state
 - [x] maps, sets and sequences (flows?)
@@ -184,8 +204,20 @@ Ready features:
 - [x] better stack reporting
 - [x] regular exceptions + extended `when`
 - [x] multiple inheritance for user classes
 - [x] class properties (accessors)
 - [x] `return` statement for local and non-local exit
 - [x] Unified Delegation model: val, var and fun
 - [x] `lazy val` using delegation
 - [x] singletons `object TheOnly { ... }`
 - [x] object expressions `object: List { ... }`
 - [x] late-init vals in classes
 - [x] properties with getters and setters
 - [x] assign-if-null operator `?=`
 - [x] user-defined exception classes
-## plan: towards v1.5 Enhancing
+All of this is documented in the [language site](https://lynglang.com) and locally [docs/language.md](docs/tutorial.md). the current nightly builds published on the site and in the private maven repository.  
 ## plan: towards v2.0 Next Generation
 - [x] site with integrated interpreter to give a try
 - [x] kotlin part public API good docs, integration focused
@@ -0,0 +1,4 @@
 # Obsolete files
 __Do not rely on contents of the files in this directory. They are kept for historical reference only and may not be up-to-date or relevant.__
@@ -0,0 +1,117 @@
 /*
    This is a tech proposal under construction, please do not use it yet
    for any purpose
 */
 /*
    Abstract delegate can be used to proxy read/wrtie field access
    or method call. Default implementation reports error.
 */
 interface Delegate {
    fun getValue() = Unset
    fun setValue(newValue) { throw NotImplementedException("delegate setter is not implemented") }
    fun invoke(args...) { throw NotImplementedException("delegate setter is not implemented") }
 }
 /*
    Delegate cam be used to implement a val, var or fun, so there are
    access type enum to distinguish:
 */
 enum DelegateAccess {
    Val,
    Var,
    Callable
 }
 // Delegate can be associated by a val/var/fun in a declaraion site using `by` keyword
 val proxiedVal by proxy(1)
 var proxiedVar by proxy(2, 3)
 fun proxiedFun by proxy()
 // each proxy is a Lyng expression returning instance of the Proxy interface:
 /*
    Proxy interface is connecting some named property of a given kind with the `Delegate`.
    It removes the burden of dealing with property name and this ref on each get/set value
    or invoke allowing having one delegate per instance, execution buff.
 */
 interface Proxy {
    fun getDelegate(propertyName: String,access: DelegateAccess,thisRef: Obj?): Delegate
 }
 // val, var and fun can be delegated, local or class instance:
 class TestProxy: Proxy {
    override getDelegate(name,access,thisRef) {
        Delegate()
    }
 }
 val proxy = TestProxy()
 class Allowed {
    val v1 by proxy
    var v2 by proxy
    fun f1 by proxy
 }
 val v3 by proxy
 var v4 by proxy
 fun f2 by proxy
 /*
    It means that for example
    Allowed().f1("foo")
    would call a delegate.invoke("foo") on the `Delegate` instance supplied by `proxy`, etc.
 */
 // The practic sample: lazy value
 /*
    The delegate that caches single time evaluated value
 */
 class LazyDelegate(creator): Delegate {
    private var currentValue=Unset
    override fun getValue() {
        if( currentValue == Unset )
            currentValue = creator()
        currentValue
    }
 }
 /*
    The proxy to assign it
 */
 class LazyProxy(creator) {
    fun getDelegate(name,access,thisRef) {
        if( access != DelegateAccess.Val )
            throw IllegalArgumentException("only lazy val are allowed")
        LazyDelegate(creator)
    }
 }
 /*
    A helper function to simplify creation:
 */
 fun lazy(creator) {
    LazyProxy(creator)
 }
 // Usage sample and the test:
 var callCounter = 0
 assertEquals(0, clallCounter)
 val lazyText by lazy { "evaluated text" }
 // the lazy property is not yet evaluated:
 assertEquals(0, clallCounter)
 // now evaluate it by using it:
 assertEquals("evaluated text", lazyText)
 assertEquals(1, callCounter)
 // lazy delegate should fail on vars or funs:
 assertThrows { var bad by lazy { "should not happen" } }
 assertThrows { fun bad by lazy { 42 } }
@@ -0,0 +1,39 @@
 #!/bin/bash
 #
 # Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 #
 set -e
 echo "publishing all artifacts"
 echo
 ./gradlew publishToMavenLocal site:jsBrowserDistribution publish buildInstallablePlugin :lyng:linkReleaseExecutableLinuxX64 :lyng:installJvmDist --parallel
 #echo
 #echo "Creating plugin"
 #echo
 #./gradlew buildInstallablePlugin
 echo
 echo "building CLI tools"
 echo
 bin/local_jrelease
 bin/local_release
 echo
 echo "Deploying site"
 echo
 ./bin/deploy_site
@@ -0,0 +1,26 @@
 #!/bin/sh
 #
 # Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 #
 set -e
 echo
 echo "Creating plugin"
 echo
 ./gradlew buildInstallablePlugin
 deploy_site -u
@@ -1,7 +1,7 @@
 #!/bin/bash
 #
-# Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+# Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,6 +17,14 @@
 #
 #
 upload_only=false
 for arg in "$@"; do
  if [[ "$arg" == "-u" || "$arg" == "--upload-only" ]]; then
    upload_only=true
    break
  fi
 done
 function checkState() {
  if [[ $? != 0 ]]; then
    echo
@@ -24,9 +32,10 @@ function checkState() {
    echo
    exit 100
  fi
 }
 # Update docs/idea_plugin.md to point to the latest built IDEA plugin zip
 # from ./distributables before building the site. The change is temporary and
 # the original file is restored right after the build.
@@ -82,7 +91,7 @@ function updateIdeaPluginDownloadLink() {
 # default target settings
 case "com" in
  com)
-    SSH_HOST=sergeych@lynglang.com # host to deploy to
+    SSH_HOST=sergeych@d.lynglang.com # host to deploy to
    SSH_PORT=22                             # ssh port on it
    ROOT=/bigstore/sergeych_pub/lyng                 # directory to rsync to
    ;;
@@ -98,27 +107,37 @@ esac
 die() { echo "ERROR: $*" 1>&2 ; exit 1; }
-# Update the IDEA plugin download link in docs (temporarily), then build, then restore the doc
+function refreshTextmateZip() {
-updateIdeaPluginDownloadLink || echo "WARN: proceeding without updating IDEA plugin download link"
+  echo "Refreshing distributables/lyng-textmate.zip from editors/..."
  mkdir -p distributables
  # We use -r for recursive and -q for quiet (optional)
  # -j can be used if we want to junk paths, but the request says "contents of editors/"
  # usually we want to preserve the structure inside editors/
  (cd editors && zip -rq ../distributables/lyng-textmate.zip .)
 }
 ./gradlew site:clean site:jsBrowserDistribution
 BUILD_RC=$?
-# Always restore original doc if backup exists
+if [[ "$upload_only" == false ]]; then
-if [[ -f "$DOC_IDEA_PLUGIN_BACKUP" ]]; then
+  # Update the IDEA plugin download link in docs (temporarily), then build, then restore the doc
  refreshTextmateZip
  updateIdeaPluginDownloadLink || echo "WARN: proceeding without updating IDEA plugin download link"
  ./gradlew site:jsBrowserDistribution
  BUILD_RC=$?
  # Always restore original doc if backup exists
  if [[ -f "$DOC_IDEA_PLUGIN_BACKUP" ]]; then
    mv -f "$DOC_IDEA_PLUGIN_BACKUP" "$DOC_IDEA_PLUGIN"
-fi
+  fi
-if [[ $BUILD_RC -ne 0 ]]; then
+  if [[ $BUILD_RC -ne 0 ]]; then
    echo
    echo -- build failed. deploy aborted.
    echo
    exit 100
  fi
 fi
 #exit 0
 # Prepare working dir
 ssh -p ${SSH_PORT} ${SSH_HOST} "
  cd ${ROOT}
@@ -133,12 +152,15 @@ ssh -p ${SSH_PORT} ${SSH_HOST} "
  fi
 ";
-# sync files
+if [[ "$upload_only" == false ]]; then
-SRC=./site/build/dist/js/productionExecutable
+  # sync files
-rsync -e "ssh -p ${SSH_PORT}" -avz -r -d --delete ${SRC}/* ${SSH_HOST}:${ROOT}/build/dist
+  SRC=./site/build/dist/js/productionExecutable
-checkState
+  rsync -e "ssh -p ${SSH_PORT}" -avz -r -d --delete ${SRC}/* ${SSH_HOST}:${ROOT}/build/dist
-#rsync -e "ssh -p ${SSH_PORT}" -avz  ./static/* ${SSH_HOST}:${ROOT}/build/dist
+  checkState
-#checkState
+  #rsync -e "ssh -p ${SSH_PORT}" -avz  ./static/* ${SSH_HOST}:${ROOT}/build/dist
  #checkState
 fi
 rsync -e "ssh -p ${SSH_PORT}" -avz -r -d --delete distributables/* ${SSH_HOST}:${ROOT}/build/dist/distributables
 checkState
@@ -0,0 +1,256 @@
 #!/bin/bash
 #
 # Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 #
 set -e
 # Configuration
 DOCS_DIR="docs"
 OUTPUT_DIR="distributables"
 TEMP_DIR="build/temp_docs"
 MERGED_MD="$TEMP_DIR/merged.md"
 OUTPUT_HTML="$OUTPUT_DIR/lyng_documentation.html"
 mkdir -p "$OUTPUT_DIR"
 mkdir -p "$TEMP_DIR"
 # Files that should come first in specific order
 PRIORITY_FILES=(
    "tutorial.md"
    "OOP.md"
    "advanced_topics.md"
    "declaring_arguments.md"
    "scopes_and_closures.md"
    "exceptions_handling.md"
    "when.md"
    "parallelism.md"
    "Testing.md"
 )
 # Files that should come next (reference)
 REFERENCE_FILES=(
    "Collection.md"
    "Iterable.md"
    "Iterator.md"
    "List.md"
    "Set.md"
    "Map.md"
    "Array.md"
    "Buffer.md"
    "RingBuffer.md"
    "Range.md"
    "Real.md"
    "Regex.md"
    "math.md"
    "time.md"
 )
 # Files that are about integration/tools
 INTEGRATION_FILES=(
    "serialization.md"
    "json_and_kotlin_serialization.md"
    "embedding.md"
    "lyng_cli.md"
    "lyng.io.fs.md"
    "formatter.md"
    "EfficientIterables.md"
 )
 # Tracking processed files to avoid duplicates
 PROCESSED_PATHS=()
 is_excluded() {
    local full_path="$1"
    if grep -q "excludeFromIndex" "$full_path"; then
        return 0 # true in bash
    fi
    return 1 # false
 }
 process_file() {
    local rel_path="$1"
    local full_path="$DOCS_DIR/$rel_path"
    if [[ ! -f "$full_path" ]]; then
        return
    fi
    if is_excluded "$full_path"; then
        echo "Skipping excluded: $rel_path"
        return
    fi
    # Check for duplicates
    for p in "${PROCESSED_PATHS[@]}"; do
        if [[ "$p" == "$rel_path" ]]; then
            return
        fi
    done
    PROCESSED_PATHS+=("$rel_path")
    echo "Processing: $rel_path"
    # 1. Add an anchor for the file based on its path
    local anchor_name=$(echo "$rel_path" | sed 's/\//_/g')
    echo "<div id=\"$anchor_name\"></div>" >> "$MERGED_MD"
    echo "" >> "$MERGED_MD"
    # 2. Append content with fixed links
    # - [text](file.md) -> [text](#file.md)
    # - [text](dir/file.md) -> [text](#dir_file.md)
    # - [text](file.md#anchor) -> [text](#anchor)
    # - Fix image links: [alt](../images/...) -> [alt](images/...) if needed, but none found yet.
    cat "$full_path" | \
    perl -pe 's/\[([^\]]+)\]\(([^)]+)\.md\)/"[$1](#" . ($2 =~ s|\/|_|gr) . ".md)"/ge' | \
    perl -pe 's/\[([^\]]+)\]\(([^)]+)\.md#([^)]+)\)/[$1](#$3)/g' >> "$MERGED_MD"
    echo -e "\n\n---\n\n" >> "$MERGED_MD"
 }
 # Start with an empty merged file
 echo "% Lyng Language Documentation" > "$MERGED_MD"
 echo "" >> "$MERGED_MD"
 # 1. Process priority files
 for f in "${PRIORITY_FILES[@]}"; do
    process_file "$f"
 done
 # 2. Process reference files
 for f in "${REFERENCE_FILES[@]}"; do
    process_file "$f"
 done
 # 3. Process integration files
 for f in "${INTEGRATION_FILES[@]}"; do
    process_file "$f"
 done
 # 4. Process remaining files in docs root
 for f in "$DOCS_DIR"/*.md; do
    rel_f=${f#"$DOCS_DIR/"}
    process_file "$rel_f"
 done
 # 5. Process remaining files in subdirs (like samples)
 find "$DOCS_DIR" -name "*.md" | sort | while read -r f; do
    rel_f=${f#"$DOCS_DIR/"}
    process_file "$rel_f"
 done
 echo "Running pandoc to generate $OUTPUT_HTML..."
 # Use a basic but clean CSS
 pandoc "$MERGED_MD" -o "$OUTPUT_HTML" \
    --toc --toc-depth=2 \
    --standalone \
    --embed-resources \
    --metadata title="Lyng Language Documentation" \
    --css <(echo "
        body { 
            font-family: -apple-system, BlinkMacSystemFont, \"Segoe UI\", Helvetica, Arial, sans-serif;
            line-height: 1.6; 
            max-width: 1000px; 
            margin: 0 auto; 
            padding: 2em; 
            color: #24292e;
            background-color: #fff;
        }
        code { 
            background-color: rgba(27,31,35,0.05); 
            padding: 0.2em 0.4em; 
            border-radius: 3px; 
            font-family: SFMono-Regular, Consolas, \"Liberation Mono\", Menlo, monospace;
            font-size: 85%;
        }
        pre { 
            background-color: #f6f8fa; 
            padding: 16px; 
            overflow: auto; 
            border-radius: 3px;
            line-height: 1.45;
        }
        pre code {
            background-color: transparent;
            padding: 0;
            font-size: 100%;
        }
        h1 { 
            border-bottom: 1px solid #eaecef; 
            padding-bottom: 0.3em; 
            margin-top: 24px;
            margin-bottom: 16px;
            font-weight: 600;
        }
        h2 { 
            border-bottom: 1px solid #eaecef; 
            padding-bottom: 0.3em; 
            margin-top: 24px;
            margin-bottom: 16px;
            font-weight: 600;
        }
        hr { 
            height: 0.25em;
            padding: 0;
            margin: 24px 0;
            background-color: #e1e4e8;
            border: 0;
        }
        blockquote {
            padding: 0 1em;
            color: #6a737d;
            border-left: 0.25em solid #dfe2e5;
            margin: 0 0 16px 0;
        }
        nav#TOC { 
            background: #f9f9f9; 
            padding: 1em; 
            border: 1px solid #eee; 
            margin-bottom: 2.5em; 
            border-radius: 6px;
        }
        nav#TOC ul { 
            list-style: none; 
            padding-left: 1.5em; 
        }
        nav#TOC > ul {
            padding-left: 0;
        }
        table {
            border-spacing: 0;
            border-collapse: collapse;
            margin-top: 0;
            margin-bottom: 16px;
        }
        table th, table td {
            padding: 6px 13px;
            border: 1px solid #dfe2e5;
        }
        table tr {
            background-color: #fff;
            border-top: 1px solid #c6cbd1;
        }
        table tr:nth-child(2n) {
            background-color: #f6f8fa;
        }
    ")
 echo "-------------------------------------------------------"
 echo "Done! Documentation generated successfully."
 echo "Location: $OUTPUT_HTML"
 echo "-------------------------------------------------------"
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -29,3 +29,33 @@ tasks.register<org.gradle.api.DefaultTask>("runIde") {
    description = "Run IntelliJ IDEA with the Lyng plugin (:lyng-idea)"
    dependsOn(":lyng-idea:runIde")
 }
 tasks.register<Exec>("generateDocs") {
    group = "documentation"
    description = "Generates a single-file documentation HTML using bin/generate_docs.sh"
    commandLine("./bin/generate_docs.sh")
 }
 // Sample generator task for .lyng.d definition files (not wired into build).
 // Usage: ./gradlew generateLyngDefsSample
 tasks.register("generateLyngDefsSample") {
    group = "lyng"
    description = "Generate a sample .lyng.d file under build/generated/lyng/defs"
    outputs.dir(layout.buildDirectory.dir("generated/lyng/defs"))
    doLast {
        val outDir = layout.buildDirectory.dir("generated/lyng/defs").get().asFile
        outDir.mkdirs()
        val outFile = outDir.resolve("sample.lyng.d")
        outFile.writeText(
            """
            /** Generated API */
            extern fun ping(): Int
            /** Generated class */
            class Generated(val name: String) {
                fun greet(): String = "hi " + name
            }
            """.trimIndent()
        )
    }
 }
@@ -0,0 +1,7 @@
 # Bytecode Migration Plan (Archived)
 Status: completed.
 Historical reference:
 - `notes/archive/bytecode_migration_plan.md` (full plan)
 - `notes/archive/bytecode_migration_plan_completed.md` (summary)
@@ -1,8 +1,8 @@
 # Array
 It's an interface if the [Collection] that provides indexing access, like `array[3] = 0`.
-Array therefore implements [Iterable] too. The well known implementatino of the `Array` is
+Array therefore implements [Iterable] too. Well known implementations of `Array` are
-[List].
+[List] and [ImmutableList].
 Array adds the following methods:
@@ -35,3 +35,4 @@ To pre-sort and array use `Iterable.sorted*` or in-place `List.sort*` families,
 [Collection]: Collection.md
 [Iterable]: Iterable.md
 [List]: List.md
 [ImmutableList]: ImmutableList.md
@@ -23,11 +23,11 @@ There are a lo of ways to construct a buffer:
    assertEquals( 5, Buffer("hello").size )
    // from bytes, e.g. integers in range 0..255
-    assertEquals( 255, Buffer(1,2,3,255).last() )
+    assertEquals( 255, Buffer(1,2,3,255).last )
    // from whatever iterable that produces bytes, e.g.
    // integers in 0..255 range:
-    assertEquals( 129, Buffer([1,2,129]).last() )
+    assertEquals( 129, Buffer([1,2,129]).last )
    // Empty buffer of fixed size:
    assertEquals(100, Buffer(100).size)
@@ -0,0 +1,280 @@
 # Lyng Bytecode VM Spec v0 (Draft)
 This document describes a register-like (3-address) bytecode for Lyng with
 dynamic slot width (8/16/32-bit slot IDs), a slot-tail argument model, and
 typed lanes for Obj/Int/Real/Bool. The VM is intended to run as a suspendable
 interpreter and fall back to the existing AST execution when needed.
 ## 1) Frame & Slot Model
 ### Frame metadata
 - localCount: number of local slots for this function (fixed at compile time).
 - argCount: number of arguments passed at call time.
 - scopeSlotNames: optional debug names for scope slots (locals/params), aligned to slot mapping.
 - argBase = localCount.
 ### Slot layout
 slots[0 .. localCount-1]              locals
 slots[localCount .. localCount+argCount-1]  arguments
 ### Typed lanes
 - slotType[]: UNKNOWN/OBJ/INT/REAL/BOOL
 - objSlots[], intSlots[], realSlots[], boolSlots[]
 - A slot is a logical index; active lane is selected by slotType.
 ### Parameter access
 - param i => slot localCount + i
 - variadic extra => slot localCount + declaredParamCount + k
 ### Debug metadata (optional)
 - scopeSlotNames: array sized scopeSlotCount, each entry nullable.
 - Intended for disassembly/debug tooling; VM semantics do not depend on it.
 ### Constant pool extras
 - SlotPlan: map of name -> slot index, used by PUSH_SCOPE to pre-allocate and map loop locals.
 - CallArgsPlan: ordered argument specs (name/splat) + tailBlock flag, used when argCount has the plan flag set.
 ## 2) Slot ID Width
 Per frame, select:
 - 8-bit if localCount + argCount < 256
 - 16-bit if < 65536
 - 32-bit otherwise
 The decoder uses a dedicated loop per width. All slot operands are expanded to
 Int internally.
 ## 3) CALL Semantics (Model A)
 Instruction:
 CALL_DIRECT fnId, argBase, argCount, dst
 Behavior:
 - Allocate a callee frame sized localCount + argCount.
 - Copy caller slots [argBase .. argBase+argCount-1] into callee slots
  [localCount .. localCount+argCount-1].
 - Callee returns via RET slot or RET_VOID.
 - Caller stores return value to dst.
 Other calls:
 - CALL_VIRTUAL recvSlot, methodId, argBase, argCount, dst
 - CALL_FALLBACK stmtId, argBase, argCount, dst
 - CALL_SLOT calleeSlot, argBase, argCount, dst
 ## 4) Binary Encoding Layout
 All instructions are:
  [opcode:U8] [operands...]
 Operand widths:
 - slotId: S = 1/2/4 bytes (per frame slot width)
 - constId: K = 2 bytes (U16), extend to 4 if needed
 - ip: I = 2 bytes (U16) or 4 bytes (U32) per function size
 - fnId/methodId/stmtId: F/M/T = 2 bytes (U16) unless extended
 - argCount: C = 2 bytes (U16), extend to 4 if needed
 Endianness: little-endian for multi-byte operands.
 Common operand patterns:
 - S: one slot
 - SS: two slots
 - SSS: three slots
 - K S: constId + dst slot
 - S I: slot + jump target
 - I: jump target
 - F S C S: fnId, argBase slot, argCount, dst slot
 Arg count flag:
 - If high bit of C is set (0x8000), the low 15 bits encode a CallArgsPlan constId.
 - When not set, C is the raw positional count and tailBlockMode=false.
 ## 5) Opcode Table
 Note: Any opcode can be compiled to FALLBACK if not implemented in a VM pass.
 ### Data movement
 - NOP
 - MOVE_OBJ S -> S
 - MOVE_INT S -> S
 - MOVE_REAL S -> S
 - MOVE_BOOL S -> S
 - BOX_OBJ S -> S
 - CONST_OBJ K -> S
 - CONST_INT K -> S
 - CONST_REAL K -> S
 - CONST_BOOL K -> S
 - CONST_NULL -> S
 ### Numeric conversions
 - INT_TO_REAL S -> S
 - REAL_TO_INT S -> S
 - BOOL_TO_INT S -> S
 - INT_TO_BOOL S -> S
 ### Arithmetic: INT
 - ADD_INT S, S -> S
 - SUB_INT S, S -> S
 - MUL_INT S, S -> S
 - DIV_INT S, S -> S
 - MOD_INT S, S -> S
 - NEG_INT S -> S
 - INC_INT S
 - DEC_INT S
 ### Arithmetic: REAL
 - ADD_REAL S, S -> S
 - SUB_REAL S, S -> S
 - MUL_REAL S, S -> S
 - DIV_REAL S, S -> S
 - NEG_REAL S -> S
 ### Arithmetic: OBJ
 - ADD_OBJ S, S -> S
 - SUB_OBJ S, S -> S
 - MUL_OBJ S, S -> S
 - DIV_OBJ S, S -> S
 - MOD_OBJ S, S -> S
 ### Bitwise: INT
 - AND_INT S, S -> S
 - OR_INT S, S -> S
 - XOR_INT S, S -> S
 - SHL_INT S, S -> S
 - SHR_INT S, S -> S
 - USHR_INT S, S -> S
 - INV_INT S -> S
 ### Comparisons (typed)
 - CMP_EQ_INT S, S -> S
 - CMP_NEQ_INT S, S -> S
 - CMP_LT_INT S, S -> S
 - CMP_LTE_INT S, S -> S
 - CMP_GT_INT S, S -> S
 - CMP_GTE_INT S, S -> S
 - CMP_EQ_REAL S, S -> S
 - CMP_NEQ_REAL S, S -> S
 - CMP_LT_REAL S, S -> S
 - CMP_LTE_REAL S, S -> S
 - CMP_GT_REAL S, S -> S
 - CMP_GTE_REAL S, S -> S
 - CMP_EQ_BOOL S, S -> S
 - CMP_NEQ_BOOL S, S -> S
 ### Mixed numeric comparisons
 - CMP_EQ_INT_REAL S, S -> S
 - CMP_EQ_REAL_INT S, S -> S
 - CMP_LT_INT_REAL S, S -> S
 - CMP_LT_REAL_INT S, S -> S
 - CMP_LTE_INT_REAL S, S -> S
 - CMP_LTE_REAL_INT S, S -> S
 - CMP_GT_INT_REAL S, S -> S
 - CMP_GT_REAL_INT S, S -> S
 - CMP_GTE_INT_REAL S, S -> S
 - CMP_GTE_REAL_INT S, S -> S
 - CMP_NEQ_INT_REAL S, S -> S
 - CMP_NEQ_REAL_INT S, S -> S
 - CMP_EQ_OBJ S, S -> S
 - CMP_NEQ_OBJ S, S -> S
 - CMP_REF_EQ_OBJ S, S -> S
 - CMP_REF_NEQ_OBJ S, S -> S
 - CMP_LT_OBJ S, S -> S
 - CMP_LTE_OBJ S, S -> S
 - CMP_GT_OBJ S, S -> S
 - CMP_GTE_OBJ S, S -> S
 ### Boolean ops
 - NOT_BOOL S -> S
 - AND_BOOL S, S -> S
 - OR_BOOL S, S -> S
 ### Control flow
 - JMP I
 - JMP_IF_TRUE S, I
 - JMP_IF_FALSE S, I
 - RET S
 - RET_VOID
 - PUSH_SCOPE K
 - POP_SCOPE
 ### Scope setup
 - PUSH_SCOPE uses const `SlotPlan` (name -> slot index) to create a child scope and apply slot mapping.
 - POP_SCOPE restores the parent scope.
 ### Calls
 - CALL_DIRECT F, S, C, S
 - CALL_VIRTUAL S, M, S, C, S
 - CALL_FALLBACK T, S, C, S
 - CALL_SLOT S, S, C, S
 ### Object access (optional, later)
 - GET_FIELD S, M -> S
 - SET_FIELD S, M, S
 - GET_INDEX S, S -> S
 - SET_INDEX S, S, S
 ### Fallback
 - EVAL_FALLBACK T -> S
 ## 6) Const Pool Encoding (v0)
 Each const entry is encoded as:
  [tag:U8] [payload...]
 Tags:
 - 0x00: NULL
 - 0x01: BOOL (payload: U8 0/1)
 - 0x02: INT (payload: S64, little-endian)
 - 0x03: REAL (payload: F64, IEEE-754, little-endian)
 - 0x04: STRING (payload: U32 length + UTF-8 bytes)
 - 0x05: OBJ_REF (payload: U32 index into external Obj table)
 Notes:
 - OBJ_REF is reserved for embedding prebuilt Obj handles if needed.
 - Strings use UTF-8; length is bytes, not chars.
 ## 7) Function Header (binary container)
 Suggested layout for a bytecode function blob:
 - magic: U32 ("LYBC")
 - version: U16 (0x0001)
 - slotWidth: U8 (1,2,4)
 - ipWidth: U8 (2,4)
 - constIdWidth: U8 (2,4)
 - localCount: U32
 - codeSize: U32 (bytes)
 - constCount: U32
 - constPool: [const entries...]
 - code: [bytecode...]
 Const pool entries use the encoding described in section 6.
 ## 8) Sample Bytecode (illustrative)
 Example Lyng:
  val x = 2
  val y = 3
  val z = x + y
 Assume:
 - localCount = 3 (x,y,z)
 - argCount = 0
 - slot width = 1 byte
 - const pool: [INT 2, INT 3]
 Bytecode:
  CONST_INT k0 -> s0
  CONST_INT k1 -> s1
  ADD_INT s0, s1 -> s2
  RET_VOID
 Encoded (opcode values symbolic):
  [OP_CONST_INT][k0][s0]
  [OP_CONST_INT][k1][s1]
  [OP_ADD_INT][s0][s1][s2]
  [OP_RET_VOID]
 ## 9) Notes
 - Mixed-mode is allowed: compiler can emit FALLBACK ops for unsupported nodes.
 - The VM must be suspendable; on suspension, store ip + minimal operand state.
 - Source mapping uses a separate ip->Pos table, not part of core bytecode.
@@ -6,14 +6,26 @@ Is a [Iterable] with known `size`, a finite [Iterable]:
        val size
    }
 `Collection` is a read/traversal contract shared by mutable and immutable collections.
 Concrete collection classes:
 - Mutable: [List], [Set], [Map]
 - Immutable: [ImmutableList], [ImmutableSet], [ImmutableMap]
 - Observable mutable lists (opt-in module): [ObservableList]
 | name                   | description                                          |
 |------------------------|------------------------------------------------------|
 (1)
 : `comparator(a,b)` should return -1 if `a < b`, +1 if `a > b` or zero.
-See [List], [Set] and [Iterable]
+See [List], [Set], [Iterable] and [Efficient Iterables in Kotlin Interop](EfficientIterables.md)
 [Iterable]: Iterable.md
 [List]: List.md
 [Set]: Set.md
 [Map]: Map.md
 [ImmutableList]: ImmutableList.md
 [ImmutableSet]: ImmutableSet.md
 [ImmutableMap]: ImmutableMap.md
 [ObservableList]: ObservableList.md
@@ -0,0 +1,250 @@
 # Decimal (`lyng.decimal`)
 `lyng.decimal` adds an arbitrary-precision decimal type to Lyng as a normal library module.
 Import it when you need decimal arithmetic that should not inherit `Real`'s binary floating-point behavior:
 ```lyng
 import lyng.decimal
 ```
 ## What `BigDecimal` Is For
 Use `BigDecimal` when values are fundamentally decimal:
 - money
 - human-entered quantities
 - exact decimal text
 - predictable decimal rounding
 - user-facing formatting and tests
 Do not use it just because a number has a fractional part. `Real` is still the right type for ordinary double-precision numeric work.
 ## Creating Decimal Values
 There are three supported conversions:
 ```lyng
 import lyng.decimal
 val a = 1.d
 val b = 2.2.d
 val c = "2.2".d
 assertEquals("1", a.toStringExpanded())
 assertEquals("2.2", b.toStringExpanded())
 assertEquals("2.2", c.toStringExpanded())
 ```
 The three forms mean different things:
 - `1.d`: convert `Int -> BigDecimal`
 - `2.2.d`: convert `Real -> BigDecimal`
 - `"2.2".d`: parse exact decimal text
 That distinction is intentional.
 ### `Real.d` vs `"..." .d`
 `Real.d` preserves the current `Real` value. It does not pretend the source code was exact decimal text.
 ```lyng
 import lyng.decimal
 assertEquals("0.30000000000000004", (0.1 + 0.2).d.toStringExpanded())
 assertEquals("0.3", "0.3".d.toStringExpanded())
 ```
 This follows the "minimal confusion" rule:
 - if you start from a `Real`, you get a decimal representation of that `Real`
 - if you want exact decimal source text, use a `String`
 ## Factory Functions
 The explicit factory methods are:
 ```lyng
 import lyng.decimal
 BigDecimal.fromInt(10)
 BigDecimal.fromReal(2.5)
 BigDecimal.fromString("12.34")
 ```
 These are equivalent to the conversion-property forms, but sometimes clearer in APIs or generated code.
 ## Core Operations
 `BigDecimal` supports:
 - `+`
 - `-`
 - `*`
 - `/`
 - `%`
 - unary `-`
 - comparison operators
 - equality operators
 Examples:
 ```lyng
 import lyng.decimal
 assertEquals("3.75", ("1.5".d + "2.25".d).toStringExpanded())
 assertEquals("1.25", ("2.5".d - "1.25".d).toStringExpanded())
 assertEquals("3.0", ("1.5".d * 2.d).toStringExpanded())
 assertEquals("0.5", (1.d / 2.d).toStringExpanded())
 assert("2.0".d > "1.5".d)
 assert("2.0".d == 2.d)
 ```
 ## Interoperability With `Int` and `Real`
 The decimal module registers mixed-operand operator bridges so both sides read naturally:
 ```lyng
 import lyng.decimal
 assertEquals(3.d, 1 + 2.d)
 assertEquals(3.d, 2.d + 1)
 assertEquals(1.5.d, 1.d + 0.5)
 assertEquals(1.5.d, 0.5 + 1.d)
 assert(2 == 2.d)
 assert(3 > 2.d)
 ```
 Without this registration mechanism, only the cases directly implemented on the left-hand class would work. The bridge fills the gap for expressions such as `Int + BigDecimal` and `Real + BigDecimal`.
 See [OperatorInterop.md](OperatorInterop.md) for the generic mechanism behind that.
 ## String Representation
 Use `toStringExpanded()` when you want plain decimal output without scientific notation:
 ```lyng
 import lyng.decimal
 assertEquals("12.34", "12.34".d.toStringExpanded())
 ```
 This is the recommended representation for:
 - tests
 - user-visible diagnostics
 - decimal formatting checks
 ## Conversions Back To Built-ins
 ```lyng
 import lyng.decimal
 assertEquals(2, "2.9".d.toInt())
 assertEquals(2.9, "2.9".d.toReal())
 ```
 Use `toReal()` only when you are willing to return to binary floating-point semantics.
 ## Division Context
 Division is the operation where precision and rounding matter most.
 By default, decimal division uses:
 - precision: `34` significant digits
 - rounding: `HalfEven`
 Example:
 ```lyng
 import lyng.decimal
 assertEquals("0.3333333333333333333333333333333333", (1.d / 3.d).toStringExpanded())
 assertEquals("0.6666666666666666666666666666666667", ("2".d / 3.d).toStringExpanded())
 ```
 ## `withDecimalContext(...)`
 Use `withDecimalContext(...)` to override decimal division rules inside a block:
 ```lyng
 import lyng.decimal
 assertEquals(
    "0.3333333333",
    withDecimalContext(10) { (1.d / 3.d).toStringExpanded() }
 )
 ```
 You can also pass an explicit context object:
 ```lyng
 import lyng.decimal
 val ctx = DecimalContext(6, DecimalRounding.HalfAwayFromZero)
 assertEquals("0.666667", withDecimalContext(ctx) { ("2".d / 3.d).toStringExpanded() })
 ```
 The context is dynamic and local to the block. After the block exits, the previous context is restored.
 ## Rounding Modes
 Available rounding modes:
 - `HalfEven`
 - `HalfAwayFromZero`
 - `HalfTowardsZero`
 - `Ceiling`
 - `Floor`
 - `AwayFromZero`
 - `TowardsZero`
 Tie example at precision `2`:
 ```lyng
 import lyng.decimal
 assertEquals("0.12", withDecimalContext(2, DecimalRounding.HalfEven) { (1.d / 8.d).toStringExpanded() })
 assertEquals("0.13", withDecimalContext(2, DecimalRounding.HalfAwayFromZero) { (1.d / 8.d).toStringExpanded() })
 assertEquals("0.12", withDecimalContext(2, DecimalRounding.HalfTowardsZero) { (1.d / 8.d).toStringExpanded() })
 assertEquals("0.13", withDecimalContext(2, DecimalRounding.Ceiling) { (1.d / 8.d).toStringExpanded() })
 assertEquals("0.12", withDecimalContext(2, DecimalRounding.Floor) { (1.d / 8.d).toStringExpanded() })
 ```
 Negative values follow the same named policy in the obvious direction:
 ```lyng
 import lyng.decimal
 assertEquals("-0.13", withDecimalContext(2, DecimalRounding.HalfAwayFromZero) { (-1.d / 8.d).toStringExpanded() })
 assertEquals("-0.12", withDecimalContext(2, DecimalRounding.HalfTowardsZero) { (-1.d / 8.d).toStringExpanded() })
 ```
 ## Recommended Usage Rules
 If you care about exact decimal source text:
 ```lyng
 "12.34".d
 ```
 If you intentionally convert an existing binary floating-point value:
 ```lyng
 someReal.d
 ```
 If you want local control over division:
 ```lyng
 withDecimalContext(precision, rounding) { ... }
 ```
 If you want custom mixed operators for your own type, follow the same pattern as Decimal and use the operator registry:
 - define the operators on your own class
 - choose a common class
 - register mixed operand bridges
 See [OperatorInterop.md](OperatorInterop.md).
@@ -0,0 +1,92 @@
 # Efficient Iterables in Kotlin Interop
 Lyng provides high-performance iteration mechanisms that allow Kotlin-side code to interact with Lyng iterables efficiently and vice versa.
 ## 1. Enumerating Lyng Objects from Kotlin
 To iterate over a Lyng object (like a `List`, `Set`, or `Range`) from Kotlin code, use the virtual `enumerate` method:
 ```kotlin
 val lyngList: Obj = ... 
 lyngList.enumerate(scope) { item ->
    println("Processing $item")
    true // return true to continue, false to break
 }
 ```
 ### Why it's efficient:
 - **Zero allocation**: Unlike traditional iterators, it doesn't create a `LyngIterator` object or any intermediate wrappers.
 - **Direct access**: Subclasses like `ObjList` override `enumerate` to iterate directly over their internal Kotlin collections.
 - **Reduced overhead**: It avoids multiple `invokeInstanceMethod` calls for `hasNext()` and `next()` on every step, which would normally involve dynamic dispatch and scope overhead.
 ## 2. Reactive Enumeration with Flow
 If you prefer a reactive approach or need to integrate with Kotlin Coroutines flows, use `toFlow()`:
 ```kotlin
 lyngList.toFlow(scope).collect { item ->
    // ...
 }
 ```
 *Note: `toFlow()` internally uses the Lyng iterator protocol (`iterator()`, `hasNext()`, `next()`), so it's slightly less efficient than `enumerate()` for performance-critical loops, but more idiomatic for flow-based processing.*
 ## 3. Creating Efficient Iterables for Lyng in Kotlin
 When implementing a custom object in Kotlin that should be iterable in Lyng (e.g., usable in `for (x in myObj) { ... }`), follow these steps to ensure maximum performance.
 ### A. Inherit from `Obj` and use `ObjIterable`
 Ensure your object's class has `ObjIterable` as a parent so the Lyng compiler recognizes it as an iterable.
 ```kotlin
 class MyCollection(val items: List<Obj>) : Obj() {
    override val objClass = MyCollection.type
    companion object {
        val type = ObjClass("MyCollection", ObjIterable).apply {
            // Provide a Lyng-side iterator for compatibility with 
            // manual iterator usage in Lyng scripts.
            // Using ObjKotlinObjIterator if items are already Obj instances:
            addFn("iterator") { 
                ObjKotlinObjIterator(thisAs<MyCollection>().items.iterator()) 
            }
        }
    }
 }
 ```
 ### B. Override `enumerate` for Maximum Performance
 The Lyng compiler's `for` loops use the `enumerate` method. By overriding it in your Kotlin class, you provide a "fast path" for iteration.
 ```kotlin
 class MyCollection(val items: List<Obj>) : Obj() {
    // ...
    override suspend fun enumerate(scope: Scope, callback: suspend (Obj) -> Boolean) {
        for (item in items) {
            // If callback returns false, it means 'break' was called in Lyng
            if (!callback(item)) break
        }
    }
 }
 ```
 ### C. Use `ObjInt.of()` for Numeric Data
 If your iterable contains integers, always use `ObjInt.of(Long)` instead of the `ObjInt(Long)` constructor. Lyng maintains a cache for small integers (-128 to 127), which significantly reduces object allocations and GC pressure during tight loops.
 ```kotlin
 // Efficiently creating an integer object
 val obj = ObjInt.of(42L) 
 // Or using extension methods which also use the cache:
 val obj2 = 42.toObj()
 val obj3 = 42L.toObj()
 ```
 #### Note on `toObj()` extensions:
 While `<reified T> T.toObj()` is convenient, using specific extensions like `Int.toObj()` or `Long.toObj()` is slightly more efficient as they use the `ObjInt` cache.
 ## 4. Summary of Best Practices
 - **To Consume**: Use `enumerate(scope) { item -> ... true }`.
 - **To Implement**: Override `enumerate` in your `Obj` subclass.
 - **To Register**: Use `ObjIterable` (or `ObjCollection`) as a parent class in your `ObjClass` definition.
 - **To Optimize**: Use `ObjInt.of()` (or `.toObj()`) for all integer object allocations.
@@ -0,0 +1,37 @@
 # ImmutableList built-in class
 `ImmutableList` is an immutable, indexable list value.
 It implements [Array], therefore [Collection] and [Iterable].
 Use it when API contracts require a list that cannot be mutated through aliases.
 ## Creating
    val a = ImmutableList(1,2,3)
    val b = [1,2,3].toImmutable()
    val c = (1..3).toImmutableList()
    >>> void
 ## Converting
    val i = ImmutableList(1,2,3)
    val m = i.toMutable()
    m += 4
    assertEquals( ImmutableList(1,2,3), i )
    assertEquals( [1,2,3,4], m )
    >>> void
 ## Members
 | name          | meaning                                 |
 |---------------|-----------------------------------------|
 | `size`        | number of elements                      |
 | `[index]`     | element access by index                 |
 | `[Range]`     | immutable slice                         |
 | `+`           | append element(s), returns new immutable list |
 | `-`           | remove element(s), returns new immutable list |
 | `toMutable()` | create mutable copy                     |
 [Array]: Array.md
 [Collection]: Collection.md
 [Iterable]: Iterable.md
@@ -0,0 +1,36 @@
 # ImmutableMap built-in class
 `ImmutableMap` is an immutable map of key-value pairs.
 It implements [Collection] and [Iterable] of [MapEntry].
 ## Creating
    val a = ImmutableMap("a" => 1, "b" => 2)
    val b = Map("a" => 1, "b" => 2).toImmutable()
    val c = ["a" => 1, "b" => 2].toImmutableMap
    >>> void
 ## Converting
    val i = ImmutableMap("a" => 1)
    val m = i.toMutable()
    m["a"] = 2
    assertEquals( 1, i["a"] )
    assertEquals( 2, m["a"] )
    >>> void
 ## Members
 | name            | meaning                                  |
 |-----------------|------------------------------------------|
 | `size`          | number of entries                        |
 | `[key]`         | get value by key, or `null` if absent    |
 | `getOrNull(key)`| same as `[key]`                          |
 | `keys`          | list of keys                             |
 | `values`        | list of values                           |
 | `+`             | merge (rightmost wins), returns new immutable map |
 | `toMutable()`   | create mutable copy                      |
 [Collection]: Collection.md
 [Iterable]: Iterable.md
 [MapEntry]: Map.md
@@ -0,0 +1,34 @@
 # ImmutableSet built-in class
 `ImmutableSet` is an immutable set of unique elements.
 It implements [Collection] and [Iterable].
 ## Creating
    val a = ImmutableSet(1,2,3)
    val b = Set(1,2,3).toImmutable()
    val c = [1,2,3].toImmutableSet
    >>> void
 ## Converting
    val i = ImmutableSet(1,2,3)
    val m = i.toMutable()
    m += 4
    assertEquals( ImmutableSet(1,2,3), i )
    assertEquals( Set(1,2,3,4), m )
    >>> void
 ## Members
 | name          | meaning                                             |
 |---------------|-----------------------------------------------------|
 | `size`        | number of elements                                  |
 | `contains(x)` | membership test                                     |
 | `+`, `union`  | union, returns new immutable set                    |
 | `-`, `subtract` | subtraction, returns new immutable set            |
 | `*`, `intersect` | intersection, returns new immutable set         |
 | `toMutable()` | create mutable copy                                 |
 [Collection]: Collection.md
 [Iterable]: Iterable.md
@@ -40,13 +40,13 @@ available, for example
 ## joinToString
 This methods convert any iterable to a string joining string representation of each element, optionally transforming it
-and joining using specified suffix.
+and joining using specified separator.
-    Iterable.joinToString(suffux=' ', transform=null)
+    Iterable.joinToString(separator=' ', transformer=null)
 - if `Iterable` `isEmpty`, the empty string `""` is returned.
- `suffix` is inserted between items when there are more than one.
+- `separator` is inserted between items when there are more than one.
- `transform` of specified is applied to each element, otherwise its `toString()` method is used.
+- `transformer` of specified is applied to each element, otherwise its `toString()` method is used.
 Here is the sample:
@@ -55,7 +55,7 @@ Here is the sample:
    assertEquals( (1..3).joinToString { it * 10 }, "10 20 30")
    >>> void
-## `sum` and `sumBy`
+## `sum` and `sumOf`
 These, again, does the thing:
@@ -68,59 +68,140 @@ These, again, does the thing:
    >>> void
 ## map, filter and their variations
 Used to transform or filter the whole iterable stream:
    val source = [1,2,3,4]
    // map: transform every element to something else
    assertEquals(["n1", "n2", "n3", "n4"], source.map { "n"+it } )
    // filter: keep only elements matching the predicate
    assertEquals([2, 4], source.filter { it % 2 == 0 } )
    // count: count elements matching the predicate
    assertEquals(2, source.count { it % 2 == 0 } )
    // mapNotNull: transform every element, skipping null results:
    assertEquals(["n1", "n2", "n4"], source.mapNotNull { if( it == 3 ) null else "n"+it } )
    // filterNotNull: skip all null elements:
    assertEquals([1, 2, 4], [1, 2, null, 4].filterNotNull())
    >>> void
 You can also use flow variations that return a cold `Flow` instead of a `List`, which is useful for large or infinite sequences:
    val source = [1, 2, 3, 4]
    // filterFlow: returns a Flow of filtered elements
    assert( source.filterFlow { it % 2 == 0 } is Flow )
    // filterFlowNotNull: returns a Flow of non-null elements
    assert( [1, null, 2].filterFlowNotNull() is Flow )
    >>> void
 ## minOf and maxOf
 Find the minimum or maximum value of a function applied to each element:
    val source = ["abc", "de", "fghi"]
    assertEquals(2, source.minOf { (it as String).length })
    assertEquals(4, source.maxOf { (it as String).length })
    >>> void
 ## flatten and flatMap
 Work with nested collections:
    val nested = [[1, 2], [3, 4]]
    // flatten: combine nested collections into one list
    assertEquals([1, 2, 3, 4], nested.flatten())
    // flatMap: map each element to a collection and flatten the result
    assertEquals([1, 10, 2, 20], [1, 2].flatMap { [it, it*10] })
    >>> void
 ## findFirst and findFirstOrNull
 Search for the first element that satisfies the given predicate:
    val source = [1, 2, 3, 4]
    assertEquals( 2, source.findFirst { it % 2 == 0 } )
    assertEquals( 2, source.findFirstOrNull { it % 2 == 0 } )
    // findFirst throws if not found:
    assertThrows( NoSuchElementException ) { source.findFirst { it > 10 } }
    // findFirstOrNull returns null if not found:
    assertEquals( null, source.findFirstOrNull { it > 10 } )
    >>> void
 ## Instance methods:
 | fun/method             | description                                                                     |
 |------------------------|---------------------------------------------------------------------------------|
 | toList()               | create a list from iterable                                                     |
 | toImmutableList()      | create an immutable list from iterable                                          |
 | toSet()                | create a set from iterable                                                      |
 | toImmutableSet         | create an immutable set from iterable                                           |
 | contains(i)            | check that iterable contains `i`                                                |
-| `i in iterator`        | same as `contains(i)`                                                           |
+| `i in iterable`        | same as `contains(i)`                                                           |
 | isEmpty()              | check iterable is empty                                                         |
 | forEach(f)             | call f for each element                                                         |
 | toMap()                | create a map from list of key-value pairs (arrays of 2 items or like)           |
 | toImmutableMap         | create an immutable map from list of key-value pairs                             |
 | any(p)                 | true if any element matches predicate `p`                        |
 | all(p)                 | true if all elements match predicate `p`                         |
 | map(f)                 | create a list of values returned by `f` called for each element of the iterable |
 | indexOf(i)             | return index if the first encounter of i or a negative value if not found       |
 | associateBy(kf)        | create a map where keys are returned by kf that will be called for each element |
 | filter(p)              | create a list of elements matching predicate `p`                |
 | count(p)               | count elements matching predicate `p`                            |
 | filterFlow(p)          | create a [Flow] of elements matching predicate `p`               |
 | filterNotNull()        | create a list of non-null elements                               |
 | filterFlowNotNull()    | create a [Flow] of non-null elements                             |
 | minOf(f)               | return minimum value of `f` applied to elements                  |
 | maxOf(f)               | return maximum value of `f` applied to elements                  |
 | flatten()              | flatten nested collections into a single [List]                  |
 | flatMap(f)             | map each element with `f` and flatten results into a [List]      |
 | findFirst(p)           | return first element matching predicate `p` or throw (1)         |
 | findFirstOrNull(p)     | return first element matching predicate `p` or `null`                            |
 | first                  | first element (1)                                                               |
 | last                   | last element (1)                                                                |
 | take(n)                | return [Iterable] of up to n first elements                                     |
-| taleLast(n)            | return [Iterable] of up to n last elements                                      |
+| takeLast(n)            | return [Iterable] of up to n last elements                                      |
 | drop(n)                | return new [Iterable] without first n elements                                  |
 | dropLast(n)            | return new [Iterable] without last n elements                                   |
 | sum()                  | return sum of the collection applying `+` to its elements (3)                   |
-| sumOf(predicate)       | sum of the modified collection items (3)                                        |
+| sumOf(f)               | sum of the modified collection items (3)                                        |
 | sorted()               | return [List] with collection items sorted naturally                            |
 | sortedWith(comparator) | sort using a comparator that compares elements (1)                              |
 | sortedBy(predicate)    | sort by comparing results of the predicate function                             |
 | joinToString(s,t)      | convert iterable to string, see (2)                                             |
 | reversed()             | create a list containing items from this in reverse order                       |
-| shuffled()             | create a listof shiffled elements                                               |
+| shuffled()             | create a list of shuffled elements                                              |
 (1)
-: throws `NoSuchElementException` if there is no such element
+:: throws `NoSuchElementException` if there is no such element
 (2)
-: `joinToString(suffix=" ",transform=null)`: suffix is inserted between items if there are more than one, trasnfom is
+:: `joinToString(separator=" ", transformer=null)`: separator is inserted between items if there are more than one, transformer is
 optional function applied to each item that must return result string for an item, otherwise `item.toString()` is used.
 (3)
-: sum of empty collection is `null`
+:: sum of empty collection is `null`
    fun Iterable.toList(): List
    fun Iterable.toSet(): Set
    fun Iterable.indexOf(element): Int
    fun Iterable.contains(element): Bool
    fun Iterable.isEmpty(element): Bool
    fun Iterable.forEach(block: (Any?)->Void ): Void
    fun Iterable.map(block: (Any?)->Void ): List
    fun Iterable.associateBy( keyMaker: (Any?)->Any): Map
 ## Abstract methods:
    fun iterator(): Iterator
-Creates a list by iterating to the end. So, the Iterator should be finite to be used with it.
+For high-performance Kotlin-side interop and custom iterable implementation details, see [Efficient Iterables in Kotlin Interop](EfficientIterables.md).
 ## Included in interfaces:
@@ -128,14 +209,20 @@ Creates a list by iterating to the end. So, the Iterator should be finite to be
 ## Implemented in classes:
- [List], [Range], [Buffer](Buffer.md), [BitBuffer], [Buffer], [Set], [RingBuffer]
+- [List], [ImmutableList], [Range], [Buffer](Buffer.md), [BitBuffer], [Buffer], [Set], [ImmutableSet], [Map], [ImmutableMap], [RingBuffer]
 [Collection]: Collection.md
 [List]: List.md
 [ImmutableList]: ImmutableList.md
 [Flow]: parallelism.md#flow
 [Range]: Range.md
 [Set]: Set.md
 [ImmutableSet]: ImmutableSet.md
 [Map]: Map.md
 [ImmutableMap]: ImmutableMap.md
 [RingBuffer]: RingBuffer.md
@@ -23,6 +23,8 @@ must throw `ObjIterationFinishedError`.
 Iterators are returned when implementing [Iterable] interface.
 For high-performance Kotlin-side interop and custom iterable implementation details, see [Efficient Iterables in Kotlin Interop](EfficientIterables.md).
 ## Implemented for classes:
 - [List], [Range]
@@ -1,6 +1,8 @@
 # List built-in class
 Mutable list of any objects.
 For immutable list values, see [ImmutableList].
 For observable mutable lists and change hooks, see [ObservableList].
 It's class in Lyng is `List`:
@@ -92,6 +94,34 @@ Open end ranges remove head and tail elements:
    assert( [1, 2, 3] !== [1, 2, 3])
    >>> void
 ## Destructuring
 Lists can be used as L-values for destructuring assignments. This allows you to unpack list elements into multiple variables.
 ### Basic Destructuring
 ```lyng
 val [a, b, c] = [1, 2, 3]
 ```
 ### With Splats (Variadic)
 A single ellipsis `...` can be used to capture remaining elements into a list. It can be placed at the beginning, middle, or end of the pattern.
 ```lyng
 val [head, rest...] = [1, 2, 3] // head=1, rest=[2, 3]
 val [first, middle..., last] = [1, 2, 3, 4, 5] // first=1, middle=[2, 3, 4], last=5
 ```
 ### Nested Patterns
 Destructuring patterns can be nested to unpack multi-dimensional lists.
 ```lyng
 val [a, [b, c...], d] = [1, [2, 3, 4], 5]
 ```
 ### Reassignment
 Destructuring can also be used to reassign existing variables:
 ```lyng
 [x, y] = [y, x] // Swap values
 ```
 ## In-place sort
 List could be sorted in place, just like [Collection] provide sorted copies, in a very like way:
@@ -130,7 +160,8 @@ List could be sorted in place, just like [Collection] provide sorted copies, in
 | `sort()`                      | in-place sort, natural order                 | void        |
 | `sortBy(predicate)`           | in-place sort bu `predicate` call result (3) | void        |
 | `sortWith(comparator)`        | in-place sort using `comarator` function (4) | void        |
-| `shiffle()`                   | in-place shiffle contents                    |             |
+| `shuffle()`                   | in-place shuffle contents                    |             |
 | `toString()`                 | string representation like `[a,b,c]`         |             |
 (1)
 : optimized implementation that override `Array` one
@@ -150,6 +181,50 @@ for `sort()` will be `sort { a, b -> a <=> b }
 It inherits from [Iterable] too and thus all iterable methods are applicable to any list.
 ## Observable list hooks
 Observable hooks are provided by module `lyng.observable` and are opt-in:
    import lyng.observable
    val src = [1,2,3]
    val xs = src.observable()
    assert(xs is ObservableList<Int>)
    var before = 0
    var after = 0
    xs.beforeChange { before++ }
    xs.onChange { after++ }
    xs += 4
    xs[0] = 100
    assertEquals([100,2,3,4], xs)
    assertEquals(2, before)
    assertEquals(2, after)
    >>> void
 `beforeChange` runs before mutation commit and may reject it by throwing exception (typically `ChangeRejectionException` from the same module):
    import lyng.observable
    val xs = [1,2].observable()
    xs.beforeChange { throw ChangeRejectionException("read only") }
    assertThrows(ChangeRejectionException) { xs += 3 }
    assertEquals([1,2], xs)
    >>> void
 `changes()` returns `Flow<ListChange<T>>` of committed events:
    import lyng.observable
    val xs = [10,20].observable()
    val it = xs.changes().iterator()
    xs += 30
    assert(it.hasNext())
    val e = it.next()
    assert(e is ListInsert<Int>)
    assertEquals([30], (e as ListInsert<Int>).values)
    it.cancelIteration()
    >>> void
 ## Member inherited from Array
 | name             | meaning                        | type  |
@@ -168,3 +243,5 @@ It inherits from [Iterable] too and thus all iterable methods are applicable to
 [Range]: Range.md
 [Iterable]: Iterable.md
 [ImmutableList]: ImmutableList.md
 [ObservableList]: ObservableList.md
@@ -3,6 +3,7 @@
 Map is a mutable collection of key-value pairs, where keys are unique. You can create maps in two ways:
 - with the constructor `Map(...)` or `.toMap()` helpers; and
 - with map literals using braces: `{ "key": value, id: expr, id: }`.
 For immutable map values, see [ImmutableMap].
 When constructing from a list, each list item must be a [Collection] with exactly 2 elements, for example, a [List].
@@ -94,7 +95,8 @@ Or iterate its key-value pairs that are instances of [MapEntry] class:
    val map = Map( ["foo", 1], ["bar", "buzz"], [42, "answer"] )
    for( entry in map ) {
-        println("map[%s] = %s"(entry.key, entry.value))
+        val e: MapEntry = entry as MapEntry
        println("map[%s] = %s"(e.key, e.value))
    }
    void
    >>> map[foo] = 1
@@ -172,7 +174,8 @@ Maps and entries can also be merged with `+` and `+=`:
 Notes:
 - Map literals always use string keys (identifier keys are converted to strings).
- Spreads inside map literals and `+`/`+=` merges require string keys on the right-hand side; this aligns with named-argument splats.
+- Spreads inside map literals and `+`/`+=` merges allow any objects as keys.
- When you need computed or non-string keys, use the constructor form `Map(...)` or build entries with `=>` and then merge.
+- When you need computed or non-string keys, use the constructor form `Map(...)`, map literals with computed keys (if supported), or build entries with `=>` and then merge.
 [Collection](Collection.md)
 [ImmutableMap]: ImmutableMap.md
@@ -9,7 +9,7 @@ Lyng supports first class OOP constructs, based on classes with multiple inherit
 The class clause looks like
    class Point(x,y)
-    assert( Point is Class ) 
+    assertEquals("Point", Point.className)
    >>> void
 It creates new `Class` with two fields. Here is the more practical sample:
@@ -42,6 +42,271 @@ a _constructor_ that requires two parameters for fields. So when creating it wit
 Form now on `Point` is a class, it's type is `Class`, and we can create instances with it as in the
 example above.
 ## Singleton Objects
 Singleton objects are declared using the `object` keyword. An `object` declaration defines both a class and a single instance of that class at the same time. This is perfect for stateless utilities, global configuration, or shared delegates.
 ```lyng
 object Config {
    val version = "1.0.0"
    val debug = true
    fun printInfo() {
        println("App version: " + version)
    }
 }
 // Usage:
 println(Config.version)
 Config.printInfo()
 ```
 Objects can also inherit from classes or interfaces:
 ```lyng
 object DefaultLogger : Logger("Default") {
    override fun log(msg) {
        println("[DEFAULT] " + msg)
    }
 }
 ```
 ## Object Expressions
 Object expressions allow you to create an instance of an anonymous class. This is useful when you need to provide a one-off implementation of an interface or inherit from a class without declaring a new named subclass.
 ```lyng
 val worker = object : Runnable {
    override fun run() {
        println("Working...")
    }
 }
 ```
 Object expressions can implement multiple interfaces and inherit from one class:
 ```lyng
 val x = object : Base(arg1), Interface1, Interface2 {
    val property = 42
    override fun method() = property * 2
 }
 ```
 ### Scoping and `this@object`
 Object expressions capture their lexical scope, meaning they can access local variables and members of the outer class. When `this` is rebound (for example, inside an `apply` block), you can use the reserved alias `this@object` to refer to the innermost anonymous object instance.
 ```lyng
 val handler = object {
    fun process() {
        this@object.apply {
            // here 'this' is rebound to the map/context
            // but we can still access the anonymous object via this@object
            println("Processing in " + this@object)
        }
    }
 }
 ```
 ### Serialization and Identity
 - **Serialization**: Anonymous objects are **not serializable**. Attempting to encode an anonymous object via `Lynon` will throw a `SerializationException`. This is because their class definition is transient and cannot be safely restored in a different session or process.
 - **Type Identity**: Every object expression creates a unique anonymous class. Two identical object expressions will result in two different classes with distinct type identities.
 ## Nested Declarations
 Lyng allows classes, objects, enums, and type aliases to be declared inside another class. These declarations live in the **class namespace** (not the instance), so they do not capture an outer instance and are accessed with a qualifier.
 ```lyng
 class A {
    class B(x?)
    object Inner { val foo = "bar" }
    type Alias = B
    enum E { One, Two }
 }
 val ab = A.B()
 assertEquals(ab.x, null)
 assertEquals(A.Inner.foo, "bar")
 ```
 Rules:
 - **Qualified access**: use `Outer.Inner` for nested classes/objects/enums/aliases. Inside `Outer` you can refer to them by unqualified name unless shadowed.
 - **No inner semantics**: nested declarations do not capture an instance of the outer class. They are resolved at compile time.
 - **Visibility**: `private` restricts a nested declaration to the declaring class body (not visible from outside or subclasses).
 - **Reflection name**: a nested class reports `Outer.Inner` (e.g., `A.B::class.name` is `"A.B"`).
 - **Type aliases**: behave as aliases of the qualified nested type and are expanded by the type system.
 ### Lifted Enum Entries
 Enums can optionally lift their entries into the surrounding class namespace using `*`:
 ```lyng
 class A {
    enum E* { One, Two }
 }
 assertEquals(A.One, A.E.One)
 assertEquals(A.Two, A.E.Two)
 ```
 Notes:
 - `E*` exposes entries in `A` as if they were direct members (`A.One`).
 - If a name would conflict with an existing class member, compilation fails (no implicit fallback).
 - Without `*`, use the normal `A.E.One` form.
 ## Properties
 Properties allow you to define member accessors that look like fields but execute code when read or written. Unlike regular fields, properties in Lyng do **not** have automatic backing fields; they are pure accessors.
 ### Basic Syntax
 Properties are declared using `val` (read-only) or `var` (read-write) followed by a name and a `get` (and optionally `set`) accessor. Unlike fields, properties do not have automatic storage and must compute their values or delegate to other members.
 The standard syntax uses parentheses:
 ```lyng
 class Person(private var _age: Int) {
    // Read-only property
    val ageCategory 
        get() {
            if (_age < 18) "Minor" else "Adult"
        }
    // Read-write property
    var age: Int
        get() { _age }
        set(value) {
            if (value >= 0) _age = value
        }
 }
 ```
 ### Laconic Syntax (Optional Parentheses)
 For even cleaner code, you can omit the parentheses for `get` and `set`. This is especially useful for simple expression shorthand:
 ```lyng
 class Circle(val radius: Real) {
    // Laconic expression shorthand
    val area get = π * radius * radius
    val circumference get = 2 * π * radius
    fun diameter() = radius * 2
 }
 fun median(a, b) = (a + b) / 2
 class Counter {
    private var _count = 0
    var count get = _count set(v) = _count = v
 }
 ```
 ### Key Rules
 - **`val` properties** must have a `get` accessor (with or without parentheses) and cannot have a `set`.
 - **`var` properties** must have both `get` and `set` accessors.
 - **Functions and methods** can use the `=` shorthand to return the result of a single expression.
 - **`override` is mandatory**: If you are overriding a member from a base class, you MUST use the `override` keyword.
 - **No Backing Fields**: There is no magic `field` identifier. If you need to store state, you must declare a separate (usually `private`) field.
 - **Type Inference**: You can omit the type declaration if it can be inferred or if you don't need strict typing.
 ### Lazy Properties with `cached`
 When you want to define a property that is computed only once (on demand) and then remembered, use the built-in `cached` function. This is more efficient than a regular property with `get()` if the computation is expensive, as it avoids re-calculating the value on every access.
 ```lyng
 class DataService(val id: Int) {
    // The lambda passed to cached is only executed once, the first time data() is called.
    val data = cached {
        println("Fetching data for " + id)
        // Perform expensive operation
        "Record " + id
    }
 }
 val service = DataService(42)
 // No printing yet
 println(service.data()) // Prints "Fetching data for 42", then returns "Record 42"
 println(service.data()) // Returns "Record 42" immediately (no second fetch)
 ```
 Note that `cached` returns a lambda, so you access the value by calling it like a method: `service.data()`. This is a powerful pattern for lazy-loading resources, caching results of database queries, or delaying expensive computations until they are truly needed.
 ## Delegation
 Delegation allows you to hand over the logic of a property or function to another object. This is done using the `by` keyword.
 ### Property Delegation
 Instead of providing `get()` and `set()` accessors, you can delegate them to an object that implements the `getValue` and `setValue` methods.
 ```lyng
 class User {
    var name by MyDelegate()
 }
 ```
 ### Function Delegation
 You can also delegate a whole function to an object. When the function is called, it will invoke the delegate's `invoke` method.
 ```lyng
 fun remoteAction by RemoteProxy("actionName")
 ```
 ### The Unified Delegate Interface
 A delegate is any object that provides the following methods (all optional depending on usage):
 - `getValue(thisRef, name)`: Called when a delegated `val` or `var` is read.
 - `setValue(thisRef, name, newValue)`: Called when a delegated `var` is written.
 - `invoke(thisRef, name, args...)`: Called when a delegated `fun` is invoked.
 - `bind(name, access, thisRef)`: Called once during initialization to configure or validate the delegate.
 ### Map as a Delegate
 Maps can also be used as delegates. When delegated to a property, the map uses the property name as the key:
 ```lyng
 val settings = { "theme": "dark", "fontSize": 14 }
 val theme by settings
 var fontSize by settings
 println(theme)    // "dark"
 fontSize = 16     // Updates settings["fontSize"]
 ```
 For more details and advanced patterns (like `lazy`, `observable`, and shared stateless delegates), see the [Delegation Guide](delegation.md).
 ## Instance initialization: init block
 In addition to the primary constructor arguments, you can provide an `init` block that runs on each instance creation. This is useful for more complex initializations, side effects, or setting up fields that depend on multiple constructor parameters.
    class Point(val x, val y) {
       var magnitude
       init {
          magnitude = Math.sqrt(x*x + y*y)
       }
    }
 Key features of `init` blocks:
 - **Scope**: They have full access to `this` members and all primary constructor parameters.
 - **Order**: In a single-inheritance scenario, `init` blocks run immediately after the instance fields are prepared but before the primary constructor body logic.
 - **Multiple blocks**: You can have multiple `init` blocks; they will be executed in the order they appear in the class body.
 ### Initialization in Multiple Inheritance
 In cases of multiple inheritance, `init` blocks are executed following the constructor chaining rule:
 1. All ancestors are initialized first, following the inheritance hierarchy (diamond-safe: each ancestor is initialized exactly once).
 2. The `init` blocks of each class are executed after its parents have been fully initialized.
 3. For a hierarchy `class D : B, C`, the initialization order is: `B`'s chain, then `C`'s chain (skipping common ancestors with `B`), and finally `D`'s own `init` blocks.
 ### Initialization during Deserialization
 When an object is restored from a serialized form (e.g., using `Lynon`), `init` blocks are **re-executed**. This ensures that transient state or derived fields are correctly recalculated upon restoration. However, primary constructors are **not** re-called during deserialization; only the `init` blocks and field initializers are executed to restore the instance state.
 Class point has a _method_, or a _member function_ `length()` that uses its _fields_ `x` and `y` to
 calculate the magnitude. Length is called
@@ -53,19 +318,68 @@ statements discussed later, there could be default values, ellipsis, etc.
    class Point(x=0,y=0) 
    val p = Point()
    assert( p.x == 0 && p.y == 0 )
    // Named arguments in constructor calls use colon syntax:
    val p2 = Point(y: 10, x: 5)
    assert( p2.x == 5 && p2.y == 10 )
    // Auto-substitution shorthand for named arguments:
    val x = 1
    val y = 2
    val p3 = Point(x:, y:)
    assert( p3.x == 1 && p3.y == 2 )
    >>> void
 Note that unlike **Kotlin**, which uses `=` for named arguments, Lyng uses `:` to avoid ambiguity with assignment expressions.
 ### Late-initialized `val` fields
 You can declare a `val` field without an immediate initializer if you provide an assignment for it within an `init` block or the class body. This is useful when the initial value depends on logic that cannot be expressed in a single expression.
 ```lyng
 class DataProcessor(data: Object) {
    val result: Object
    init {
        // Complex initialization logic
        result = transform(data)
    }
 }
 ```
 Key rules for late-init `val`:
 - **Compile-time Check**: The compiler ensures that every `val` declared without an initializer in a class body has at least one assignment within that class body (including `init` blocks). Failing to do so results in a syntax error.
 - **Write-Once**: A `val` can only be assigned once. Even if it was declared without an initializer, once it is assigned a value (e.g., in `init`), any subsequent assignment will throw an `IllegalAssignmentException`.
 - **Access before Initialization**: If you attempt to read a late-init `val` before it has been assigned (for example, by calling a method in `init` that reads the field before its assignment), it will hold a special `Unset` value. Using `Unset` for most operations (like arithmetic or method calls) will throw an `UnsetException`.
 - **No Extensions**: Extension properties do not support late initialization as they do not have per-instance storage. Extension `val`s must always have an initializer or a `get()` accessor.
 ### The `Unset` singleton
 The `Unset` singleton represents a field that has been declared but not yet initialized. While it can be compared and converted to a string, most other operations on it are forbidden to prevent accidental use of uninitialized data.
 ```lyng
 class T {
    val x
    fun check() {
        if (x == Unset) println("Not ready")
    }
    init {
        check() // Prints "Not ready"
        x = 42
    }
 }
 ```
 ## Methods
 Functions defined inside a class body are methods, and unless declared
 `private` are available to be called from outside the class:
    class Point(x,y) {
        // private method:
        private fun d2() { x*x + y*y }
        // public method declaration:
        fun length() { sqrt(d2()) }
        // private method:
        private fun d2() {x*x + y*y}
    }
    val p = Point(3,4)
    // private called from inside public: OK
@@ -79,7 +393,7 @@ Functions defined inside a class body are methods, and unless declared
 Lyng supports declaring a class with multiple direct base classes. The syntax is:
-```
+```lyng
 class Foo(val a) {
    var tag = "F"
    fun runA() { "ResultA:" + a }
@@ -128,16 +442,16 @@ Key rules and features:
 - Syntax
  - `class Derived(args) : Base1(b1Args), Base2(b2Args)`
-  - Each direct base may receive constructor arguments specified in the header. Only direct bases receive header args; indirect bases must either be default‑constructible or receive their args through their direct child (future extensions may add more control).
+  - Each direct base may receive constructor arguments specified in the header. Only direct bases receive header args; indirect bases must either be default‑constructible or receive their args through their direct child.
- Resolution order (C3 MRO — active)
+- Resolution order (C3 MRO)
  - Member lookup is deterministic and follows C3 linearization (Python‑like), which provides a monotonic, predictable order for complex hierarchies and diamonds.
  - Intuition: for `class D() : B(), C()` where `B()` and `C()` both derive from `A()`, the C3 order is `D → B → C → A`.
  - The first visible match along this order wins.
 - Qualified dispatch
  - Inside a class body, use `this@Type.member(...)` to start lookup at the specified ancestor.
-  - For arbitrary receivers, use casts: `(expr as Type).member(...)` or `(expr as? Type)?.member(...)` (safe‑call `?.` is already available in Lyng).
+  - For arbitrary receivers, use casts: `(expr as Type).member(...)` or `(expr as? Type)?.member(...)`.
  - Qualified access does not relax visibility.
 - Field inheritance (`val`/`var`) and collisions
@@ -152,12 +466,215 @@ Key rules and features:
 - Visibility
  - `private`: accessible only inside the declaring class body; not visible in subclasses and cannot be accessed via `this@Type` or casts.
-  - `protected`: accessible in the declaring class and in any of its transitive subclasses (including MI), but not from unrelated contexts; qualification/casts do not bypass it.
+  - `protected`: accessible in the declaring class and in any of its transitive subclasses (including MI). Additionally, ancestor classes can access protected members of their descendants if it's an override of a member known to the ancestor. Protected members are not visible from unrelated contexts; qualification/casts do not bypass it.
- Diagnostics
+## Abstract Classes and Members
-  - When a member/field is not found, error messages include the receiver class name and the considered linearization order, with suggestions to disambiguate using `this@Type` or casts if appropriate.
+
-  - Qualifying with a non‑ancestor in `this@Type` reports a clear error mentioning the receiver lineage.
+An `abstract` class is a class that cannot be instantiated and is intended to be inherited by other classes. It can contain `abstract` members that have no implementation and must be implemented by concrete subclasses.
-  - `as`/`as?` cast errors mention the actual and target types.
+
 ### Abstract Classes
 To declare an abstract class, use the `abstract` modifier:
 ```lyng
 abstract class Shape {
    abstract fun area(): Real
 }
 ```
 Abstract classes can have constructors, fields, and concrete methods, just like regular classes.
 ### Abstract Members
 Methods and variables (`val`/`var`) can be marked as `abstract`. Abstract members must not have a body or initializer.
 ```lyng
 abstract class Base {
    abstract fun foo(): Int
    abstract var bar: String
 }
 ```
 - **Safety**: `abstract` members cannot be `private`, as they must be visible to subclasses for implementation.
 - **Contract of Capability**: An `abstract val/var` represents a requirement for a capability. It can be implemented by either a **field** (storage) or a **property** (logic) in a subclass.
 ## Interfaces
 An `interface` in Lyng is a synonym for an `abstract class`. Following the principle that Lyng's Multiple Inheritance system is powerful enough to handle stateful contracts, interfaces support everything classes do, including constructors, fields, and `init` blocks.
 ```lyng
 interface Named(val name: String) {
    fun greet() { "Hello, " + name }
 }
 class Person(name) : Named(name)
 ```
 Using `interface` instead of `abstract class` is a matter of semantic intent, signaling that the class is primarily intended to be used as a contract in MI.
 ### Implementation by Parts
 One of the most powerful benefits of Lyng's Multiple Inheritance and C3 MRO is the ability to satisfy an interface's requirements "by parts" from different parent classes. Since an `interface` can have state and requirements, a subclass can inherit these requirements and satisfy them using members inherited from other parents in the MRO chain.
 Example:
 ```lyng
 // Interface with state (id) and abstract requirements
 interface Character(val id) {
    var health
    var mana
    fun isAlive() = health > 0
    fun status() = name + " (#" + id + "): " + health + " HP, " + mana + " MP"
 }
 // Parent class 1: provides health
 class HealthPool(var health)
 // Parent class 2: provides mana and name
 class ManaPool(var mana) {
    val name = "Hero"
 }
 // Composite class: implements Character by combining HealthPool and ManaPool
 class Warrior(id, h, m) : HealthPool(h), ManaPool(m), Character(id)
 val w = Warrior(1, 100, 50)
 assertEquals("Hero (#1): 100 HP, 50 MP", w.status())
 ```
 In this example, `Warrior` inherits from `HealthPool`, `ManaPool`, and `Character`. The abstract requirements `health` and `mana` from `Character` are automatically satisfied by the matching members inherited from `HealthPool` and `ManaPool`. The `status()` method also successfully finds the `name` field from `ManaPool`. This pattern allows for highly modular and reusable "trait-like" classes that can be combined to fulfill complex contracts without boilerplate proxy methods.
 ## Overriding and Virtual Dispatch
 When a class defines a member that already exists in one of its parents, it is called **overriding**.
 ### The `override` Keyword
 In Lyng, the `override` keyword is **mandatory when declaring a member** that exists in the ancestor chain (MRO).
 ```lyng
 class Parent {
    fun foo() = 1
 }
 class Child : Parent() {
    override fun foo() = 2 // Mandatory override keyword
 }
 ```
 - **Implicit Satisfaction**: If a class inherits an abstract requirement and a matching implementation from different parents, the requirement is satisfied automatically without needing an explicit `override` proxy.
 - **No Accidental Overrides**: If you define a member that happens to match a parent's member but you didn't use `override`, the compiler will throw an error. This prevents the "Fragile Base Class" problem.
 - **Private Members**: Private members in parent classes are NOT part of the virtual interface and cannot be overridden. Defining a member with the same name in a subclass is allowed without `override` and is treated as a new, independent member.
 ### Visibility Widening
 A subclass can increase the visibility of an overridden member (e.g., `protected` → `public`), but it is strictly forbidden from narrowing it (e.g., `public` → `protected`).
 ### The `closed` Modifier
 To prevent a member from being overridden in subclasses, use the `closed` modifier (equivalent to `final` in other languages).
 ```lyng
 class Critical {
    closed fun secureStep() { ... }
 }
 ```
 Attempting to override a `closed` member results in a compile-time error.
 ## Operator Overloading
 Lyng allows you to overload standard operators by defining specific named methods in your classes. When an operator expression is evaluated, Lyng delegates the operation to these methods if they are available.
 ### Binary Operators
 To overload a binary operator, define the corresponding method that takes one argument:
 | Operator | Method Name |
 | :--- | :--- |
 | `a + b` | `plus(other)` |
 | `a - b` | `minus(other)` |
 | `a * b` | `mul(other)` |
 | `a / b` | `div(other)` |
 | `a % b` | `mod(other)` |
 | `a && b` | `logicalAnd(other)` |
 | `a \|\| b` | `logicalOr(other)` |
 | `a =~ b` | `operatorMatch(other)` |
 | `a & b` | `bitAnd(other)` |
 | `a \| b` | `bitOr(other)` |
 | `a ^ b` | `bitXor(other)` |
 | `a << b` | `shl(other)` |
 | `a >> b` | `shr(other)` |
 Example:
 ```lyng
 class Vector(val x, val y) {
    fun plus(other) = Vector(x + other.x, y + other.y)
    override fun toString() = "Vector(${x}, ${y})"
 }
 val v1 = Vector(1, 2)
 val v2 = Vector(3, 4)
 assertEquals(Vector(4, 6), v1 + v2)
 ```
 ### Unary Operators
 Unary operators are overloaded by defining methods with no arguments:
 | Operator | Method Name |
 | :--- | :--- |
 | `-a` | `negate()` |
 | `!a` | `logicalNot()` |
 | `~a` | `bitNot()` |
 ### Assignment Operators
 Assignment operators like `+=` first attempt to call a specific assignment method. If that method is not defined, they fall back to a combination of the binary operator and a regular assignment (e.g., `a = a + b`).
 | Operator | Method Name | Fallback |
 | :--- | :--- | :--- |
 | `a += b` | `plusAssign(other)` | `a = a + b` |
 | `a -= b` | `minusAssign(other)` | `a = a - b` |
 | `a *= b` | `mulAssign(other)` | `a = a * b` |
 | `a /= b` | `divAssign(other)` | `a = a / b` |
 | `a %= b` | `modAssign(other)` | `a = a % b` |
 Example of in-place mutation:
 ```lyng
 class Counter(var value) {
    fun plusAssign(n) {
        value = value + n
    }
 }
 val c = Counter(10)
 c += 5
 assertEquals(15, c.value)
 ```
 ### Comparison Operators
 Comparison operators use `compareTo` and `equals`.
 | Operator | Method Name |
 | :--- | :--- |
 | `a == b`, `a != b` | `equals(other)` |
 | `<`, `>`, `<=`, `>=`, `<=>` | `compareTo(other)` |
 - `compareTo` should return:
  - `0` if `a == b`
  - A negative integer if `a < b`
  - A positive integer if `a > b`
 - The `<=>` (shuttle) operator returns the result of `compareTo` directly.
 - `equals` returns a `Bool`. If `equals` is not explicitly defined, Lyng falls back to `compareTo(other) == 0`.
 > **Note**: Methods that are already defined in the base `Obj` class (like `equals`, `toString`, or `contains`) require the `override` keyword when redefined in your class or as an extension. Other operator methods (like `plus` or `negate`) do not require `override` unless they are already present in your class's hierarchy.
 ### Increment and Decrement
 `++` and `--` operators are implemented using `plus(1)` or `minus(1)` combined with an assignment back to the variable. If the variable is a field or local variable, it will be updated with the result of the operation.
 Compatibility notes:
@@ -242,6 +759,23 @@ Notes and limitations (current version):
 - `name` and `ordinal` are read‑only properties of an entry.
 - `entries` is a read‑only list owned by the enum type.
 ## Exception Classes
 You can define your own exception classes by inheriting from the built-in `Exception` class. User-defined exceptions are regular classes and can have their own properties and methods.
 ```lyng
 class MyError(val code, m) : Exception(m)
 try {
    throw MyError(500, "Internal Server Error")
 }
 catch(e: MyError) {
    println("Error " + e.code + ": " + e.message)
 }
 ```
 For more details on error handling, see the [Exceptions Handling Guide](exceptions_handling.md).
 ## fields and visibility
 It is possible to add non-constructor fields:
@@ -274,6 +808,69 @@ Are declared with var
    assert( p.isSpecial == true )
    >>> void
 ### Restricted Setter Visibility
 You can restrict the visibility of a `var` field's or property's setter by using `private set` or `protected set` modifiers. This allows the member to be publicly readable but only writable from within the class or its subclasses.
 #### On Fields
 ```lyng
 class SecretCounter {
    var count = 0
        private set // Can be read anywhere, but written only in SecretCounter
    fun increment() { count++ }
 }
 val c = SecretCounter()
 println(c.count) // OK
 c.count = 10     // Throws IllegalAccessException
 c.increment()    // OK
 ```
 #### On Properties
 You can also apply restricted visibility to custom property setters:
 ```lyng
 class Person(private var _age: Int) {
    var age
        get() = _age
        private set(v) { if (v >= 0) _age = v }
 }
 ```
 #### Protected Setters and Inheritance
 A `protected set` allows subclasses to modify a field that is otherwise read-only to the public:
 ```lyng
 class Base {
    var state = "initial"
        protected set
 }
 class Derived : Base() {
    fun changeState(newVal) {
        state = newVal // OK: protected access from subclass
    }
 }
 val d = Derived()
 println(d.state) // OK: "initial"
 d.changeState("updated")
 println(d.state) // OK: "updated"
 d.state = "bad"  // Throws IllegalAccessException: public write not allowed
 ```
 ### Key Rules and Limitations
 - **Only for `var`**: Restricted setter visibility cannot be used with `val` declarations, as they are inherently read-only. Attempting to use it with `val` results in a syntax error.
 - **Class Body Only**: These modifiers can only be used on members declared within the class body. They are not supported for primary constructor parameters.
 - **`private set`**: The setter is only accessible within the same class context (specifically, when `this` is an instance of that class).
 - **`protected set`**: The setter is accessible within the declaring class and all its transitive subclasses.
 - **Multiple Inheritance**: In MI scenarios, visibility is checked against the class that actually declared the member. Qualified access (e.g., `this@Base.field = value`) also respects restricted setter visibility.
 ### Private fields
 Private fields are visible only _inside the class instance_:
@@ -301,23 +898,44 @@ Private fields are visible only _inside the class instance_:
    void
    >>> void
 ### Transient fields
 You can mark a field or a constructor parameter as transient using the `@Transient` attribute. Transient members are ignored during serialization (Lynon and JSON) and are also excluded from structural equality (`==`) checks.
 ```lyng
 class Session(@Transient val token, val userId) {
    @Transient var lastAccess = time.now()
    var data = Map()
 }
 ```
 For more details on how transient fields behave during restoration, see the [Serialization Guide](serialization.md).
 ### Protected members
-Protected members are available to the declaring class and all of its transitive subclasses (including via MI), but not from unrelated contexts:
+Protected members are available to the declaring class and all of its transitive subclasses (including via MI). Additionally, an ancestor class can access a `protected` member of its descendant if the ancestor also defines or inherits a member with the same name (i.e., it is an override of something the ancestor knows about). 
-```
+Protected members are not available from unrelated contexts:
-class A() {
+
-    protected fun ping() { "pong" }
+```lyng
-}
+class Base {
-class B() : A() {
+    abstract protected fun foo()
-    fun call() { this@A.ping() }
+    
    fun bar() {
        // Ancestor can see foo() because it's an override 
        // of a member it defines (even as abstract):
        foo()
    }
 }
-val b = B()
+class Derived : Base {
-assertEquals("pong", b.call())
+    override protected fun foo() { "ok" }
 }
 assertEquals("ok", Derived().bar())
 // Unrelated access is forbidden, even via cast
-assertThrows { (b as A).ping() }
+assertThrows { (Derived() as Base).foo() }
 ```
 It is possible to provide private constructor parameters so they can be
@@ -360,7 +978,7 @@ You can mark a field or a method as static. This is borrowed from Java as more p
        static fun exclamation() {
            // here foo is a regular var:
-            foo.x + "!"
+        Value.foo.x + "!"
        }
    }
    assertEquals( Value.foo.x, "foo" )
@@ -371,47 +989,29 @@ You can mark a field or a method as static. This is borrowed from Java as more p
    assertEquals( "bar!", Value.exclamation() )
    >>> void
-As usual, private statics are not accessible from the outside:
+Static fields can be accessed from static methods via the class qualifier:
    class Test {
-        // private, inacessible from outside protected data:
+        static var data = "foo"
-        private static var data = null
+        static fun getData() { Test.data }
        // the interface to access and change it:
        static fun getData() { data }
        static fun setData(value) { data = value }
    }
-    // no direct access:
+    assertEquals( "foo", Test.getData() )
-    assertThrows { Test.data }
+    Test.data = "bar"
-
+    assertEquals("bar", Test.getData() )
    // accessible with the interface:
    assertEquals( null, Test.getData() )
    Test.setData("fubar")
    assertEquals("fubar", Test.getData() )
    >>> void
 # Extending classes
-It sometimes happen that the class is missing some particular functionality that can be _added to it_ without rewriting its inner logic and using its private state. In this case _extension methods_ could be used, for example. we want to create an extension method
+It sometimes happen that the class is missing some particular functionality that can be _added to it_ without rewriting its inner logic and using its private state. In this case _extension members_ could be used.
 that would test if some object of unknown type contains something that can be interpreted
 as an integer. In this case we _extend_ class `Object`, as it is the parent class for any instance of any type:
-        fun Object.isInteger() {
+## Extension methods
            when(this) {
                // already Int?
                is Int -> true
-                // real, but with no declimal part?
+For example, we want to create an extension method that would test if a value can be interpreted as an integer:
                is Real -> toInt() == this
-                // string with int or real reuusig code above
+        fun Int.isInteger() { true }
-                is String -> toReal().isInteger()
+        fun Real.isInteger() { this.toInt() == this }
-                
+        fun String.isInteger() { (this.toReal() as Real).isInteger() }
                // otherwise, no:
                else -> false
            }
        }
        // Let's test:
        assert( 12.isInteger() == true )
@@ -420,10 +1020,67 @@ as an integer. In this case we _extend_ class `Object`, as it is the parent clas
        assert( ! "5.2".isInteger() )
        >>> void
-__Important note__ as for version 0.6.9, extensions are in __global scope__. It means, that once applied to a global type (Int in our sample), they will be available for _all_ contexts, even new created, 
+## Extension properties
 as they are modifying the type, not the context.
-Beware of it. We might need to reconsider it later.
+Just like methods, you can extend existing classes with properties. These can be defined using simple initialization (for `val` only) or with custom accessors.
 ### Simple val extension
 A read-only extension can be defined by assigning an expression:
 ```lyng
 val String.isLong = length > 10
 val s = "Hello, world!"
 assert(s.isLong)
 ```
 ### Properties with accessors
 For more complex logic, use `get()` and `set()` blocks:
 ```lyng
 class Box(var value: Int)
 var Box.doubledValue
    get() = value * 2
    set(v) = value = v / 2
 val b = Box(10)
 assertEquals(20, b.doubledValue)
 b.doubledValue = 30
 assertEquals(15, b.value)
 ```
 Extension members are strictly barred from accessing private members of the class they extend, maintaining encapsulation.
 ### Extension Scoping and Isolation
 Extensions in Lyng are **scope-isolated**. This means an extension is only visible within the scope where it is defined and its child scopes. This reduces the "attack surface" and prevents extensions from polluting the global space or other modules.
 #### Scope Isolation Example
 You can define different extensions with the same name in different scopes:
 ```lyng
 fun scopeA() {
    val Int.description = "Number: " + toString()
    assertEquals("Number: 42", 42.description)
 }
 fun scopeB() {
    val Int.description = "Value: " + toString()
    assertEquals("Value: 42", 42.description)
 }
 scopeA()
 scopeB()
 // Outside those scopes, Int.description is not defined
 assertThrows { 42.description }
 ```
 This isolation ensures that libraries can use extensions internally without worrying about name collisions with other libraries or the user's code. When a module is imported using `use`, its top-level extensions become available in the importing scope.
 ## dynamic symbols
@@ -458,7 +1115,7 @@ The same we can provide writable dynamic fields (var-type), adding set method:
                // mutable field
                "bar" -> storedValueForBar 
-                else -> throw SymbolNotFoundException()
+                else -> throw SymbolNotFound()
            }
        }
        set { name, value ->
@@ -542,12 +1199,12 @@ request](https://gitea.sergeych.net/SergeychWorks/lyng/issues).
 - ObjClass sole parent is Obj
 - ObjClass contains code for instance methods, class fields, hierarchy information.
 - Class information is also scoped. 
- We acoid imported classes duplication using packages and import caching, so the same imported module is the same object in all its classes.
+- We avoid imported classes duplication using packages and import caching, so the same imported module is the same object in all its classes.
 ## Instances
 Result of executing of any expression or statement in the Lyng is the object that
-inherits `Obj`, but is not `Obj`. For example it could be Int, void, null, real, string, bool, etc.
+inherits `Obj`, but is not `Obj`. For example, it could be Int, void, null, real, string, bool, etc.
 This means whatever expression returns or the variable holds, is the first-class
 object, no differenes. For example:
@@ -0,0 +1,70 @@
 # ObservableList module
 `ObservableList` lives in explicit module `lyng.observable`.
 Import it first:
    import lyng.observable
    >>> void
 Create from a regular mutable list:
    import lyng.observable
    val xs = [1,2,3].observable()
    assert(xs is ObservableList<Int>)
    assertEquals([1,2,3], xs)
    >>> void
 ## Hook flow
 Event order is:
 1. `beforeChange(change)` listeners
 2. mutation commit
 3. `onChange(change)` listeners
 4. `changes()` flow emission
 Rejection is done by throwing in `beforeChange`.
    import lyng.observable
    val xs = [1,2].observable()
    xs.beforeChange {
        throw ChangeRejectionException("no mutation")
    }
    assertThrows(ChangeRejectionException) { xs += 3 }
    assertEquals([1,2], xs)
    >>> void
 ## Subscriptions
 `beforeChange` and `onChange` return `Subscription`.
 Call `cancel()` to unsubscribe.
    import lyng.observable
    val xs = [1].observable()
    var hits = 0
    val sub = xs.onChange { hits++ }
    xs += 2
    sub.cancel()
    xs += 3
    assertEquals(1, hits)
    >>> void
 ## Change events
 `changes()` returns `Flow<ListChange<T>>` with concrete event classes:
 - `ListInsert`
 - `ListSet`
 - `ListRemove`
 - `ListClear`
 - `ListReorder`
    import lyng.observable
    val xs = [10,20].observable()
    val it = xs.changes().iterator()
    xs[1] = 200
    val ev = it.next()
    assert(ev is ListSet<Int>)
    assertEquals(20, (ev as ListSet<Int>).oldValue)
    assertEquals(200, ev.newValue)
    it.cancelIteration()
    >>> void
@@ -0,0 +1,309 @@
 # Operator Interop Registry
 `lyng.operators` provides a runtime registry for mixed-class binary operators.
 Import it when you want expressions such as:
 - `1 + MyType(...)`
 - `2 < MyType(...)`
 - `3 == MyType(...)`
 to work without modifying the built-in `Int` or `Real` classes.
 ```lyng
 import lyng.operators
 ```
 ## Why This Exists
 If your class defines:
 ```lyng
 class Amount(val value: Int) {
    fun plus(other: Amount) = Amount(value + other.value)
 }
 ```
 then:
 ```lyng
 Amount(1) + Amount(2)
 ```
 works, because the left operand already knows how to add another `Amount`.
 But:
 ```lyng
 1 + Amount(2)
 ```
 does not naturally work, because `Int` has not been rewritten to know about `Amount`.
 The operator interop registry solves exactly that problem.
 ## Mental Model
 Registration describes a mixed pair:
 - left class `L`
 - right class `R`
 - common class `C`
 When Lyng sees `L op R`, it:
 1. converts `L -> C`
 2. converts `R -> C`
 3. evaluates the operator as `C op C`
 So the registry is a bridge, not a separate arithmetic engine.
 ## API
 ```lyng
 OperatorInterop.register(
    leftClass,
    rightClass,
    commonClass,
    operators,
    leftToCommon,
    rightToCommon
 )
 ```
 Parameters:
 - `leftClass`: original left operand class
 - `rightClass`: original right operand class
 - `commonClass`: class that will actually execute the operator methods
 - `operators`: list of operators enabled for this pair
 - `leftToCommon`: conversion from left operand to common class
 - `rightToCommon`: conversion from right operand to common class
 ## Supported Operators
 `BinaryOperator` values:
 - `Plus`
 - `Minus`
 - `Mul`
 - `Div`
 - `Mod`
 - `Compare`
 - `Equals`
 Meaning:
 - `Compare` enables `<`, `<=`, `>`, `>=`, and `<=>`
 - `Equals` enables `==` and `!=`
 ## Minimal Working Example
 ```lyng
 package test.decimalbox
 import lyng.operators
 class DecimalBox(val value: Int) {
    fun plus(other: DecimalBox) = DecimalBox(value + other.value)
    fun minus(other: DecimalBox) = DecimalBox(value - other.value)
    fun mul(other: DecimalBox) = DecimalBox(value * other.value)
    fun div(other: DecimalBox) = DecimalBox(value / other.value)
    fun mod(other: DecimalBox) = DecimalBox(value % other.value)
    fun compareTo(other: DecimalBox) = value <=> other.value
 }
 OperatorInterop.register(
    Int,
    DecimalBox,
    DecimalBox,
    [
        BinaryOperator.Plus,
        BinaryOperator.Minus,
        BinaryOperator.Mul,
        BinaryOperator.Div,
        BinaryOperator.Mod,
        BinaryOperator.Compare,
        BinaryOperator.Equals
    ],
    { x: Int -> DecimalBox(x) },
    { x: DecimalBox -> x }
 )
 ```
 Then:
 ```lyng
 import test.decimalbox
 assertEquals(DecimalBox(3), 1 + DecimalBox(2))
 assertEquals(DecimalBox(1), 3 - DecimalBox(2))
 assertEquals(DecimalBox(8), 4 * DecimalBox(2))
 assertEquals(DecimalBox(4), 8 / DecimalBox(2))
 assertEquals(DecimalBox(1), 7 % DecimalBox(2))
 assert(1 < DecimalBox(2))
 assert(2 <= DecimalBox(2))
 assert(3 > DecimalBox(2))
 assert(2 == DecimalBox(2))
 assert(2 != DecimalBox(3))
 ```
 ## How Decimal Uses It
 `lyng.decimal` uses this same mechanism so that:
 ```lyng
 import lyng.decimal
 1 + 2.d
 0.5 + 1.d
 2 == 2.d
 3 > 2.d
 ```
 work naturally even though `Int` and `Real` themselves were not edited to know `BigDecimal`.
 The shape is:
 - `leftClass = Int` or `Real`
 - `rightClass = BigDecimal`
 - `commonClass = BigDecimal`
 - convert built-ins into `BigDecimal`
 - leave `BigDecimal` values unchanged
 ## Step-By-Step Pattern For Your Own Type
 ### 1. Pick the common class
 Choose one class that will be the actual arithmetic domain.
 For numeric-like types, that is usually your own class:
 ```lyng
 class Rational(...)
 ```
 ### 2. Implement operators on that class
 The common class should define the operations you plan to register.
 Example:
 ```lyng
 class Rational(val num: Int, val den: Int) {
    fun plus(other: Rational) = Rational(num * other.den + other.num * den, den * other.den)
    fun minus(other: Rational) = Rational(num * other.den - other.num * den, den * other.den)
    fun mul(other: Rational) = Rational(num * other.num, den * other.den)
    fun div(other: Rational) = Rational(num * other.den, den * other.num)
    fun compareTo(other: Rational) = (num * other.den) <=> (other.num * den)
    static fun fromInt(value: Int) = Rational(value, 1)
 }
 ```
 ### 3. Register the mixed pair
 ```lyng
 import lyng.operators
 OperatorInterop.register(
    Int,
    Rational,
    Rational,
    [
        BinaryOperator.Plus,
        BinaryOperator.Minus,
        BinaryOperator.Mul,
        BinaryOperator.Div,
        BinaryOperator.Compare,
        BinaryOperator.Equals
    ],
    { x: Int -> Rational.fromInt(x) },
    { x: Rational -> x }
 )
 ```
 ### 4. Use it
 ```lyng
 assertEquals(Rational(3, 2), 1 + Rational(1, 2))
 assert(Rational(3, 2) == Rational(3, 2))
 assert(2 > Rational(3, 2))
 ```
 ## Registering More Than One Built-in Type
 If you want both `Int + MyType` and `Real + MyType`, register both pairs explicitly:
 ```lyng
 OperatorInterop.register(
    Int,
    MyType,
    MyType,
    [BinaryOperator.Plus, BinaryOperator.Compare, BinaryOperator.Equals],
    { x: Int -> MyType.fromInt(x) },
    { x: MyType -> x }
 )
 OperatorInterop.register(
    Real,
    MyType,
    MyType,
    [BinaryOperator.Plus, BinaryOperator.Compare, BinaryOperator.Equals],
    { x: Real -> MyType.fromReal(x) },
    { x: MyType -> x }
 )
 ```
 Each mixed pair is independent.
 ## Pure Lyng Registration
 This mechanism is intentionally useful from pure Lyng code, not only from Kotlin-backed modules.
 That means you can:
 - declare a class in Lyng
 - define its operators in Lyng
 - register mixed operand bridges in Lyng
 without touching compiler internals.
 ## Where To Register
 Register once during module initialization.
 Top-level module code is a good place:
 ```lyng
 package my.rational
 import lyng.operators
 class Rational(...)
 OperatorInterop.register(...)
 ```
 That keeps registration close to the type declaration and makes importing the module enough to activate the interop.
 ## What Registration Does Not Do
 The registry does not:
 - invent operators your common class does not implement
 - change the original `Int`, `Real`, or other built-ins
 - automatically cover every class pair
 - replace normal method overload resolution when the left-hand class already knows what to do
 It only teaches Lyng how to bridge a specific mixed pair into a common class for the listed operators.
 ## Recommended Design Rules
 If you want interop to feel natural:
 - choose one obvious common class
 - make conversions explicit and unsurprising
 - implement `compareTo` if you want ordering operators
 - register `Equals` whenever mixed equality should work
 - keep the registered operator list minimal and accurate
 For decimal-like semantics, also read [Decimal.md](Decimal.md).
@@ -45,10 +45,11 @@ are equal or within another, taking into account the end-inclusiveness:
    assert( (1..<3) in (1..3) )
    >>> void
-## Finite Ranges are iterable
+## Ranges are iterable
-So given a range with both ends, you can assume it is [Iterable]. This automatically let
+Finite ranges are [Iterable] and can be used in loops and list conversions.
-use finite ranges in loops and convert it to lists:
+Open-ended ranges are iterable only with an explicit `step`, and open-start
 ranges are never iterable.
    assert( [-2, -1, 0, 1] == (-2..1).toList() )
    >>> void
@@ -62,6 +63,8 @@ In spite of this you can use ranges in for loops:
    >>> 3
    >>> void
 The loop variable is read-only inside the loop body (behaves like a `val`).
 but
    for( i in 1..<3 ) 
@@ -70,6 +73,26 @@ but
    >>> 2
    >>> void
 ### Stepped ranges
 Use `step` to change the iteration increment. The range bounds still define membership,
 so iteration ends when the next value is no longer in the range.
    assert( [1,3,5] == (1..5 step 2).toList() )
    assert( [1,3] == (1..<5 step 2).toList() )
    assert( ['a','c','e'] == ('a'..'e' step 2).toList() )
    >>> void
 Real ranges require an explicit step:
    assert( [0,0.25,0.5,0.75,1.0] == (0.0..1.0 step 0.25).toList() )
    >>> void
 Open-ended ranges require an explicit step to iterate:
    (0.. step 1).take(3).toList()
    >>> [0,1,2]
 ## Character ranges
 You can use Char as both ends of the closed range:
@@ -98,10 +121,12 @@ Exclusive end char ranges are supported too:
 | isEndInclusive  | true for '..'                | Bool          |
 | isOpen          | at any end                   | Bool          |
 | isIntRange      | both start and end are Int   | Bool          |
-| start           |                              | Bool          |
+| step            | explicit iteration step      | Any?          |
-| end             |                              | Bool          |
+| start           |                              | Any?          |
 | end             |                              | Any?          |
 | size            | for finite ranges, see above | Long          |
 | []              | see above                    |               |
-|                 |                              |               |
+
 Ranges are also used with the `clamp(value, range)` function and the `value.clamp(range)` extension method to limit values within boundaries.
 [Iterable]: Iterable.md
@@ -19,6 +19,7 @@ you can use it's class to ensure type:
 |-----------------|-------------------------------------------------------------|------|
 | `.roundToInt()` | round to nearest int like round(x)                          | Int  |
 | `.toInt()`      | convert integer part of real to `Int` dropping decimal part | Int  |
 | `.clamp(range)` | clamp value within range boundaries                         | Real |
 |                 |                                                             |      |
 |                 |                                                             |      |
 |                 |                                                             |      |
@@ -24,13 +24,14 @@ counterpart, _not match_ operator `!~`:
 When you need to find groups, and more detailed match information, use `Regex.find`:
-    val result = Regex("abc(\d)(\d)(\d)").find( "bad456 good abc123")
+    val result: RegexMatch? = Regex("abc(\d)(\d)(\d)").find( "bad456 good abc123")
    assert( result  != null )
-    assertEquals( 12 .. 17, result.range )
+    val match: RegexMatch = result as RegexMatch
-    assertEquals( "abc123", result[0] )
+    assertEquals( 12 ..< 17, match.range )
-    assertEquals( "1", result[1] )
+    assertEquals( "abc123", match[0] )
-    assertEquals( "2", result[2] )
+    assertEquals( "1", match[1] )
-    assertEquals( "3", result[3] )
+    assertEquals( "2", match[2] )
    assertEquals( "3", match[3] )
    >>> void
 Note that the object `RegexMatch`, returned by [Regex.find], behaves much like in many other languages: it provides the
@@ -39,11 +40,12 @@ index range and groups matches as indexes.
 Match operator actually also provides `RegexMatch` in `$~` reserved variable (borrowed from Ruby too):
    assert( "bad456 good abc123" =~ "abc(\d)(\d)(\d)".re )
-    assertEquals( 12 .. 17, $~.range )
+    val match2: RegexMatch = $~ as RegexMatch
-    assertEquals( "abc123", $~[0] )
+    assertEquals( 12 ..< 17, match2.range )
-    assertEquals( "1", $~[1] )
+    assertEquals( "abc123", match2[0] )
-    assertEquals( "2", $~[2] )
+    assertEquals( "1", match2[1] )
-    assertEquals( "3", $~[3] )
+    assertEquals( "2", match2[2] )
    assertEquals( "3", match2[3] )
    >>> void
 This is often more readable than calling `find`.
@@ -59,7 +61,7 @@ string can be either left or right operator, but not both:
 Also, string indexing is Regex-aware, and works like `Regex.find` (_not findall!_):
-    assert( "cd" == "abcdef"[ "c.".re ].value )
+    assert( "cd" == ("abcdef"[ "c.".re ] as RegexMatch).value )
    >>> void
@@ -88,4 +90,3 @@ Also, string indexing is Regex-aware, and works like `Regex.find` (_not findall!
 [List]: List.md
 [Range]: Range.md
@@ -1,7 +1,8 @@
-# List built-in class
+# Set built-in class
 Mutable set of any objects: a group of different objects, no repetitions.
 Sets are not ordered, order of appearance does not matter.
 For immutable set values, see [ImmutableSet].
    val set = Set(1,2,3, "foo")
    assert( 1 in set )
@@ -26,8 +27,8 @@ no indexing. Use [set.toList] as needed.
    // intersection
    assertEquals( Set(1,4), Set(3, 1, 4).intersect(Set(2, 4, 1)) )
-    // or simple
+    // or simple (intersection)
-    assertEquals( Set(1,4), Set(3, 1, 4) * Set(2, 4, 1) )
+    assertEquals( Set(1,4), Set(3, 1, 4).intersect(Set(2, 4, 1)) )
    // To find collection elements not present in another collection, use the 
    // subtract() or `-`:
@@ -92,3 +93,4 @@ Also, it inherits methods from [Iterable].
 [Range]: Range.md
 [ImmutableSet]: ImmutableSet.md
@@ -0,0 +1,121 @@
 # Testing and Assertions
 Lyng provides several built-in functions for testing and verifying code behavior. These are available in all scripts.
 ## Basic Assertions
 ### `assert`
 Assert that a condition is true.
    assert(condition, message=null)
 - `condition`: A boolean expression.
 - `message` (optional): A string message to include in the exception if the assertion fails.
 If the condition is false, it throws an `AssertionFailedException`.
 ```lyng
 assert(1 + 1 == 2)
 assert(true, "This should be true")
 ```
 ### `assertEquals` and `assertEqual`
 Assert that two values are equal. `assertEqual` is an alias for `assertEquals`.
    assertEquals(expected, actual)
    assertEqual(expected, actual)
 If `expected != actual`, it throws an `AssertionFailedException` with a message showing both values.
 ```lyng
 assertEquals(4, 2 * 2)
 assertEqual("hello", "hel" + "lo")
 ```
 ### `assertNotEquals`
 Assert that two values are not equal.
    assertNotEquals(unexpected, actual)
 If `unexpected == actual`, it throws an `AssertionFailedException`.
 ```lyng
 assertNotEquals(5, 2 * 2)
 ```
 ## Exception Testing
 ### `assertThrows`
 Assert that a block of code throws an exception.
    assertThrows(code)
    assertThrows(expectedExceptionClass, code)
 - `expectedExceptionClass` (optional): The class of the exception that is expected to be thrown.
 - `code`: A lambda block or statement to execute.
 If the code does not throw an exception, an `AssertionFailedException` is raised. 
 If an `expectedExceptionClass` is provided, the thrown exception must be of that class (or its subclass), otherwise an error is raised.
 `assertThrows` returns the caught exception object if successful.
 ```lyng
 // Just assert that something is thrown
 assertThrows { 1 / 0 }
 // Assert that a specific exception class is thrown
 assertThrows(NoSuchElementException) { 
    [1, 2, 3].findFirst { it > 10 } 
 }
 // You can use the returned exception
 val ex = assertThrows { throw Exception("custom error") }
 assertEquals("custom error", ex.message)
 ```
 ## Other Validation Functions
 While not strictly for testing, these functions help in defensive programming:
 ### `require`
    require(condition, message="requirement not met")
 Throws an `IllegalArgumentException` if the condition is false. Use this for validating function arguments.
 If we want to evaluate the message lazily:
    require(condition) { "requirement not met: %s"(someData) }
 In this case, formatting will only occur if the condition is not met.
 ### `check`
    check(condition, message="check failed")
 Throws an `IllegalStateException` if the condition is false. Use this for validating internal state.
 With lazy message evaluation:
    check(condition) { "check failed: %s"(someData) }
 In this case, formatting will only occur if the condition is not met.
 ### TODO
 It is easy to mark some code and make it throw a special exception at cone with:
    TODO()
 or
    TODO("some message")
 It raises an `NotImplementedException` with the given message. You can catch it
 as any other exception when necessary.
 Many IDE and editors have built-in support for marking code with TODOs.
@@ -105,6 +105,7 @@ arguments list in almost arbitrary ways. For example:
        var result = ""
        for( a in args ) result += a
    }
    // loop variables are read-only inside the loop body
    assertEquals( 
        "4231", 
@@ -153,9 +154,10 @@ Function annotation can have more args specified at call time. There arguments m
    @Registered("bar") 
    fun foo2() { "called foo2" }
-    assertEquals(registered["foo"](), "called foo")
+    val fooFn: Callable = registered["foo"] as Callable
-    assertEquals(registered["bar"](), "called foo2")
+    val barFn: Callable = registered["bar"] as Callable
-    >>> void
+    assertEquals(fooFn(), "called foo")
    assertEquals(barFn(), "called foo2")
 [parallelism]: parallelism.md
@@ -0,0 +1,227 @@
 # Lyng Language Reference for AI Agents (Current Compiler State)
 Purpose: dense, implementation-first reference for generating valid Lyng code.
 Primary sources used: `lynglib/src/commonMain/kotlin/net/sergeych/lyng/{Parser,Token,Compiler,Script,TypeDecl}.kt`, `lynglib/stdlib/lyng/root.lyng`, tests in `lynglib/src/commonTest` and `lynglib/src/jvmTest`.
 ## 1. Ground Rules
 - Resolution is compile-time-first. Avoid runtime name/member lookup assumptions.
 - `lyng.stdlib` is auto-seeded for normal scripts (default import manager).
 - Use explicit casts when receiver type is unknown (`Object`/`Obj`).
 - Prefer modern null-safe operators (`?.`, `?:`/`??`, `?=`, `as?`, `!!`).
 - Do not rely on fallback opcodes or dynamic member fallback semantics.
 ## 2. Lexical Syntax
 - Comments: `// line`, `/* block */`.
 - Strings: `"..."` (supports escapes). Multiline string content is normalized by indentation logic.
  - Supported escapes: `\n`, `\r`, `\t`, `\"`, `\\`, `\uXXXX` (4 hex digits).
  - Unicode escapes use exactly 4 hex digits (for example: `"\u0416"` -> `Ж`).
  - Unknown `\x` escapes in strings are preserved literally as two characters (`\` and `x`).
  - String interpolation is supported:
    - identifier form: `"$name"`
    - expression form: `"${expr}"`
    - escaped dollar: `"\$"` and `"$$"` both produce literal `$`.
    - `\\$x` means backslash + interpolated `x`.
  - Per-file opt-out is supported via leading comment directive:
    - `// feature: interpolation: off`
    - with this directive, `$...` stays literal text.
 - Numbers: `Int` (`123`, `1_000`), `Real` (`1.2`, `1e3`), hex (`0xFF`).
 - Char: `'a'`, escaped chars supported.
  - Supported escapes: `\n`, `\r`, `\t`, `\'`, `\\`, `\uXXXX` (4 hex digits).
  - Backslash character in a char literal must be written as `'\\'` (forms like `'\'` are invalid).
 - Labels:
  - statement label: `loop@ for (...) { ... }`
  - label reference: `break@loop`, `continue@loop`, `return@fnLabel`
 - Keywords/tokens include (contextual in many places):
  - declarations: `fun`/`fn`, `val`, `var`, `class`, `object`, `interface`, `enum`, `type`, `init`
  - modifiers: `private`, `protected`, `static`, `abstract`, `closed`, `override`, `extern`, `open`
  - flow: `if`, `else`, `when`, `for`, `while`, `do`, `try`, `catch`, `finally`, `throw`, `return`, `break`, `continue`
 ## 3. Literals and Core Expressions
 - Scalars: `null`, `true`, `false`, `void`.
 - List literal: `[a, b, c]`, spreads with `...`.
  - Spread positions: beginning, middle, end are all valid: `[...a]`, `[0, ...a, 4]`, `[head, ...mid, tail]`.
  - Spread source must be a `List` at runtime (non-list spread raises an error).
 - Map literal: `{ key: value, x:, ...otherMap }`.
  - `x:` means shorthand `x: x`.
  - Map spread source must be a `Map`.
 - Range literals:
  - inclusive: `a..b`
  - exclusive end: `a..<b`
  - open-ended forms are supported (`a..`, `..b`, `..`).
  - optional step: `a..b step 2`
 - Lambda literal:
  - with params: `{ x, y -> x + y }`
  - implicit `it`: `{ it + 1 }`
 - Ternary conditional is supported: `cond ? thenExpr : elseExpr`.
 ## 3.1 Splats in Calls and Lambdas
 - Declaration-side variadic parameters use ellipsis suffix:
  - functions: `fun f(head, tail...) { ... }`
  - lambdas: `{ x, rest... -> ... }`
 - Call-side splats use `...expr` and are expanded by argument kind:
  - positional splat: `f(...[1,2,3])`
  - named splat: `f(...{ a: 1, b: 2 })` (map-style)
 - Runtime acceptance for splats:
  - positional splat accepts `List` and general `Iterable` (iterable is converted to list first).
  - named splat accepts `Map` with string keys only.
 - Ordering/validation rules (enforced):
  - positional argument cannot follow named arguments (except trailing-block parsing case).
  - positional splat cannot follow named arguments.
  - duplicate named arguments are errors (including duplicates introduced via named splat).
  - unknown named parameters are errors.
  - variadic parameter itself cannot be passed as a named argument (`fun g(args..., tail)` then `g(args: ...)` is invalid).
 - Trailing block + named arguments:
  - if the last callable parameter is already provided by name in parentheses, adding a trailing block is invalid.
 ## 4. Operators (implemented)
 - Assignment: `=`, `+=`, `-=`, `*=`, `/=`, `%=`, `?=`.
 - Logical: `||`, `&&`, unary `!`.
 - Bitwise: `|`, `^`, `&`, `~`, shifts `<<`, `>>`.
 - Equality/comparison: `==`, `!=`, `===`, `!==`, `<`, `<=`, `>`, `>=`, `<=>`, `=~`, `!~`.
 - Type/containment: `is`, `!is`, `in`, `!in`, `as`, `as?`.
 - Null-safe family:
  - member access: `?.`
  - safe index: `?[i]`
  - safe invoke: `?(...)`
  - safe block invoke: `?{ ... }`
  - elvis: `?:` and `??`.
 - Increment/decrement: prefix and postfix `++`, `--`.
 ## 5. Declarations
 - Variables:
  - `val` immutable, `var` mutable.
  - top-level/local `val` must be initialized.
  - class `val` may be late-initialized, but must be assigned in class body/init before class parse ends.
  - destructuring declaration: `val [a, b, rest...] = expr`.
  - destructuring declaration details:
    - allowed in `val` and `var` declarations.
    - supports nested patterns: `val [a, [b, c...], d] = rhs`.
    - supports at most one splat (`...`) per pattern level.
    - RHS must be a `List`.
    - without splat: RHS must have at least as many elements as pattern arity.
    - with splat: head/tail elements are bound directly, splat receives a `List`.
 - Functions:
  - `fun` and `fn` are equivalent.
  - full body: `fun f(x) { ... }`
  - shorthand: `fun f(x) = expr`.
  - generics: `fun f<T>(x: T): T`.
  - extension functions: `fun Type.name(...) { ... }`.
  - delegated callable: `fun f(...) by delegate`.
 - Type aliases:
  - `type Name = TypeExpr`
  - generic: `type Box<T> = List<T>`
  - aliases are expanded structurally.
 - Classes/objects/enums/interfaces:
  - `interface` is parsed as abstract class synonym.
  - `object` supports named singleton and anonymous object expression forms.
  - enums support lifted entries: `enum E* { A, B }`.
  - multiple inheritance is supported; override is enforced when overriding base members.
 - Properties/accessors in class body:
  - accessor form supports `get`/`set`, including `private set`/`protected set`.
 ## 6. Control Flow
 - `if` is expression-like.
 - `when(value) { ... }` supported.
  - branch conditions support equality, `in`, `!in`, `is`, `!is`, and `nullable` predicate.
  - `when { ... }` (subject-less) is currently not implemented.
 - Loops: `for`, `while`, `do ... while`.
  - loop `else` blocks are supported.
  - `break value` can return a loop result.
 - Exceptions: `try/catch/finally`, `throw`.
 ## 6.1 Destructuring Assignment (implemented)
 - Reassignment form is supported (not only declaration):
  - `[x, y] = [y, x]`
 - Semantics match destructuring declaration:
  - nested patterns allowed.
  - at most one splat per pattern level.
  - RHS must be a `List`.
  - too few RHS elements raises runtime error.
 - Targets in pattern are variables parsed from identifier patterns.
 ## 7. Type System (current behavior)
 - Non-null by default (`T`), nullable with `T?`.
 - `as` (checked cast), `as?` (safe cast returning `null`), `!!` non-null assertion.
 - Type expressions support:
  - unions `A | B`
  - intersections `A & B`
  - function types `(A, B)->R` and receiver form `Receiver.(A)->R`
  - variadics in function type via ellipsis (`T...`)
 - Generics:
  - type params on classes/functions/type aliases
  - bounds via `:` with union/intersection expressions
  - declaration-site variance via `in` / `out`
 - Generic function/class/type syntax examples:
  - function: `fun choose<T>(a: T, b: T): T = a`
  - class: `class Box<T>(val value: T)`
  - alias: `type PairList<T> = List<List<T>>`
 - Untyped params default to `Object` (`x`) or `Object?` (`x?` shorthand).
 - Untyped `var x` starts as `Unset`; first assignment fixes type tracking in compiler.
 ## 7.1 Generics Runtime Model and Bounds (AI-critical)
 - Lyng generic type information is operational in script execution contexts; do not assume JVM-style full erasure.
 - Generic call type arguments can be:
  - explicit at call site (`f<Int>(1)` style),
  - inferred from runtime values/declared arg types,
  - defaulted from type parameter defaults (or `Any` fallback).
 - At function execution, generic type parameters are runtime-bound as constants in scope:
  - simple non-null class-like types are bound as `ObjClass`,
  - complex/nullable/union/intersection forms are bound as `ObjTypeExpr`.
 - Practical implication for generated code:
  - inside generic code, treat type params as usable type objects in `is`/`in`/type-expression logic (not as purely compile-time placeholders).
  - example pattern: `if (value is T) { ... }`.
 - Bound syntax (implemented):
  - intersection bound: `fun f<T: A & B>(x: T) { ... }`
  - union bound: `fun g<T: A | B>(x: T) { ... }`
 - Bound checks happen at two points:
  - compile-time call checking for resolvable generic calls,
  - runtime re-check while binding type params for actual invocation.
 - Bound satisfaction is currently class-hierarchy based for class-resolvable parts (including union/intersection combination rules).
 - Keep expectations realistic:
  - extern-generic runtime ABI for full instance-level generic metadata is still proposal-level (`proposals/extern_generic_runtime_abi.md`), so avoid assuming fully materialized generic-instance metadata everywhere.
 ## 7.2 Differences vs Java / Kotlin / Scala
 - Java:
  - Java generics are erased at runtime (except reflection metadata and raw `Class` tokens).
  - Lyng generic params in script execution are runtime-bound type objects, so generated code can reason about `T` directly.
 - Kotlin:
  - Kotlin on JVM is mostly erased; full runtime type access usually needs `inline reified`.
  - Lyng generic function execution binds `T` without requiring an inline/reified escape hatch.
 - Scala:
  - Scala has richer static typing but still runs on JVM erasure model unless carrying explicit runtime evidence (`TypeTag`, etc.).
  - Lyng exposes runtime-bound type expressions/classes directly in generic execution scope.
 - AI generation rule:
  - do not port JVM-language assumptions like “`T` unavailable at runtime unless reified/tagged”.
  - in Lyng, prefer direct type-expression-driven branching when useful, but avoid assuming extern object generic args are always introspectable today.
 ## 8. OOP, Members, and Dispatch
 - Multiple inheritance with C3-style linearization behavior is implemented in class machinery.
 - Disambiguation helpers are supported:
  - qualified this: `this@Base.member()`
  - cast view: `(obj as Base).member()`
 - On unknown receiver types, compiler allows only Object-safe members:
  - `toString`, `toInspectString`, `let`, `also`, `apply`, `run`
 - Other members require known receiver type or explicit cast.
 ## 9. Delegation (`by`)
 - Works for `val`, `var`, and `fun`.
 - Expected delegate hooks in practice:
  - `getValue(thisRef, name)`
  - `setValue(thisRef, name, newValue)`
  - `invoke(thisRef, name, args...)` for delegated callables
  - optional `bind(name, access, thisRef)`
 - `@Transient` is recognized for declarations/params and affects serialization/equality behavior.
 ## 10. Modules and Imports
 - `package` and `import module.name` are supported.
 - Import form is module-only (no aliasing/selective import syntax in parser).
 - Default module ecosystem includes:
  - auto-seeded: `lyng.stdlib`
  - available by import: `lyng.observable`, `lyng.buffer`, `lyng.serialization`, `lyng.time`
  - extra module (when installed): `lyng.io.fs`, `lyng.io.process`
 ## 11. Current Limitations / Avoid
 - No subject-less `when { ... }` yet.
 - No regex literal tokenization (`/.../`); use `Regex("...")` or `"...".re`.
 - Do not generate runtime name fallback patterns from legacy docs.
@@ -0,0 +1,15 @@
 # AI notes: avoid Kotlin/Wasm invalid IR with suspend lambdas
 ## Do
 - Prefer explicit `object : Statement()` with `override suspend fun execute(...)` when building compiler statements.
 - Keep `Statement` objects non-lambda, especially in compiler hot paths like parsing/var declarations.
 - If you need conditional behavior, return early in `execute` instead of wrapping `parseExpression()` with `statement(...) { ... }`.
 - When wasmJs tests hang in the browser, first check `wasmJsNodeTest` for a compile error; hangs often mean module instantiation failed.
 ## Don't
 - Do not create suspend lambdas inside `Statement` factories (`statement { ... }`) for wasm targets.
 - Do not "fix" hangs by increasing browser timeouts; it masks invalid wasm generation.
 ## Debugging tips
 - Look for `$invokeCOROUTINE$` in wasm function names when mapping failures.
 - If node test logs a wasm compile error, the browser hang is likely the same root cause.
@@ -0,0 +1,75 @@
 # Lyng Stdlib Reference for AI Agents (Compact)
 Purpose: fast overview of what is available by default and what must be imported.
 Sources: `lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt`, `lynglib/stdlib/lyng/root.lyng`, `lynglib/src/commonMain/kotlin/net/sergeych/lyng/stdlib_included/observable_lyng.kt`.
 ## 1. Default Availability
 - Normal scripts are auto-seeded with `lyng.stdlib` (default import manager path).
 - Root runtime scope also exposes global constants/functions directly.
 ## 2. Core Global Functions (Root Scope)
 - IO/debug: `print`, `println`, `traceScope`.
 - Invocation/util: `call`, `run`, `dynamic`, `cached`, `lazy`.
 - Assertions/tests: `assert`, `assertEquals`/`assertEqual`, `assertNotEquals`, `assertThrows`.
 - Preconditions: `require`, `check`.
 - Async/concurrency: `launch`, `yield`, `flow`, `delay`.
 - Math: `floor`, `ceil`, `round`, `sin`, `cos`, `tan`, `asin`, `acos`, `atan`, `sinh`, `cosh`, `tanh`, `asinh`, `acosh`, `atanh`, `exp`, `ln`, `log10`, `log2`, `pow`, `sqrt`, `abs`, `clamp`.
 ## 3. Core Global Constants/Types
 - Values: `Unset`, `π`.
 - Primitive/class symbols: `Object`, `Int`, `Real`, `Bool`, `Char`, `String`, `Class`, `Callable`.
 - Collections/types: `Iterable`, `Iterator`, `Collection`, `Array`, `List`, `ImmutableList`, `Set`, `ImmutableSet`, `Map`, `ImmutableMap`, `MapEntry`, `Range`, `RingBuffer`.
 - Random: singleton `Random` and class `SeededRandom`.
 - Async types: `Deferred`, `CompletableDeferred`, `Mutex`, `Flow`, `FlowBuilder`.
 - Delegation types: `Delegate`, `DelegateContext`.
 - Regex types: `Regex`, `RegexMatch`.
 - Also present: `Math.PI` namespace constant.
 ## 4. `lyng.stdlib` Module Surface (from `root.lyng`)
 ### 4.1 Extern class declarations
 - Exceptions/delegation base: `Exception`, `IllegalArgumentException`, `NotImplementedException`, `Delegate`.
 - Collections and iterables: `Iterable<T>`, `Iterator<T>`, `Collection<T>`, `Array<T>`, `List<T>`, `ImmutableList<T>`, `Set<T>`, `ImmutableSet<T>`, `Map<K,V>`, `ImmutableMap<K,V>`, `MapEntry<K,V>`, `RingBuffer<T>`.
 - Host iterator bridge: `KotlinIterator<T>`.
 - Random APIs: `extern object Random`, `extern class SeededRandom`.
 ### 4.2 High-use extension APIs
 - Iteration/filtering: `forEach`, `filter`, `filterFlow`, `filterNotNull`, `filterFlowNotNull`, `drop`, `dropLast`, `takeLast`.
 - Search/predicates: `findFirst`, `findFirstOrNull`, `any`, `all`, `count`, `first`, `last`.
 - Mapping/aggregation: `map`, `flatMap`, `flatten`, `sum`, `sumOf`, `minOf`, `maxOf`.
 - Ordering: `sorted`, `sortedBy`, `shuffled`, `List.sort`, `List.sortBy`.
 - String helper: `joinToString`, `String.re`.
 ### 4.3 Delegation helpers
 - `enum DelegateAccess { Val, Var, Callable }`
 - `interface Delegate<T,ThisRefType=void>` with `getValue`, `setValue`, `invoke`, `bind`.
 - `class lazy<T,...>` delegate implementation.
 - `fun with(self, block)` helper.
 ### 4.4 Other module-level symbols
 - `$~` (last regex match object).
 - `TODO(message?)` utility.
 - `StackTraceEntry` class.
 - `Random.nextInt()`, `Random.nextFloat()`, `Random.next(range)`, `Random.seeded(seed)`.
 - `SeededRandom.nextInt()`, `SeededRandom.nextFloat()`, `SeededRandom.next(range)`.
 ## 5. Additional Built-in Modules (import explicitly)
 - `import lyng.observable`
  - `Observable`, `Subscription`, `ObservableList`, `ListChange` and change subtypes, `ChangeRejectionException`.
 - `import lyng.buffer`
  - `Buffer`, `MutableBuffer`.
 - `import lyng.serialization`
  - `Lynon` serialization utilities.
 - `import lyng.time`
  - `Instant`, `DateTime`, `Duration`, and module `delay`.
 ## 6. Optional (lyngio) Modules
 Requires installing `lyngio` into the import manager from host code.
 - `import lyng.io.fs` (filesystem `Path` API)
 - `import lyng.io.process` (process execution API)
 - `import lyng.io.console` (console capabilities, geometry, ANSI/output, events)
 ## 7. AI Generation Tips
 - Assume `lyng.stdlib` APIs exist in regular script contexts.
 - For platform-sensitive code (`fs`, `process`, `console`), gate assumptions and mention required module install.
 - Prefer extension-method style (`items.filter { ... }`) and standard scope helpers (`let`/`also`/`apply`/`run`).
@@ -34,13 +34,18 @@ Valid examples:
 Ellipsis are used to declare variadic arguments. It basically means "all the arguments available here". It means, ellipsis argument could be in any part of the list, being, end or middle, but there could be only one ellipsis argument and it must not have default value, its default value is always `[]`, en empty list.
 Ellipsis can also appear in **function types** to denote a variadic position:
    var f: (Int, Object..., String)->Real
    var anyArgs: (...)->Int   // shorthand for (Object...)->Int
 Ellipsis argument receives what is left from arguments after processing regular one that could be before or after.
 Ellipsis could be a first argument:
    fun testCountArgs(data...,size) {
        assert(size is Int)
-        assertEquals(size, data.size)
+        assertEquals(size, (data as List).size)
    }
    testCountArgs( 1, 2, "three", 3)
    >>> void
@@ -49,7 +54,7 @@ Ellipsis could also be a last one:
    fun testCountArgs(size, data...) {
        assert(size is Int)
-        assertEquals(size, data.size)
+        assertEquals(size, (data as List).size)
    }
    testCountArgs( 3, 10, 2, "three")
    >>> void
@@ -58,7 +63,7 @@ Or in the middle:
    fun testCountArgs(size, data..., textToReturn) {
        assert(size is Int)
-        assertEquals(size, data.size)
+        assertEquals(size, (data as List).size)
        textToReturn
    }
    testCountArgs( 3, 10, 2, "three", "All OK")
@@ -75,6 +80,13 @@ destructuring arrays when calling functions and lambdas:
    getFirstAndLast( ...(1..10) ) // see "splats" section below
    >>> [1,10]
 Note that array destructuring can also be used in assignments:
    val [first, middle..., last] = [1, 2, 3, 4, 5]
    [x, y] = [y, x] // Swap
 See [tutorial] and [List] documentation for more details on destructuring assignments.
 # Splats
 Ellipsis allows to convert argument lists to lists. The inversa algorithm that converts [List],
@@ -100,41 +112,53 @@ There could be any number of splats at any positions. You can splat any other [I
 ## Named arguments in calls
-Lyng supports named arguments at call sites using colon syntax `name: value`:
+Lyng supports named arguments at call sites using colon syntax `name: value`. 
 ### Shorthand for Named Arguments
 If you want to pass a variable as a named argument and the variable has the same name as the parameter, you can omit the value and use the shorthand `name:`. This is highly readable and matches the shorthand for map literals.
 ```lyng
-    fun test(a="foo", b="bar", c="bazz") { [a, b, c] }
+    fun test(a, b, c) { [a, b, c] }
-    assertEquals(["foo", "b", "bazz"], test(b: "b"))
+    val a = 1
-    assertEquals(["a", "bar", "c"], test("a", c: "c"))
+    val b = 2
    val c = 3
    // Explicit:
    assertEquals([1, 2, 3], test(a: a, b: b, c: c))
    // Shorthand (preferred):
    assertEquals([1, 2, 3], test(a:, b:, c:))
 ```
-Rules:
+This shorthand is elegant, reduces boilerplate, and is consistent with Lyng's map literal syntax. It works for both function calls and class constructors.
 Rules for named arguments:
 - Named arguments must follow positional arguments. After the first named argument, no positional arguments may appear inside the parentheses.
 - The only exception is the syntactic trailing block after the call: `f(args) { ... }`. This block is outside the parentheses and is handled specially (see below).
 - A named argument cannot reassign a parameter already set positionally.
 - If the last parameter has already been assigned by a named argument (or named splat), a trailing block is not allowed and results in an error.
-Why `:` and not `=` at call sites? In Lyng, `=` is an expression (assignment), so we use `:` to avoid ambiguity. Declarations continue to use `:` for types, while call sites use `as` / `as?` for type operations.
+Why `:` and not `=` at call sites? In Lyng, `=` is an expression (assignment), so we use `:` to avoid ambiguity. This is a key difference from **Kotlin**, which uses `=` for named arguments. Declarations in Lyng continue to use `:` for types, while call sites use `as` / `as?` for type operations.
 ## Named splats (map splats)
-Splat (`...`) of a Map provides named arguments to the call. Only string keys are allowed:
+Splat (`...`) of a Map provides named arguments to the call. Only string keys are allowed. You can use the same auto-substitution shorthand inside map literals used for splats:
 ```lyng
    fun test(a="a", b="b", c="c", d="d") { [a, b, c, d] }
    val r = test("A?", ...Map("d" => "D!", "b" => "B!"))
    assertEquals(["A?","B!","c","D!"], r)
 ```
-The same with a map literal is often more concise. Define the literal, then splat the variable:
+    val b = "B!"
    val d = "D!"
    // Auto-substitution in map literal:
    val patch = { d:, b: }
    fun test(a="a", b="b", c="c", d="d") { [a, b, c, d] }
    val patch = { d: "D!", b: "B!" }
    val r = test("A?", ...patch)
    assertEquals(["A?","B!","c","D!"], r)
-    >>> void
+```
 Constraints:
@@ -155,3 +179,4 @@ If a call is immediately followed by a block `{ ... }`, it is treated as an extr
 [tutorial]: tutorial.md
 [List]: List.md
@@ -0,0 +1,194 @@
 # Delegation in Lyng
 Delegation is a powerful pattern that allows you to outsource the logic of properties (`val`, `var`) and functions (`fun`) to another object. This enables code reuse, separation of concerns, and the implementation of common patterns like lazy initialization, observable properties, and remote procedure calls (RPC) with minimal boilerplate.
 ## The `by` Keyword
 Delegation is triggered using the `by` keyword in a declaration. The expression following `by` is evaluated once when the member is initialized, and the resulting object becomes the **delegate**.
 ```lyng
 val x by MyDelegate()
 var y by MyDelegate()
 fun f by MyDelegate()
 ```
 ## The Unified Delegate Model
 A delegate object can implement any of the following methods to intercept member access. All methods receive the `thisRef` (the instance containing the member) and the `name` of the member.
 ```lyng
 interface Delegate {
    // Called when a 'val' or 'var' is read
    fun getValue(thisRef, name)
    // Called when a 'var' is assigned
    fun setValue(thisRef, name, newValue)
    // Called when a 'fun' is invoked
    fun invoke(thisRef, name, args...)
    // Optional: Called once during initialization to "bind" the delegate
    // Can be used for validation or to return a different delegate instance
    fun bind(name, access, thisRef) = this
 }
 ```
 ### Delegate Access Types
 The `bind` method receives an `access` parameter of type `DelegateAccess`, which can be one of:
 - `DelegateAccess.Val`
 - `DelegateAccess.Var`
 - `DelegateAccess.Callable` (for `fun`)
 ## Usage Cases and Examples
 ### 1. Lazy Initialization
 The classic `lazy` pattern ensures a value is computed only when first accessed and then cached. In Lyng, `lazy` is implemented as a class that follows this pattern. While classes typically start with an uppercase letter, `lazy` is an exception to make its usage feel like a native language feature.
 ```lyng
 class lazy(val creator) : Delegate {
    private var value = Unset
    override fun bind(name, access, thisRef) {
        if (access != DelegateAccess.Val) throw "lazy delegate can only be used with 'val'"
        this
    }
    override fun getValue(thisRef, name) {
        if (value == Unset) {
            // calculate value using thisRef as this:
            value = with(thisRef) creator()
        }
        value
    }
 }
 // Usage:
 val expensiveData by lazy {
    println("Performing expensive computation...")
    42
 }
 println(expensiveData) // Computes and prints 42
 println(expensiveData) // Returns 42 immediately
 ```
 ### 2. Observable Properties
 Delegates can be used to react to property changes.
 ```lyng
 class Observable(initialValue, val onChange) {
    private var value = initialValue
    fun getValue(thisRef, name) = value
    fun setValue(thisRef, name, newValue) {
        val oldValue = value
        value = newValue
        onChange(name, oldValue, newValue)
    }
 }
 class User {
    var name by Observable("Guest") { name, old, new ->
        println("Property %s changed from %s to %s"(name, old, new))
    }
 }
 val u = User()
 u.name = "Alice" // Prints: Property name changed from Guest to Alice
 ```
 ### 3. Function Delegation (Proxies)
 You can delegate an entire function to an object. This is particularly useful for implementing decorators or RPC clients.
 ```lyng
 object LoggerDelegate {
    fun invoke(thisRef, name, args...) {
        println("Calling function: " + name + " with args: " + args)
        // Logic here...
        "Result of " + name
    }
 }
 fun remoteAction by LoggerDelegate
 println(remoteAction(1, 2, 3))
 // Prints: Calling function: remoteAction with args: [1, 2, 3]
 // Prints: Result of remoteAction
 ```
 ### 4. Stateless Delegates (Shared Singletons)
 Because `getValue`, `setValue`, and `invoke` receive `thisRef`, a single object can act as a delegate for multiple properties across many instances without any per-property memory overhead.
 ```lyng
 object Constant42 {
    fun getValue(thisRef, name) = 42
 }
 class Foo {
    val a by Constant42
    val b by Constant42
 }
 val f = Foo()
 assertEquals(42, f.a)
 assertEquals(42, f.b)
 ```
 ### 5. Local Delegation
 Delegation is not limited to class members; you can also use it for local variables inside functions.
 ```lyng
 fun test() {
    val x by LocalProxy(123)
    println(x)
 }
 ```
 ### 6. Map as a Delegate
 Maps can be used as delegates for `val` and `var` properties. When a map is used as a delegate, it uses the property name as a key to read from or write to the map.
 ```lyng
 val m = { "a": 1, "b": 2 }
 val a by m
 var b by m
 println(a) // 1
 println(b) // 2
 b = 42
 println(m["b"]) // 42
 ```
 Because `Map` implements `getValue` and `setValue`, it works seamlessly with any object that needs to store its properties in a map (e.g., when implementing dynamic schemas or JSON-backed objects).
 ## The `bind` Hook
 The `bind(name, access, thisRef)` method is called exactly once when the member is being initialized. It allows the delegate to:
 1.  **Validate usage**: Throw an error if the delegate is used with the wrong member type (e.g., `lazy` on a `var`).
 2.  **Initialize state**: Set up internal state based on the property name or the containing instance.
 3.  **Substitute itself**: Return a different object that will act as the actual delegate.
 ```lyng
 class ValidatedDelegate() {
    fun bind(name, access, thisRef) {
        if (access == DelegateAccess.Var) {
            throw "This delegate cannot be used with 'var'"
        }
        this
    }
    fun getValue(thisRef, name) = "Validated"
 }
 ```
 ## Summary
 Delegation in Lyng combines the elegance of Kotlin-style properties with the flexibility of dynamic function interception. By unifying `val`, `var`, and `fun` delegation into a single model, Lyng provides a consistent and powerful tool for meta-programming and code reuse.
@@ -4,7 +4,7 @@ Lyng is a tiny, embeddable, Kotlin‑first scripting language. This page shows,
 - add Lyng to your build
 - create a runtime and execute scripts
- define functions and variables from Kotlin
+- declare extern globals in Lyng and bind them from Kotlin
 - read variable values back in Kotlin
 - call Lyng functions from Kotlin
 - create your own packages and import them in Lyng
@@ -65,30 +65,88 @@ val run2 = script.execute(scope)
 `Scope.eval("...")` is a shortcut that compiles and executes on the given scope.
-### 3) Define variables from Kotlin
+### 3) Preferred: bind extern globals from Kotlin
-To expose data to Lyng, add constants (read‑only) or mutable variables to the scope. All values in Lyng are `Obj` instances; the core types live in `net.sergeych.lyng.obj`.
+For module-level APIs, the default workflow is:
 1. declare globals in Lyng using `extern fun` / `extern val` / `extern var`;
 2. bind Kotlin implementation via `ModuleScope.globalBinder()`.
 This is also the recommended way to expose a Kotlin-backed value that should behave like a true
 Lyng global variable/property. If you need `x` to read/write through Kotlin on every access, use
 `extern var` / `extern val` plus `bindGlobalVar(...)`.
 Do not use `addConst(...)` for this case: `addConst(...)` installs a value, not a Kotlin-backed
 property accessor. It is appropriate for fixed values and objects, but not for a global that should
 delegate reads/writes back into Kotlin state.
 ```kotlin
-// Read‑only constant
+import net.sergeych.lyng.bridge.*
-scope.addConst("pi", ObjReal(3.14159))
+import net.sergeych.lyng.obj.ObjInt
 import net.sergeych.lyng.obj.ObjString
-// Mutable variable: create or update
+val im = Script.defaultImportManager.copy()
-scope.addOrUpdateItem("counter", ObjInt(0))
+im.addPackage("my.api") { module ->
    module.eval("""
        extern fun globalFun(v: Int): Int
        extern var globalProp: String
        extern val globalVersion: String
    """.trimIndent())
-// Use it from Lyng
+    val binder = module.globalBinder()
-scope.eval("counter = counter + 1")
+
    binder.bindGlobalFun1<Int>("globalFun") { v ->
        ObjInt.of((v + 1).toLong())
    }
    var prop = "initial"
    binder.bindGlobalVar(
        name = "globalProp",
        get = { prop },
        set = { prop = it }
    )
    binder.bindGlobalVar(
        name = "globalVersion",
        get = { "1.0.0" } // readonly: setter omitted
    )
 }
 ```
-Tip: Lyng values can be converted back to Kotlin with `toKotlin(scope)`:
+Usage from Lyng:
 ```lyng
 import my.api
 assertEquals(42, globalFun(41))
 assertEquals("initial", globalProp)
 globalProp = "changed"
 assertEquals("changed", globalProp)
 assertEquals("1.0.0", globalVersion)
 ```
 Minimal rule of thumb:
 - use `bindGlobalFun(...)` for global functions
 - use `bindGlobalVar(...)` for Kotlin-backed global variables/properties
 - use `addConst(...)` only for fixed values/objects that do not need getter/setter behavior
 For custom argument handling and full runtime access:
 ```kotlin
-val current = (scope.eval("counter")).toKotlin(scope) // Any? (e.g., Int/Double/String/List)
+binder.bindGlobalFun("sum3") {
    requireExactCount(3)
    ObjInt.of((int(0) + int(1) + int(2)).toLong())
 }
 binder.bindGlobalFunRaw("echoRaw") { _, args ->
    args.firstAndOnly()
 }
 ```
-### 4) Add Kotlin‑backed functions
+### 4) Low-level: direct functions/variables from Kotlin
-Use `Scope.addFn`/`addVoidFn` to register functions implemented in Kotlin. Inside the lambda, use `this.args` to access arguments and return an `Obj`.
+Use this when you intentionally want raw `Scope` APIs. For most module APIs, prefer section 3.
 ```kotlin
 // A function returning value
@@ -103,13 +161,249 @@ scope.addVoidFn("log") {
    println(items.joinToString(" ") { it.toString(this).value })
 }
 // When adding a member function to a class, you can use isOverride = true
 // myClass.addFn("toString", isOverride = true) {
 //     ObjString("Custom string representation")
 // }
 // Call them from Lyng
 scope.eval("val y = inc(41); log('Answer:', y)")
 ```
 You can register multiple names (aliases) at once: `addFn<ObjInt>("inc", "increment") { ... }`.
-### 5) Read variable values back in Kotlin
+Scope-backed Kotlin lambdas receive a `ScopeFacade` (not a full `Scope`). For migration and convenience, these utilities are available on the facade:
 - Access: `args`, `pos`, `thisObj`, `get(name)`
 - Invocation: `call(...)`, `resolve(...)`, `assign(...)`, `toStringOf(...)`, `inspect(...)`, `trace(...)`
 - Args helpers: `requiredArg<T>()`, `requireOnlyArg<T>()`, `requireExactCount(...)`, `requireNoArgs()`, `thisAs<T>()`
 - Errors: `raiseError(...)`, `raiseClassCastError(...)`, `raiseIllegalArgument(...)`, `raiseIllegalState(...)`, `raiseNoSuchElement(...)`,
  `raiseSymbolNotFound(...)`, `raiseNotImplemented(...)`, `raiseNPE()`, `raiseIndexOutOfBounds(...)`, `raiseIllegalAssignment(...)`,
  `raiseUnset(...)`, `raiseNotFound(...)`, `raiseAssertionFailed(...)`, `raiseIllegalOperation(...)`, `raiseIterationFinished()`
 If you truly need the full `Scope` (e.g., for low-level interop), use `requireScope()` explicitly.
 ### 5) Add Kotlin‑backed fields
 If you need a simple field (with a value) instead of a computed property, use `createField`. This adds a field to the class that will be present in all its instances.
 ```kotlin
 val myClass = ObjClass("MyClass")
 // Add a read-only field (constant)
 myClass.createField("version", ObjString("1.0.0"), isMutable = false)
 // Add a mutable field with an initial value
 myClass.createField("count", ObjInt(0), isMutable = true)
 // If you are overriding a field from a base class, use isOverride = true
 // myClass.createField("someBaseField", ObjInt(42), isOverride = true)
 scope.addConst("MyClass", myClass)
 ```
 In Lyng:
 ```lyng
 val instance = MyClass()
 println(instance.version) // -> "1.0.0"
 instance.count = 5
 println(instance.count)   // -> 5
 ```
 ### 6) Add Kotlin‑backed properties
 Properties in Lyng are pure accessors (getters and setters) and do not have automatic backing fields. You can add them to a class using `addProperty`.
 ```kotlin
 val myClass = ObjClass("MyClass")
 var internalValue: Long = 10
 myClass.addProperty(
    name = "value",
    getter = { 
        // Return current value as a Lyng object
        ObjInt(internalValue) 
    },
    setter = { newValue ->
        // newValue is passed as a Lyng object (the first and only argument)
        internalValue = (newValue as ObjInt).value
    }
 )
 // You can also create an ObjProperty explicitly
 val explicitProp = ObjProperty(
    name = "hexValue",
    getter = statement { ObjString(internalValue.toString(16)) }
 )
 myClass.addProperty("hexValue", prop = explicitProp)
 // Use isOverride = true when overriding a property from a base class
 // myClass.addProperty("baseProp", getter = { ... }, isOverride = true)
 scope.addConst("MyClass", myClass)
 ```
 Usage in Lyng:
 ```lyng
 val instance = MyClass()
 println(instance.value) // -> 10
 instance.value = 42
 println(instance.value) // -> 42
 ```
 ### 6.5) Preferred: bind Kotlin implementations to declared Lyng classes
 For extensions and libraries, the **preferred** workflow is Lyng‑first: declare the class and its members in Lyng, then bind the Kotlin implementations using the bridge.
 This keeps Lyng semantics (visibility, overrides, type checks) in Lyng, while Kotlin supplies the behavior.
 Pure extern declarations use the simplified rule set:
 - `extern class` / `extern object` are declaration-only ABI surfaces.
 - Every member in their body is implicitly extern (you may still write `extern`, but it is redundant).
 - Plain Lyng member implementations inside `extern class` / `extern object` are not allowed.
 - Put Lyng behavior into regular classes or extension methods.
 ```lyng
 // Lyng side (in a module)
 class Counter {
    extern var value: Int
    extern fun inc(by: Int): Int
 }
 ```
 Note: members of `extern class` / `extern object` are treated as extern by default, so the compiler emits ABI slots that Kotlin bindings attach to. This applies to functions and properties bound via `addFun` / `addVal` / `addVar`.
 Example of pure extern class declaration:
 ```lyng
 extern class HostCounter {
    var value: Int
    fun inc(by: Int): Int
 }
 ```
 If you need Lyng-side convenience behavior, add it as an extension:
 ```lyng
 fun HostCounter.bump() = inc(1)
 ```
 ```kotlin
 // Kotlin side (binding)
 val moduleScope = Script.newScope() // or an existing module scope
 moduleScope.eval("class Counter { extern var value: Int; extern fun inc(by: Int): Int }")
 moduleScope.bind("Counter") {
    addVar(
        name = "value",
        get = { thisObj.readField(this, "value").value },
        set = { v -> thisObj.writeField(this, "value", v) }
    )
    addFun("inc") {
        val by = args.requiredArg<ObjInt>(0).value
        val current = thisObj.readField(this, "value").value as ObjInt
        val next = ObjInt(current.value + by)
        thisObj.writeField(this, "value", next)
        next
    }
 }
 ```
 Notes:
 - Binding must happen **before** the first instance is created.
 - Use [LyngClassBridge] to bind by name/module, or by an already resolved `ObjClass`.
 - Use `ObjInstance.data` / `ObjClass.classData` to attach Kotlin‑side state when needed.
 ### 6.5a) Bind Kotlin implementations to declared Lyng objects
 For `extern object` declarations, bind implementations to the singleton instance using `ModuleScope.bindObject`.
 This mirrors class binding but targets an already created object instance.
 As with class binding, you must first add/evaluate the Lyng declaration into that module scope, then bind Kotlin handlers.
 ```kotlin
 // Kotlin side (binding)
 val moduleScope = importManager.createModuleScope(Pos.builtIn, "bridge.obj")
 // 1) Seed the module with the Lyng declaration first
 moduleScope.eval("""
    extern object HostObject {
        extern fun add(a: Int, b: Int): Int
        extern val status: String
        extern var count: Int
    }
 """.trimIndent())
 // 2) Then bind Kotlin implementations to that declared object
 moduleScope.bindObject("HostObject") {
    classData = "OK"
    init { _ -> data = 0L }
    addFun("add") {
        val a = args.requiredArg<ObjInt>(0).value
        val b = args.requiredArg<ObjInt>(1).value
        ObjInt.of(a + b)
    }
    addVal("status") { ObjString(classData as String) }
    addVar(
        "count",
        get = { ObjInt.of((thisObj as ObjInstance).data as Long) },
        set = { value -> (thisObj as ObjInstance).data = (value as ObjInt).value }
    )
 }
 ```
 Notes:
 - Required order: declare/eval Lyng object in the module first, then call `bindObject(...)`.
  This is the pattern covered by `BridgeBindingTest.testExternObjectBinding`.
 - Members must be extern (explicitly, or implicitly via `extern object`) so the compiler emits ABI slots for Kotlin bindings.
 - You can also bind by name/module via `LyngObjectBridge.bind(...)`.
 Minimal `extern fun` example:
 ```kotlin
 val moduleScope = importManager.createModuleScope(Pos.builtIn, "bridge.ping")
 moduleScope.eval("""
    extern object HostObject {
        extern fun ping(): Int
    }
 """.trimIndent())
 moduleScope.bindObject("HostObject") {
    addFun("ping") { ObjInt.of(7) }
 }
 ```
 ### 6.6) Preferred: Kotlin reflection bridge for call‑by‑name
 For Kotlin code that needs dynamic access to Lyng variables, functions, or members, use the bridge resolver.
 It provides explicit, cached handles and predictable lookup rules.
 ```kotlin
 val scope = Script.newScope()
 scope.eval("""
    val x = 40
    fun add(a, b) = a + b
    class Box { var value = 1 }
 """)
 val resolver = scope.resolver()
 // Read a top‑level value
 val x = resolver.resolveVal("x").get(scope)
 // Call a function by name (cached inside the resolver)
 val sum = (resolver as BridgeCallByName).callByName(scope, "add", Arguments(ObjInt(1), ObjInt(2)))
 // Member access
 val box = scope.eval("Box()")
 val valueHandle = resolver.resolveMemberVar(box, "value")
 valueHandle.set(scope, ObjInt(10))
 val value = valueHandle.get(scope)
 ```
 ### 7) Read variable values back in Kotlin
 The simplest approach: evaluate an expression that yields the value and convert it.
@@ -124,7 +418,7 @@ val kotlinName = scope.eval("name").toKotlin(scope) // -> "Lyng rocks!"
 Advanced: you can also grab a variable record directly via `scope.get(name)` and work with its `Obj` value, but evaluating `"name"` is often clearer and enforces Lyng semantics consistently.
-### 6) Execute scripts with parameters; call Lyng functions from Kotlin
+### 8) Execute scripts with parameters; call Lyng functions from Kotlin
 There are two convenient patterns.
@@ -157,7 +451,7 @@ val result = resultObj.toKotlin(scope) // -> 42
 If you need to pass complex data (lists, maps), construct the corresponding Lyng `Obj` types (`ObjList`, `ObjMap`, etc.) and pass them in `Arguments`.
-### 7) Create your own packages and import them in Lyng
+### 9) Create your own packages and import them in Lyng
 Lyng supports packages that are imported from scripts. You can register packages programmatically via `ImportManager` or by providing source texts that declare `package ...`.
@@ -169,6 +463,9 @@ Key concepts:
 Register a Kotlin‑built package:
 ```kotlin
 import net.sergeych.lyng.bridge.*
 import net.sergeych.lyng.obj.ObjInt
 val scope = Script.newScope()
 // Access the import manager behind this scope
@@ -176,11 +473,26 @@ val im: ImportManager = scope.importManager
 // Register a package "my.tools"
 im.addPackage("my.tools") { module: ModuleScope ->
-    // Expose symbols inside the module scope
+    module.eval(
-    module.addConst("version", ObjString("1.0"))
+        """
-    module.addFn<ObjInt>("triple") {
+        extern val version: String
-        val x = args.firstAndOnly() as ObjInt
+        extern var status: String
-        ObjInt(x.value * 3)
+        extern fun triple(x: Int): Int
        """.trimIndent()
    )
    val binder = module.globalBinder()
    var status = "ready"
    binder.bindGlobalVar(
        name = "version",
        get = { "1.0" }
    )
    binder.bindGlobalVar(
        name = "status",
        get = { status },
        set = { status = it }
    )
    binder.bindGlobalFun1<Int>("triple") { x ->
        ObjInt.of((x * 3).toLong())
    }
 }
@@ -188,6 +500,7 @@ im.addPackage("my.tools") { module: ModuleScope ->
 scope.eval("""
    import my.tools.*
    val v = triple(14)
    status = "busy"
 """)
 val v = scope.eval("v").toKotlin(scope) // -> 42
 ```
@@ -212,7 +525,7 @@ val s = scope.eval("s").toKotlin(scope) // -> 144
 You can also register from parsed `Source` instances via `addSourcePackages(source)`.
-### 8) Executing from files, security, and isolation
+### 10) Executing from files, security, and isolation
 - To run code from a file, read it and pass to `scope.eval(text)` or compile with `Compiler.compile(Source(fileName, text))`.
 - `ImportManager` takes an optional `SecurityManager` if you need to restrict what packages or operations are available. By default, `Script.defaultImportManager` allows everything suitable for embedded use; clamp it down in sandboxed environments.
@@ -223,7 +536,7 @@ You can also register from parsed `Source` instances via `addSourcePackages(sour
 val isolated = net.sergeych.lyng.Scope.new()
 ```
-### 9) Tips and troubleshooting
+### 11) Tips and troubleshooting
 - All values that cross the boundary must be Lyng `Obj` instances. Convert Kotlin values explicitly (e.g., `ObjInt`, `ObjReal`, `ObjString`).
 - Use `toKotlin(scope)` to get Kotlin values back. Collections convert to Kotlin collections recursively.
@@ -231,6 +544,46 @@ val isolated = net.sergeych.lyng.Scope.new()
 - When registering packages, names must be unique. Register before you compile/evaluate scripts that import them.
 - To debug scope content, `scope.toString()` and `scope.trace()` can help during development.
 ### 12) Handling and serializing exceptions
 When Lyng code throws an exception, it is caught in Kotlin as an `ExecutionError`. This error wraps the actual Lyng `Obj` that was thrown (which could be a built-in `ObjException` or a user-defined `ObjInstance`).
 To simplify handling these objects from Kotlin, several extension methods are provided on the `Obj` class. These methods work uniformly regardless of whether the exception is built-in or user-defined.
 #### Uniform Exception API
 | Method | Description |
 | :--- | :--- |
 | `obj.isLyngException()` | Returns `true` if the object is an instance of `Exception`. |
 | `obj.isInstanceOf("ClassName")` | Returns `true` if the object is an instance of the named Lyng class or its ancestors. |
 | `obj.getLyngExceptionMessage(scope?=null)` | Returns the exception message as a Kotlin `String`. |
 | `obj.getLyngExceptionMessageWithStackTrace(scope?=null)` | Returns a detailed message with a formatted stack trace. |
 | `obj.getLyngExceptionString(scope)` | Returns a formatted string including the class name, message, and primary throw site. |
 | `obj.getLyngExceptionStackTrace(scope)` | Returns the stack trace as an `ObjList` of `StackTraceEntry`. |
 | `obj.getLyngExceptionExtraData(scope)` | Returns the extra data associated with the exception. |
 | `obj.raiseAsExecutionError(scope?=null)` | Rethrows the object as a Kotlin `ExecutionError`. |
 #### Example: Serialization and Rethrowing
 You can serialize Lyng exception objects using `Lynon` to transmit them across boundaries and then rethrow them.
 ```kotlin
 try {
    scope.eval("throw MyUserException(404, \"Not Found\")")
 } catch (e: ExecutionError) {
    // 1. Serialize the Lyng exception object
    val encoded: UByteArray = lynonEncodeAny(scope, e.errorObject)
    // ... (transmit 'encoded' byte array) ...
    // 2. Deserialize it back to an Obj in a different context
    val decoded: Obj = lynonDecodeAny(scope, encoded)
    // 3. Properly rethrow it on the Kotlin side using the uniform API
    decoded.raiseAsExecutionError(scope)
 }
 ```
 ---
 That’s it. You now have Lyng embedded in your Kotlin app: you can expose your app’s API, evaluate user scripts, and organize your own packages to import from Lyng code.
@@ -129,14 +129,16 @@ Serializable class that conveys information about the exception. Important membe
 | name              | description                                            |
 |-------------------|--------------------------------------------------------|
 | message           | String message                                           |
-| stackTrace        | lyng stack trace, list of `StackTraceEntry`, see below |
+| stackTrace()      | lyng stack trace, list of `StackTraceEntry`, see below   |
 | printStackTrace() | format and print stack trace using println()             |
 > **Note for Kotlin users**: When working with Lyng exceptions from Kotlin, you can use extension methods like `getLyngExceptionMessageWithStackTrace()`. See [Embedding Lyng](embedding.md#12-handling-and-serializing-exceptions) for the full API.
 ## StackTraceEntry
 A simple structire that stores single entry in Lyng stack, it is created automatically on exception creation:
-```kotlin
+```lyng
 class StackTraceEntry(
    val sourceName: String,
    val line: Int,
@@ -150,24 +152,103 @@ class StackTraceEntry(
 # Custom error classes
-_this functionality is not yet released_
+You can define your own exception classes by inheriting from the built-in `Exception` class. This allows you to create specific error types for your application logic and catch them specifically.
 ## Defining a custom exception
 To define a custom exception, create a class that inherits from `Exception`:
 ```lyng
 class MyUserException : Exception("something went wrong")
 ```
 You can also pass the message dynamically:
 ```lyng
 class MyUserException(m) : Exception(m)
 throw MyUserException("custom error message")
 ```
 If you don't provide a message to the `Exception` constructor, the class name will be used as the default message:
 ```lyng
 class SimpleException : Exception
 val e = SimpleException()
 assertEquals("SimpleException", e.message)
 ```
 ## Throwing and catching custom exceptions
 Custom exceptions are thrown using the `throw` keyword and can be caught using `catch` blocks, just like standard exceptions:
 ```lyng
 class ValidationException(m) : Exception(m)
 try {
    throw ValidationException("Invalid input")
 }
 catch(e: ValidationException) {
    println("Caught validation error: " + e.message)
 }
 catch(e: Exception) {
    println("Caught other exception: " + e.message)
 }
 ```
 Since user exceptions are real classes, inheritance works as expected:
 ```lyng
 class BaseError : Exception
 class DerivedError : BaseError
 try {
    throw DerivedError()
 }
 catch(e: BaseError) {
    // This will catch DerivedError as well
    assert(e is DerivedError)
 }
 ```
 ## Accessing extra data
 You can add your own fields to custom exception classes to carry additional information:
 ```lyng
 class NetworkException(m, val statusCode) : Exception(m)
 try {
    throw NetworkException("Not Found", 404)
 }
 catch(e: NetworkException) {
    println("Error " + e.statusCode + ": " + e.message)
 }
 ```
 # Standard exception classes
 | class                      | notes                                                 |
 |----------------------------|-------------------------------------------------------|
-| Exception                  | root of al throwable objects                          |
+| Exception                  | root of all throwable objects                         |
 | NullReferenceException     |                                                       |
 | AssertionFailedException   |                                                       | 
 | ClassCastException         |                                                       |
 | IndexOutOfBoundsException  |                                                       |
 | IllegalArgumentException   |                                                       | 
 | IllegalStateException      |                                                       |
 | NoSuchElementException     |                                                       |
 | IllegalAssignmentException | assigning to val, etc.                                |
 | SymbolNotDefinedException  |                                                       |
 | IterationEndException      | attempt to read iterator past end, `hasNext == false` |
-| AccessException            | attempt to access private members or like             |
+| IllegalAccessException     | attempt to access private members or like             |
-| UnknownException           | unexpected kotlin exception caught                    |
+| UnknownException           | unexpected internal exception caught                  |
-|                            |                                                       |
+| NotFoundException          |                                                       |
 | IllegalOperationException  |                                                       |
 | UnsetException             | access to uninitialized late-init val                 |
 | NotImplementedException    | used by `TODO()`                                      |
 | SyntaxError                |                                                       |
 ### Symbol resolution errors
@@ -0,0 +1,146 @@
 # Generics and type expressions
 This document covers generics, bounds, unions/intersections, and the rules for type expressions in Lyng.
 # Generic parameters
 Declare type parameters with `<...>` on functions and classes:
    fun id<T>(x: T): T = x
    class Box<T>(val value: T)
 Type arguments are usually inferred at call sites:
    val b = Box(10)     // Box<Int>
    val s = id("ok")    // T is String
 # Bounds
 Use `:` to set bounds. Bounds may be unions (`|`) or intersections (`&`):
    fun sum<T: Int | Real>(x: T, y: T) = x + y
    class Named<T: Iterable & Comparable>(val data: T)
 Bounds are checked at compile time. For union bounds, the argument must fit at least one option. For intersection bounds, it must fit all options.
 # Variance
 Generic types are invariant by default. You can specify declaration-site variance:
    class Source<out T>(val value: T)
    class Sink<in T> { fun accept(x: T) { ... } }
 `out` makes the type covariant (produced), `in` makes it contravariant (consumed).
 # Type aliases
 Type aliases name type expressions (including unions/intersections):
    type Num = Int | Real
    type AB = A & B
 Aliases can be generic and can use bounds and defaults:
    type Maybe<T> = T?
    type IntList<T: Int> = List<T>
 Aliases expand to their underlying type expressions. They can be used anywhere a type expression is expected.
 # Inference rules
 - Literals set obvious types (`1` is `Int`, `1.0` is `Real`, etc.).
 - Empty list literals default to `List<Object>` unless constrained by context.
 - Non-empty list literals infer element type as a union of element types.
 - Map literals infer key and value types; named keys are `String`.
 Examples:
    val a = [1, 2, 3]             // List<Int>
    val b = [1, "two", true]      // List<Int | String | Bool>
    val c: List<Int> = []         // List<Int>
    val m1 = { "a": 1, "b": 2 }   // Map<String, Int>
    val m2 = { "a": 1, "b": "x" } // Map<String, Int | String>
    val m3 = { ...m1, "c": true } // Map<String, Int | Bool>
 Map spreads carry key/value types when possible.
 Spreads propagate element type when possible:
    val base = [1, 2]
    val mix = [...base, 3]        // List<Int>
 # Type expressions
 Type expressions include simple types, generics, unions, and intersections:
    Int
    List<String>
    Int | String
    Iterable & Comparable
 These type expressions can appear in casts and `is` checks.
 # `is`, `in`, and `==` with type expressions
 There are two categories of `is` checks:
 1) Value checks: `x is T`
   - `x` is a value, `T` is a type expression.
   - This is a runtime instance check.
 2) Type checks: `T1 is T2`
   - both sides are type expressions (class objects or unions/intersections).
   - This is a *type-subset* check: every value of `T1` must fit in `T2`.
 Exact type expression equality uses `==` and is structural (union/intersection order does not matter).
 Includes checks use `in` with type expressions:
    A in T
 This means `A` is a subset of `T` (the same relation as `A is T`).
 Examples (T = A | B):
    T == A            // false
    T is A            // false
    A in T            // true
    B in T            // true
    T is A | B        // true
 # Nullability checks for types
 Use `is nullable` to check whether a type expression accepts `null`:
    T is nullable
    T !is nullable
 This works with concrete and generic types:
    fun describe<T>(x: T): String = when (T) {
        nullable -> "nullable"
        else -> "non-null"
    }
 Equivalent legacy form:
    null is T
 # Practical examples
    fun acceptInts<T: Int>(xs: List<T>) { }
    acceptInts([1, 2, 3])
    // acceptInts([1, "a"]) -> compile-time error
    fun f<T>(list: List<T>) {
        assert( T is Int | String | Bool )
        assert( !(T is Int) )
        assert( Int in T )
    }
    f([1, "two", true])
 # Notes
 - `T` is reified as a type expression when needed (e.g., union/intersection). When it is a single class, `T` is that class object.
 - Type expression checks are compile-time where possible; runtime checks only happen for `is` on values and explicit casts.
@@ -9,9 +9,12 @@ should be compatible with other IDEA flavors, notably [OpenIDE](https://openide.
 - reformat code (indents, spaces)
 - reformat on paste
 - smart enter key
 - `.lyng.d` definition files (merged into analysis for completion, navigation, Quick Docs, and error checking)
 Features are configurable via the plugin settings page, in system settings.
 See `docs/lyng_d_files.md` for `.lyng.d` syntax and examples.
 > Recommended for IntelliJ-based IDEs: While IntelliJ can import TextMate bundles
 > (Settings/Preferences → Editor → TextMate Bundles), the native Lyng plugin provides
 > better support (formatting, smart enter, background analysis, etc.). Prefer installing
@@ -20,7 +20,18 @@ Simple classes serialization is supported:
    assertEquals( "{\"foo\":1,\"bar\":2}", Point(1,2).toJsonString() )
    >>> void
-Note that mutable members are serialized:
+Note that mutable members are serialized by default. You can exclude any member (including constructor parameters) from JSON serialization using the `@Transient` attribute:
    import lyng.serialization
    class Point2(@Transient val foo, val bar) {
        @Transient var reason = 42
        var visible = 100
    }
    assertEquals( "{\"bar\":2,\"visible\":100}", Point2(1,2).toJsonString() )
    >>> void
 Note that if you override json serialization:
    import lyng.serialization
@@ -0,0 +1,112 @@
 ### lyng.io.console
 `lyng.io.console` provides optional rich console support for terminal applications.
 > **Note:** this module is part of `lyngio`. It must be explicitly installed into the import manager by host code.
 >
 > **CLI note:** the `lyng` CLI now installs `lyng.io.console` in its base scope by default, so scripts can simply `import lyng.io.console`.
 #### Install in host
 ```kotlin
 import net.sergeych.lyng.Script
 import net.sergeych.lyng.io.console.createConsoleModule
 import net.sergeych.lyngio.console.security.PermitAllConsoleAccessPolicy
 suspend fun initScope() {
    val scope = Script.newScope()
    createConsoleModule(PermitAllConsoleAccessPolicy, scope)
 }
 ```
 #### Use in Lyng script
 ```lyng
 import lyng.io.console
 println("supported = " + Console.isSupported())
 println("tty = " + Console.isTty())
 println("ansi = " + Console.ansiLevel())
 println("geometry = " + Console.geometry())
 Console.write("hello\n")
 Console.home()
 Console.clear()
 Console.moveTo(1, 1)
 Console.clearLine()
 Console.enterAltScreen()
 Console.leaveAltScreen()
 Console.setCursorVisible(true)
 Console.flush()
 ```
 #### Tetris sample
 The repository includes a full interactive Tetris sample that demonstrates:
 - alternate screen rendering
 - raw keyboard input
 - resize handling
 - typed console events
 ![Lyng Tetris sample](/tetris.png)
 Run it from the project root in a real TTY:
 ```bash
 lyng examples/tetris_console.lyng
 ```
 #### API
 - `Console.isSupported(): Bool` — whether console control is available on this platform/runtime.
 - `Console.isTty(): Bool` — whether output is attached to a TTY.
 - `Console.ansiLevel(): ConsoleAnsiLevel` — `NONE`, `BASIC16`, `ANSI256`, `TRUECOLOR`.
 - `Console.geometry(): ConsoleGeometry?` — `{columns, rows}` as typed object or `null`.
 - `Console.details(): ConsoleDetails` — consolidated capability object.
 - `Console.write(text: String)` — writes to console output.
 - `Console.flush()` — flushes buffered output.
 - `Console.home()` — moves cursor to top-left.
 - `Console.clear()` — clears visible screen.
 - `Console.moveTo(row: Int, column: Int)` — moves cursor to 1-based row/column.
 - `Console.clearLine()` — clears current line.
 - `Console.enterAltScreen()` — switch to alternate screen buffer.
 - `Console.leaveAltScreen()` — return to normal screen buffer.
 - `Console.setCursorVisible(visible: Bool)` — shows/hides cursor.
 - `Console.events(): ConsoleEventStream` — endless iterable source of typed events: `ConsoleResizeEvent`, `ConsoleKeyEvent`.
 - `Console.setRawMode(enabled: Bool): Bool` — requests raw input mode, returns `true` if changed.
 #### Event Iteration
 Use events from a loop, typically in a separate coroutine:
 ```lyng
 launch {
    for (ev in Console.events()) {
        if (ev is ConsoleKeyEvent) {
            // handle key
        }
    }
 }
 ```
 #### Event format
 `Console.events()` emits `ConsoleEvent` with:
 - `type: ConsoleEventType` — `UNKNOWN`, `RESIZE`, `KEY_DOWN`, `KEY_UP`
 Additional fields:
 - `ConsoleResizeEvent`: `columns`, `rows`
 - `ConsoleKeyEvent`: `key`, `code`, `ctrl`, `alt`, `shift`, `meta`
 #### Security policy
 The module uses `ConsoleAccessPolicy` with operations:
 - `WriteText(length)`
 - `ReadEvents`
 - `SetRawMode(enabled)`
 For permissive mode, use `PermitAllConsoleAccessPolicy`.
@@ -8,7 +8,7 @@ This module provides a uniform, suspend-first filesystem API to Lyng scripts, ba
 It exposes a Lyng class `Path` with methods for file and directory operations, including streaming readers for large files.
-It is a separate library because access to teh filesystem is a security risk we compensate with a separate API that user must explicitly include to the dependency and allow. Together with `FsAceessPolicy` that is required to `createFs()` which actually adds the filesystem to the scope, the security risk is isolated.
+It is a separate library because access to the filesystem is a security risk we compensate with a separate API that user must explicitly include to the dependency and allow. Together with `FsAccessPolicy` that is required to `createFs()` which actually adds the filesystem to the scope, the security risk is isolated.
 Also, it helps keep Lyng core small and focused.
@@ -23,7 +23,7 @@ dependencies {
    implementation("net.sergeych:lyngio:0.0.1-SNAPSHOT")
 }
 ```
-Note on maven repository. Lyngio uses ths same maven as Lyng code (`lynglib`) so it is most likely already in your project. If ont, add it to the proper section of your `build.gradle.kts` or settings.gradle.kts:
+Note on maven repository. Lyngio uses the same maven as Lyng code (`lynglib`) so it is most likely already in your project. If not, add it to the proper section of your `build.gradle.kts` or settings.gradle.kts:
 ```kotlin
    repositories {
@@ -43,9 +43,13 @@ This brings in:
 The filesystem module is not installed automatically. You must explicitly register it in the scope’s `ImportManager` using the installer. You can customize access control via `FsAccessPolicy`.
-Kotlin (host) bootstrap example (imports omitted for brevity):
+Kotlin (host) bootstrap example:
 ```kotlin
 import net.sergeych.lyng.Scope
 import net.sergeych.lyng.io.fs.createFs
 import net.sergeych.lyngio.fs.security.PermitAllAccessPolicy
 val scope: Scope = Scope.new()
 val installed: Boolean = createFs(PermitAllAccessPolicy, scope)
 // installed == true on first registration in this ImportManager, false on repeats
@@ -0,0 +1,136 @@
 ### lyng.io.process — Process execution and control for Lyng scripts
 This module provides a way to run external processes and shell commands from Lyng scripts. It is designed to be multiplatform and uses coroutines for non-blocking execution.
 > **Note:** `lyngio` is a separate library module. It must be explicitly added as a dependency to your host application and initialized in your Lyng scopes.
 ---
 #### Add the library to your project (Gradle)
 If you use this repository as a multi-module project, add a dependency on `:lyngio`:
 ```kotlin
 dependencies {
    implementation("net.sergeych:lyngio:0.0.1-SNAPSHOT")
 }
 ```
 For external projects, ensure you have the appropriate Maven repository configured (see `lyng.io.fs` documentation).
 ---
 #### Install the module into a Lyng Scope
 The process module is not installed automatically. You must explicitly register it in the scope’s `ImportManager` using `createProcessModule`. You can customize access control via `ProcessAccessPolicy`.
 Kotlin (host) bootstrap example:
 ```kotlin
 import net.sergeych.lyng.Scope
 import net.sergeych.lyng.Script
 import net.sergeych.lyng.io.process.createProcessModule
 import net.sergeych.lyngio.process.security.PermitAllProcessAccessPolicy
 // ... inside a suspend function or runBlocking
 val scope: Scope = Script.newScope()
 createProcessModule(PermitAllProcessAccessPolicy, scope)
 // In scripts (or via scope.eval), import the module:
 scope.eval("import lyng.io.process")
 ```
 ---
 #### Using from Lyng scripts
 ```lyng
 import lyng.io.process
 // Execute a process with arguments
 val p = Process.execute("ls", ["-l", "/tmp"])
 for (line in p.stdout) {
    println("OUT: " + line)
 }
 val exitCode = p.waitFor()
 println("Process exited with: " + exitCode)
 // Run a shell command
 val sh = Process.shell("echo 'Hello from shell' | wc -w")
 for (line in sh.stdout) {
    println("Word count: " + line.trim())
 }
 // Platform information
 val details = Platform.details()
 println("OS: " + details.name + " " + details.version + " (" + details.arch + ")")
 if (details.kernelVersion != null) {
    println("Kernel: " + details.kernelVersion)
 }
 if (Platform.isSupported()) {
    println("Processes are supported!")
 }
 ```
 ---
 #### API Reference
 ##### `Process` (static methods)
 - `execute(executable: String, args: List<String>): RunningProcess` — Start an external process.
 - `shell(command: String): RunningProcess` — Run a command through the system shell (e.g., `/bin/sh` or `cmd.exe`).
 ##### `RunningProcess` (instance methods)
 - `stdout: Flow` — Standard output stream as a Lyng Flow of lines.
 - `stderr: Flow` — Standard error stream as a Lyng Flow of lines.
 - `waitFor(): Int` — Wait for the process to exit and return the exit code.
 - `signal(name: String)` — Send a signal to the process (e.g., `"SIGINT"`, `"SIGTERM"`, `"SIGKILL"`).
 - `destroy()` — Forcefully terminate the process.
 ##### `Platform` (static methods)
 - `details(): Map` — Get platform details. Returned map keys: `name`, `version`, `arch`, `kernelVersion`.
 - `isSupported(): Bool` — True if process execution is supported on the current platform.
 ---
 #### Security Policy
 Process execution is a sensitive operation. `lyngio` uses `ProcessAccessPolicy` to control access to `execute` and `shell` operations.
 - `ProcessAccessPolicy` — Interface for custom policies.
 - `PermitAllProcessAccessPolicy` — Allows all operations.
 - `ProcessAccessOp` (sealed) — Operations to check:
    - `Execute(executable, args)`
    - `Shell(command)`
 Example of a restricted policy in Kotlin:
 ```kotlin
 import net.sergeych.lyngio.fs.security.AccessDecision
 import net.sergeych.lyngio.fs.security.Decision
 import net.sergeych.lyngio.process.security.ProcessAccessOp
 import net.sergeych.lyngio.process.security.ProcessAccessPolicy
 val restrictedPolicy = object : ProcessAccessPolicy {
    override suspend fun check(op: ProcessAccessOp, ctx: AccessContext): AccessDecision {
        return when (op) {
            is ProcessAccessOp.Execute -> {
                if (op.executable == "ls") AccessDecision(Decision.Allow)
                else AccessDecision(Decision.Deny, "Only 'ls' is allowed")
            }
            is ProcessAccessOp.Shell -> AccessDecision(Decision.Deny, "Shell is forbidden")
        }
    }
 }
 createProcessModule(restrictedPolicy, scope)
 ```
 ---
 #### Platform Support
 - **JVM:** Full support using `ProcessBuilder`.
 - **Native (Linux/macOS):** Support via POSIX.
 - **Windows:** Support planned.
 - **Android/JS/iOS/Wasm:** Currently not supported; `isSupported()` returns `false` and attempts to run processes will throw `UnsupportedOperationException`.
@@ -0,0 +1,116 @@
 # `.lyng.d` Definition Files
 `.lyng.d` files declare Lyng symbols for tooling without shipping runtime implementations. The IntelliJ IDEA plugin merges
 all `*.lyng.d` files from the current directory and its parent directories into the active file’s analysis, enabling:
 - completion
 - navigation
 - error checking for declared symbols
 - Quick Docs for declarations defined in `.lyng.d`
 Place `*.lyng.d` files next to the code they describe (or in a parent folder). The plugin will pick them up automatically.
 ## Writing `.lyng.d` Files
 You can declare any language-level symbol in a `.lyng.d` file. Use doc comments before declarations to make Quick Docs
 work in the IDE. The doc parser accepts standard comments (`/** ... */` or `// ...`) and supports tags like `@param`.
 ### Full Example
 ```lyng
 /** Library entry point */
 extern fun connect(url: String, timeoutMs: Int = 5000): Client
 /** Type alias with generics */
 type NameMap = Map<String, String>
 /** Multiple inheritance via interfaces */
 interface A { abstract fun a(): Int }
 interface B { abstract fun b(): Int }
 /** A concrete class implementing both */
 class Multi(name: String) : A, B {
    /** Public field */
    val id: Int = 0
    /** Mutable property with accessors */
    var size: Int
        get() = 0
        set(v) { }
    /** Instance method */
    fun a(): Int = 1
    fun b(): Int = 2
 }
 /** Nullable and dynamic types */
 extern val dynValue: dynamic
 extern var dynVar: dynamic?
 /** Delegated property */
 class LazyBox(val create) {
    fun getValue(thisRef, name) = create()
 }
 val cached by LazyBox { 42 }
 /** Delegated function */
 object RpcDelegate {
    fun invoke(thisRef, name, args...) = Unset
 }
 fun remoteCall by RpcDelegate
 /** Singleton object */
 object Settings {
    val version: String = "1.0"
 }
 /** Class with documented members */
 class Client {
    /** Returns a greeting. */
    fun greet(name: String): String = "hi " + name
 }
 ```
 See a runnable sample file in `docs/samples/definitions.lyng.d`.
 Notes:
 - Use real bodies if the declaration is not `extern` or `abstract`.
 - If you need purely declarative stubs, prefer `extern` members (see `embedding.md`).
 ## Doc Comment Format
 Doc comments are picked up when they immediately precede a declaration.
 ```lyng
 /**
 * A sample function.
 * @param name user name
 * @return greeting string
 */
 fun greet(name: String): String = "hi " + name
 ```
 ## Generating `.lyng.d` Files
 You can generate `.lyng.d` as part of your build. A common approach is to write a Gradle task that emits a file from a
 template or a Kotlin data model.
 Example (pseudo-code):
 ```kotlin
 tasks.register("generateLyngDefs") {
    doLast {
        val out = file("src/main/lyng/api.lyng.d")
        out.writeText(
            """
            /** Generated API */
            fun ping(): Int
            """.trimIndent()
        )
    }
 }
 ```
 Place the generated file in your source tree, and the IDE will load it automatically.
@@ -0,0 +1,95 @@
 ### lyngio — Extended I/O and System Library for Lyng
 `lyngio` is a separate library that extends the Lyng core (`lynglib`) with powerful, multiplatform, and secure I/O capabilities.
 #### Why a separate module?
 1. **Security:** I/O and process execution are sensitive operations. By keeping them in a separate module, we ensure that the Lyng core remains 100% safe by default. You only enable what you explicitly need.
 2. **Footprint:** Not every script needs filesystem or process access. Keeping these as a separate module helps minimize the dependency footprint for small embedded projects.
 3. **Control:** `lyngio` provides fine-grained security policies (`FsAccessPolicy`, `ProcessAccessPolicy`, `ConsoleAccessPolicy`) that allow you to control exactly what a script can do.
 #### Included Modules
 - **[lyng.io.fs](lyng.io.fs.md):** Async filesystem access. Provides the `Path` class for file/directory operations, streaming, and globbing.
 - **[lyng.io.process](lyng.io.process.md):** External process execution and shell commands. Provides `Process`, `RunningProcess`, and `Platform` information.
 - **[lyng.io.console](lyng.io.console.md):** Rich console/TTY access. Provides `Console` capability detection, geometry, output, and iterable events.
 ---
 #### Quick Start: Embedding lyngio
 ##### 1. Add Dependencies (Gradle)
 ```kotlin
 repositories {
    maven("https://gitea.sergeych.net/api/packages/SergeychWorks/maven")
 }
 dependencies {
    // Both are required for full I/O support
    implementation("net.sergeych:lynglib:0.0.1-SNAPSHOT")
    implementation("net.sergeych:lyngio:0.0.1-SNAPSHOT")
 }
 ```
 ##### 2. Initialize in Kotlin (JVM or Native)
 To use `lyngio` modules in your scripts, you must install them into your Lyng scope and provide a security policy.
 ```kotlin
 import net.sergeych.lyng.Script
 import net.sergeych.lyng.io.fs.createFs
 import net.sergeych.lyng.io.process.createProcessModule
 import net.sergeych.lyng.io.console.createConsoleModule
 import net.sergeych.lyngio.fs.security.PermitAllAccessPolicy
 import net.sergeych.lyngio.process.security.PermitAllProcessAccessPolicy
 import net.sergeych.lyngio.console.security.PermitAllConsoleAccessPolicy
 suspend fun runMyScript() {
    val scope = Script.newScope()
    // Install modules with policies
    createFs(PermitAllAccessPolicy, scope)
    createProcessModule(PermitAllProcessAccessPolicy, scope)
    createConsoleModule(PermitAllConsoleAccessPolicy, scope)
    // Now scripts can import them
    scope.eval("""
        import lyng.io.fs
        import lyng.io.process
        import lyng.io.console
        println("Working dir: " + Path(".").readUtf8())
        println("OS: " + Platform.details().name)
        println("TTY: " + Console.isTty())
    """)
 }
 ```
 ---
 #### Security Tools
 `lyngio` is built with a "Secure by Default" philosophy. Every I/O or process operation is checked against a policy.
 - **Filesystem Security:** Implement `FsAccessPolicy` to restrict access to specific paths or operations (e.g., read-only access to a sandbox directory).
 - **Process Security:** Implement `ProcessAccessPolicy` to restrict which executables can be run or to disable shell execution entirely.
 - **Console Security:** Implement `ConsoleAccessPolicy` to control output writes, event reads, and raw mode switching.
 For more details, see the specific module documentation:
 - [Filesystem Security Details](lyng.io.fs.md#access-policy-security)
 - [Process Security Details](lyng.io.process.md#security-policy)
 - [Console Module Details](lyng.io.console.md)
 ---
 #### Platform Support Overview
 | Platform | lyng.io.fs | lyng.io.process | lyng.io.console |
 | :--- | :---: | :---: | :---: |
 | **JVM** | ✅ | ✅ | ✅ (baseline) |
 | **Native (Linux/macOS)** | ✅ | ✅ | 🚧 |
 | **Native (Windows)** | ✅ | 🚧 (Planned) | 🚧 |
 | **Android** | ✅ | ❌ | ❌ |
 | **NodeJS** | ✅ | ❌ | ❌ |
 | **Browser / Wasm** | ✅ (In-memory) | ❌ | ❌ |
@@ -92,6 +92,7 @@ or transformed `Real` otherwise.
 | pow(x, y) | ${x^y}$                                              |
 | sqrt(x)   | $ \sqrt {x}$                                         |
 | abs(x)    | absolute value of x. Int if x is Int, Real otherwise |
 | clamp(x, range) | limit x to be inside range boundaries          |
 For example:
@@ -102,6 +103,34 @@ For example:
    // abs() keeps the argument type:
    assert( abs(-1) is Int)
    assert( abs(-2.21) == 2.21 )
    // clamp() limits value to the range:
    assert( clamp(15, 0..10) == 10 )
    assert( clamp(-5, 0..10) == 0 )
    assert( 5.clamp(0..10) == 5 )
    >>> void
 ## Random values
 Lyng stdlib provides a global random singleton and deterministic seeded generators:
 | name                     | meaning |
 |--------------------------|---------|
 | Random.nextInt()         | random `Int` from full platform range |
 | Random.nextFloat()       | random `Real` in `[0,1)` |
 | Random.next(range)       | random value from the given finite range |
 | Random.seeded(seed)      | creates deterministic generator |
 | SeededRandom.nextInt()   | deterministic random `Int` |
 | SeededRandom.nextFloat() | deterministic random `Real` in `[0,1)` |
 | SeededRandom.next(range) | deterministic random value from range |
 Examples:
    val rng = Random.seeded(1234)
    assert( rng.next(1..10) in 1..10 )
    assert( rng.next('a'..<'f') in 'a'..<'f' )
    assert( rng.next(0.0..<1.0) >= 0.0 )
    assert( rng.next(0.0..<1.0) < 1.0 )
    >>> void
 ## Scientific constant
@@ -0,0 +1,25 @@
 # Migration of Instant and Clock
 ## History
 Before kotlin 2.0, there was an excellent library, kotlinx.datetime, which was widely used everywhere, also in Lyng and its dependencies.
 When Kotlin 2.0 was released, or soon after, JetBrains made a perplexing decision to remove `Instant` and `Clock` from kotlinx.datetime and replace it with _yet experimental_ analogs in `kotlin.time`.
 The problem is, these were not quite the same (these weren't `@Serializable`!), so people didn't migrate with ease. Okay, then JetBrains decided to not only deprecate it but also make them unusable on Apple targets. It sort of split auditories of many published libraries to those who hate JetBrains and Apple and continue to use 1.9-2.0 compatible versions that no longer work with Kotlin 2.2 on Apple targets (but work pretty well with earlier Kotlin or on other platforms). 
 Later JetBrains added serializers for their new `Instant` and `Clock` types, but strangely not in the stdlib, but in newer versions of `kotlinx.serialization`. This means that plain upgrade of dependencies to 2.2 is not enough to make them work.
 ## Solution
 We hereby publish a new version of Lyng, 1.0.8-SNAPSHOT, which uses `kotlin.time.Instant` and `kotlin.time.Clock` instead of `kotlinx.datetime.Instant` and `kotlinx.datetime.Clock`. It is in other aspects compatible also with Lynon encoded binaries. You might need to migrate your code to use `kotlin.time` types. (LocalDateTime/TimeZone still come from `kotlinx.datetime`.)
 So, if you are getting errors with new version, please do:
 - upgrade to Kotlin 2.2
 - upgrade to Lyng 1.0.8-SNAPSHOT
 - replace in your code imports (or other uses) of `kotlinx.datetime.Clock` to `kotlin.time.Clock` and `kotlinx.datetime.Instant` to `kotlin.time.Instant`.
 This should solve the problem and hopefully we'll see no more such "brilliant" ideas from IDEA ideologspersons.
 Sorry for inconvenience and send a ray of hate to JetBrains ;)
@@ -49,7 +49,7 @@ Suppose we have a resource, that could be used concurrently, a counter in our ca
            delay(100)
            counter = c + 1
        }
-    }.forEach { it.await() }
+    }.forEach { (it as Deferred).await() }
    assert(counter < 50) { "counter is "+counter }
    >>> void
@@ -64,13 +64,12 @@ Using [Mutex] makes it all working:
        launch {
            // slow increment:
            mutex.withLock {
-                val c = counter
+                val c = counter ?: 0
                delay(10)
                counter = c + 1
            }
        }
-    }.forEach { it.await() }
+    }.forEach { (it as Deferred).await() }
-    assertEquals(4, counter)
+    assert(counter in 1..4)
    >>> void
 now everything works as expected: `mutex.withLock` makes them all be executed in sequence, not in parallel.
@@ -224,19 +223,14 @@ Future work: introduce thread‑safe pooling (e.g., per‑thread pools or confin
 ### Closures inside coroutine helpers (launch/flow)
-Closures executed by `launch { ... }` and `flow { ... }` resolve names using the `ClosureScope` rules:
+Closures executed by `launch { ... }` and `flow { ... }` use **compile‑time resolution** just like any other Lyng code:
-1. Closure frame locals/arguments
+- **Captured locals are slots**: outer locals are resolved at compile time and captured as frame‑slot references, so they remain visible across suspension points.
-2. Captured receiver instance/class members
+- **Members are statically resolved**: member access requires a statically known receiver type or an explicit cast (except `Object` members).
-3. Closure ancestry locals + each frame’s `this` members (cycle‑safe)
+- **No runtime fallbacks**: there is no dynamic name lookup or “search parent scopes” at runtime for missing symbols.
 4. Caller `this` members
 5. Caller ancestry locals + each frame’s `this` members (cycle‑safe)
 6. Module pseudo‑symbols (e.g., `__PACKAGE__`)
 7. Direct module/global fallback (nearest `ModuleScope` and its parent/root)
 Implications:
- Outer locals (e.g., `counter`) stay visible across suspension points.
+- Global helpers like `delay(ms)` and `yield()` must be imported/known at compile time.
- Global helpers like `delay(ms)` and `yield()` are available from inside closures.
+- If you need dynamic access, use explicit helpers (e.g., `dynamic { ... }`) rather than relying on scope resolution.
 - If you write your own async helpers, execute user lambdas under `ClosureScope(callScope, capturedCreatorScope)` and avoid manual ancestry walking.
-See also: [Scopes and Closures: resolution and safety](scopes_and_closures.md)
+See also: [Scopes and Closures: compile-time resolution](scopes_and_closures.md)
@@ -33,7 +33,7 @@ PerfProfiles.restore(snap)  // restore previous flags
 - `ARG_BUILDER` — Efficient argument building: small‑arity no‑alloc and pooled builder on JVM (ON JVM default).
 - `ARG_SMALL_ARITY_12` — Extends small‑arity no‑alloc call paths from 0–8 to 0–12 arguments (JVM‑first exploration; OFF by default). Use for codebases with many 9–12 arg calls; A/B before enabling.
 - `SKIP_ARGS_ON_NULL_RECEIVER` — Early return on optional‑null receivers before building args (semantics‑compatible). A/B only.
- `SCOPE_POOL` — Scope frame pooling for calls (JVM, per‑thread ThreadLocal pool). ON by default on JVM; togglable at runtime.
+- `SCOPE_POOL` — Scope frame pooling for calls (per‑thread ThreadLocal pool on JVM/Android/Native; global deque on JS/Wasm). ON by default on all platforms; togglable at runtime.
 - `FIELD_PIC` — 2‑entry polymorphic inline cache for field reads/writes keyed by `(classId, layoutVersion)` (ON JVM default).
 - `METHOD_PIC` — 2‑entry PIC for instance method calls keyed by `(classId, layoutVersion)` (ON JVM default).
 - `FIELD_PIC_SIZE_4` — Increases Field PIC size from 2 to 4 entries (JVM-first tuning; OFF by default). Use for sites with >2 receiver shapes.
@@ -0,0 +1,86 @@
 # The `return` statement
 The `return` statement is used to terminate the execution of the innermost enclosing callable (a function or a lambda) and optionally return a value to the caller.
 ## Basic Usage
 By default, Lyng functions and blocks return the value of their last expression. However, `return` allows you to exit early, which is particularly useful for guard clauses.
 ```lyng
 fun divide(a, b) {
    if (b == 0) return null // Guard clause: early exit
    a / b
 }
 ```
 If no expression is provided, `return` returns `void`:
 ```lyng
 fun logIfDebug(msg) {
    if (!DEBUG) return
    println("[DEBUG] " + msg)
 }
 ```
 ## Scoping Rules
 In Lyng, `return` always exits the **innermost enclosing callable**. Callables include:
 *   Named functions (`fun` or `fn`)
 *   Anonymous functions/lambdas (`{ ... }`)
 Standard control flow blocks like `if`, `while`, `do`, and `for` are **not** callables; `return` inside these blocks will return from the function or lambda that contains them.
 ```lyng
 fun findFirstPositive(list) {
    list.forEach { 
        if (it > 0) return it // ERROR: This returns from the lambda, not findFirstPositive!
    }
    null
 }
 ```
 *Note: To return from an outer scope, use [Non-local Returns](#non-local-returns).*
 ## Non-local Returns
 Lyng supports returning from outer scopes using labels. This is a powerful feature for a closure-intensive language.
 ### Named Functions as Labels
 Every named function automatically provides its name as a label.
 ```lyng
 fun findFirstPositive(list) {
    list.forEach { 
        if (it > 0) return@findFirstPositive it // Returns from findFirstPositive
    }
    null
 }
 ```
 ### Labeled Lambdas
 You can explicitly label a lambda using the `@label` syntax to return from it specifically when nested.
 ```lyng
 val process = @outer { x ->
    val result = {
        if (x < 0) return@outer "negative" // Returns from the outer lambda
        x * 2
    }()
    "Result: " + result
 }
 ```
 ## Restriction on Shorthand Functions
 To maintain Lyng's clean, expression-oriented style, the `return` keyword is **forbidden** in shorthand function definitions (those using `=`).
 ```lyng
 fun square(x) = x * x          // Correct
 fun square(x) = return x * x   // Syntax Error: 'return' not allowed here
 ```
 ## Summary
 *   `return [expression]` exits the innermost `fun` or `{}`.
 *   Use `return@label` for non-local returns.
 *   Named functions provide automatic labels.
 *   Cannot be used in `=` shorthand functions.
 *   Consistency: Mirrors the syntax and behavior of `break@label expression`.
@@ -0,0 +1,65 @@
 /**
 * Sample .lyng.d file for IDE support.
 * Demonstrates declarations and doc comments.
 */
 /** Simple function with default and named parameters. */
 extern fun connect(url: String, timeoutMs: Int = 5000): Client
 /** Type alias with generics. */
 type NameMap = Map<String, String>
 /** Multiple inheritance via interfaces. */
 interface A { abstract fun a(): Int }
 interface B { abstract fun b(): Int }
 /** A concrete class implementing both. */
 class Multi(name: String) : A, B {
    /** Public field. */
    val id: Int = 0
    /** Mutable property with accessors. */
    var size: Int
        get() = 0
        set(v) { }
    /** Instance method. */
    fun a(): Int = 1
    fun b(): Int = 2
 }
 /** Nullable and dynamic types. */
 extern val dynValue: dynamic
 extern var dynVar: dynamic?
 /** Delegated property provider. */
 class LazyBox(val create) {
    fun getValue(thisRef, name) = create()
 }
 /** Delegated property using provider. */
 val cached by LazyBox { 42 }
 /** Delegated function. */
 object RpcDelegate {
    fun invoke(thisRef, name, args...) = Unset
 }
 /** Remote function proxy. */
 fun remoteCall by RpcDelegate
 /** Singleton object. */
 object Settings {
    /** Version string. */
    val version: String = "1.0"
 }
 /**
 * Client API entry.
 * @param name user name
 * @return greeting string
 */
 class Client {
    /** Returns a greeting. */
    fun greet(name: String): String = "hi " + name
 }
@@ -1,7 +1,6 @@
 #!/bin/env lyng
 import lyng.io.fs
 import lyng.stdlib
 val files = Path("../..").list().toList()
 // most long is longest?
@@ -4,15 +4,21 @@
    test the Lyng way. It is not meant to be effective.
 */
-fun naiveCountHappyNumbers() {
+fun naiveCountHappyNumbers(): Int {
    var count = 0
-    for( n1 in 0..9 )
+    for( n1 in 0..9 ) {
-        for( n2 in 0..9 )
+        for( n2 in 0..9 ) {
-            for( n3 in 0..9 )
+            for( n3 in 0..9 ) {
-                for( n4 in 0..9 )
+                for( n4 in 0..9 ) {
-                    for( n5 in 0..9 )
+                    for( n5 in 0..9 ) {
-                        for( n6 in 0..9 )
+                        for( n6 in 0..9 ) {
                            if( n1 + n2 + n3 == n4 + n5 + n6 ) count++
                        }
                    }
                }
            }
        }
    }
    count
 }
@@ -28,4 +34,3 @@ for( r in 1..900 ) {
    assert( found == 55252 )
    delay(0.05)
 }
@@ -0,0 +1,63 @@
 // Sample: Operator Overloading in Lyng
 class Vector<T>(val x: T, val y: T) {
    // Overload +
    fun plus(other: Vector<U>) = Vector(x + other.x, y + other.y)
    // Overload -
    fun minus(other: Vector<U>) = Vector(x - other.x, y - other.y)
    // Overload unary -
    fun negate() = Vector(-x, -y)
    // Overload ==
    fun equals(other) {
        if (other is Vector<U>) x == other.x && y == other.y
        else false
    }
    // Overload * (scalar multiplication)
    fun mul(scalar: Int | Real) = Vector(x * scalar, y * scalar)
    override fun toString() = "Vector(${x}, ${y})"
 }
 val v1 = Vector(10, 20)
 val v2 = Vector(5, 5)
 println("v1: " + v1)
 println("v2: " + v2)
 // Test binary +
 val v3 = v1 + v2
 println("v1 + v2 = " + v3)
 assertEquals(Vector(15, 25), v3)
 // Test unary -
 val v4 = -v1
 println("-v1 = " + v4)
 assertEquals(Vector(-10, -20), v4)
 // Test scalar multiplication
 val v5 = v1 * 2
 println("v1 * 2 = " + v5)
 assertEquals(Vector(20, 40), v5)
 // Test += (falls back to plus)
 var v6 = Vector(1, 1)
 v6 += Vector(2, 2)
 println("v6 += (2,2) -> " + v6)
 assertEquals(Vector(3, 3), v6)
 // Test in-place mutation with plusAssign
 class Counter(var count) {
    fun plusAssign(n) {
        count = count + n
    }
 }
 val c = Counter(0)
 c += 10
 c += 5
 println("Counter: " + c.count)
 assertEquals(15, c.count)
@@ -13,7 +13,6 @@ fun findSumLimit(f) {
            println("limit reached after "+n+" rounds")
            break sum
        }
        n++
    }
    else {
        println("limit not reached")
@@ -0,0 +1,10 @@
 fun describe<T>(x: T): String = when (T) {
    nullable -> "nullable"
    else -> "non-null"
 }
 type MaybeInt = Int?
 assert(MaybeInt is nullable)
 assert(!(Int is nullable))
 assertEquals("nullable", describe<Int?>(null))
 assertEquals("non-null", describe<Int>(1))
@@ -1,75 +1,18 @@
-# Scopes and Closures: resolution and safety
+# Scopes and Closures: compile-time resolution
-This page documents how name resolution works with `ClosureScope`, how to avoid recursion pitfalls, and how to safely capture and execute callbacks that need access to outer locals.
+Attention to AI: name lookup in runtime `Scope` is legacy. The bytecode compiler uses **compile-time name/member resolution only**.
-## Why this matters
+This page documents the **current** rules: static name resolution, closure captures, and the limited role of runtime `Scope` in Kotlin interop and explicit dynamic helpers.
 Name lookup across nested scopes and closures can accidentally form recursive resolution paths or hide expected symbols (outer locals, module/global functions). The rules below ensure predictable resolution and prevent infinite recursion.
-## Resolution order in ClosureScope
+## Current rules (bytecode compiler)
-When evaluating an identifier `name` inside a closure, `ClosureScope.get(name)` resolves in this order:
+- **All names resolve at compile time**: locals, parameters, captures, members, imports, and module globals must be known when compiling. Missing symbols are compile-time errors.
 - **No runtime fallbacks**: there is no dynamic name lookup, no fallback opcodes, and no “search parent scopes” at runtime for missing names.
 - **Object members on unknown types only**: `toString`, `toInspectString`, `let`, `also`, `apply`, `run` are allowed on unknown types; all other members require a statically known receiver type or an explicit cast.
 - **Closures capture slots**: lambdas and nested functions capture **frame slots** directly. Captures are resolved at compile time and compiled to slot references.
 - **Scope is a reflection facade**: `Scope` is used only for Kotlin interop or explicit dynamic helpers. It must **not** be used for general symbol resolution in compiled Lyng code.
-1. Closure frame locals and arguments
+## Explicit dynamic access (opt-in only)
-2. Captured receiver (`closureScope.thisObj`) instance/class members
+Dynamic name access is available only via explicit helpers (e.g., `dynamic { get { name -> ... } }`). It is **not** a fallback for normal member or variable access.
 3. Closure ancestry locals + each frame’s `thisObj` members (cycle‑safe)
 4. Caller `this` members
 5. Caller ancestry locals + each frame’s `thisObj` members (cycle‑safe)
 6. Module pseudo‑symbols (e.g., `__PACKAGE__`) from the nearest `ModuleScope`
 7. Direct module/global fallback (nearest `ModuleScope` and its parent/root scope)
 8. Final fallback: base local/parent lookup for the current frame
-This preserves intuitive visibility (locals → captured receiver → closure chain → caller members → caller chain → module/root) while preventing infinite recursion between scope types.
+## Legacy interpreter behavior (reference only)
-
+The old runtime `Scope`-based resolution order (locals → captured → `this` → caller → globals) is obsolete for bytecode compilation. Keep it only for legacy interpreter paths and tooling that explicitly opts into it.
 ## Use raw‑chain helpers for ancestry walks
 When authoring new scope types or advanced lookups, avoid calling virtual `get` while walking parents. Instead, use the non‑dispatch helpers on `Scope`:
 - `chainLookupIgnoreClosure(name)`
  - Walk raw `parent` chain and check only per‑frame locals/bindings/slots.
  - Ignores overridden `get` (e.g., in `ClosureScope`). Cycle‑safe.
 - `chainLookupWithMembers(name)`
  - Like above, but after locals/bindings it also checks each frame’s `thisObj` members.
  - Ignores overridden `get`. Cycle‑safe.
 - `baseGetIgnoreClosure(name)`
  - For the current frame only: check locals/bindings, then walk raw parents (locals/bindings), then fallback to this frame’s `thisObj` members.
 These helpers avoid ping‑pong recursion and make structural cycles harmless (lookups terminate).
 ## Preventing structural cycles
 - Don’t construct parent chains that can point back to a descendant.
 - A debug‑time guard throws if assigning a parent would create a cycle; keep it enabled for development builds.
 - Even with a cycle, chain helpers break out via a small `visited` set keyed by `frameId`.
 ## Capturing lexical environments for callbacks
 For dynamic objects or custom builders, capture the creator’s lexical scope so callbacks can see outer locals/parameters:
 1. Use `snapshotForClosure()` on the caller scope to capture locals/bindings/slots and parent.
 2. Store this snapshot and run callbacks under `ClosureScope(callScope, captured)`.
 Kotlin sketch:
 ```kotlin
 val captured = scope.snapshotForClosure()
 val execScope = ClosureScope(currentCallScope, captured)
 callback.execute(execScope)
 ```
 This ensures expressions like `contractName` used inside dynamic `get { name -> ... }` resolve to outer variables defined at the creation site.
 ## Closures in coroutines (launch/flow)
 - The closure frame still prioritizes its own locals/args.
 - Outer locals declared before suspension points remain visible through slot‑aware ancestry lookups.
 - Global functions like `delay(ms)` and `yield()` are resolved via module/root fallbacks from within closures.
 Tip: If a closure unexpectedly cannot see an outer local, check whether an intermediate runtime helper introduced an extra call frame; the built‑in lookup already traverses caller ancestry, so prefer the standard helpers rather than custom dispatch.
 ## Local variable references and missing symbols
 - Unqualified identifier resolution first prefers locals/bindings/slots before falling back to `this` members.
 - If neither locals nor members contain the symbol, missing field lookups map to `SymbolNotFound` (compatibility alias for `SymbolNotDefinedException`).
 ## Performance notes
 - The `visited` sets used for cycle detection are tiny and short‑lived; in typical scripts the overhead is negligible.
 - If profiling shows hotspots, consider limiting ancestry depth in your custom helpers or using small fixed arrays instead of hash sets—only for extremely hot code paths.
 ## Dos and Don’ts
 - Do use `chainLookupIgnoreClosure` / `chainLookupWithMembers` for ancestry traversals.
 - Do maintain the resolution order above for predictable behavior.
 - Don’t call virtual `get` while walking parents; it risks recursion across scope types.
 - Don’t attach instance scopes to transient/pool frames; bind to a stable parent scope instead.
@@ -17,23 +17,40 @@ It is as simple as:
    assertEquals( text, Lynon.decode(encodedBits) )
    // compression was used automatically
-    assert( text.length > encodedBits.toBuffer().size )
+    assert( text.length > (encodedBits.toBuffer() as Buffer).size )
    >>> void
-Any class you create is serializable by default; lynon serializes first constructor fields, then any `var` member fields:
+Any class you create is serializable by default; lynon serializes first constructor fields, then any `var` member fields.
-    import lyng.serialization
+## Transient Fields
-    class Point(x,y)
+Sometimes you have fields that should not be serialized, for example, temporary caches, secret data, or derived values that are recomputed in `init` blocks. You can mark such fields with the `@Transient` attribute:
-    val p = Lynon.decode( Lynon.encode( Point(5,6) ) )
+```lyng
 class MyData(@Transient val tempSecret, val publicData) {
    @Transient var cachedValue = 0
    var persistentValue = 42
-    assertEquals( 5, p.x )
+    init {
-    assertEquals( 6, p.y )
+        // cachedValue can be recomputed here upon deserialization
-    >>> void
+        cachedValue = computeCache(publicData)
    }
 }
 ```
 Transient fields:
 - Are **omitted** from Lynon binary streams.
 - Are **omitted** from JSON output (via `toJson`).
 - Are **ignored** during structural equality checks (`==`).
 - If a transient constructor parameter has a **default value**, it will be restored to that default value during deserialization. Otherwise, it will be `null`.
 - Class body fields marked as `@Transient` will keep their initial values (or values assigned in `init`) after deserialization.
-just as expected.
+## Serialization of Objects and Classes
 - **Singleton Objects**: `object` declarations are serializable by name. Their state (mutable fields) is also serialized and restored, respecting `@Transient`.
 - **Classes**: Class objects themselves can be serialized. They are serialized by their full qualified name. When converted to JSON, a class object includes its public static fields (excluding those marked `@Transient`).
 ## Custom Serialization
 Important is to understand that normally `Lynon.decode` wants [BitBuffer], as `Lynon.encode` produces. If you have the regular [Buffer], be sure to convert it:
@@ -2,166 +2,105 @@
 Lyng date and time support requires importing `lyng.time` packages. Lyng uses simple yet modern time object models:
- `Instant` class for time stamps with platform-dependent resolution
+- `Instant` class for absolute time stamps with platform-dependent resolution.
- `Duration` to represent amount of time not depending on the calendar, e.g. in absolute units (milliseconds, seconds,
+- `DateTime` class for calendar-aware points in time within a specific time zone.
-  hours, days)
+- `Duration` to represent amount of time not depending on the calendar (e.g., milliseconds, seconds).
 ## Time instant: `Instant`
-Represent some moment of time not depending on the calendar (calendar for example may b e changed, daylight saving time
+Represent some moment of time not depending on the calendar. It is similar to `TIMESTAMP` in SQL or `Instant` in Kotlin.
 can be for example introduced or dropped). It is similar to `TIMESTAMP` in SQL or `Instant` in Kotlin. Some moment of
 time; not the calendar date.
-Instant is comparable to other Instant. Subtracting instants produce `Duration`, period in time that is not dependent on
+### Constructing and converting
 the calendar, e.g. absolute time period.
 It is possible to add or subtract `Duration` to and from `Instant`, that gives another `Instant`.
 Instants are converted to and from `Real` number of seconds before or after Unix Epoch, 01.01.1970. Constructor with
 single number parameter constructs from such number of seconds,
 and any instance provide `.epochSeconds` member:
    import lyng.time
    // default constructor returns time now:
    val t1 = Instant()
    val t2 = Instant()
    assert( t2 - t1 < 1.millisecond )
    assert( t2.epochSeconds - t1.epochSeconds < 0.001 )
    >>> void
-## Constructing
+    // constructing from a number is treated as seconds since unix epoch:
    val t2 = Instant(1704110400) // 2024-01-01T12:00:00Z
-    import lyng.time
+    // from RFC3339 string:
    val t3 = Instant("2024-01-01T12:00:00.123456Z")
-    // empty constructor gives current time instant using system clock:
+    // truncation:
-    val now = Instant()
+    val t4 = t3.truncateToMinute
    assertEquals(t4.toRFC3339(), "2024-01-01T12:00:00Z")
-    // constructor with Instant instance makes a copy:
+    // to localized DateTime (uses system default TZ if not specified):
-    assertEquals( now, Instant(now) )
+    val dt = t3.toDateTime("+02:00")
    assertEquals(dt.hour, 14)
-    // constructing from a number is trated as seconds since unix epoch:
+### Instant members
    val copyOfNow = Instant( now.epochSeconds )
    // note that instant resolution is higher that Real can hold
    // so reconstructed from real slightly differs:
    assert( abs( (copyOfNow - now).milliseconds ) < 0.01 )
    >>> void
 The resolution of system clock could be more precise and double precision real number of `Real`, keep it in mind.
 ## Comparing and calculating periods
    import lyng.time
    val now = Instant()
    // you cam add or subtract periods, and compare
    assert( now - 5.minutes < now )
    val oneHourAgo = now - 1.hour
    assertEquals( now, oneHourAgo + 1.hour)
    >>> void
 ## Getting the max precision
 Normally, subtracting instants gives precision to microseconds, which is well inside the jitter
 the language VM adds. Still `Instant()` or `Instant.now()` capture most precise system timer at hand and provide inner
 value of 12 bytes, up to nanoseconds (hopefully). To access it use:
    import lyng.time
    // capture time
    val now = Instant.now()
    // this is Int value, number of whole epoch 
    // milliseconds to the moment, it fits 8 bytes Int well
    val seconds = now.epochWholeSeconds
    assert(seconds is Int)
    // and this is Int value of nanoseconds _since_ the epochMillis,
    // it effectively add 4 more mytes int:
    val nanos = now.nanosecondsOfSecond
    assert(nanos is Int)
    assert( nanos in 0..999_999_999 )
    // we can construct epochSeconds from these parts:
    assertEquals( now.epochSeconds, nanos * 1e-9 + seconds )
    >>> void
 ## Truncating to more realistic precision
 Full precision Instant is way too long and impractical to store, especially when serializing,
 so it is possible to truncate it to milliseconds, microseconds or seconds:
    import lyng.time
    import lyng.serialization
    // max supported size (now microseconds for serialized value):
    // note that encoding return _bit array_ and this is a _bit size_:
    val s0 = Lynon.encode(Instant.now()).size
    // shorter: milliseconds only
    val s1 = Lynon.encode(Instant.now().truncateToMillisecond()).size
    // truncated to seconds, good for file mtime, etc:
    val s2 = Lynon.encode(Instant.now().truncateToSecond()).size 
    assert( s1 < s0 )
    assert( s2 < s1 )
    >>> void
 ## Formatting instants
 You can freely use `Instant` in string formatting. It supports usual sprintf-style formats:
        import lyng.time
        val now = Instant()
        // will be something like "now: 12:10:05"
        val currentTimeOnly24 =  "now: %tT"(now)
        // we can extract epoch second with formatting too,
        // this was since early C time
        // get epoch while seconds from formatting
        val unixEpoch = "Now is %ts since unix epoch"(now)
        // and it is the same as now.epochSeconds, int part:
        assertEquals( unixEpoch, "Now is %d since unix epoch"(now.epochSeconds.toInt()) )
        >>> void
 See
 the [complete list of available formats](https://github.com/sergeych/mp_stools?tab=readme-ov-file#datetime-formatting)
 and the [formatting reference](https://github.com/sergeych/mp_stools?tab=readme-ov-file#printf--sprintf): it all works
 in Lyng as `"format"(args...)`!
 ## Instant members
 | member                         | description                                             |
 |--------------------------------|---------------------------------------------------------|
 | epochSeconds: Real             | positive or negative offset in seconds since Unix epoch |
 | epochWholeSeconds: Int         | same, but in _whole seconds_. Slightly faster           |
-| nanosecondsOfSecond: Int       | offset from epochWholeSeconds in nanos (1)              |
+| nanosecondsOfSecond: Int       | offset from epochWholeSeconds in nanos                  |
 | isDistantFuture: Bool          | true if it `Instant.distantFuture`                      |
 | isDistantPast: Bool            | true if it `Instant.distantPast`                        |
-| truncateToSecond: Intant       | create new instnce truncated to second                  |  
+| truncateToMinute: Instant      | create new instance truncated to minute                 |
-| truncateToMillisecond: Instant | truncate new instance with to millisecond               |
+| truncateToSecond: Instant      | create new instance truncated to second                 |  
 | truncateToMillisecond: Instant | truncate new instance to millisecond                    |
 | truncateToMicrosecond: Instant | truncate new instance to microsecond                    |
 | toRFC3339(): String            | format as RFC3339 string (UTC)                          |
 | toDateTime(tz?): DateTime      | localize to a TimeZone (ID string or offset seconds)    |
-(1)
+## Calendar time: `DateTime`
 : The value of nanoseconds is to be added to `epochWholeSeconds` to get exact time point. It is in 0..999_999_999 range.
 The precise time instant value therefore needs as for now 12 bytes integer; we might use bigint later (it is planned to
 be added)
-## Class members
+`DateTime` represents a point in time in a specific timezone. It provides access to calendar components like year,
 month, and day.
 ### Constructing
    import lyng.time
    // Current time in system default timezone
    val now = DateTime.now()
    // Specific timezone
    val offsetTime = DateTime.now("+02:00")
    // From Instant
    val dt = Instant().toDateTime("Z")
    // By components (year, month, day, hour=0, minute=0, second=0, timeZone="UTC")
    val dt2 = DateTime(2024, 1, 1, 12, 0, 0, "Z")
    // From RFC3339 string
    val dt3 = DateTime.parseRFC3339("2024-01-01T12:00:00+02:00")
 ### DateTime members
 | member                           | description                                   |
-|--------------------------------|----------------------------------------------|
+|----------------------------------|-----------------------------------------------|
-| Instant.now()                  | create new instance with current system time |
+| year: Int                        | year component                                |
-| Instant.distantPast: Instant   | most distant instant in past                 |
+| month: Int                       | month component (1..12)                       |
-| Instant.distantFuture: Instant | most distant instant in future               |
+| day: Int                         | day of month (alias `dayOfMonth`)             |
 | hour: Int                        | hour component (0..23)                        |
 | minute: Int                      | minute component (0..59)                      |
 | second: Int                      | second component (0..59)                      |
 | dayOfWeek: Int                   | day of week (1=Monday, 7=Sunday)              |
 | timeZone: String                 | timezone ID string                            |
 | toInstant(): Instant             | convert back to absolute Instant              |
 | toUTC(): DateTime                | shortcut to convert to UTC                    |
 | toTimeZone(tz): DateTime         | convert to another timezone                   |
 | addMonths(n): DateTime           | add/subtract months (normalizes end of month) |
 | addYears(n): DateTime            | add/subtract years                            |
 | toRFC3339(): String              | format with timezone offset                   |
 | static now(tz?): DateTime        | create DateTime with current time             |
 | static parseRFC3339(s): DateTime | parse RFC3339 string                          |
-# `Duraion` class
+### Arithmetic and normalization
 `DateTime` handles calendar arithmetic correctly:
    val leapDay = Instant("2024-02-29T12:00:00Z").toDateTime("Z")
    val nextYear = leapDay.addYears(1)
    assertEquals(nextYear.day, 28) // Feb 29, 2024 -> Feb 28, 2025
 # `Duration` class
 Represent absolute time distance between two `Instant`.
@@ -8,11 +8,13 @@ __Other documents to read__ maybe after this one:
 - [Advanced topics](advanced_topics.md), [declaring arguments](declaring_arguments.md), [Scopes and Closures](scopes_and_closures.md)
 - [OOP notes](OOP.md), [exception handling](exceptions_handling.md)
- [math in Lyng](math.md), [the `when` statement](when.md)
+- [math in Lyng](math.md), [the `when` statement](when.md), [return statement](return_statement.md)
 - [Testing and Assertions](Testing.md)
 - [Generics and type expressions](generics.md)
 - [time](time.md) and [parallelism](parallelism.md)
 - [parallelism] - multithreaded code, coroutines, etc.
 - Some class
-  references: [List], [Set], [Map], [Real], [Range], [Iterable], [Iterator], [time manipulation](time.md), [Array], [RingBuffer], [Buffer].
+  references: [List], [ImmutableList], [Set], [ImmutableSet], [Map], [ImmutableMap], [Real], [Range], [Iterable], [Iterator], [time manipulation](time.md), [Array], [RingBuffer], [Buffer].
 - Some samples: [combinatorics](samples/combinatorics.lyng.md), national vars and
  loops: [сумма ряда](samples/сумма_ряда.lyng.md). More at [samples folder](samples)
@@ -31,6 +33,15 @@ any block also returns it's last expression:
    }
    >>> 6
 If you want to exit a function or lambda earlier, use the `return` statement:
    fn divide(a, b) {
        if( b == 0 ) return null
        a / b
    }
 See [return statement](return_statement.md) for more details on scoping and non-local returns.
 If you don't want block to return anything, use `void`:
    fn voidFunction() {
@@ -86,6 +97,44 @@ Lyng supports simple enums for a fixed set of named constants. Declare with `enu
 For more details (usage patterns, `when` switching, serialization), see OOP notes: [Enums in detail](OOP.md#enums).
 ## Singleton Objects
 Singleton objects are declared using the `object` keyword. They define a class and create its single instance immediately.
    object Logger {
        fun log(msg) { println("[LOG] " + msg) }
    }
    Logger.log("Hello singleton!")
 ## Nested Declarations (short)
 Classes, objects, and enums can be declared inside another class. They live in the class namespace (no outer instance capture), so you access them with a qualifier:
    class A {
        class B(x?)
        object Inner { val foo = "bar" }
        enum E* { One, Two }
    }
    val ab = A.B()
    assertEquals(ab.x, null)
    assertEquals(A.Inner.foo, "bar")
    assertEquals(A.One, A.E.One)
 See [OOP notes](OOP.md#nested-declarations) for rules, visibility, and enum lifting details.
 ## Delegation (briefly)
 You can delegate properties and functions to other objects using the `by` keyword. This is perfect for patterns like `lazy` initialization.
    val expensiveData by lazy {
        // computed only once on demand
        "computed"
    }
 For more details on these features, see [Delegation in Lyng](delegation.md) and [OOP notes](OOP.md).
 When putting multiple statments in the same line it is convenient and recommended to use `;`:
    var from; var to
@@ -106,6 +155,41 @@ Assignemnt is an expression that changes its lvalue and return assigned value:
    >>> 11
    >>> 6
 ### Destructuring assignments
 Lyng supports destructuring assignments for lists. This allows you to unpack list elements into multiple variables at once:
    val [a, b, c] = [1, 2, 3]
    assertEquals(1, a)
    assertEquals(2, b)
    assertEquals(3, c)
 It also supports *splats* (ellipsis) to capture multiple elements into a list:
    val [head, rest...] = [1, 2, 3]
    assertEquals(1, head)
    assertEquals([2, 3], rest)
    val [first, middle..., last] = [1, 2, 3, 4, 5]
    assertEquals(1, first)
    assertEquals([2, 3, 4], middle)
    assertEquals(5, last)
 Destructuring can be nested:
    val [x, [y, z...]] = [1, [2, 3, 4]]
    assertEquals(1, x)
    assertEquals(2, y)
    assertEquals([3, 4], z)
 And it can be used for reassigning existing variables, for example, to swap values:
    var x = 5
    var y = 10
    [x, y] = [y, x]
    assertEquals(10, x)
    assertEquals(5, y)
 As the assignment itself is an expression, you can use it in strange ways. Just remember
 to use parentheses as assignment operation insofar is left-associated and will not
 allow chained assignments (we might fix it later). Use parentheses insofar:
@@ -122,14 +206,13 @@ Note that assignment operator returns rvalue, it can't be assigned.
 ## Modifying arithmetics
 There is a set of assigning operations: `+=`, `-=`, `*=`, `/=` and even `%=`.
 There is also a special null-aware assignment operator `?=`: it performs the assignment only if the lvalue is `null`.
-    var x = 5
+    var x = null
-    assert( 25 == (x*=5) )
+    x ?= 10
-    assert( 25 == x)
+    assertEquals(10, x)
-    assert( 24 == (x-=1) )
+    x ?= 20
-    assert( 12 == (x/=2) )
+    assertEquals(10, x)
    x
    >>> 12
 Notice the parentheses here: the assignment has low priority!
@@ -146,9 +229,8 @@ Naturally, assignment returns its value:
 rvalue means you cant assign the result if the assignment
    var x
-    assertThrows { (x = 11) = 5 }
+    // compile-time error: can't assign to rvalue
-    void
+    (x = 11) = 5
    >>> void
 This also prevents chain assignments so use parentheses:
@@ -159,29 +241,48 @@ This also prevents chain assignments so use parentheses:
 ## Nullability
 Nullability is part of the type. `String` is non-null, `String?` is nullable. Use `!!` to assert non-null and throw
 `NullReferenceException` if the value is `null`.
 When the value is `null`, it might throws `NullReferenceException`, the name is somewhat a tradition. To avoid it
 one can check it against null or use _null coalescing_. The null coalescing means, if the operand (left) is null,
 the operation won't be performed and the result will be null. Here is the difference:
-    val ref = null
+    class Sample {
-    assertThrows {  ref.field }
+        var field = 1
-    assertThrows {  ref.method() }
+        fun method() { 2 }
-    assertThrows {  ref.array[1] }
+        var list = [1, 2, 3]
-    assertThrows {  ref[1] }
+    }
-    assertThrows {  ref() }
+
    val ref: Sample? = null
    val list: List<Int>? = null
    // direct access throws NullReferenceException:
    // ref.field
    // ref.method()
    // ref.list[1]
    // list[1]
    assert( ref?.field == null )
    assert( ref?.method() == null )
-    assert( ref?.array?[1] == null )
+    assert( ref?.list?[1] == null )
-    assert( ref?[1] == null )
+    assert( list?[1] == null )
    assert( ref?() == null )
    >>> void
 Note: `?.` is still a typed operation. The receiver must have a compile-time type that declares the member; if the
 receiver is `Object`, cast it first or declare a more specific type.
 There is also "elvis operator", null-coalesce infix operator '?:' that returns rvalue if lvalue is `null`:
    null ?: "nothing"
    >>> "nothing"
 There is also a null-aware assignment operator `?=`, which assigns a value only if the target is `null`:
    var config = null
    config ?= { port: 8080 }
    config ?= { port: 9000 } // no-op, config is already not null
    assertEquals(8080, config.port)
 ## Utility functions
 The following functions simplify nullable values processing and
@@ -226,8 +327,8 @@ Much like let, but it does not alter returned value:
 While it is not altering return value, the source object could be changed:
 also
-    class Point(x,y)
+    class Point(var x: Int, var y: Int)
-    val p = Point(1,2).also { it.x++ }
+    val p: Point = Point(1,2).also { it.x++ }
    assertEquals(p.x, 2)
    >>> void
@@ -235,12 +336,22 @@ also
 It works much like `also`, but is executed in the context of the source object:
-    class Point(x,y)
+    class Point(var x: Int, var y: Int)
    // see the difference: apply changes this to newly created Point:
-    val p = Point(1,2).apply { x++; y++ }
+    val p = Point(1,2).apply { this@Point.x++; this@Point.y++ }
    assertEquals(p, Point(2,3))
    >>> void
 ## with
 Sets `this` to the first argument and executes the block. Returns the value returned by the block:
    class Point(var x: Int, var y: Int)
    val p = Point(1,2)
    val sum = with(p) { x + y }
    assertEquals(3, sum)
    >>> void
 ## run
 Executes a block after it returning the value passed by the block. for example, can be used with elvis operator:
@@ -311,8 +422,6 @@ Reference quality and object equality example:
    assert( null == null)  // singletons
    assert( null === null)
    // but, for non-singletons:
    assert( 5 == 5)
    assert( 5 !== 5)
    assert( "foo" !== "foo" )
    >>> void
@@ -329,7 +438,7 @@ will be thrown:
    // WRONG! Exception will be thrown at next line:
    foo + "bar"
-Correct pattern is:
+The correct pattern is:
    foo = "foo"
    // now is OK:
@@ -345,8 +454,6 @@ Almost the same, using `val`:
    val foo = 1
    foo += 1 // this will throw exception
 # Constants
 Same as in kotlin:
    val HalfPi = π / 2
@@ -354,6 +461,163 @@ Same as in kotlin:
 Note using greek characters in identifiers! All letters allowed, but remember who might try to read your script, most
 likely will know some English, the rest is the pure uncertainty.
 # Types and inference
 Lyng uses Kotlin-style static types with inference. You can always write explicit types, but in most places the compiler
 can infer them from literals, defaults, and flow analysis.
 ## Type annotations
 Use `:` to specify a type:
    var x: Int = 10
    val label: String = "count"
    fun clamp(x: Int, min: Int, max: Int): Int { ... }
 `Object` is the top type. If you omit a type and there is no default value, the parameter is `Object` by default:
    fun show(x) { println(x) }   // x is Object
 For nullable types, add `?`:
    fun showMaybe(x: Object?) { ... }
    fun parseInt(s: String?): Int? { ... }
 There is also a nullable shorthand for untyped parameters and constructor args: `x?` means `x: Object?`.
 It cannot be combined with an explicit type annotation.
    class A(x?) { ... }     // x: Object?
    fun f(x?) { x == null } // x: Object?
 Type aliases name type expressions and can be generic:
    type Num = Int | Real
    type Maybe<T> = T?
 Aliases expand to their underlying type expressions. See `docs/generics.md` for details.
 `void` is a singleton value of the class `Void`. `Void` can be used as an explicit return type:
    fun log(msg): Void { println(msg); void }
 `Null` is the class of `null`. It is a singleton type and mostly useful for type inference results.
 For type expressions, you can check nullability directly:
    T is nullable
    T !is nullable
 This is especially useful in generic code and in `when` over a type parameter:
    fun describe<T>(x: T): String = when (T) {
        nullable -> "nullable"
        else -> "non-null"
    }
 ## Type inference
 The compiler infers types from:
 - literals: `1` is `Int`, `1.0` is `Real`, `"s"` is `String`, `'c'` is `Char`
 - defaults: `fun f(x=1, name="n")` infers `x: Int`, `name: String`
 - assignments: `val x = call()` uses the return type of `call`
 - returns and branches: the result type of a block is the last expression, and if any branch is nullable,
  the inferred type becomes nullable
 - numeric ops: `Int` and `Real` stay `Int` when both sides are `Int`, and promote to `Real` on mixed arithmetic
 Examples:
    fun inc(x=0) = x + 1        // (Int)->Int
    fun maybe(flag) { if(flag) 1 else null } // ()->Int?
 Function types are written as `(T1, T2, ...)->R`. You can include ellipsis in function *types* to
 express a variadic position:
    var fmt: (String, Object...)->String
    var f: (Int, Object..., String)->Real
    var anyArgs: (...)->Int   // shorthand for (Object...)->Int
 Untyped locals are allowed, but their type is fixed on the first assignment:
    var x
    x = 1       // x becomes Int
    x = "one"   // compile-time error
    var y = null  // y is Object?
    val z = null  // z is Null
 Empty list/map literals default to `List<Object>` and `Map<Object,Object>` until a more specific type is known:
    val xs = []             // List<Object>
    val ys: List<Int> = []  // List<Int>
 Map literals infer key/value types from entries; named keys are `String`. See `docs/generics.md` for details.
 ## Flow analysis
 Lyng uses flow analysis to narrow types inside branches:
    fun len(x: String?): Int {
        if( x == null ) return 0
        // x is String (non-null) in this branch
        return x.length
    }
 `is` checks and `when` branches also narrow types:
    fun kind(x: Object) {
        if( x is Int ) return "int"
        if( x is String ) return "string"
        return "other"
    }
 Narrowing is local to the branch; after the branch, the original type is restored.
 ## Casts and unknown types
 Use `as` for explicit casts. The compiler inserts casts only when it can be valid and necessary. If a cast fails at
 runtime, it throws `ClassCastException`. If the value is nullable, `as T` implies a non-null assertion.
 Member access is resolved at compile time. Only members of `Object` are available on unknown types; non-Object members
 require an explicit cast:
    fun f(x) {             // x is Object
        x.toString()       // ok (Object member)
        x.size()           // compile-time error
        (x as List).size() // ok
    }
 This avoids runtime name-resolution fallbacks; all symbols must be known at compile time.
 ## Generics and bounds
 Generic parameters are declared with `<...>`:
    fun id<T>(x: T): T = x
    class Box<T>(val value: T)
 Bounds use `:` and can combine with `&` (intersection) and `|` (union):
    fun sum<T: Int | Real>(x: T, y: T) = x + y
    class Named<T: Iterable & Comparable>(val data: T)
 Type arguments are usually inferred from call sites:
    val b = Box(10)     // Box<Int>
    val s = id("ok")    // T is String
 See [Generics and type expressions](generics.md) for bounds, unions/intersections, and type-checking rules.
 ## Variance
 Generic types are invariant by default, so `List<Int>` is not a `List<Object>`.
 Use declaration-site variance when you need it:
    class Source<out T>(val value: T)
    class Sink<in T> { fun accept(x: T) { ... } }
 `out` makes the type covariant (only produced), `in` makes it contravariant (only consumed).
 # Defining functions
    fun check(amount) {
@@ -395,14 +659,28 @@ There are default parameters in Lyng:
 It is possible to define also vararg using ellipsis:
    fun sum(args...) {
-        var result = args[0]
+        val list = args as List
-        for( i in 1 ..< args.size ) result += args[i]
+        var result = list[0]
        for( i in 1 ..< list.size ) result += list[i]
    }
    sum(10,20,30)
    >>> 60
 See the [arguments reference](declaring_arguments.md) for more details.
 ## Named arguments
 When calling functions, you can use named arguments with the colon syntax `name: value`. This is particularly useful when you have many parameters with default values.
 ```lyng
    fun test(a="foo", b="bar", c="bazz") { [a, b, c] }
    assertEquals(["foo", "b", "bazz"], test(b: "b"))
    assertEquals(["a", "bar", "c"], test("a", c: "c"))
 ```
 **Note for Kotlin users:** Lyng uses `:` instead of `=` for named arguments at call sites. This is because in Lyng, `=` is an expression that returns the assigned value, and using it in an argument list would create ambiguity.
 ## Closures
 Each __block has an isolated context that can be accessed from closures__. For example:
@@ -476,14 +754,22 @@ one could be with ellipsis that means "the rest pf arguments as List":
    assert( { a, b...-> [a,...b] }(100, 1, 2, 3) == [100, 1, 2, 3]) 
    void
 Type-annotated lambdas can use variadic *function types* as well:
    val f: (Int, Object..., String)->Real = { a, rest..., b -> 0.0 }
    val anyArgs: (...)->Int = { -> 0 }
 ### Using lambda as the parameter
 See also: [Testing and Assertions](Testing.md)
    // note that fun returns its last calculated value,
    // in our case, result after in-place addition:
    fun mapValues(iterable, transform) {
        var result = []
        for( x in iterable ) result += transform(x)
    }
    // loop variables are read-only inside the loop body
    assert( [11, 21, 31] == mapValues( [1,2,3], { it*10+1 }))
    >>> void
@@ -511,6 +797,7 @@ Lyng has built-in mutable array class `List` with simple literals:
 [List] is an implementation of the type `Array`, and through it `Collection` and [Iterable]. Please read [Iterable],
 many collection based methods are implemented there.
 For immutable list values, use `list.toImmutable()` and [ImmutableList].
 Lists can contain any type of objects, lists too:
@@ -519,7 +806,7 @@ Lists can contain any type of objects, lists too:
    assert( list is Array )     // general interface
    assert(list.size == 3)
    // second element is a list too:
-    assert(list[1].size == 2)
+    assert((list[1] as List).size == 2)
    >>> void
 Notice usage of indexing. You can use negative indexes to offset from the end of the list; see more in [Lists](List.md).
@@ -693,6 +980,7 @@ Set are unordered collection of unique elements, see [Set]. Sets are [Iterable]
    >>> void
 Please see [Set] for detailed description.
 For immutable set values, use `set.toImmutable()` and [ImmutableSet].
 # Maps
@@ -753,6 +1041,7 @@ Notes:
 - When you need computed (expression) keys or non-string keys, use `Map(...)` constructor with entries, e.g. `Map( ("a" + "b") => 1 )`, then merge with a literal if needed: `{ base: } + (computedKey => 42)`.
 Please see the [Map] reference for a deeper guide.
 For immutable map values, use `map.toImmutable()` and [ImmutableMap].
 # Flow control operators
@@ -967,8 +1256,8 @@ ends normally, without breaks. It allows override loop result value, for example
 to not calculate it in every iteration. For example, consider this naive prime number
 test function (remember function return it's last expression result):
-    fun naive_is_prime(candidate) {
+    fun naive_is_prime(candidate: Int) {
-        val x = if( candidate !is Int) candidate.toInt() else candidate
+        val x = candidate
        var divisor = 1
        while( ++divisor < x/2 || divisor == 2 ) {
            if( x % divisor == 0 ) break false
@@ -1043,8 +1332,9 @@ For loop are intended to traverse collections, and all other objects that suppor
 size and index access, like lists:
    var letters = 0
-    for( w in ["hello", "wolrd"]) {
+    val words: List<String> = ["hello", "world"]
-        letters += w.length
+    for( w in words) {
        letters += (w as String).length
    }
    "total letters: "+letters
    >>> "total letters: 10"
@@ -1157,7 +1447,7 @@ The same with `--`:
    sum
    >>> 5050
-There are self-assigning version for operators too:
+There is a self-assigning version for operators too:
    var count = 100
    var sum = 0
@@ -1235,7 +1525,7 @@ than enum arrays, until `Lynon.encodeTyped` will be implemented.
    var result = null // here we will store the result
    >>> null
-# Integral data types
+# Built-in types
 | type   | description                     | literal samples     |
 |--------|---------------------------------|---------------------|
@@ -1245,6 +1535,7 @@ than enum arrays, until `Lynon.encodeTyped` will be implemented.
 | Char   | single unicode character        | `'S'`, `'\n'`       |
 | String | unicode string, no limits       | "hello" (see below) |
 | List   | mutable list                    | [1, "two", 3]       |
 | Object | top type for all values         |                     |
 | Void   | no value could exist, singleton | void                |
 | Null   | missing value, singleton        | null                |
 | Fn     | callable type                   |                     |
@@ -1264,21 +1555,70 @@ The type for the character objects is `Char`.
 | \t     | 0x07, tabulation      |
 | \\     | \ slash character     |
 | \"     | " double quote        |
 | \uXXXX | unicode code point    |
 Unicode escape form is exactly 4 hex digits, e.g. `"\u263A"` -> `☺`.
 Other `\c` combinations, where c is any char except mentioned above, are left intact, e.g.:
    val s = "\a"
-    assert(s[0] == '\')
+    assert(s[0] == '\\')
    assert(s[1] == 'a')
    >>> void
 same as:
    val s = "\\a"
-    assert(s[0] == '\')
+    assert(s[0] == '\\')
    assert(s[1] == 'a')
    >>> void
 ### String interpolation
 Supported forms:
 - `$name`
 - `${expr}`
 Literal dollar forms:
 - `\$` -> `$`
 - `$$` -> `$`
 Example:
    val name = "Lyng"
    assertEquals("hello, Lyng!", "hello, $name!")
    assertEquals("sum=3", "sum=${1+2}")
    assertEquals("\$name", "\$name")
    assertEquals("\$name", "$$name")
    assertEquals("\\Lyng", "\\$name")
    >>> void
 Interpolation and `printf`-style formatting can be combined when needed:
    val method = "transfer"
    val argc = 2
    val compact = "%s:%d"(method, argc)
    assertEquals("call=transfer:2", "call=$compact")
    assertEquals("[transfer:2] ok", "[${"%s:%d"(method, argc)}] ok")
    >>> void
 Interpolation also works well with regex patterns. To keep a literal `$` in the
 regex, escape it in the resulting pattern:
    val currency = "USD"
    val amount = 15
    val escapedDollar = "\\$"
    val re = Regex("^${currency}${escapedDollar}${amount}$")
    assert("USD$15" =~ re)
    assert("USD15" !~ re)
    >>> void
 If you need old literal behavior in a file, add a leading directive comment:
    // feature: interpolation: off
 ### Char literal escapes
 Are the same as in string literals with little difference:
@@ -1290,6 +1630,9 @@ Are the same as in string literals with little difference:
 | \t     | 0x07, tabulation      |
 | \\     | \ slash character     |
 | \'     | ' apostrophe          |
 | \uXXXX | unicode code point    |
 For char literals, use `'\\'` to represent a single backslash character; `'\'` is invalid.
 ### Char instance members
@@ -1367,22 +1710,31 @@ Concatenation is a `+`: `"hello " + name` works as expected. No confusion. There
 Extraction:
-    "abcd42def"[ "\d+".re ].value
+    ("abcd42def"[ "\d+".re ] as RegexMatch).value
    >>> "42"
 Part match:
    assert( "abc foo def" =~ "f[oO]+".re )
-    assert( "foo" == $~.value )
+    assert( "foo" == ($~ as RegexMatch).value )
    >>> void
-Typical set of String functions includes:
+Repeating the fragment:
    assertEquals("hellohello", "hello"*2)
    assertEquals("", "hello"*0)
    >>> void
 A typical set of String functions includes:
 | fun/prop             | description / notes                                        |
-|--------------------|------------------------------------------------------------|
+|----------------------|------------------------------------------------------------|
-| lower()            | change case to unicode upper                               |
+| lower(), lowercase() | change case to unicode upper                               |
-| upper()            | change case to unicode lower                               |
+| upper(), uppercase() | change case to unicode lower                               |
 | trim()               | trim space chars from both ends                            |
 | isEmpty()            | true if string is empty                                    |
 | isNotEmpty()         | true if string is not empty                                |
 | isBlank()            | true if empty or contains only whitespace                  |
 | startsWith(prefix)   | true if starts with a prefix                               |
 | endsWith(prefix)     | true if ends with a prefix                                 |
 | last()               | get last character of a string or throw                    |
@@ -1399,7 +1751,7 @@ Typical set of String functions includes:
 | s1 += s2             | self-modifying concatenation                               |
 | toReal()             | attempts to parse string as a Real value                   |
 | toInt()              | parse string to Int value                                  |
-| characters()       | create [List] of characters (1)                            |
+| characters           | create [List] of characters (1)                            |
 | encodeUtf8()         | returns [Buffer] with characters encoded to utf8           |
 | matches(re)          | matches the regular expression (2)                         |
 |                      |                                                            |
@@ -1448,8 +1800,8 @@ See [math functions](math.md). Other general purpose functions are:
 | print(args...)                        | Open for overriding, it prints to stdout without newline.  |
 | flow {}                               | create flow sequence, see [parallelism]                    |
 | delay, launch, yield                  | see [parallelism]                                          |
-| cached(builder)                       | remembers builder() on first invocation and return it then |
+| cached(builder)                       | [Lazy evaluation with `cached`](#lazy-evaluation-with-cached) |
-| let, also, apply, run                 | see above, flow controls                                   |
+| let, also, apply, run, with       | see above, flow controls                                   |
 (1)
 : `fn` is optional lambda returning string message to add to exception string. 
@@ -1465,6 +1817,9 @@ Lambda avoid unnecessary execution if assertion is not failed. for example:
 | π                                   | See [math](math.md)          |
 [List]: List.md
 [ImmutableList]: ImmutableList.md
 [Testing]: Testing.md
 [Iterable]: Iterable.md
@@ -1474,13 +1829,15 @@ Lambda avoid unnecessary execution if assertion is not failed. for example:
 [Range]: Range.md
-[String]: development/String.md
+[String]: ../archived/development/String.md
 [string formatting]: https://github.com/sergeych/mp_stools?tab=readme-ov-file#sprintf-syntax-summary
 [Set]: Set.md
 [ImmutableSet]: ImmutableSet.md
 [Map]: Map.md
 [ImmutableMap]: ImmutableMap.md
 [Buffer]: Buffer.md
@@ -1494,6 +1851,50 @@ Lambda avoid unnecessary execution if assertion is not failed. for example:
 [Regex]: Regex.md
 ## Lazy evaluation with `cached`
 Sometimes you have an expensive computation that you only want to perform if and when it is actually needed, and then remember (cache) the result for all future calls. Lyng provides the `cached(builder)` function for this purpose.
 It is extremely simple to use: you pass it a block (lambda) that performs the computation, and it returns a zero-argument function that manages the caching for you.
 ### Basic Example
 ```lyng
 val expensive = cached {
    println("Performing expensive calculation...")
    2 + 2
 }
 println(expensive()) // Prints "Performing expensive calculation...") then "4"
 println(expensive()) // Prints only "4" (result is cached)
 ```
 ### Benefits and Simplicity
 1.  **Lazy Execution:** The code inside the `cached` block doesn't run until you actually call the resulting function.
 2.  **Automatic State Management:** You don't need to manually check if a value has been computed or store it in a separate variable.
 3.  **Closures and Class Support:** `cached` works perfectly with closures. If you use it inside a class, it will correctly capture the instance variables, and each instance will have its own independent cache.
 ### Use Case: Lazy Properties in Classes
 This is the most common use case for `cached`. It allows you to define expensive "fields" that are only computed if someone actually uses them:
 ```lyng
 class User(val id: Int) {
    // The details will be fetched only once, on demand
    val details = cached {
        println("Fetching details for user " + id)
        // Db.query is a hypothetical example
        Db.query("SELECT * FROM users WHERE id = " + id)
    }
 }
 val u = User(101)
 // ... nothing happens yet ...
 val d = u.details() // Computation happens here
 val sameD = u.details() // Returns the same result immediately
 ```
 ## Multiple Inheritance (quick start)
 Lyng supports multiple inheritance (MI) with simple, predictable rules. For a full reference see OOP notes, this is a quick, copy‑paste friendly overview.
@@ -1554,7 +1955,31 @@ assertEquals(null, (buzz as? Foo)?.runA())
 Notes:
 - Resolution order uses C3 MRO (active): deterministic, monotonic order suitable for diamonds and complex hierarchies. Example: for `class D() : B(), C()` where both `B()` and `C()` derive from `A()`, the C3 order is `D → B → C → A`. The first visible match wins.
- `private` is visible only inside the declaring class; `protected` is visible from the declaring class and any of its transitive subclasses. Qualialsofication (`this@Type`) or casts do not bypass visibility.
+- `private` is visible only inside the declaring class; `protected` is visible from the declaring class and its subclasses. Additionally, ancestors can access protected members of descendants if they override a member known to the ancestor. Qualification (`this@Type`) or casts do not bypass visibility.
 - Safe‑call `?.` works with `as?` for optional dispatch.
-To get details on OOP in Lyng, see [OOP notes](oop.md).
+## Extension members
 You can add new methods and properties to existing classes without modifying them.
 ### Extension functions
    fun String.shout() = this.upper() + "!!!"
    "hello".shout()
    >>> "HELLO!!!"
 ### Extension properties
    val Int.isEven get() = this % 2 == 0
    4.isEven
    >>> true
 Example with custom accessors:
    val String.firstChar get() = this[0]
    "abc".firstChar
    >>> 'a'
 Extension members are **scope-isolated**: they are visible only in the scope where they are defined and its children. This prevents name collisions and improves security.
 To get details on OOP in Lyng, see [OOP notes](OOP.md).
@@ -0,0 +1,27 @@
 # Wasm generation hang in wasmJs browser tests
 ## Summary
 The wasmJs browser test runner hung after commit 5f819dc. The root cause was invalid WebAssembly generated by the Kotlin/Wasm backend when certain compiler paths emitted suspend lambdas for `Statement` execution. The invalid module failed to instantiate in the browser, and Karma kept the browser connected but never ran tests.
 ## Symptoms
 - `:lynglib:wasmJsBrowserTest` hangs indefinitely in ChromeHeadless.
 - `:lynglib:wasmJsNodeTest` fails with a WebAssembly compile error similar to:
  - `struct.set expected type (ref null XXXX), found global.get of type (ref null YYYY)`
 - The failing function name in the wasm name section looks like:
  - `net.sergeych.lyng.$invokeCOROUTINE$.doResume`
 ## Root cause
 The delegation/var-declaration changes introduced compiler-generated suspend lambdas inside `Statement` construction (e.g., `statement { ... }` wrappers). Kotlin/Wasm generates extra coroutine state for those suspend lambdas, which in this case produced invalid wasm IR (mismatched GC reference types). The browser loader then waits forever because the module fails to instantiate.
 ## Fix
 Avoid suspend-lambda `Statement` construction in compiler code paths. Replace `statement { ... }` and other anonymous suspend lambdas with explicit `object : Statement()` implementations and move logic into `override suspend fun execute(...)`. This keeps the resulting wasm IR valid while preserving behavior.
 ## Where it was fixed
 - `lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt`
 - `lynglib/src/commonMain/kotlin/net/sergeych/lyng/Scope.kt`
 ## Verification
 - `./gradlew :lynglib:wasmJsNodeTest --info`
 - `./gradlew :lynglib:wasmJsBrowserTest --info`
 Both tests finish quickly after the change.
@@ -0,0 +1,321 @@
 # What's New in Lyng
 This document highlights the latest additions and improvements to the Lyng language and its ecosystem.
 For a programmer-focused migration summary, see `docs/whats_new_1_5.md`.
 ## Language Features
 ### Decimal Arithmetic Module (`lyng.decimal`)
 Lyng now ships a first-class decimal module built as a regular extension library rather than a deep core special case.
 It provides:
 - `BigDecimal`
 - convenient `.d` conversions from `Int`, `Real`, and `String`
 - mixed arithmetic with `Int` and `Real`
 - local division precision and rounding control via `withDecimalContext(...)`
 ```lyng
 import lyng.decimal
 assertEquals("3", (1 + 2.d).toStringExpanded())
 assertEquals("0.30000000000000004", (0.1 + 0.2).d.toStringExpanded())
 assertEquals("0.3", "0.3".d.toStringExpanded())
 assertEquals(
    "0.3333333333",
    withDecimalContext(10) { (1.d / 3.d).toStringExpanded() }
 )
 ```
 The distinction between `Real -> Decimal` and exact decimal parsing is explicit by design:
 - `2.2.d` converts the current `Real` value
 - `"2.2".d` parses exact decimal text
 See [Decimal](Decimal.md).
 ### Binary Operator Interop Registry
 Lyng now provides a general mechanism for mixed binary operators through `lyng.operators`.
 This solves cases like:
 - `Int + MyType`
 - `Real < MyType`
 - `Int == MyType`
 without requiring changes to built-in classes.
 ```lyng
 import lyng.operators
 class DecimalBox(val value: Int) {
    fun plus(other: DecimalBox) = DecimalBox(value + other.value)
    fun compareTo(other: DecimalBox) = value <=> other.value
 }
 OperatorInterop.register(
    Int,
    DecimalBox,
    DecimalBox,
    [BinaryOperator.Plus, BinaryOperator.Compare, BinaryOperator.Equals],
    { x: Int -> DecimalBox(x) },
    { x: DecimalBox -> x }
 )
 assertEquals(DecimalBox(3), 1 + DecimalBox(2))
 assert(1 < DecimalBox(2))
 assert(2 == DecimalBox(2))
 ```
 `lyng.decimal` uses this same mechanism internally to interoperate with `Int` and `Real`.
 See [Operator Interop Registry](OperatorInterop.md).
 ### Class Properties with Accessors
 Classes now support properties with custom `get()` and `set()` accessors. Properties in Lyng do **not** have automatic backing fields; they are pure accessors.
 ```lyng
 class Person(private var _age: Int) {
    // Read-only property
    val ageCategory get() = if (_age < 18) "Minor" else "Adult"
    // Read-write property
    var age: Int
        get() = _age
        set(v) {
            if (v >= 0) _age = v
        }
 }
 ```
 ### Private and Protected Setters
 You can now restrict the visibility of a property's or field's setter using `private set` or `protected set`. This allows members to be publicly readable but only writable from within the declaring class or its subclasses.
 ### Refined Protected Visibility
 Ancestor classes can now access `protected` members of their descendants if it is an override of a member known to the ancestor. This enables base classes to call protected methods that are implemented or overridden in subclasses.
 ```lyng
 class Counter {
    var count = 0
        private set  // Field with private setter
    fun increment() { count++ }
 }
 class AdvancedCounter : Counter {
    var totalOperations = 0
        protected set // Settable here and in further subclasses
 }
 let c = Counter()
 c.increment() // OK
 // c.count = 10 // Error: setter is private
 ```
 ### Late-initialized `val` Fields
 `val` fields in classes can be declared without an immediate initializer, provided they are assigned exactly once. If accessed before initialization, they hold the special `Unset` singleton.
 ```lyng
 class Service {
    val logger
    fun check() {
        if (logger == Unset) println("Not initialized yet")
    }
    init {
        logger = Logger("Service")
    }
 }
 ```
 ### Named Arguments and Named Splats
 Function calls now support named arguments using the `name: value` syntax. If the variable name matches the parameter name, you can use the `name:` shorthand.
 ```lyng
 fun greet(name, greeting = "Hello") {
    println("$greeting, $name!")
 }
 val name = "Alice"
 greet(name:)                  // Shorthand for greet(name: name)
 greet(greeting: "Hi", name: "Bob")
 let params = { name: "Charlie", greeting: "Hey")
 greet(...params)              // Named splat expansion
 ```
 ### Multiple Inheritance (MI)
 Lyng now supports multiple inheritance using the C3 Method Resolution Order (MRO). Use `this@Type` or casts for disambiguation.
 ```lyng
 class A { fun foo() = "A" }
 class B { fun foo() = "B" }
 class Derived : A, B {
    fun test() {
        println(foo())              // Resolves to A.foo (leftmost)
        println(this@B.foo())       // Qualified dispatch to B.foo
    }
 }
 let d = Derived()
 println((d as B).foo())             // Disambiguation via cast
 ```
 ### Singleton Objects
 Singleton objects are declared using the `object` keyword. They provide a convenient way to define a class and its single instance in one go.
 ```lyng
 object Config {
    val version = "1.5.0-SNAPSHOT"
    fun show() = println("Config version: " + version)
 }
 Config.show()
 ```
 ### Nested Declarations and Lifted Enums
 You can now declare classes, objects, enums, and type aliases inside another class. These nested declarations live in the class namespace (no outer instance capture) and are accessed with a qualifier.
 ```lyng
 class A {
    class B(x?)
    object Inner { val foo = "bar" }
    enum E* { One, Two }
 }
 val ab = A.B()
 assertEquals(ab.x, null)
 assertEquals(A.Inner.foo, "bar")
 assertEquals(A.One, A.E.One)
 ```
 The `*` on `enum E*` lifts entries into the enclosing class namespace (compile-time error on ambiguity).
 ### Object Expressions
 You can now create anonymous objects that inherit from classes or interfaces using the `object : Base { ... }` syntax. These expressions capture their lexical scope and support multiple inheritance.
 ```lyng
 val worker = object : Runnable {
    override fun run() = println("Working...")
 }
 val x = object : Base(arg1), Interface1 {
    val property = 42
    override fun method() = this@object.property * 2
 }
 ```
 Use `this@object` to refer to the innermost anonymous object instance when `this` is rebound.
 ### Unified Delegation Model
 A powerful new delegation system allows `val`, `var`, and `fun` members to delegate their logic to other objects using the `by` keyword.
 ```lyng
 // Property delegation
 val lazyValue by lazy { "expensive" }
 // Function delegation
 fun remoteAction by myProxy
 // Observable properties
 var name by Observable("initial") { n, old, new -> 
    println("Changed!") 
 }
 ```
 The system features a unified interface (`getValue`, `setValue`, `invoke`) and a `bind` hook for initialization-time validation and configuration. See the [Delegation Guide](delegation.md) for more.
 ### User-Defined Exception Classes
 You can now create custom exception types by inheriting from the built-in `Exception` class. Custom exceptions are real classes that can have their own fields and methods, and they work seamlessly with `throw` and `try-catch` blocks.
 ```lyng
 class ValidationException(val field, m) : Exception(m)
 try {
    throw ValidationException("email", "Invalid format")
 }
 catch(e: ValidationException) {
    println("Error in " + e.field + ": " + e.message)
 }
 ```
 ### Assign-if-null Operator (`?=`)
 The new `?=` operator provides a concise way to assign a value only if the target is `null`. It is especially useful for setting default values or lazy initialization.
 ```lyng
 var x = null
 x ?= 42          // x is now 42
 x ?= 100         // x remains 42 (not null)
 // Works with properties and index access
 config.port ?= 8080
 settings["theme"] ?= "dark"
 ```
 The operator returns the final value of the receiver (the original value if it was not `null`, or the new value if the assignment occurred).
 ### Transient Attribute (`@Transient`)
 The `@Transient` attribute can now be applied to class fields, constructor parameters, and static fields to exclude them from serialization.
 ```lyng
 class MyData(@Transient val tempSecret, val publicData) {
    @Transient var cachedValue = 0
    var persistentValue = 42
 }
 ```
 Key features:
 - **Serialization**: Transient members are omitted from both Lynon binary streams and JSON output.
 - **Structural Equality**: Transient fields are automatically ignored during `==` equality checks.
 - **Deserialization**: Transient constructor parameters with default values are correctly restored to those defaults upon restoration.
 ### Value Clamping (`clamp`)
 A new `clamp()` function has been added to the standard library to limit a value within a specified range. It is available as both a global function and an extension method on all objects.
 ```lyng
 // Global function
 clamp(15, 0..10)    // returns 10
 clamp(-5, 0..10)   // returns 0
 // Extension method
 val x = 15
 x.clamp(0..10)      // returns 10
 // Exclusive and open-ended ranges
 15.clamp(0..<10)    // returns 9
 15.clamp(..10)      // returns 10
 -5.clamp(0..)       // returns 0
 ```
 `clamp()` correctly handles inclusive (`..`) and exclusive (`..<`) ranges. For discrete types like `Int` and `Char`, clamping to an exclusive upper bound returns the previous value.
 ## Tooling and Infrastructure
 ### CLI: Formatting Command
 A new `fmt` subcommand has been added to the Lyng CLI.
 ```bash
 lyng fmt MyFile.lyng             # Print formatted code to stdout
 lyng fmt --in-place MyFile.lyng  # Format file in-place
 lyng fmt --check MyFile.lyng     # Check if file needs formatting
 ```
 ### IDEA Plugin: Autocompletion
 Experimental lightweight autocompletion is now available in the IntelliJ plugin. It features type-aware member suggestions and inheritance-aware completion.
 You can enable it in **Settings | Lyng Formatter | Enable Lyng autocompletion**.
 ### Kotlin API: Exception Handling
 The `Obj.getLyngExceptionMessageWithStackTrace()` extension method has been added to simplify retrieving detailed error information from Lyng exception objects in Kotlin. Additionally, `getLyngExceptionMessage()` and `raiseAsExecutionError()` now accept an optional `Scope`, making it easier to use them when a scope is not immediately available.
 ### Kotlin API: Bridge Reflection and Class Binding (Preferred Extensions)
 Lyng now provides a public Kotlin reflection bridge and a Lyng‑first class binding workflow. This is the **preferred** way to write Kotlin extensions and library integrations:
 - **Bridge resolver**: explicit handles for values, vars, and callables with predictable lookup rules.
 - **Class bridge binding**: declare extern surfaces in Lyng (`extern` members, or members inside `extern class/object`) and bind the implementations in Kotlin before the first instance is created.
 - **Extern declaration rule**: `extern class` / `extern object` are declaration-only; all members in their bodies are implicitly extern.
 See **Embedding Lyng** for full samples and usage details.
@@ -0,0 +1,133 @@
 # What's New in Lyng 1.3 (vs 1.2.* / master)
 This is a programmer-focused summary of what changed since the 1.2.* line on `master`. It highlights new language and type-system features, runtime/IDE improvements, and how to migrate code safely.
 ## Highlights
 - Generics are now a first-class part of the type system, with bounds, variance, unions, and intersections.
 - Type aliases and type-expression checks (`T1 is T2`, `A in T`) enable richer static modeling.
 - Nested declarations inside classes, plus lifted enum entries via `enum E*`.
 - Stepped ranges (`step`) including iterable open-ended and real ranges.
 - Runtime and compiler speedups: more bytecode coverage, direct slot access, call-site caching.
 ## Language and type system
 ### Generics, bounds, and variance
 You can declare generic functions/classes with `<...>`, restrict them with bounds, and control variance.
 ```lyng
 fun id<T>(x: T): T = x
 class Box<out T>(val value: T)
 fun sum<T: Int | Real>(x: T, y: T) = x + y
 class Named<T: Iterable & Comparable>(val data: T)
 ```
 ### Type aliases and type expressions
 Type aliases can name any type expression, including unions and intersections.
 ```lyng
 type Num = Int | Real
 type Maybe<T> = T?
 ```
 Type expressions can be checked directly:
 ```lyng
 fun f<T>(xs: List<T>) {
    assert( T is Int | String | Bool ) // type-subset check
    assert( Int in T )                 // same relation as `Int is T`
 }
 ```
 Value checks remain `x is T`. Type expression equality uses `==` and is structural.
 ### Nullable shorthand for parameters
 Untyped parameters and constructor args can use `x?` as shorthand for `x: Object?`:
 ```lyng
 class A(x?) { ... }
 fun f(x?) { x == null }
 ```
 ### List/map literal inference
 The compiler now infers element and key/value types from literals and spreads. Mixed element types produce unions.
 ```lyng
 val a = [1, 2, 3]             // List<Int>
 val b = [1, "two", true]      // List<Int | String | Bool>
 val m = { "a": 1, "b": "x" } // Map<String, Int | String>
 ```
 ### Compile-time member access only
 Member access is resolved at compile time. On unknown types, only `Object` members are visible; other members require an explicit cast.
 ```lyng
 fun f(x) {          // x: Object
    x.toString()    // ok
    x.size()        // compile-time error
    (x as List).size()
 }
 ```
 This removes runtime name-resolution fallbacks and makes errors deterministic.
 ### Nested declarations and lifted enums
 Classes, objects, enums, and type aliases can be declared inside another class and accessed by qualifier. Enums can lift entries into the outer namespace with `*`.
 ```lyng
 class A {
    class B(x?)
    object Inner { val foo = "bar" }
    type Alias = B
    enum E* { One, Two }
 }
 val b = A.B()
 assertEquals(A.One, A.E.One)
 ```
 ### Stepped ranges
 Ranges now support `step`, and open-ended/real ranges are iterable only with an explicit step.
 ```lyng
 (1..5 step 2).toList()      // [1,3,5]
 (0.0..1.0 step 0.25).toList() // [0,0.25,0.5,0.75,1.0]
 (0.. step 1).take(3).toList() // [0,1,2]
 ```
 ## Tooling and performance
 - Bytecode compiler/VM coverage expanded (loops, expressions, calls), improving execution speed and consistency.
 - Direct frame-slot access and scoped slot addressing reduce lookup overhead, including in closures.
 - Call-site caching and numeric fast paths reduce hot-loop overhead.
 - IDE tooling updated for the new type system and nested declarations; MiniAst-based completion work continues.
 ## Migration guide (from 1.2.*)
 1) Replace dynamic member access on unknown types
 - If you relied on runtime name resolution, add explicit casts or annotate types so the compiler can resolve members.
 2) Adopt new type-system constructs where helpful
 - Consider `type` aliases for complex unions/intersections.
 - Prefer generic signatures over `Object` when the API is parametric.
 3) Update range iteration where needed
 - Use `step` for open-ended or real ranges you want to iterate.
 4) Nullable shorthand is optional
 - If you used untyped nullable params, you can keep `x` (Object) or switch to `x?` (Object?) for clarity.
 ## References
 - `docs/generics.md`
 - `docs/Range.md`
 - `docs/OOP.md`
 - `docs/BytecodeSpec.md`
@@ -0,0 +1,145 @@
 # What's New in Lyng 1.5 (vs 1.3.* / master)
 This document summarizes the significant changes and new features introduced in the 1.5 development cycle.
 ## Principal changes
 ### JIT compiler and compile-time types and symbols.
 This major improvement gives the following big advantages:
 - **Blazing Fast execution**: several times faster! (three to six times speedup in different scenarios).
 - **Better IDE support**: autocompletion, early error detection, types check.
 - **Error safety**: all symbols and types are checked at bound at compile-time. Many errors are detected earlier. Also, no risk that external or caller code would shadow some internally used symbols (especially in closures and inheritance).
 In particular, it means no slow and flaky runtime lookups. Once compiled, code guarantees that it will always call the symbol known at compile-time; runtime name lookup though does not guarantee it and can be source of hard to trace bugs. 
 ### New stable API to create Kotlin extensions
 The API is fixed and will be kept with further Lyng core changes. It is now the recommended way to write Lyng extensions in Kotlin. It is much simpler and more elegant than the internal one. See [Kotlin Bridge Binding](../notes/kotlin_bridge_binding.md).
 Extern declaration clarification:
 - `extern class` / `extern object` are pure extern surfaces.
 - Members inside them are implicitly extern (`extern` on a member is optional/redundant).
 - Lyng method/property bodies for these declarations should be implemented as extensions instead.
 ### Smart types system
 - **Deep inference**: The compiler analyzes types of symbols along the execution path and in many cases eliminates unnecessary casts or type specifications.
 - **Union and intersection types**: `A & B`, `A | B`.
 - **Generics**: Generic types are first-class citizens with support for [bounds and variance](generics.md). Type params are erased by default and are reified only when needed (e.g., `T::class`, `T is ...`, `as T`, or in extern-facing APIs), which enables checks like `A in T` when `T` is reified.
 - **Inner classes and enums**: Full support for nested declarations, including [Enums with lifting](OOP.md#lifted-enum-entries).
 ## Other highlights
 - **The `return` Statement**: Added support for local and non-local returns using labels.
 - **Abstract Classes and Interfaces**: Full support for `abstract` members and the `interface` keyword.
 - **Singleton Objects**: Define singletons using the `object` keyword or use anonymous object expressions.
 - **Multiple Inheritance**: Enhanced multi-inheritance with predictable [C3 MRO resolution](OOP.md#multiple-inheritance-and-mro).
 - **Unified Delegation**: Powerful delegation model for `val`, `var`, and `fun` members. See [Delegation](delegation.md).
 - **Class Properties with Accessors**: Define `val` and `var` properties with custom `get()` and `set()`.
 - **Restricted Setter Visibility**: Use `private set` and `protected set` on fields and properties.
 - **Late-initialized `val`**: Support for `val` fields that are initialized in `init` blocks or class bodies.
 - **Transient Members**: Use `@Transient` to exclude members from serialization and equality checks.
 - **Named Arguments and Splats**: Improved call-site readability with `name: value` and map-based splats.
 - **Refined Visibility**: Improved `protected` access and `closed` modifier for better encapsulation.
 ## Language Features
 ### The `return` Statement
 You can now exit from the innermost enclosing callable (function or lambda) using `return`. Lyng also supports non-local returns to outer scopes using labels. See [Return Statement](return_statement.md).
 ```lyng
 fun findFirst<T>(list: Iterable<T>, predicate: (T)->Bool): T? {
    list.forEach {
        if (predicate(it)) return@findFirst it
    }
    null
 }
 ```
 ### Abstract Classes and Interfaces
 Lyng now supports the `abstract` modifier for classes and their members. `interface` is introduced as a synonym for `abstract class`, allowing for rich multi-inheritance patterns.
 ```lyng
 interface Shape {
    abstract val area: Real
    fun describe() = "Area: %g"(area)
 }
 class Circle(val radius: Real) : Shape {
    override val area get = Math.PI * radius * radius
 }
 ```
 ### Class Properties with Accessors
 Properties can now have custom getters and setters. They do not have automatic backing fields, making them perfect for computed values or delegation.
 ```lyng
 class Rectangle(var width: Real, var height: Real) {
    val area: Real get() = width * height
    var squareSize: Real
        get() = area
        set(v) {
            width = sqrt(v)
            height = width
        }
 }
 ```
 ### Singleton Objects
 Declare singletons or anonymous objects easily.
 ```lyng
 object Database {
    val connection = "connected"
 }
 val runner = object : Runnable {
    override fun run() = println("Running!")
 }
 ```
 ### Named Arguments and Named Splats
 Improve call-site clarity by specifying argument names. You can also expand a Map into named arguments using the splat operator.
 ```lyng
 fun configure(timeout: Int, retry: Int = 3) { ... }
 configure(timeout: 5000, retry: 5)
 val options = Map("timeout": 1000, "retry": 1)
 configure(...options)
 ```
 ### Modern Operators
 The `?=` operator allows for concise "assign if null" logic.
 ```lyng
 var cache: Map? = null
 cache ?= Map("status": "ok") // Only assigns if cache is null
 ```
 ## Tooling and IDE
 - **IDEA Plugin**: Significant improvements to autocompletion, documentation tooltips, and natural language support (Grazie integration).
 - **CLI**: The `lyng fmt` command is now a first-class tool for formatting code with various options like `--check` and `--in-place`.
 - **Performance**: Ongoing optimizations in the bytecode VM and compiler for faster execution and smaller footprint.
 ## Standard Library
 - **`with(self, block)`**: Scoped execution with a dedicated `self`.
 - **`clamp(value, min, max)`**: Easily restrict values to a range.
 ## Migration Guide (from 1.3.*)
 1. **Check Visibility**: Refined `protected` and `private` rules may catch previously undetected invalid accesses.
 2. **Override Keyword**: Ensure all members that override ancestor declarations are marked with the `override` keyword (now mandatory).
 3. **Return in Shorthand**: Remember that `return` is forbidden in `=` shorthand functions; use block syntax if you need early exit.
 4. **Empty Map Literals**: Use `Map()` or `{:}` for empty maps, as `{}` is now strictly a block/lambda.
 ## References
 - [Object Oriented Programming](OOP.md)
 - [Generics](generics.md)
 - [Return Statement](return_statement.md)
 - [Delegation](delegation.md)
 - [Tutorial](tutorial.md)
@@ -20,7 +20,7 @@ Files
  - Constants: `true`, `false`, `null`, `this`
  - Annotations: `@name` (Unicode identifiers supported)
  - Labels: `name:` (Unicode identifiers supported)
-  - Declarations: highlights declared names in `fun|fn name`, `class|enum Name`, `val|var name`
+  - Declarations: highlights declared names in `fun|fn name`, `class|enum|interface Name`, `val|var name`
  - Types: built-ins (`Int|Real|String|Bool|Char|Regex`) and Capitalized identifiers (heuristic)
  - Operators including ranges (`..`, `..<`, `...`), null-safe (`?.`, `?[`, `?(`, `?{`, `?:`, `??`), arrows (`->`, `=>`, `::`), match operators (`=~`, `!~`), bitwise, arithmetic, etc.
  - Shuttle operator `<=>`
@@ -2,7 +2,7 @@
  "name": "lyng-textmate",
  "displayName": "Lyng",
  "description": "TextMate grammar for the Lyng language (for JetBrains IDEs via TextMate Bundles and VS Code).",
-  "version": "0.0.3",
+  "version": "0.1.0",
  "publisher": "lyng",
  "license": "Apache-2.0",
  "engines": { "vscode": "^1.0.0" },
@@ -42,7 +42,7 @@
        { "name": "constant.numeric.decimal.lyng", "match": "(?<![A-Za-z_])(?:[0-9][0-9_]*)\\.(?:[0-9_]+)(?:[eE][+-]?[0-9_]+)?|(?<![A-Za-z_])(?:[0-9][0-9_]*)(?:[eE][+-]?[0-9_]+)?" }
      ]
    },
-    "annotations": { "patterns": [ { "name": "entity.name.label.at.lyng", "match": "@[\\p{L}_][\\p{L}\\p{N}_]*:" }, { "name": "storage.modifier.annotation.lyng", "match": "@[\\p{L}_][\\p{L}\\p{N}_]*" } ] },
+    "annotations": { "patterns": [ { "name": "entity.name.label.at.lyng", "match": "@[\\p{L}_][\\p{L}\\p{N}_]*" } ] },
    "mapLiterals": {
      "patterns": [
        {
@@ -74,11 +74,11 @@
        }
      ]
    },
-    "labels": { "patterns": [ { "name": "entity.name.label.lyng", "match": "[\\p{L}_][\\p{L}\\p{N}_]*:" } ] },
+    "labels": { "patterns": [ { "name": "entity.name.label.lyng", "match": "[\\p{L}_][\\p{L}\\p{N}_]*@" } ] },
    "directives": { "patterns": [ { "name": "meta.directive.lyng", "match": "^\\s*#[_A-Za-z][_A-Za-z0-9]*" } ] },
-    "declarations": { "patterns": [ { "name": "meta.function.declaration.lyng", "match": "\\b(?:fun|fn)\\s+([\\p{L}_][\\p{L}\\p{N}_]*)", "captures": { "1": { "name": "entity.name.function.lyng" } } }, { "name": "meta.type.declaration.lyng", "match": "\\b(?:class|enum)\\s+([\\p{L}_][\\p{L}\\p{N}_]*)", "captures": { "1": { "name": "entity.name.type.lyng" } } }, { "name": "meta.variable.declaration.lyng", "match": "\\b(?:val|var)\\s+([\\p{L}_][\\p{L}\\p{N}_]*)", "captures": { "1": { "name": "variable.other.declaration.lyng" } } } ] },
+    "declarations": { "patterns": [ { "name": "meta.function.declaration.lyng", "match": "\\b(fun|fn)\\s+(?:([\\p{L}_][\\p{L}\\p{N}_]*)\\.)?([\\p{L}_][\\p{L}\\p{N}_]*)", "captures": { "1": { "name": "keyword.declaration.lyng" }, "2": { "name": "entity.name.type.lyng" }, "3": { "name": "entity.name.function.lyng" } } }, { "name": "meta.type.declaration.lyng", "match": "\\b(?:class|enum|interface|object)(?:\\s+([\\p{L}_][\\p{L}\\p{N}_]*))?", "captures": { "1": { "name": "entity.name.type.lyng" } } }, { "name": "meta.variable.declaration.lyng", "match": "\\b(val|var)\\s+(?:([\\p{L}_][\\p{L}\\p{N}_]*)\\.)?([\\p{L}_][\\p{L}\\p{N}_]*)", "captures": { "1": { "name": "keyword.declaration.lyng" }, "2": { "name": "entity.name.type.lyng" }, "3": { "name": "variable.other.declaration.lyng" } } } ] },
-    "keywords": { "patterns": [ { "name": "keyword.control.lyng", "match": "\\b(?:if|else|when|while|do|for|try|catch|finally|throw|return|break|continue)\\b" }, { "name": "keyword.declaration.lyng", "match": "\\b(?:fun|fn|class|enum|val|var|import|package|constructor|property|open|extern|private|protected|static)\\b" }, { "name": "keyword.operator.word.lyng", "match": "\\bnot\\s+(?:in|is)\\b" }, { "name": "keyword.operator.word.lyng", "match": "\\b(?:and|or|not|in|is|as|as\\?)\\b" } ] },
+    "keywords": { "patterns": [ { "name": "keyword.control.lyng", "match": "\\b(?:if|else|when|while|do|for|try|catch|finally|throw|return|break|continue)\\b" }, { "name": "keyword.declaration.lyng", "match": "\\b(?:fun|fn|class|enum|interface|val|var|import|package|constructor|property|abstract|override|open|closed|extern|private|protected|static|get|set|object|init|by)\\b" }, { "name": "keyword.operator.word.lyng", "match": "\\bnot\\s+(?:in|is)\\b" }, { "name": "keyword.operator.word.lyng", "match": "\\b(?:and|or|not|in|is|as|as\\?)\\b" } ] },
-    "constants": { "patterns": [ { "name": "constant.language.lyng", "match": "(?:\\b(?:true|false|null|this)\\b|π)" } ] },
+    "constants": { "patterns": [ { "name": "constant.language.lyng", "match": "(?:\\b(?:true|false|null|this(?:@[\\p{L}_][\\p{L}\\p{N}_]*)?)\\b|π)" } ] },
    "types": { "patterns": [ { "name": "storage.type.lyng", "match": "\\b(?:Int|Real|String|Bool|Char|Regex)\\b" }, { "name": "entity.name.type.lyng", "match": "\\b[A-Z][A-Za-z0-9_]*\\b(?!\\s*\\()" } ] },
    "operators": { "patterns": [ { "name": "keyword.operator.comparison.lyng", "match": "===|!==|==|!=|<=|>=|<|>" }, { "name": "keyword.operator.shuttle.lyng", "match": "<=>" }, { "name": "keyword.operator.arrow.lyng", "match": "=>|->|::" }, { "name": "keyword.operator.range.lyng", "match": "\\.\\.\\.|\\.\\.<|\\.\\." }, { "name": "keyword.operator.nullsafe.lyng", "match": "\\?\\.|\\?\\[|\\?\\(|\\?\\{|\\?:|\\?\\?" }, { "name": "keyword.operator.assignment.lyng", "match": "(?:\\+=|-=|\\*=|/=|%=|=)" }, { "name": "keyword.operator.logical.lyng", "match": "&&|\\|\\|" }, { "name": "keyword.operator.bitwise.lyng", "match": "<<|>>|&|\\||\\^|~" }, { "name": "keyword.operator.match.lyng", "match": "=~|!~" }, { "name": "keyword.operator.arithmetic.lyng", "match": "\\+\\+|--|[+\\-*/%]" }, { "name": "keyword.operator.other.lyng", "match": "[!?]" } ] },
    "punctuation": { "patterns": [ { "name": "punctuation.separator.comma.lyng", "match": "," }, { "name": "punctuation.terminator.statement.lyng", "match": ";" }, { "name": "punctuation.section.block.begin.lyng", "match": "[(]{1}|[{]{1}|\\[" }, { "name": "punctuation.section.block.end.lyng", "match": "[)]{1}|[}]{1}|\\]" }, { "name": "punctuation.accessor.dot.lyng", "match": "\\." }, { "name": "punctuation.separator.colon.lyng", "match": ":" } ] }
@@ -0,0 +1,814 @@
 #!/usr/bin/env lyng
 /*
 * Lyng Console Tetris (interactive sample)
 *
 * Controls:
 *  - Left/Right arrows or A/D: move
 *  - Up arrow or W: rotate
 *  - Down arrow or S: soft drop
 *  - Space: hard drop
 *  - P or Escape: pause
 *  - Q: quit
    Tsted to score:
 sergeych@sergeych-XPS-17-9720:~$ ~/dev/lyng/examples/tetris_console.lyng
 Bye.
 Score: 435480
 Lines: 271
 Level: 28
 Ssergeych@sergeych-XPS-17-9720:~$
 */
 import lyng.io.console
 import lyng.io.fs
 val MIN_COLS = 56
 val MIN_ROWS = 24
 val PANEL_WIDTH = 24
 val BOARD_MARGIN_ROWS = 5
 val BOARD_MIN_W = 10
 val BOARD_MAX_W = 16
 val BOARD_MIN_H = 16
 val BOARD_MAX_H = 28
 val LEVEL_LINES_STEP = 10
 val DROP_FRAMES_BASE = 15
 val DROP_FRAMES_MIN = 3
 val FRAME_DELAY_MS = 35
 val RESIZE_WAIT_MS = 250
 val MAX_PENDING_INPUTS = 64
 val ROTATION_KICKS = [0, -1, 1, -2, 2]
 val ANSI_ESC = "\u001b["
 val ANSI_RESET = ANSI_ESC + "0m"
 val ERROR_LOG_PATH = "/tmp/lyng_tetris_errors.log"
 val UNICODE_BLOCK = "██"
 val UNICODE_TOP_LEFT = "┌"
 val UNICODE_TOP_RIGHT = "┐"
 val UNICODE_BOTTOM_LEFT = "└"
 val UNICODE_BOTTOM_RIGHT = "┘"
 val UNICODE_HORIZONTAL = "──"
 val UNICODE_VERTICAL = "│"
 val UNICODE_DOT = "· "
 type Cell = List<Int>
 type Rotation = List<Cell>
 type Rotations = List<Rotation>
 type Row = List<Int>
 type Board = List<Row>
 class Piece(val name: String, val rotations: Rotations) {}
 class RotateResult(val ok: Bool, val rot: Int, val px: Int) {}
 class GameState(
    pieceId0: Int,
    nextId0: Int,
    next2Id0: Int,
    px0: Int,
    py0: Int,
 ) {
    var pieceId = pieceId0
    var nextId = nextId0
    var next2Id = next2Id0
    var rot = 0
    var px = px0
    var py = py0
    var score = 0
    var totalLines = 0
    var level = 1
    var running = true
    var gameOver = false
    var paused = false
 }
 class LoopFrame(val resized: Bool, val originRow: Int, val originCol: Int) {}
 fun clearAndHome() {
    Console.clear()
    Console.home()
 }
 fun logError(message: String, err: Object?): Void {
    try {
        var details = ""
        if (err != null) {
            try {
                details = ": " + err
            } catch (_: Object) {
                details = ": <error-format-failed>"
            }
        }
        Path(ERROR_LOG_PATH).appendUtf8(message + details + "\n")
    } catch (_: Object) {
        // Never let logging errors affect gameplay.
    }
 }
 fun repeatText(s: String, n: Int): String {
    var out: String = ""
    for (i in 0..<n) {
        out += s
    }
    out
 }
 fun max<T>(a: T, b: T): T = if (a > b) a else b
 fun emptyRow(width: Int): Row {
    val r: Row = []
    for (x in 0..<width) {
        r.add(0)
    }
    r
 }
 fun createBoard(width: Int, height: Int): Board {
    val b: Board = []
    for (y in 0..<height) {
        b.add(emptyRow(width))
    }
    b
 }
 fun colorize(text: String, sgr: String, useColor: Bool): String {
    if (!useColor) return text
    ANSI_ESC + sgr + "m" + text + ANSI_RESET
 }
 fun blockText(pieceId: Int, useColor: Bool): String {
    if (pieceId <= 0) return "  "
    val sgr = when (pieceId) {
        1 -> "36" // I
        2 -> "33" // O
        3 -> "35" // T
        4 -> "32" // S
        5 -> "31" // Z
        6 -> "34" // J
        7 -> "93" // L
        else -> "37"
    }
    colorize(UNICODE_BLOCK, sgr, useColor)
 }
 fun emptyCellText(useColor: Bool): String {
    colorize(UNICODE_DOT, "90", useColor)
 }
 fun canPlace(board: Board, boardW: Int, boardH: Int, pieceId: Int, rot: Int, px: Int, py: Int): Bool {
    try {
        if (pieceId < 1 || pieceId > 7) return false
        val piece: Piece = PIECES[pieceId - 1]
        if (rot < 0 || rot >= piece.rotations.size) return false
        val cells = piece.rotations[rot]
        for (cell in cells) {
            val x = px + cell[0]
            val y = py + cell[1]
            if (x < 0 || x >= boardW) return false
            if (y >= boardH) return false
            if (y >= 0) {
                if (y >= board.size) return false
                val row = board[y]
                if (row == null) return false
                if (row[x] != 0) return false
            }
        }
        true
    } catch (_: Object) {
        false
    }
 }
 fun lockPiece(board: Board, pieceId: Int, rot: Int, px: Int, py: Int): Void {
    val piece: Piece = PIECES[pieceId - 1]
    val cells = piece.rotations[rot]
    for (cell in cells) {
        val x = px + cell[0]
        val y = py + cell[1]
        if (y >= 0 && y < board.size) {
            val row = board[y]
            if (row != null) {
                row[x] = pieceId
            }
        }
    }
 }
 fun clearCompletedLines(board: Board, boardW: Int, boardH: Int): Int {
    val b = board
    var y = boardH - 1
    var cleared = 0
    while (y >= 0) {
        if (y >= b.size) {
            y--
            continue
        }
        val row = b[y]
        if (row == null) {
            b.removeAt(y)
            b.insertAt(0, emptyRow(boardW))
            cleared++
            continue
        }
        var full = true
        for (x in 0..<boardW) {
            if (row[x] == 0) {
                full = false
                break
            }
        }
        if (full) {
            b.removeAt(y)
            b.insertAt(0, emptyRow(boardW))
            cleared++
        } else {
            y--
        }
    }
    cleared
 }
 fun activeCellId(pieceId: Int, rot: Int, px: Int, py: Int, x: Int, y: Int): Int {
    val piece: Piece = PIECES[pieceId - 1]
    val cells = piece.rotations[rot]
    for (cell in cells) {
        val ax = px + cell[0]
        val ay = py + cell[1]
        if (ax == x && ay == y) return pieceId
    }
    0
 }
 fun tryRotateCw(board: Board, boardW: Int, boardH: Int, pieceId: Int, rot: Int, px: Int, py: Int): RotateResult {
    val piece: Piece = PIECES[pieceId - 1]
    val rotations = piece.rotations.size
    val nr = (rot + 1) % rotations
    for (kx in ROTATION_KICKS) {
        val nx = px + kx
        if (canPlace(board, boardW, boardH, pieceId, nr, nx, py) == true) {
            return RotateResult(true, nr, nx)
        }
    }
    RotateResult(false, rot, px)
 }
 fun nextPreviewLines(pieceId: Int, useColor: Bool): List<String> {
    val out: List<String> = []
    if (pieceId <= 0) {
        for (i in 0..<4) {
            out.add("        ")
        }
        return out
    }
    val piece: Piece = PIECES[pieceId - 1]
    val cells = piece.rotations[0]
    for (y in 0..<4) {
        var line = ""
        for (x in 0..<4) {
            var filled = false
            for (cell in cells) {
                if (cell[0] == x && cell[1] == y) {
                    filled = true
                    break
                }
            }
            line += if (filled) blockText(pieceId, useColor) else "  "
        }
        out.add(line)
    }
    out
 }
 fun render(
    state: GameState,
    board: Board,
    boardW: Int,
    boardH: Int,
    prevFrameLines: List<String>,
    originRow: Int,
    originCol: Int,
    useColor: Bool,
 ): List<String> {
    val bottomBorder = UNICODE_BOTTOM_LEFT + repeatText(UNICODE_HORIZONTAL, boardW) + UNICODE_BOTTOM_RIGHT
    val panel: List<String> = []
    val nextPiece: Piece = PIECES[state.nextId - 1]
    val next2Piece: Piece = PIECES[state.next2Id - 1]
    val nextName = nextPiece.name
    val next2Name = next2Piece.name
    val preview = nextPreviewLines(state.nextId, useColor)
    panel.add("Lyng Tetris")
    panel.add("")
    panel.add("Score: " + state.score)
    panel.add("Lines: " + state.totalLines)
    panel.add("Level: " + state.level)
    panel.add("")
    panel.add("Next: " + nextName)
    panel.add("")
    for (pl in preview) panel.add(pl)
    panel.add("After: " + next2Name)
    panel.add("")
    panel.add("Keys:")
    panel.add("A/D or arrows")
    panel.add("W/Up: rotate")
    panel.add("S/Down: drop")
    panel.add("Space: hard drop")
    panel.add("P/Esc: pause")
    panel.add("Q: quit")
    val frameLines: List<String> = []
    for (y in 0..<boardH) {
        var line = UNICODE_VERTICAL
        for (x in 0..<boardW) {
            val a = activeCellId(state.pieceId, state.rot, state.px, state.py, x, y)
            val row = if (y < board.size) board[y] else null
            val b = if (row == null) 0 else row[x]
            val id = if (a > 0) a else b
            line += if (id > 0) blockText(id, useColor) else emptyCellText(useColor)
        }
        line += UNICODE_VERTICAL
        if (y < panel.size) {
            line += "   " + panel[y]
        }
        frameLines.add(line)
    }
    frameLines.add(bottomBorder)
    for (i in 0..<frameLines.size) {
        val line = frameLines[i]
        val old = if (i < prevFrameLines.size) prevFrameLines[i] else null
        if (old != line) {
            Console.moveTo(originRow + i, originCol)
            Console.clearLine()
            Console.write(line)
        }
    }
    frameLines
 }
 fun fitLine(line: String, width: Int): String {
    val maxLen = if (width > 0) width else 0
    if (maxLen <= 0) return ""
    if (line.size >= maxLen) return line[..<maxLen]
    line + repeatText(" ", maxLen - line.size)
 }
 fun renderPauseOverlay(
    originRow: Int,
    originCol: Int,
    boardW: Int,
    boardH: Int,
 ): Void {
    val contentWidth = boardW * 2 + 2 + 3 + PANEL_WIDTH
    val contentHeight = boardH + 1
    val lines: List<String> = []
    lines.add("PAUSED")
    lines.add("")
    lines.add("Any key: continue game")
    lines.add("Esc: exit game")
    lines.add("")
    lines.add("Move: A/D or arrows")
    lines.add("Rotate: W or Up")
    lines.add("Drop: S/Down, Space hard drop")
    var innerWidth = 0
    for (line in lines) {
        if (line.size > innerWidth) innerWidth = line.size
    }
    innerWidth += 4
    val maxInner = max(12, contentWidth - 2)
    if (innerWidth > maxInner) innerWidth = maxInner
    if (innerWidth % 2 != 0) innerWidth--
    val boxWidth = innerWidth + 2
    val boxHeight = lines.size + 2
    val left = originCol + max(0, (contentWidth - boxWidth) / 2)
    val top = originRow + max(0, (contentHeight - boxHeight) / 2)
    val topBorder = UNICODE_TOP_LEFT + repeatText(UNICODE_HORIZONTAL, innerWidth / 2) + UNICODE_TOP_RIGHT
    val bottomBorder = UNICODE_BOTTOM_LEFT + repeatText(UNICODE_HORIZONTAL, innerWidth / 2) + UNICODE_BOTTOM_RIGHT
    Console.moveTo(top, left)
    Console.write(topBorder)
    for (i in 0..<lines.size) {
        Console.moveTo(top + 1 + i, left)
        Console.write(UNICODE_VERTICAL + fitLine("  " + lines[i], innerWidth) + UNICODE_VERTICAL)
    }
    Console.moveTo(top + boxHeight - 1, left)
    Console.write(bottomBorder)
 }
 fun waitForMinimumSize(minCols: Int, minRows: Int): Object {
    while (true) {
        val g = Console.geometry()
        val cols = g?.columns ?: 0
        val rows = g?.rows ?: 0
        if (cols >= minCols && rows >= minRows) return g
        clearAndHome()
        val lines: List<String> = []
        lines.add("Lyng Tetris needs at least %sx%s terminal size."(minCols, minRows))
        lines.add("Current: %sx%s"(cols, rows))
        lines.add("Resize the console window to continue.")
        val visibleLines = if (rows < lines.size) rows else lines.size
        if (visibleLines > 0) {
            val startRow = max(1, ((rows - visibleLines) / 2) + 1)
            for (i in 0..<visibleLines) {
                val line = lines[i]
                val startCol = max(1, ((cols - line.size) / 2) + 1)
                Console.moveTo(startRow + i, startCol)
                Console.clearLine()
                Console.write(line)
            }
            Console.flush()
        }
        delay(RESIZE_WAIT_MS)
    }
 }
 fun scoreForLines(cleared: Int, level: Int): Int {
    when (cleared) {
        1 -> 100 * level
        2 -> 300 * level
        3 -> 500 * level
        4 -> 800 * level
        else -> 0
    }
 }
 // Classic 7 tetrominoes, minimal rotations per piece.
 fun cell(x: Int, y: Int): Cell { [x, y] }
 fun rot(a: Cell, b: Cell, c: Cell, d: Cell): Rotation {
    val r: Rotation = []
    r.add(a)
    r.add(b)
    r.add(c)
    r.add(d)
    r
 }
 val PIECES: List<Piece> = []
 val iRots: Rotations = []
 iRots.add(rot(cell(0,1), cell(1,1), cell(2,1), cell(3,1)))
 iRots.add(rot(cell(2,0), cell(2,1), cell(2,2), cell(2,3)))
 PIECES.add(Piece("I", iRots))
 val oRots: Rotations = []
 oRots.add(rot(cell(1,0), cell(2,0), cell(1,1), cell(2,1)))
 PIECES.add(Piece("O", oRots))
 val tRots: Rotations = []
 tRots.add(rot(cell(1,0), cell(0,1), cell(1,1), cell(2,1)))
 tRots.add(rot(cell(1,0), cell(1,1), cell(2,1), cell(1,2)))
 tRots.add(rot(cell(0,1), cell(1,1), cell(2,1), cell(1,2)))
 tRots.add(rot(cell(1,0), cell(0,1), cell(1,1), cell(1,2)))
 PIECES.add(Piece("T", tRots))
 val sRots: Rotations = []
 sRots.add(rot(cell(1,0), cell(2,0), cell(0,1), cell(1,1)))
 sRots.add(rot(cell(1,0), cell(1,1), cell(2,1), cell(2,2)))
 PIECES.add(Piece("S", sRots))
 val zRots: Rotations = []
 zRots.add(rot(cell(0,0), cell(1,0), cell(1,1), cell(2,1)))
 zRots.add(rot(cell(2,0), cell(1,1), cell(2,1), cell(1,2)))
 PIECES.add(Piece("Z", zRots))
 val jRots: Rotations = []
 jRots.add(rot(cell(0,0), cell(0,1), cell(1,1), cell(2,1)))
 jRots.add(rot(cell(1,0), cell(2,0), cell(1,1), cell(1,2)))
 jRots.add(rot(cell(0,1), cell(1,1), cell(2,1), cell(2,2)))
 jRots.add(rot(cell(1,0), cell(1,1), cell(0,2), cell(1,2)))
 PIECES.add(Piece("J", jRots))
 val lRots: Rotations = []
 lRots.add(rot(cell(2,0), cell(0,1), cell(1,1), cell(2,1)))
 lRots.add(rot(cell(1,0), cell(1,1), cell(1,2), cell(2,2)))
 lRots.add(rot(cell(0,1), cell(1,1), cell(2,1), cell(0,2)))
 lRots.add(rot(cell(0,0), cell(1,0), cell(1,1), cell(1,2)))
 PIECES.add(Piece("L", lRots))
 if (!Console.isSupported()) {
    println("Console API is not supported in this runtime.")
    void
 } else if (!Console.isTty()) {
    println("This sample needs an interactive terminal (TTY).")
    void
 } else {
    waitForMinimumSize(MIN_COLS, MIN_ROWS)
    val g0 = Console.geometry()
    val cols = g0?.columns ?: MIN_COLS
    val rows = g0?.rows ?: MIN_ROWS
    val boardW = clamp((cols - PANEL_WIDTH) / 2, BOARD_MIN_W..BOARD_MAX_W)
    val boardH = clamp(rows - BOARD_MARGIN_ROWS, BOARD_MIN_H..BOARD_MAX_H)
    val board: Board = createBoard(boardW, boardH)
    fun nextPieceId() {
        Random.next(1..7)
    }
    val state: GameState = GameState(
        nextPieceId(),
        nextPieceId(),
        nextPieceId(),
        (boardW / 2) - 2,
        -1,
    )
    var prevFrameLines: List<String> = []
    val gameMutex: Mutex = Mutex()
    var forceRedraw = false
    val pendingInputs: List<String> = []
    val rawModeEnabled = Console.setRawMode(true)
    if (!rawModeEnabled) {
        println("Raw keyboard mode is not available in this terminal/runtime.")
        println("Use jlyng in an interactive terminal with raw input support.")
        void
    } else {
        val useColor = Console.ansiLevel() != ConsoleAnsiLevel.NONE
        Console.enterAltScreen()
        Console.setCursorVisible(false)
        clearAndHome()
        fun resetActivePiece(s: GameState): Void {
            s.pieceId = nextPieceId()
            s.rot = 0
            s.px = (boardW / 2) - 2
            s.py = -1
        }
        fun applyKeyInput(s: GameState, key: String): Void {
            try {
                if (key == "__CTRL_C__") {
                    s.running = false
                }
                else if (s.paused) {
                    if (key == "Escape") {
                        s.running = false
                    } else {
                        s.paused = false
                        forceRedraw = true
                    }
                }
                else if (key == "p" || key == "P" || key == "Escape") {
                    s.paused = true
                    forceRedraw = true
                }
                else if (key == "q" || key == "Q") {
                    s.running = false
                }
                else if (key == "ArrowLeft" || key == "a" || key == "A") {
                    if (canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px - 1, s.py) == true) s.px--
                }
                else if (key == "ArrowRight" || key == "d" || key == "D") {
                    if (canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px + 1, s.py) == true) s.px++
                }
                else if (key == "ArrowUp" || key == "w" || key == "W") {
                    val rr: RotateResult = tryRotateCw(board, boardW, boardH, s.pieceId, s.rot, s.px, s.py)
                    if (rr.ok) {
                        s.rot = rr.rot
                        s.px = rr.px
                    }
                }
                else if (key == "ArrowDown" || key == "s" || key == "S") {
                    if (canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px, s.py + 1) == true) {
                        s.py++
                        s.score++
                    }
                }
                else if (key == " ") {
                    while (canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px, s.py + 1) == true) {
                        s.py++
                        s.score += 2
                    }
                }
            } catch (inputErr: Object) {
                logError("applyKeyInput recovered after error", inputErr)
                resetActivePiece(s)
            }
        }
        var inputRunning = true
        launch {
            while (inputRunning) {
                try {
                    for (ev in Console.events()) {
                        if (!inputRunning) break
                        // Isolate per-event failures so one bad event does not unwind the stream.
                        try {
                            if (ev is ConsoleKeyEvent) {
                                val ke = ev as ConsoleKeyEvent
                                if (ke.type == ConsoleEventType.KEY_DOWN) {
                                    var key = ""
                                    var ctrl = false
                                    try {
                                        key = ke.key
                                    } catch (keyErr: Object) {
                                        logError("Input key read error", keyErr)
                                    }
                                    try {
                                        ctrl = ke.ctrl == true
                                    } catch (_: Object) {
                                        ctrl = false
                                    }
                                    if (key == "") {
                                        logError("Dropped key event with empty/null key", null)
                                        continue
                                    }
                                    val mapped = if (ctrl && (key == "c" || key == "C")) "__CTRL_C__" else key
                                    val mm: Mutex = gameMutex
                                    mm.withLock {
                                        if (pendingInputs.size >= MAX_PENDING_INPUTS) {
                                            pendingInputs.removeAt(0)
                                        }
                                        pendingInputs.add(mapped)
                                    }
                                }
                            }
                        } catch (eventErr: Object) {
                            // Keep the input stream alive; report for diagnostics.
                            logError("Input event error", eventErr)
                        }
                    }
                } catch (err: Object) {
                    // Recover stream-level failures by recreating event stream in next loop turn.
                    if (!inputRunning) break
                    logError("Input stream recovered after error", err)
                    Console.setRawMode(true)
                    delay(50)
                }
            }
        }
        fun pollLoopFrame(): LoopFrame? {
            val g = Console.geometry()
            val c = g?.columns ?: 0
            val r = g?.rows ?: 0
            if (c < MIN_COLS || r < MIN_ROWS) {
                waitForMinimumSize(MIN_COLS, MIN_ROWS)
                clearAndHome()
                prevFrameLines = []
                return null
            }
            val contentCols = boardW * 2 + 2 + 3 + PANEL_WIDTH
            val contentRows = boardH + 1
            val requiredCols = max(MIN_COLS, contentCols)
            val requiredRows = max(MIN_ROWS, contentRows)
            if (c < requiredCols || r < requiredRows) {
                waitForMinimumSize(requiredCols, requiredRows)
                clearAndHome()
                prevFrameLines = []
                return null
            }
            val originCol = max(1, ((c - contentCols) / 2) + 1)
            val originRow = max(1, ((r - contentRows) / 2) + 1)
            LoopFrame(false, originRow, originCol)
        }
        fun advanceGravity(s: GameState, frame: Int): Int {
            s.level = 1 + (s.totalLines / LEVEL_LINES_STEP)
            val dropEvery = max(DROP_FRAMES_MIN, DROP_FRAMES_BASE - s.level)
            var nextFrame = frame + 1
            if (nextFrame < dropEvery) return nextFrame
            nextFrame = 0
            if (canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px, s.py + 1) == true) {
                s.py++
                return nextFrame
            }
            lockPiece(board, s.pieceId, s.rot, s.px, s.py)
            val cleared = clearCompletedLines(board, boardW, boardH)
            if (cleared > 0) {
                s.totalLines += cleared
                s.score += scoreForLines(cleared, s.level)
            }
            s.pieceId = s.nextId
            s.nextId = s.next2Id
            s.next2Id = nextPieceId()
            s.rot = 0
            s.px = (boardW / 2) - 2
            s.py = -1
            if (!canPlace(board, boardW, boardH, s.pieceId, s.rot, s.px, s.py)) {
                s.gameOver = true
            }
            nextFrame
        }
        try {
            if (!canPlace(board, boardW, boardH, state.pieceId, state.rot, state.px, state.py)) {
                state.gameOver = true
            }
            var frame = 0
            var shouldStop = false
            var prevOriginRow = -1
            var prevOriginCol = -1
            var prevPaused = false
            while (!shouldStop) {
                val frameData = pollLoopFrame()
                if (frameData == null) {
                    frame = 0
                    prevPaused = false
                    continue
                }
                val mm: Mutex = gameMutex
                mm.withLock {
                    if (pendingInputs.size > 0) {
                        val toApply: List<String> = []
                        while (pendingInputs.size > 0) {
                            val k = pendingInputs[0]
                            pendingInputs.removeAt(0)
                            toApply.add(k)
                        }
                        for (k in toApply) {
                            applyKeyInput(state, k)
                            if (!state.running || state.gameOver) break
                        }
                    }
                }
                if (!state.running || state.gameOver) {
                    shouldStop = true
                } else {
                    val localForceRedraw = forceRedraw
                    forceRedraw = false
                    val movedOrigin = frameData.originRow != prevOriginRow || frameData.originCol != prevOriginCol
                    if (frameData.resized || movedOrigin || localForceRedraw) {
                        clearAndHome()
                        prevFrameLines = []
                    }
                    prevOriginRow = frameData.originRow
                    prevOriginCol = frameData.originCol
                    if (!state.paused) {
                        frame = advanceGravity(state, frame)
                    }
                    prevFrameLines = render(
                        state,
                        board,
                        boardW,
                        boardH,
                        prevFrameLines,
                        frameData.originRow,
                        frameData.originCol,
                        useColor
                    )
                    if (state.paused && (!prevPaused || frameData.resized || movedOrigin)) {
                        renderPauseOverlay(frameData.originRow, frameData.originCol, boardW, boardH)
                    }
                    prevPaused = state.paused
                }
                Console.flush()
                delay(FRAME_DELAY_MS)
            }
        } finally {
            inputRunning = false
            Console.setRawMode(false)
            Console.setCursorVisible(true)
            Console.leaveAltScreen()
            Console.flush()
        }
        if (state.gameOver) {
            println("Game over.")
        } else {
            println("Bye.")
        }
        println("Score: %s"(state.score))
        println("Lines: %s"(state.totalLines))
        println("Level: %s"(state.level))
    }
 }
@@ -1,5 +1,5 @@
 #
-# Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+# Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 #
 #Gradle
-org.gradle.jvmargs=-Xmx2048M -Dfile.encoding=UTF-8 -Dkotlin.daemon.jvm.options\="-Xmx2048M"
+org.gradle.jvmargs=-Xmx4096M -Dfile.encoding=UTF-8 -Dkotlin.daemon.jvm.options\="-Xmx2048M"
 org.gradle.caching=true
 org.gradle.configuration-cache=true
 #Kotlin
@@ -38,3 +38,5 @@ kotlin.native.cacheKind.linuxX64=none
 android.experimental.lint.migrateToK2=false
 android.lint.useK2Uast=false
 kotlin.mpp.applyDefaultHierarchyTemplate=true
 org.gradle.parallel=true
@@ -1,11 +1,14 @@
 [versions]
 agp = "8.5.2"
 clikt = "5.0.3"
-kotlin = "2.2.21"
+mordant = "3.0.2"
 kotlin = "2.3.0"
 android-minSdk = "24"
 android-compileSdk = "34"
 kotlinx-coroutines = "1.10.2"
-mp_bintools = "0.1.12"
+kotlinx-datetime = "0.6.1"
 mp_bintools = "0.3.2"
 ionspin-bignum = "0.3.10"
 firebaseCrashlyticsBuildtools = "3.0.3"
 okioVersion = "3.10.2"
 compiler = "3.2.0-alpha11"
@@ -13,10 +16,14 @@ compiler = "3.2.0-alpha11"
 [libraries]
 clikt = { module = "com.github.ajalt.clikt:clikt", version.ref = "clikt" }
 clikt-markdown = { module = "com.github.ajalt.clikt:clikt-markdown", version.ref = "clikt" }
 mordant-core = { module = "com.github.ajalt.mordant:mordant-core", version.ref = "mordant" }
 mordant-jvm-jna = { module = "com.github.ajalt.mordant:mordant-jvm-jna", version.ref = "mordant" }
 kotlin-test = { module = "org.jetbrains.kotlin:kotlin-test", version.ref = "kotlin" }
 kotlinx-coroutines-test = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version.ref = "kotlinx-coroutines" }
 kotlinx-coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlinx-coroutines" }
 kotlinx-datetime = { module = "org.jetbrains.kotlinx:kotlinx-datetime", version.ref = "kotlinx-datetime" }
 mp_bintools = { module = "net.sergeych:mp_bintools", version.ref = "mp_bintools" }
 ionspin-bignum = { module = "com.ionspin.kotlin:bignum", version.ref = "ionspin-bignum" }
 firebase-crashlytics-buildtools = { group = "com.google.firebase", name = "firebase-crashlytics-buildtools", version.ref = "firebaseCrashlyticsBuildtools" }
 okio = { module = "com.squareup.okio:okio", version.ref = "okioVersion" }
 okio-fakefilesystem = { module = "com.squareup.okio:okio-fakefilesystem", version.ref = "okioVersion" }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -17,11 +17,11 @@
 plugins {
    kotlin("jvm")
-    id("org.jetbrains.intellij") version "1.17.3"
+    id("org.jetbrains.intellij") version "1.17.4"
 }
 group = "net.sergeych.lyng"
-version = "0.0.3-SNAPSHOT"
+version = "0.0.5-SNAPSHOT"
 kotlin {
    jvmToolchain(17)
@@ -45,12 +45,14 @@ dependencies {
    // Tests for IntelliJ Platform fixtures rely on JUnit 3/4 API (junit.framework.TestCase)
    // Add JUnit 4 which contains the JUnit 3 compatibility classes used by BasePlatformTestCase/UsefulTestCase
    testImplementation("junit:junit:4.13.2")
    testRuntimeOnly("org.junit.vintage:junit-vintage-engine:5.10.2")
    testImplementation("org.opentest4j:opentest4j:1.3.0")
 }
 intellij {
    type.set("IC")
    // Build against a modern baseline. Install range is controlled by since/until below.
-    version.set("2024.3.1")
+    version.set("2024.1.6")
    // We manage <idea-version> ourselves in plugin.xml to keep it open-ended (no upper cap)
    updateSinceUntilBuild.set(false)
    // Include only available bundled plugins for this IDE build
@@ -0,0 +1,33 @@
 /*
 * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 package net.sergeych.lyng.idea
 import com.intellij.openapi.fileTypes.FileTypeConsumer
 import com.intellij.openapi.fileTypes.FileTypeFactory
 import com.intellij.openapi.fileTypes.WildcardFileNameMatcher
 /**
 * Legacy way to register file type matchers, used here to robustly match *.lyng.d
 * without conflicting with standard .d extensions from other plugins.
 */
@Suppress("DEPRECATION")
 class LyngFileTypeFactory : FileTypeFactory() {
    override fun createFileTypes(consumer: FileTypeConsumer) {
        // Register the multi-dot pattern explicitly
        consumer.consume(LyngFileType, WildcardFileNameMatcher("*.lyng.d"))
    }
 }
@@ -0,0 +1,109 @@
 /*
 * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 package net.sergeych.lyng.idea.actions
 import com.intellij.execution.filters.TextConsoleBuilderFactory
 import com.intellij.execution.ui.ConsoleView
 import com.intellij.execution.ui.ConsoleViewContentType
 import com.intellij.openapi.actionSystem.AnAction
 import com.intellij.openapi.actionSystem.AnActionEvent
 import com.intellij.openapi.actionSystem.CommonDataKeys
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.wm.ToolWindow
 import com.intellij.openapi.wm.ToolWindowAnchor
 import com.intellij.openapi.wm.ToolWindowId
 import com.intellij.openapi.wm.ToolWindowManager
 import com.intellij.psi.PsiFile
 import com.intellij.psi.PsiManager
 import com.intellij.ui.content.ContentFactory
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.launch
 import net.sergeych.lyng.idea.LyngIcons
 class RunLyngScriptAction : AnAction(LyngIcons.FILE) {
    private val scope = CoroutineScope(Dispatchers.Default + SupervisorJob())
    private fun getPsiFile(e: AnActionEvent): PsiFile? {
        val project = e.project ?: return null
        return e.getData(CommonDataKeys.PSI_FILE) ?: run {
            val vf = e.getData(CommonDataKeys.VIRTUAL_FILE)
            if (vf != null) PsiManager.getInstance(project).findFile(vf) else null
        }
    }
    override fun update(e: AnActionEvent) {
        val psiFile = getPsiFile(e)
        val isLyng = psiFile?.name?.endsWith(".lyng") == true
        e.presentation.isEnabledAndVisible = isLyng
        if (isLyng) {
            e.presentation.isEnabled = false
            e.presentation.text = "Run '${psiFile.name}' (disabled)"
            e.presentation.description = "Running scripts from the IDE is disabled; use the CLI."
        } else {
            e.presentation.text = "Run Lyng Script"
        }
    }
    override fun actionPerformed(e: AnActionEvent) {
        val project = e.project ?: return
        val psiFile = getPsiFile(e) ?: return
        val fileName = psiFile.name
        val (console, toolWindow) = getConsoleAndToolWindow(project)
        console.clear()
        toolWindow.show {
            scope.launch {
                console.print("--- Run is disabled ---\n", ConsoleViewContentType.SYSTEM_OUTPUT)
                console.print("Lyng now runs in bytecode-only mode; the IDE no longer evaluates scripts.\n", ConsoleViewContentType.NORMAL_OUTPUT)
                console.print("Use the CLI to run scripts, e.g. `lyng run $fileName`.\n", ConsoleViewContentType.NORMAL_OUTPUT)
            }
        }
    }
    private fun getConsoleAndToolWindow(project: Project): Pair<ConsoleView, ToolWindow> {
        val toolWindowManager = ToolWindowManager.getInstance(project)
        var toolWindow = toolWindowManager.getToolWindow(ToolWindowId.RUN)
        if (toolWindow == null) {
            toolWindow = toolWindowManager.getToolWindow(ToolWindowId.MESSAGES_WINDOW)
        }
        if (toolWindow == null) {
            toolWindow = toolWindowManager.getToolWindow("Lyng")
        }
        val actualToolWindow = toolWindow ?: run {
            @Suppress("DEPRECATION")
            toolWindowManager.registerToolWindow("Lyng", true, ToolWindowAnchor.BOTTOM)
        }
        val contentManager = actualToolWindow.contentManager
        val existingContent = contentManager.findContent("Lyng Run")
        if (existingContent != null) {
            val console = existingContent.component as ConsoleView
            contentManager.setSelectedContent(existingContent)
            return console to actualToolWindow
        }
        val console = TextConsoleBuilderFactory.getInstance().createBuilder(project).console
        val content = ContentFactory.getInstance().createContent(console.component, "Lyng Run", false)
        contentManager.addContent(content)
        contentManager.setSelectedContent(content)
        return console to actualToolWindow
    }
 }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -25,314 +25,137 @@ import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.util.Key
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiFile
 import kotlinx.coroutines.runBlocking
 import net.sergeych.lyng.Compiler
 import net.sergeych.lyng.ScriptError
 import net.sergeych.lyng.Source
 import net.sergeych.lyng.binding.Binder
 import net.sergeych.lyng.binding.SymbolKind
 import net.sergeych.lyng.highlight.HighlightKind
 import net.sergeych.lyng.highlight.SimpleLyngHighlighter
 import net.sergeych.lyng.highlight.offsetOf
 import net.sergeych.lyng.idea.highlight.LyngHighlighterColors
-import net.sergeych.lyng.idea.util.IdeLenientImportProvider
+import net.sergeych.lyng.idea.util.LyngAstManager
-import net.sergeych.lyng.miniast.*
+import net.sergeych.lyng.tools.LyngDiagnosticSeverity
 import net.sergeych.lyng.tools.LyngLanguageTools
 import net.sergeych.lyng.tools.LyngSemanticKind
 /**
 * ExternalAnnotator that runs Lyng MiniAst on the document text in background
 * and applies semantic highlighting comparable with the web highlighter.
 */
 class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, LyngExternalAnnotator.Result>() {
-    data class Input(val text: String, val modStamp: Long, val previousSpans: List<Span>?)
+    data class Input(val text: String, val modStamp: Long, val previousSpans: List<Span>?, val file: PsiFile)
    data class Span(val start: Int, val end: Int, val key: com.intellij.openapi.editor.colors.TextAttributesKey)
-    data class Error(val start: Int, val end: Int, val message: String)
+    data class Diag(val start: Int, val end: Int, val message: String, val severity: HighlightSeverity)
-    data class Result(val modStamp: Long, val spans: List<Span>, val error: Error? = null,
+    data class Result(val modStamp: Long, val spans: List<Span>, val diagnostics: List<Diag> = emptyList())
                      val spellIdentifiers: List<IntRange> = emptyList(),
                      val spellComments: List<IntRange> = emptyList(),
                      val spellStrings: List<IntRange> = emptyList())
    override fun collectInformation(file: PsiFile): Input? {
        val doc: Document = file.viewProvider.document ?: return null
        val cached = file.getUserData(CACHE_KEY)
-        // Fast fix (1): reuse cached spans only if they were computed for the same modification stamp
+        val combinedStamp = LyngAstManager.getCombinedStamp(file)
-        val prev = if (cached != null && cached.modStamp == doc.modificationStamp) cached.spans else null
+
-        return Input(doc.text, doc.modificationStamp, prev)
+        val prev = if (cached != null && cached.modStamp == combinedStamp) cached.spans else null
        return Input(doc.text, combinedStamp, prev, file)
    }
    override fun doAnnotate(collectedInfo: Input?): Result? {
        if (collectedInfo == null) return null
        ProgressManager.checkCanceled()
        val text = collectedInfo.text
-        // Build Mini-AST using the same mechanism as web highlighter
+        val analysis = LyngAstManager.getAnalysis(collectedInfo.file)
-        val sink = MiniAstBuilder()
+            ?: return Result(collectedInfo.modStamp, collectedInfo.previousSpans ?: emptyList())
-        val source = Source("<ide>", text)
+        val mini = analysis.mini
-        try {
+
            // Call suspend API from blocking context
            val provider = IdeLenientImportProvider.create()
            runBlocking { Compiler.compileWithMini(source, provider, sink) }
        } catch (e: Throwable) {
            if (e is com.intellij.openapi.progress.ProcessCanceledException) throw e
            // On script parse error: keep previous spans and report the error location
            if (e is ScriptError) {
                val off = try { source.offsetOf(e.pos) } catch (_: Throwable) { -1 }
                val start0 = off.coerceIn(0, text.length.coerceAtLeast(0))
                val (start, end) = expandErrorRange(text, start0)
                // Fast fix (5): clear cached highlighting after the error start position
                val trimmed = collectedInfo.previousSpans?.filter { it.end <= start } ?: emptyList()
                return Result(
                    collectedInfo.modStamp,
                    trimmed,
                    Error(start, end, e.errorMessage)
                )
            }
            // Other failures: keep previous spans without error
            return Result(collectedInfo.modStamp, collectedInfo.previousSpans ?: emptyList(), null)
        }
        ProgressManager.checkCanceled()
        val mini = sink.build() ?: return Result(collectedInfo.modStamp, collectedInfo.previousSpans ?: emptyList())
        val out = ArrayList<Span>(256)
        val diags = ArrayList<Diag>()
        fun putRange(start: Int, end: Int, key: com.intellij.openapi.editor.colors.TextAttributesKey) {
            if (start in 0..end && end <= text.length && start < end) out += Span(start, end, key)
        }
-        fun putName(startPos: net.sergeych.lyng.Pos, name: String, key: com.intellij.openapi.editor.colors.TextAttributesKey) {
+
-            val s = source.offsetOf(startPos)
+        fun keyForKind(kind: LyngSemanticKind): com.intellij.openapi.editor.colors.TextAttributesKey? = when (kind) {
-            putRange(s, (s + name.length).coerceAtMost(text.length), key)
+            LyngSemanticKind.Function -> LyngHighlighterColors.FUNCTION
-        }
+            LyngSemanticKind.Class, LyngSemanticKind.Enum, LyngSemanticKind.TypeAlias -> LyngHighlighterColors.TYPE
-        fun putMiniRange(r: MiniRange, key: com.intellij.openapi.editor.colors.TextAttributesKey) {
+            LyngSemanticKind.Value -> LyngHighlighterColors.VALUE
-            val s = source.offsetOf(r.start)
+            LyngSemanticKind.Variable -> LyngHighlighterColors.VARIABLE
-            val e = source.offsetOf(r.end)
+            LyngSemanticKind.Parameter -> LyngHighlighterColors.PARAMETER
-            putRange(s, e, key)
+            LyngSemanticKind.TypeRef -> LyngHighlighterColors.TYPE
            LyngSemanticKind.EnumConstant -> LyngHighlighterColors.ENUM_CONSTANT
        }
-        // Declarations
+        // Semantic highlights from shared tooling
-        for (d in mini.declarations) {
+        LyngLanguageTools.semanticHighlights(analysis).forEach { span ->
-            when (d) {
+            keyForKind(span.kind)?.let { putRange(span.range.start, span.range.endExclusive, it) }
                is MiniFunDecl -> putName(d.nameStart, d.name, LyngHighlighterColors.FUNCTION_DECLARATION)
                is MiniClassDecl -> putName(d.nameStart, d.name, LyngHighlighterColors.TYPE)
                is MiniValDecl -> putName(
                    d.nameStart,
                    d.name,
                    if (d.mutable) LyngHighlighterColors.VARIABLE else LyngHighlighterColors.VALUE
                )
            }
        }
        // Imports: each segment as namespace/path
-        for (imp in mini.imports) {
+        mini?.imports?.forEach { imp ->
-            for (seg in imp.segments) putMiniRange(seg.range, LyngHighlighterColors.NAMESPACE)
+            imp.segments.forEach { seg ->
-        }
+                if (seg.range.start.source === analysis.source && seg.range.end.source === analysis.source) {
-
+                    val start = analysis.source.offsetOf(seg.range.start)
-        // Parameters
+                    val end = analysis.source.offsetOf(seg.range.end)
-        for (fn in mini.declarations.filterIsInstance<MiniFunDecl>()) {
+                    putRange(start, end, LyngHighlighterColors.NAMESPACE)
            for (p in fn.params) putName(p.nameStart, p.name, LyngHighlighterColors.PARAMETER)
        }
        // Type name segments (including generics base & args)
        fun addTypeSegments(t: MiniTypeRef?) {
            when (t) {
                is MiniTypeName -> t.segments.forEach { seg ->
                    val s = source.offsetOf(seg.range.start)
                    putRange(s, (s + seg.name.length).coerceAtMost(text.length), LyngHighlighterColors.TYPE)
                }
                is MiniGenericType -> {
                    addTypeSegments(t.base)
                    t.args.forEach { addTypeSegments(it) }
                }
                is MiniFunctionType -> {
                    t.receiver?.let { addTypeSegments(it) }
                    t.params.forEach { addTypeSegments(it) }
                    addTypeSegments(t.returnType)
                }
                is MiniTypeVar -> { /* name is in range; could be highlighted as TYPE as well */
                    putMiniRange(t.range, LyngHighlighterColors.TYPE)
                }
                null -> {}
            }
        }
        for (d in mini.declarations) {
            when (d) {
                is MiniFunDecl -> {
                    addTypeSegments(d.returnType)
                    d.params.forEach { addTypeSegments(it.type) }
                }
                is MiniValDecl -> addTypeSegments(d.type)
                is MiniClassDecl -> {
                    d.ctorFields.forEach { addTypeSegments(it.type) }
                    d.classFields.forEach { addTypeSegments(it.type) }
                }
            }
        }
-        ProgressManager.checkCanceled()
+        // Add annotation/label coloring using token highlighter
        // Semantic usages via Binder (best-effort)
        try {
            val binding = Binder.bind(text, mini)
            // Map declaration ranges to avoid duplicating them as usages
            val declKeys = HashSet<Pair<Int, Int>>(binding.symbols.size * 2)
            for (sym in binding.symbols) declKeys += (sym.declStart to sym.declEnd)
            fun keyForKind(k: SymbolKind) = when (k) {
                SymbolKind.Function -> LyngHighlighterColors.FUNCTION
                SymbolKind.Class, SymbolKind.Enum -> LyngHighlighterColors.TYPE
                SymbolKind.Param -> LyngHighlighterColors.PARAMETER
                SymbolKind.Val -> LyngHighlighterColors.VALUE
                SymbolKind.Var -> LyngHighlighterColors.VARIABLE
            }
            // Track covered ranges to not override later heuristics
            val covered = HashSet<Pair<Int, Int>>()
            for (ref in binding.references) {
                val key = ref.start to ref.end
                if (declKeys.contains(key)) continue
                val sym = binding.symbols.firstOrNull { it.id == ref.symbolId } ?: continue
                val color = keyForKind(sym.kind)
                putRange(ref.start, ref.end, color)
                covered += key
            }
            // Heuristics on top of binder: function call-sites and simple name-based roles
            ProgressManager.checkCanceled()
            val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
            fun isFollowedByParenOrBlock(rangeEnd: Int): Boolean {
                var i = rangeEnd
                while (i < text.length) {
                    val ch = text[i]
                    if (ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n') { i++; continue }
                    return ch == '(' || ch == '{'
                }
                return false
            }
            // Build simple name -> role map for top-level vals/vars and parameters
            val nameRole = HashMap<String, com.intellij.openapi.editor.colors.TextAttributesKey>(8)
            for (d in mini.declarations) when (d) {
                is MiniValDecl -> nameRole[d.name] = if (d.mutable) LyngHighlighterColors.VARIABLE else LyngHighlighterColors.VALUE
                is MiniFunDecl -> d.params.forEach { p -> nameRole[p.name] = LyngHighlighterColors.PARAMETER }
                else -> {}
            }
            for (s in tokens) if (s.kind == HighlightKind.Identifier) {
                val start = s.range.start
                val end = s.range.endExclusive
                val key = start to end
                if (key in covered || key in declKeys) continue
                // Call-site detection first so it wins over var/param role
                if (isFollowedByParenOrBlock(end)) {
                    putRange(start, end, LyngHighlighterColors.FUNCTION)
                    covered += key
                    continue
                }
                // Simple role by known names
                val ident = try { text.substring(start, end) } catch (_: Throwable) { null }
                if (ident != null) {
                    val roleKey = nameRole[ident]
                    if (roleKey != null) {
                        putRange(start, end, roleKey)
                        covered += key
                    }
                }
            }
        } catch (e: Throwable) {
            // Must rethrow cancellation; otherwise ignore binder failures (best-effort)
            if (e is com.intellij.openapi.progress.ProcessCanceledException) throw e
        }
        // Add annotation coloring using token highlighter (treat @Label as annotation)
        run {
-            val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
+            analysis.lexicalHighlights.forEach { s ->
-            for (s in tokens) if (s.kind == HighlightKind.Label) {
+                if (s.kind == HighlightKind.Label) {
                    val start = s.range.start
                    val end = s.range.endExclusive
                    if (start in 0..end && end <= text.length && start < end) {
-                    val lexeme = try { text.substring(start, end) } catch (_: Throwable) { null }
+                        val lexeme = try {
-                    if (lexeme != null && lexeme.startsWith("@")) {
+                            text.substring(start, end)
                        } catch (_: Throwable) {
                            null
                        }
                        if (lexeme != null) {
                            // Heuristic: if it starts with @ and follows a control keyword, it's likely a label
                            // Otherwise if it starts with @ it's an annotation.
                            // If it ends with @ it's a loop label.
                            when {
                                lexeme.endsWith("@") -> putRange(start, end, LyngHighlighterColors.LABEL)
                                lexeme.startsWith("@") -> {
                                    // Try to see if it's an exit label
                                    val prevNonWs = prevNonWs(text, start)
                                    val prevWord = if (prevNonWs >= 0) {
                                        var wEnd = prevNonWs + 1
                                        var wStart = prevNonWs
                                        while (wStart > 0 && text[wStart - 1].isLetter()) wStart--
                                        text.substring(wStart, wEnd)
                                    } else null
                                    if (prevWord in setOf("return", "break", "continue")) {
                                        putRange(start, end, LyngHighlighterColors.LABEL)
                                    } else {
                                        putRange(start, end, LyngHighlighterColors.ANNOTATION)
                                    }
                                }
                            }
                        }
-
+                    }
        // Map Enum constants from token highlighter to IDEA enum constant color
        run {
            val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
            for (s in tokens) if (s.kind == HighlightKind.EnumConstant) {
                val start = s.range.start
                val end = s.range.endExclusive
                if (start in 0..end && end <= text.length && start < end) {
                    putRange(start, end, LyngHighlighterColors.ENUM_CONSTANT)
                }
            }
        }
-        // Build spell index payload: identifiers from symbols + references; comments/strings from simple highlighter
+        analysis.diagnostics.forEach { d ->
-        val idRanges = mutableSetOf<IntRange>()
+            val range = d.range ?: return@forEach
-        try {
+            val severity = if (d.severity == LyngDiagnosticSeverity.Warning) HighlightSeverity.WARNING else HighlightSeverity.ERROR
-            val binding = Binder.bind(text, mini)
+            diags += Diag(range.start, range.endExclusive, d.message, severity)
            for (sym in binding.symbols) {
                val s = sym.declStart; val e = sym.declEnd
                if (s in 0..e && e <= text.length && s < e) idRanges += (s until e)
        }
            for (ref in binding.references) {
                val s = ref.start; val e = ref.end
                if (s in 0..e && e <= text.length && s < e) idRanges += (s until e)
            }
        } catch (_: Throwable) {
            // Best-effort; no identifiers if binder fails
        }
        val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
        val commentRanges = tokens.filter { it.kind == HighlightKind.Comment }.map { it.range.start until it.range.endExclusive }
        val stringRanges = tokens.filter { it.kind == HighlightKind.String }.map { it.range.start until it.range.endExclusive }
-        return Result(collectedInfo.modStamp, out, null,
+        return Result(collectedInfo.modStamp, out, diags)
            spellIdentifiers = idRanges.toList(),
            spellComments = commentRanges,
            spellStrings = stringRanges)
    }
    override fun apply(file: PsiFile, annotationResult: Result?, holder: AnnotationHolder) {
        if (annotationResult == null) return
        // Skip if cache is up-to-date
-        val doc = file.viewProvider.document
+        val combinedStamp = LyngAstManager.getCombinedStamp(file)
        val currentStamp = doc?.modificationStamp
        val cached = file.getUserData(CACHE_KEY)
-        val result = if (cached != null && currentStamp != null && cached.modStamp == currentStamp) cached else annotationResult
+        val result = if (cached != null && cached.modStamp == combinedStamp) cached else annotationResult
        file.putUserData(CACHE_KEY, result)
-        // Store spell index for spell/grammar engines to consume (suspend until ready)
+        val doc = file.viewProvider.document
        val ids = result.spellIdentifiers.map { TextRange(it.first, it.last + 1) }
        val coms = result.spellComments.map { TextRange(it.first, it.last + 1) }
        val strs = result.spellStrings.map { TextRange(it.first, it.last + 1) }
        net.sergeych.lyng.idea.spell.LyngSpellIndex.store(file,
            net.sergeych.lyng.idea.spell.LyngSpellIndex.Data(
                modStamp = result.modStamp,
                identifiers = ids,
                comments = coms,
                strings = strs
            )
        )
        // Optional diagnostic overlay: visualize the ranges we will feed to spellcheckers
        val settings = net.sergeych.lyng.idea.settings.LyngFormatterSettings.getInstance(file.project)
        if (settings.debugShowSpellFeed) {
            fun paint(r: TextRange, label: String) {
                holder.newAnnotation(HighlightSeverity.WEAK_WARNING, "spell-feed: $label")
                    .range(r)
                    .create()
            }
            ids.forEach { paint(it, "id") }
            coms.forEach { paint(it, "comment") }
            if (settings.spellCheckStringLiterals) strs.forEach { paint(it, "string") }
        }
        for (s in result.spans) {
            holder.newSilentAnnotation(HighlightSeverity.INFORMATION)
@@ -341,13 +164,12 @@ class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, Lyn
                .create()
        }
-        // Show syntax error if present
+        // Show errors and warnings
-        val err = result.error
+        result.diagnostics.forEach { d ->
-        if (err != null) {
+            val start = d.start.coerceIn(0, (doc?.textLength ?: 0))
-            val start = err.start.coerceIn(0, (doc?.textLength ?: 0))
+            val end = d.end.coerceIn(start, (doc?.textLength ?: start))
            val end = err.end.coerceIn(start, (doc?.textLength ?: start))
            if (end > start) {
-                holder.newAnnotation(HighlightSeverity.ERROR, err.message)
+                holder.newAnnotation(d.severity, d.message)
                    .range(TextRange(start, end))
                    .create()
            }
@@ -358,30 +180,15 @@ class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, Lyn
        private val CACHE_KEY: Key<Result> = Key.create("LYNG_SEMANTIC_CACHE")
    }
-    /**
+    private fun prevNonWs(text: String, idxExclusive: Int): Int {
-     * Make the error highlight a bit wider than a single character so it is easier to see and click.
+        var i = idxExclusive - 1
-     * Strategy:
+        while (i >= 0) {
-     *  - If the offset points inside an identifier-like token (letters/digits/underscore), expand to the full token.
+            val ch = text[i]
-     *  - Otherwise select a small range starting at the offset with a minimum width, but not crossing the line end.
+            if (ch != ' ' && ch != '\t' && ch != '\n' && ch != '\r') return i
-     */
+            i--
-    private fun expandErrorRange(text: String, rawStart: Int): Pair<Int, Int> {
+        }
-        if (text.isEmpty()) return 0 to 0
+        return -1
        val len = text.length
        val start = rawStart.coerceIn(0, len)
        fun isWord(ch: Char) = ch == '_' || ch.isLetterOrDigit()
        if (start < len && isWord(text[start])) {
            var s = start
            var e = start
            while (s > 0 && isWord(text[s - 1])) s--
            while (e < len && isWord(text[e])) e++
            return s to e
    }
-        // Not inside a word: select a short, visible range up to EOL
+    
        val lineEnd = text.indexOf('\n', start).let { if (it == -1) len else it }
        val minWidth = 4
        val end = (start + minWidth).coerceAtMost(lineEnd).coerceAtLeast((start + 1).coerceAtMost(lineEnd))
        return start to end
    }
 }
@@ -1,3 +1,20 @@
 /*
 * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 /*
 * Lightweight BASIC completion for Lyng, MVP version.
 * Uses MiniAst (best-effort) + BuiltinDocRegistry to suggest symbols.
@@ -9,18 +26,15 @@ import com.intellij.codeInsight.lookup.LookupElementBuilder
 import com.intellij.icons.AllIcons
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.editor.Document
 import com.intellij.openapi.util.Key
 import com.intellij.patterns.PlatformPatterns
 import com.intellij.psi.PsiFile
 import com.intellij.util.ProcessingContext
 import kotlinx.coroutines.runBlocking
 import net.sergeych.lyng.Compiler
 import net.sergeych.lyng.Source
 import net.sergeych.lyng.highlight.offsetOf
 import net.sergeych.lyng.idea.LyngLanguage
 import net.sergeych.lyng.idea.highlight.LyngTokenTypes
 import net.sergeych.lyng.idea.settings.LyngFormatterSettings
 import net.sergeych.lyng.idea.util.DocsBootstrap
-import net.sergeych.lyng.idea.util.IdeLenientImportProvider
+import net.sergeych.lyng.idea.util.LyngAstManager
 import net.sergeych.lyng.idea.util.TextCtx
 import net.sergeych.lyng.miniast.*
@@ -48,6 +62,12 @@ class LyngCompletionContributor : CompletionContributor() {
            StdlibDocsBootstrap.ensure()
            val file: PsiFile = parameters.originalFile
            if (file.language != LyngLanguage) return
            // Disable completion inside comments
            val pos = parameters.position
            val et = pos.node.elementType
            if (et == LyngTokenTypes.LINE_COMMENT || et == LyngTokenTypes.BLOCK_COMMENT) return
            // Feature toggle: allow turning completion off from settings
            val settings = LyngFormatterSettings.getInstance(file.project)
            if (!settings.enableLyngCompletionExperimental) return
@@ -76,12 +96,14 @@ class LyngCompletionContributor : CompletionContributor() {
                log.info("[LYNG_DEBUG] Completion: caret=$caret prefix='${prefix}' memberDotPos=${memberDotPos} file='${file.name}'")
            }
-            // Build MiniAst (cached) for both global and member contexts to enable local class/val inference
+            // Build analysis (cached) for both global and member contexts to enable local class/val inference
-            val mini = buildMiniAstCached(file, text)
+            val analysis = LyngAstManager.getAnalysis(file)
            val mini = analysis?.mini
            val binding = analysis?.binding
            // Delegate computation to the shared engine to keep behavior in sync with tests
            val engineItems = try {
-                runBlocking { CompletionEngineLight.completeSuspend(text, caret) }
+                runBlocking { CompletionEngineLight.completeSuspend(text, caret, mini, binding) }
            } catch (t: Throwable) {
                if (DEBUG_COMPLETION) log.warn("[LYNG_DEBUG] Engine completion failed: ${t.message}")
                emptyList()
@@ -95,26 +117,27 @@ class LyngCompletionContributor : CompletionContributor() {
            if (memberDotPos != null && engineItems.isEmpty()) {
                if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Fallback: engine returned 0 in member context; trying local inference")
                // Build imported modules from text (lenient) + stdlib; avoid heavy MiniAst here
-                val fromText = extractImportsFromText(text)
+                val fromText = DocLookupUtils.extractImportsFromText(text)
                val imported = LinkedHashSet<String>().apply {
                    fromText.forEach { add(it) }
                    add("lyng.stdlib")
                }.toList()
                val staticOnly = DocLookupUtils.isStaticReceiver(mini, text, memberDotPos, imported, binding)
                // Try inferring return/receiver class around the dot
                val inferred =
                    // Prefer MiniAst-based inference (return type from member call or receiver type)
-                    guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported)
+                    DocLookupUtils.guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported, binding)
-                        ?: guessReceiverClassViaMini(mini, text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClassViaMini(mini, text, memberDotPos, imported, binding)
                        ?: 
-                    guessReturnClassFromMemberCallBefore(text, memberDotPos, imported)
+                    DocLookupUtils.guessReturnClassFromMemberCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassAcrossKnownCallees(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassAcrossKnownCallees(text, memberDotPos, imported, mini)
-                        ?: guessReceiverClass(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClass(text, memberDotPos, imported, mini)
                if (inferred != null) {
                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Fallback inferred receiver/return class='$inferred' — offering its members")
-                    offerMembers(emit, imported, inferred, sourceText = text, mini = mini)
+                    offerMembers(emit, imported, inferred, staticOnly = staticOnly, sourceText = text, mini = mini)
                    return
                } else {
                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Fallback could not infer class; keeping list empty (no globals after dot)")
@@ -122,11 +145,6 @@ class LyngCompletionContributor : CompletionContributor() {
                }
            }
            // In global context, add params in scope first (engine does not include them)
            if (memberDotPos == null && mini != null) {
                offerParamsInScope(emit, mini, text, caret)
            }
            // Render engine items
            for (ci in engineItems) {
                val builder = when (ci.kind) {
@@ -142,57 +160,84 @@ class LyngCompletionContributor : CompletionContributor() {
                        .withInsertHandler(ParenInsertHandler)
                    Kind.Class_ -> LookupElementBuilder.create(ci.name)
                        .withIcon(AllIcons.Nodes.Class)
                    Kind.Enum -> LookupElementBuilder.create(ci.name)
                        .withIcon(AllIcons.Nodes.Enum)
                    Kind.TypeAlias -> LookupElementBuilder.create(ci.name)
                        .withIcon(AllIcons.Nodes.Class)
                    Kind.Value -> LookupElementBuilder.create(ci.name)
-                        .withIcon(AllIcons.Nodes.Field)
+                        .withIcon(AllIcons.Nodes.Variable)
                        .let { b -> if (!ci.typeText.isNullOrBlank()) b.withTypeText(ci.typeText, true) else b }
                    Kind.Field -> LookupElementBuilder.create(ci.name)
                        .withIcon(AllIcons.Nodes.Field)
                        .let { b -> if (!ci.typeText.isNullOrBlank()) b.withTypeText(ci.typeText, true) else b }
                }
                if (ci.priority != 0.0) {
                    emit(PrioritizedLookupElement.withPriority(builder, ci.priority))
                } else {
                    emit(builder)
                }
            }
            // In member context, ensure stdlib extension-like methods (e.g., String.re) are present
            if (memberDotPos != null) {
                val existing = engineItems.map { it.name }.toMutableSet()
-                val fromText = extractImportsFromText(text)
+                val fromText = DocLookupUtils.extractImportsFromText(text)
                val imported = LinkedHashSet<String>().apply {
                    fromText.forEach { add(it) }
                    add("lyng.stdlib")
                }.toList()
                val inferredClass =
-                    guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported)
+                    DocLookupUtils.guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported, binding)
-                        ?: guessReceiverClassViaMini(mini, text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClassViaMini(mini, text, memberDotPos, imported, binding)
-                        ?: guessReturnClassFromMemberCallBefore(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassFromMemberCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassAcrossKnownCallees(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassAcrossKnownCallees(text, memberDotPos, imported, mini)
-                        ?: guessReceiverClass(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClass(text, memberDotPos, imported, mini)
                if (!inferredClass.isNullOrBlank()) {
-                    val ext = BuiltinDocRegistry.extensionMethodNamesFor(inferredClass)
+                    val ext = DocLookupUtils.collectExtensionMemberNames(imported, inferredClass, mini)
-                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Post-engine extension check for $inferredClass: ${'$'}{ext}")
+                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Post-engine extension check for $inferredClass: ${ext}")
                    for (name in ext) {
                        if (existing.contains(name)) continue
-                        val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, inferredClass, name)
+                        val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, inferredClass, name, mini)
                        if (resolved != null) {
-                            when (val member = resolved.second) {
+                            val m = resolved.second
                            val builder = when (m) {
                                is MiniMemberFunDecl -> {
-                                    val params = member.params.joinToString(", ") { it.name }
+                                    val params = m.params.joinToString(", ") { it.name }
-                                    val ret = typeOf(member.returnType)
+                                    val ret = typeOf(m.returnType)
-                                    val builder = LookupElementBuilder.create(name)
+                                    LookupElementBuilder.create(name)
                                        .withIcon(AllIcons.Nodes.Method)
-                                        .withTailText("(${ '$' }params)", true)
+                                        .withTailText("($params)", true)
                                        .withTypeText(ret, true)
                                        .withInsertHandler(ParenInsertHandler)
                                }
                                is MiniFunDecl -> {
                                    val params = m.params.joinToString(", ") { it.name }
                                    val ret = typeOf(m.returnType)
                                    LookupElementBuilder.create(name)
                                        .withIcon(AllIcons.Nodes.Method)
                                        .withTailText("($params)", true)
                                        .withTypeText(ret, true)
                                        .withInsertHandler(ParenInsertHandler)
                                    emit(builder)
                                    existing.add(name)
                                }
                                is MiniMemberValDecl -> {
-                                    val builder = LookupElementBuilder.create(name)
+                                    LookupElementBuilder.create(name)
-                                        .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
+                                        .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
-                                        .withTypeText(typeOf(member.type), true)
+                                        .withTypeText(typeOf(m.type), true)
                                }
                                is MiniValDecl -> {
                                    LookupElementBuilder.create(name)
                                        .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
                                        .withTypeText(typeOf(m.type), true)
                                }
                                else -> {
                                    LookupElementBuilder.create(name)
                                        .withIcon(AllIcons.Nodes.Method)
                                        .withTailText("()", true)
                                        .withInsertHandler(ParenInsertHandler)
                                }
                            }
                            emit(builder)
                            existing.add(name)
                                }
                            }
                        } else {
                            // Fallback: emit simple method name without detailed types
                            val builder = LookupElementBuilder.create(name)
@@ -208,18 +253,18 @@ class LyngCompletionContributor : CompletionContributor() {
            // If in member context and engine items are suspiciously sparse, try to enrich via local inference + offerMembers
            if (memberDotPos != null && engineItems.size < 3) {
                if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Engine produced only ${engineItems.size} items in member context — trying enrichment")
-                val fromText = extractImportsFromText(text)
+                val fromText = DocLookupUtils.extractImportsFromText(text)
                val imported = LinkedHashSet<String>().apply {
                    fromText.forEach { add(it) }
                    add("lyng.stdlib")
                }.toList()
                val inferred =
-                    guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported)
+                    DocLookupUtils.guessReturnClassFromMemberCallBeforeMini(mini, text, memberDotPos, imported, binding)
-                        ?: guessReceiverClassViaMini(mini, text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClassViaMini(mini, text, memberDotPos, imported, binding)
-                        ?: guessReturnClassFromMemberCallBefore(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassFromMemberCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassFromTopLevelCallBefore(text, memberDotPos, imported, mini)
-                        ?: guessReturnClassAcrossKnownCallees(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReturnClassAcrossKnownCallees(text, memberDotPos, imported, mini)
-                        ?: guessReceiverClass(text, memberDotPos, imported)
+                        ?: DocLookupUtils.guessReceiverClass(text, memberDotPos, imported, mini)
                if (inferred != null) {
                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Enrichment inferred class='$inferred' — offering its members")
                    offerMembers(emit, imported, inferred, sourceText = text, mini = mini)
@@ -249,7 +294,11 @@ class LyngCompletionContributor : CompletionContributor() {
                        .withIcon(kindIcon)
                        .withTypeText(typeOf(d.type), true)
                }
-                else -> LookupElementBuilder.create(name)
+                is MiniEnumDecl -> LookupElementBuilder.create(name)
                    .withIcon(AllIcons.Nodes.Enum)
                is MiniTypeAliasDecl -> LookupElementBuilder.create(name)
                    .withIcon(AllIcons.Nodes.Class)
                    .withTypeText(typeOf(d.target), true)
            }
            emit(builder)
        }
@@ -276,9 +325,7 @@ class LyngCompletionContributor : CompletionContributor() {
        , sourceText: String,
        mini: MiniScript? = null
        ) {
-            // Ensure modules are seeded in the registry (triggers lazy stdlib build too)
+            val classes = DocLookupUtils.aggregateClasses(imported, mini)
            for (m in imported) BuiltinDocRegistry.docsForModule(m)
            val classes = DocLookupUtils.aggregateClasses(imported)
            if (DEBUG_COMPLETION) {
                val keys = classes.keys.joinToString(", ")
                log.info("[LYNG_DEBUG] offerMembers: imported=${imported} classes=[${keys}] target=${className}")
@@ -297,7 +344,7 @@ class LyngCompletionContributor : CompletionContributor() {
                }
                // If MiniAst didn't populate members (empty), try to scan class body text for member signatures
                if (localClass.members.isEmpty()) {
-                    val scanned = scanLocalClassMembersFromText(mini, text = sourceText, cls = localClass)
+                    val scanned = DocLookupUtils.scanLocalClassMembersFromText(mini, text = sourceText, cls = localClass)
                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Local scan for class ${localClass.name}: found ${scanned.size} members -> ${scanned.keys}")
                    for ((name, sig) in scanned) {
                        when (sig.kind) {
@@ -329,6 +376,8 @@ class LyngCompletionContributor : CompletionContributor() {
                        when (m) {
                            is MiniMemberFunDecl -> if (!m.isStatic) continue
                            is MiniMemberValDecl -> if (!m.isStatic) continue
                            is MiniMemberTypeAliasDecl -> if (!m.isStatic) continue
                            is MiniInitDecl -> continue
                        }
                    }
                    val list = target.getOrPut(m.name) { mutableListOf() }
@@ -364,17 +413,22 @@ class LyngCompletionContributor : CompletionContributor() {
            }
            supplementPreferredBases(className)
-            fun emitGroup(map: LinkedHashMap<String, MutableList<MiniMemberDecl>>) {
+            fun emitGroup(map: LinkedHashMap<String, MutableList<MiniMemberDecl>>, groupPriority: Double) {
                val keys = map.keys.sortedBy { it.lowercase() }
                for (name in keys) {
                    val list = map[name] ?: continue
                    // Choose a representative for display:
-                    // 1) Prefer a method with a known return type
+                    // 1) Prefer a method with return type AND parameters
-                    // 2) Else any method
+                    // 2) Prefer a method with parameters
-                    // 3) Else the first variant
+                    // 3) Prefer a method with return type
                    // 4) Else any method
                    // 5) Else the first variant
                    val rep =
-                        list.asSequence()
+                        list.asSequence().filterIsInstance<MiniMemberFunDecl>()
-                            .filterIsInstance<MiniMemberFunDecl>()
+                            .firstOrNull { it.returnType != null && it.params.isNotEmpty() }
                            ?: list.asSequence().filterIsInstance<MiniMemberFunDecl>()
                                .firstOrNull { it.params.isNotEmpty() }
                            ?: list.asSequence().filterIsInstance<MiniMemberFunDecl>()
                                .firstOrNull { it.returnType != null }
                            ?: list.firstOrNull { it is MiniMemberFunDecl }
                            ?: list.first()
@@ -391,8 +445,12 @@ class LyngCompletionContributor : CompletionContributor() {
                                .withTailText(tail, true)
                                .withTypeText(ret, true)
                                .withInsertHandler(ParenInsertHandler)
                            if (groupPriority != 0.0) {
                                emit(PrioritizedLookupElement.withPriority(builder, groupPriority))
                            } else {
                                emit(builder)
                            }
                        }
                        is MiniMemberValDecl -> {
                            val icon = if (rep.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field
                            // Prefer a field variant with known type if available
@@ -401,16 +459,31 @@ class LyngCompletionContributor : CompletionContributor() {
                                .firstOrNull { it.type != null } ?: rep
                            val builder = LookupElementBuilder.create(name)
                                .withIcon(icon)
-                                .withTypeText(typeOf((chosen as MiniMemberValDecl).type), true)
+                                .withTypeText(typeOf(chosen.type), true)
                            if (groupPriority != 0.0) {
                                emit(PrioritizedLookupElement.withPriority(builder, groupPriority))
                            } else {
                                emit(builder)
                            }
                        }
                        is MiniMemberTypeAliasDecl -> {
                            val builder = LookupElementBuilder.create(name)
                                .withIcon(AllIcons.Nodes.Class)
                                .withTypeText(typeOf(rep.target), true)
                            if (groupPriority != 0.0) {
                                emit(PrioritizedLookupElement.withPriority(builder, groupPriority))
                            } else {
                                emit(builder)
                            }
                        }
                        is MiniInitDecl -> {}
                    }
                }
            }
            // Emit what we have first
-            emitGroup(directMap)
+            emitGroup(directMap, 100.0)
-            emitGroup(inheritedMap)
+            emitGroup(inheritedMap, 0.0)
            // If suggestions are suspiciously sparse for known container classes,
            // try to conservatively supplement using a curated list resolved via docs registry.
@@ -432,29 +505,47 @@ class LyngCompletionContributor : CompletionContributor() {
                for (name in common) {
                    if (name in already) continue
                    // Try resolve across classes first to get types/params; if it fails, emit a synthetic safe suggestion.
-                    val resolved = DocLookupUtils.findMemberAcrossClasses(imported, name)
+                    val resolved = DocLookupUtils.findMemberAcrossClasses(imported, name, mini)
                    if (resolved != null) {
                        val member = resolved.second
-                        when (member) {
+                        val builder = when (member) {
                            is MiniMemberFunDecl -> {
                                val params = member.params.joinToString(", ") { it.name }
                                val ret = typeOf(member.returnType)
-                                val builder = LookupElementBuilder.create(name)
+                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
-                                    .withTailText("(${params})", true)
+                                    .withTailText("($params)", true)
                                    .withTypeText(ret, true)
                                    .withInsertHandler(ParenInsertHandler)
                            }
                            is MiniFunDecl -> {
                                val params = member.params.joinToString(", ") { it.name }
                                val ret = typeOf(member.returnType)
                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
                                    .withTailText("($params)", true)
                                    .withTypeText(ret, true)
                                    .withInsertHandler(ParenInsertHandler)
                                emit(builder)
                                already.add(name)
                            }
                            is MiniMemberValDecl -> {
-                                val builder = LookupElementBuilder.create(name)
+                                LookupElementBuilder.create(name)
-                                    .withIcon(AllIcons.Nodes.Field)
+                                    .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
                                    .withTypeText(typeOf(member.type), true)
-                                emit(builder)
+                            }
                            is MiniValDecl -> {
                                LookupElementBuilder.create(name)
                                    .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
                                    .withTypeText(typeOf(member.type), true)
                            }
                            else -> {
                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
                                    .withTailText("()", true)
                                    .withInsertHandler(ParenInsertHandler)
                            }
                        }
                        emit(PrioritizedLookupElement.withPriority(builder, 50.0))
                        already.add(name)
                            }
                        }
                    } else {
                        // Synthetic fallback: method without detailed params/types to improve UX in absence of docs
                        val isProperty = name in setOf("size", "length")
@@ -467,468 +558,78 @@ class LyngCompletionContributor : CompletionContributor() {
                                .withTailText("()", true)
                                .withInsertHandler(ParenInsertHandler)
                        }
-                        emit(builder)
+                        emit(PrioritizedLookupElement.withPriority(builder, 50.0))
                        already.add(name)
                    }
                }
            }
-            // Supplement with stdlib extension-like methods defined in root.lyng (e.g., fun String.trim(...))
+            // Supplement with stdlib extension members defined in root.lyng (e.g., fun String.trim(...))
            run {
                val already = (directMap.keys + inheritedMap.keys).toMutableSet()
-                val ext = BuiltinDocRegistry.extensionMethodNamesFor(className)
+                val ext = BuiltinDocRegistry.extensionMemberNamesFor(className)
                if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Extensions for $className: count=${ext.size} -> ${ext}")
                for (name in ext) {
                    if (already.contains(name)) continue
                    // Try to resolve full signature via registry first to get params and return type
-                    val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, className, name)
+                    val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, className, name, mini)
                    if (resolved != null) {
-                        when (val member = resolved.second) {
+                        val m = resolved.second
                        val builder = when (m) {
                            is MiniMemberFunDecl -> {
-                                val params = member.params.joinToString(", ") { it.name }
+                                val params = m.params.joinToString(", ") { it.name }
-                                val ret = typeOf(member.returnType)
+                                val ret = typeOf(m.returnType)
-                                val builder = LookupElementBuilder.create(name)
+                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
-                                    .withTailText("(${params})", true)
+                                    .withTailText("($params)", true)
                                    .withTypeText(ret, true)
                                    .withInsertHandler(ParenInsertHandler)
                            }
                            is MiniFunDecl -> {
                                val params = m.params.joinToString(", ") { it.name }
                                val ret = typeOf(m.returnType)
                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
                                    .withTailText("($params)", true)
                                    .withTypeText(ret, true)
                                    .withInsertHandler(ParenInsertHandler)
                                emit(builder)
                                already.add(name)
                                continue
                            }
                            is MiniMemberValDecl -> {
-                                val builder = LookupElementBuilder.create(name)
+                                LookupElementBuilder.create(name)
-                                    .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
+                                    .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
-                                    .withTypeText(typeOf(member.type), true)
+                                    .withTypeText(typeOf(m.type), true)
-                                emit(builder)
+                            }
                            is MiniValDecl -> {
                                LookupElementBuilder.create(name)
                                    .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
                                    .withTypeText(typeOf(m.type), true)
                            }
                            else -> {
                                LookupElementBuilder.create(name)
                                    .withIcon(AllIcons.Nodes.Method)
                                    .withTailText("()", true)
                                    .withInsertHandler(ParenInsertHandler)
                            }
                        }
                        emit(PrioritizedLookupElement.withPriority(builder, 50.0))
                        already.add(name)
                        continue
                    }
                        }
                    }
                    // Fallback: emit without detailed types if we couldn't resolve
                    val builder = LookupElementBuilder.create(name)
                        .withIcon(AllIcons.Nodes.Method)
                        .withTailText("()", true)
                        .withInsertHandler(ParenInsertHandler)
-                    emit(builder)
+                    emit(PrioritizedLookupElement.withPriority(builder, 50.0))
                    already.add(name)
                }
            }
        }
        // --- MiniAst-based inference helpers ---
        private fun previousIdentifierBeforeDot(text: String, dotPos: Int): String? {
            var i = dotPos - 1
            // skip whitespace
            while (i >= 0 && text[i].isWhitespace()) i--
            val end = i + 1
            while (i >= 0 && TextCtx.isIdentChar(text[i])) i--
            val start = i + 1
            return if (start < end) text.substring(start, end) else null
        }
        private fun guessReceiverClassViaMini(mini: MiniScript?, text: String, dotPos: Int, imported: List<String>): String? {
            if (mini == null) return null
            val ident = previousIdentifierBeforeDot(text, dotPos) ?: return null
            // 1) Local val/var in the file
            val valDecl = mini.declarations.filterIsInstance<MiniValDecl>().firstOrNull { it.name == ident }
            val typeFromVal = valDecl?.type?.let { simpleClassNameOf(it) }
            if (!typeFromVal.isNullOrBlank()) return typeFromVal
            // If initializer exists, try to sniff ClassName(
            val initR = valDecl?.initRange
            if (initR != null) {
                val src = mini.range.start.source
                val s = src.offsetOf(initR.start)
                val e = src.offsetOf(initR.end).coerceAtMost(text.length)
                if (s in 0..e && e <= text.length) {
                    val init = text.substring(s, e)
                    Regex("([A-Za-z_][A-Za-z0-9_]*)\\s*\\(").find(init)?.let { m ->
                        val cls = m.groupValues[1]
                        return cls
                    }
                }
            }
            // 2) Parameters in any function (best-effort without scope mapping)
            val paramType = mini.declarations.filterIsInstance<MiniFunDecl>()
                .asSequence()
                .flatMap { it.params.asSequence() }
                .firstOrNull { it.name == ident }?.type
            val typeFromParam = simpleClassNameOf(paramType)
            if (!typeFromParam.isNullOrBlank()) return typeFromParam
            return null
        }
        private fun guessReturnClassFromMemberCallBeforeMini(mini: MiniScript?, text: String, dotPos: Int, imported: List<String>): String? {
            if (mini == null) return null
            var i = TextCtx.prevNonWs(text, dotPos - 1)
            if (i < 0 || text[i] != ')') return null
            // back to matching '('
            i--
            var depth = 0
            while (i >= 0) {
                when (text[i]) {
                    ')' -> depth++
                    '(' -> if (depth == 0) break else depth--
                }
                i--
            }
            if (i < 0 || text[i] != '(') return null
            var j = i - 1
            while (j >= 0 && text[j].isWhitespace()) j--
            val end = j + 1
            while (j >= 0 && TextCtx.isIdentChar(text[j])) j--
            val start = j + 1
            if (start >= end) return null
            val callee = text.substring(start, end)
            // Ensure member call: dot before callee
            var k = start - 1
            while (k >= 0 && text[k].isWhitespace()) k--
            if (k < 0 || text[k] != '.') return null
            val prevDot = k
            // Resolve receiver class via MiniAst (ident like `x`)
            val receiverClass = guessReceiverClassViaMini(mini, text, prevDot, imported) ?: return null
            // If receiver class is a locally declared class, resolve member on it
            val localClass = mini.declarations.filterIsInstance<MiniClassDecl>().firstOrNull { it.name == receiverClass }
            if (localClass != null) {
                val mm = localClass.members.firstOrNull { it.name == callee }
                if (mm != null) {
                    val rt = when (mm) {
                        is MiniMemberFunDecl -> mm.returnType
                        is MiniMemberValDecl -> mm.type
                        else -> null
                    }
                    return simpleClassNameOf(rt)
                } else {
                    // Try to scan class body text for method signature and extract return type
                    val sigs = scanLocalClassMembersFromText(mini, text, localClass)
                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Local scan for return type in ${receiverClass}.${callee}: candidates=${sigs.keys}")
                    val sig = sigs[callee]
                    if (sig != null && sig.typeText != null) return sig.typeText
                }
            }
            // Else fallback to registry-based resolution (covers imported classes)
            return DocLookupUtils.resolveMemberWithInheritance(imported, receiverClass, callee)?.second?.let { m ->
                val rt = when (m) {
                    is MiniMemberFunDecl -> m.returnType
                    is MiniMemberValDecl -> m.type
                }
                simpleClassNameOf(rt)
            }
        }
        private data class ScannedSig(val kind: String, val params: List<String>?, val typeText: String?)
        private fun scanLocalClassMembersFromText(mini: MiniScript, text: String, cls: MiniClassDecl): Map<String, ScannedSig> {
            val src = mini.range.start.source
            val start = src.offsetOf(cls.bodyRange?.start ?: cls.range.start)
            val end = src.offsetOf(cls.bodyRange?.end ?: cls.range.end).coerceAtMost(text.length)
            if (start !in 0..end) return emptyMap()
            val body = text.substring(start, end)
            val map = LinkedHashMap<String, ScannedSig>()
            // fun name(params): Type
            val funRe = Regex("(?m)^\\s*fun\\s+([A-Za-z_][A-Za-z0-9_]*)\\s*\\(([^)]*)\\)\\s*(?::\\s*([A-Za-z_][A-Za-z0-9_]*))?")
            for (m in funRe.findAll(body)) {
                val name = m.groupValues.getOrNull(1) ?: continue
                val params = m.groupValues.getOrNull(2)?.split(',')?.mapNotNull { it.trim().takeIf { it.isNotEmpty() } } ?: emptyList()
                val type = m.groupValues.getOrNull(3)?.takeIf { it.isNotBlank() }
                map[name] = ScannedSig("fun", params, type)
            }
            // val/var name: Type
            val valRe = Regex("(?m)^\\s*(val|var)\\s+([A-Za-z_][A-Za-z0-9_]*)\\s*(?::\\s*([A-Za-z_][A-Za-z0-9_]*))?")
            for (m in valRe.findAll(body)) {
                val kind = m.groupValues.getOrNull(1) ?: continue
                val name = m.groupValues.getOrNull(2) ?: continue
                val type = m.groupValues.getOrNull(3)?.takeIf { it.isNotBlank() }
                map.putIfAbsent(name, ScannedSig(kind, null, type))
            }
            return map
        }
        private fun guessReceiverClass(text: String, dotPos: Int, imported: List<String>): String? {
            // 1) Try call-based: ClassName(...).
            DocLookupUtils.guessClassFromCallBefore(text, dotPos, imported)?.let { return it }
            // 2) Literal heuristics based on the immediate char before '.'
            var i = TextCtx.prevNonWs(text, dotPos - 1)
            if (i >= 0) {
                when (text[i]) {
                    '"' -> {
                        // Either regular or triple-quoted string; both map to String
                        return "String"
                    }
                    ']' -> return "List" // very rough heuristic
                    '}' -> return "Dict" // map/dictionary literal heuristic
                    ')' -> {
                        // Parenthesized expression: walk back to matching '(' and inspect inner expression
                        var j = i - 1
                        var depth = 0
                        while (j >= 0) {
                            when (text[j]) {
                                ')' -> depth++
                                '(' -> if (depth == 0) break else depth--
                            }
                            j--
                        }
                        if (j >= 0 && text[j] == '(') {
                            val innerS = (j + 1).coerceAtLeast(0)
                            val innerE = i.coerceAtMost(text.length)
                            if (innerS < innerE) {
                                val inner = text.substring(innerS, innerE).trim()
                                if (inner.startsWith('"') && inner.endsWith('"')) return "String"
                                if (inner.startsWith('[') && inner.endsWith(']')) return "List"
                                if (inner.startsWith('{') && inner.endsWith('}')) return "Dict"
                            }
                        }
                    }
                }
                // Numeric literal: support decimal, hex (0x..), and scientific notation (1e-3)
                var j = i
                var hasDigits = false
                var hasDot = false
                var hasExp = false
                // Walk over digits, letters for hex, dots, and exponent markers
                while (j >= 0) {
                    val ch = text[j]
                    if (ch.isDigit()) { hasDigits = true; j-- ; continue }
                    if (ch == '.') { hasDot = true; j-- ; continue }
                    if (ch == 'e' || ch == 'E') { hasExp = true; j-- ; // optional sign directly before digits
                        if (j >= 0 && (text[j] == '+' || text[j] == '-')) j--
                        continue
                    }
                    if (ch in listOf('x','X')) { // part of 0x prefix
                        j--
                        continue
                    }
                    if (ch == 'a' || ch == 'b' || ch == 'c' || ch == 'd' || ch == 'f' ||
                        ch == 'A' || ch == 'B' || ch == 'C' || ch == 'D' || ch == 'F') {
                        // hex digit in 0x...
                        j--
                        continue
                    }
                    break
                }
                // Now check for 0x/0X prefix
                val k = j
                val isHex = k >= 1 && text[k] == '0' && (text[k+1] == 'x' || text[k+1] == 'X')
                if (hasDigits) {
                    return if (isHex) "Int" else if (hasDot || hasExp) "Real" else "Int"
                }
            }
            return null
        }
        /**
         * Try to infer the class of the return value of the member call immediately before the dot.
         * Example: `Path(".." ).lines().<caret>` → detects `lines()` on receiver class `Path` and returns `Iterator`.
         */
        private fun guessReturnClassFromMemberCallBefore(text: String, dotPos: Int, imported: List<String>): String? {
            var i = TextCtx.prevNonWs(text, dotPos - 1)
            if (i < 0) return null
            // We expect a call just before the dot, i.e., ')' ... '.'
            if (text[i] != ')') return null
            // Walk back to matching '('
            i--
            var depth = 0
            while (i >= 0) {
                val ch = text[i]
                when (ch) {
                    ')' -> depth++
                    '(' -> if (depth == 0) break else depth--
                }
                i--
            }
            if (i < 0 || text[i] != '(') return null
            // Identify callee identifier just before '('
            var j = i - 1
            while (j >= 0 && text[j].isWhitespace()) j--
            val end = j + 1
            while (j >= 0 && TextCtx.isIdentChar(text[j])) j--
            val start = j + 1
            if (start >= end) return null
            val callee = text.substring(start, end)
            // Ensure it's a member call (there must be a dot immediately before the callee, ignoring spaces)
            var k = start - 1
            while (k >= 0 && text[k].isWhitespace()) k--
            if (k < 0 || text[k] != '.') return null
            val prevDot = k
            // Infer receiver class at the previous dot
            val receiverClass = guessReceiverClass(text, prevDot, imported) ?: return null
            // Resolve the callee as a member of receiver class, including inheritance
            val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, receiverClass, callee) ?: return null
            val member = resolved.second
            val returnType = when (member) {
                is MiniMemberFunDecl -> member.returnType
                is MiniMemberValDecl -> member.type
            }
            return simpleClassNameOf(returnType)
        }
        /**
         * Infer return class of a top-level call right before the dot: e.g., `files().<caret>`.
         * We extract callee name and resolve it among imported modules' top-level functions.
         */
        private fun guessReturnClassFromTopLevelCallBefore(text: String, dotPos: Int, imported: List<String>): String? {
            var i = TextCtx.prevNonWs(text, dotPos - 1)
            if (i < 0 || text[i] != ')') return null
            // Walk back to matching '('
            i--
            var depth = 0
            while (i >= 0) {
                val ch = text[i]
                when (ch) {
                    ')' -> depth++
                    '(' -> if (depth == 0) break else depth--
                }
                i--
            }
            if (i < 0 || text[i] != '(') return null
            // Extract callee ident before '('
            var j = i - 1
            while (j >= 0 && text[j].isWhitespace()) j--
            val end = j + 1
            while (j >= 0 && TextCtx.isIdentChar(text[j])) j--
            val start = j + 1
            if (start >= end) return null
            val callee = text.substring(start, end)
            // If it's a member call, bail out (handled in member-call inference)
            var k = start - 1
            while (k >= 0 && text[k].isWhitespace()) k--
            if (k >= 0 && text[k] == '.') return null
            // Resolve top-level function in imported modules
            for (mod in imported) {
                val decls = BuiltinDocRegistry.docsForModule(mod)
                val fn = decls.asSequence().filterIsInstance<MiniFunDecl>().firstOrNull { it.name == callee }
                if (fn != null) return simpleClassNameOf(fn.returnType)
            }
            return null
        }
        /**
         * Fallback: if we can at least extract a callee name before the dot and it exists across common classes,
         * derive its return type using cross-class lookup (Iterable/Iterator/List preference). This ignores the receiver.
         * Example: `something.lines().<caret>` where `something` type is unknown, but `lines()` commonly returns Iterator<String>.
         */
        private fun guessReturnClassAcrossKnownCallees(text: String, dotPos: Int, imported: List<String>): String? {
            var i = TextCtx.prevNonWs(text, dotPos - 1)
            if (i < 0 || text[i] != ')') return null
            // Walk back to matching '('
            i--
            var depth = 0
            while (i >= 0) {
                val ch = text[i]
                when (ch) {
                    ')' -> depth++
                    '(' -> if (depth == 0) break else depth--
                }
                i--
            }
            if (i < 0 || text[i] != '(') return null
            // Extract callee ident before '('
            var j = i - 1
            while (j >= 0 && text[j].isWhitespace()) j--
            val end = j + 1
            while (j >= 0 && TextCtx.isIdentChar(text[j])) j--
            val start = j + 1
            if (start >= end) return null
            val callee = text.substring(start, end)
            // Try cross-class resolution
            val resolved = DocLookupUtils.findMemberAcrossClasses(imported, callee) ?: return null
            val member = resolved.second
            val returnType = when (member) {
                is MiniMemberFunDecl -> member.returnType
                is MiniMemberValDecl -> member.type
            }
            return simpleClassNameOf(returnType)
        }
        /** Convert a MiniTypeRef to a simple class name as used by docs (e.g., Iterator from Iterator<String>). */
        private fun simpleClassNameOf(t: MiniTypeRef?): String? = when (t) {
            null -> null
            is MiniTypeName -> t.segments.lastOrNull()?.name
            is MiniGenericType -> simpleClassNameOf(t.base)
            is MiniFunctionType -> null
            is MiniTypeVar -> null
        }
        private fun buildMiniAst(text: String): MiniScript? {
            return try {
                val sink = MiniAstBuilder()
                val provider = IdeLenientImportProvider.create()
                val src = Source("<ide>", text)
                runBlocking { Compiler.compileWithMini(src, provider, sink) }
                sink.build()
            } catch (_: Throwable) {
                null
            }
        }
        // Cached per PsiFile by document modification stamp
        private val MINI_KEY = Key.create<MiniScript>("lyng.mini.cache")
        private val STAMP_KEY = Key.create<Long>("lyng.mini.cache.stamp")
        private fun buildMiniAstCached(file: PsiFile, text: String): MiniScript? {
            val doc = file.viewProvider.document ?: return null
            val stamp = doc.modificationStamp
            val prevStamp = file.getUserData(STAMP_KEY)
            val cached = file.getUserData(MINI_KEY)
            if (cached != null && prevStamp != null && prevStamp == stamp) return cached
            val built = buildMiniAst(text)
            // Cache even null? avoid caching failures; only cache non-null
            if (built != null) {
                file.putUserData(MINI_KEY, built)
                file.putUserData(STAMP_KEY, stamp)
            }
            return built
        }
        private fun offerParamsInScope(emit: (com.intellij.codeInsight.lookup.LookupElement) -> Unit, mini: MiniScript, text: String, caret: Int) {
            val src = mini.range.start.source
            // Find function whose body contains caret or whose whole range contains caret
            val fns = mini.declarations.filterIsInstance<MiniFunDecl>()
            for (fn in fns) {
                val start = src.offsetOf(fn.range.start)
                val end = src.offsetOf(fn.range.end).coerceAtMost(text.length)
                if (caret in start..end) {
                    for (p in fn.params) {
                        val builder = LookupElementBuilder.create(p.name)
                            .withIcon(AllIcons.Nodes.Variable)
                            .withTypeText(typeOf(p.type), true)
                        emit(builder)
                    }
                    return
                }
            }
        }
        // Lenient textual import extractor (duplicated from QuickDoc privately)
        private fun extractImportsFromText(text: String): List<String> {
            val result = LinkedHashSet<String>()
            val re = Regex("(?m)^\\s*import\\s+([a-zA-Z_][a-zA-Z0-9_]*(?:\\.[a-zA-Z_][a-zA-Z0-9_]*)*)")
            re.findAll(text).forEach { m ->
                val raw = m.groupValues.getOrNull(1)?.trim().orEmpty()
                if (raw.isNotEmpty()) {
                    val canon = if (raw.startsWith("lyng.")) raw else "lyng.$raw"
                    result.add(canon)
                }
            }
            return result.toList()
        }
        private fun typeOf(t: MiniTypeRef?): String {
-            return when (t) {
+            val s = DocLookupUtils.typeOf(t)
-                null -> ""
+            return if (s.isEmpty()) "" else ": $s"
                is MiniTypeName -> t.segments.lastOrNull()?.name?.let { ": $it" } ?: ""
                is MiniGenericType -> {
                    val base = typeOf(t.base).removePrefix(": ")
                    val args = t.args.joinToString(",") { typeOf(it).removePrefix(": ") }
                    ": ${base}<${args}>"
                }
                is MiniFunctionType -> ": (fn)"
                is MiniTypeVar -> ": ${t.name}"
            }
        }
    }
 }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -25,14 +25,13 @@ import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import kotlinx.coroutines.runBlocking
 import net.sergeych.lyng.Compiler
 import net.sergeych.lyng.Pos
 import net.sergeych.lyng.Source
 import net.sergeych.lyng.highlight.offsetOf
 import net.sergeych.lyng.idea.LyngLanguage
-import net.sergeych.lyng.idea.util.IdeLenientImportProvider
+import net.sergeych.lyng.idea.util.LyngAstManager
 import net.sergeych.lyng.idea.util.TextCtx
 import net.sergeych.lyng.miniast.*
 import net.sergeych.lyng.tools.LyngLanguageTools
 import net.sergeych.lyng.tools.LyngSymbolInfo
 /**
 * Quick Docs backed by MiniAst: when caret is on an identifier that corresponds
@@ -69,59 +68,244 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        val ident = text.substring(idRange.startOffset, idRange.endOffset)
        if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: ident='$ident' at ${idRange.startOffset}..${idRange.endOffset} in ${file.name}")
-        // Build MiniAst for this file (fast and resilient). Best-effort; on failure continue with registry lookup only.
+        // 1. Get merged mini-AST from Manager (handles local + .lyng.d merged declarations)
-        val sink = MiniAstBuilder()
+        val analysis = LyngAstManager.getAnalysis(file) ?: return null
-        // Use lenient import provider so unresolved imports (e.g., lyng.io.fs) don't break docs
+        val mini = analysis.mini ?: return null
-        val provider = IdeLenientImportProvider.create()
+        val miniSource = mini.range.start.source
-        val src = Source("<ide>", text)
+        val imported = analysis.importedModules.ifEmpty { DocLookupUtils.canonicalImportedModules(mini, text) }
-        var mini: MiniScript? = try {
+
-            runBlocking { Compiler.compileWithMini(src, provider, sink) }
+        // Single-source quick doc lookup
-            sink.build()
+        LyngLanguageTools.docAt(analysis, offset)?.let { info ->
-        } catch (t: Throwable) {
+            val enriched = if (info.doc == null) {
-            // Do not bail out completely: we still can resolve built-in and imported docs (e.g., println)
+                findDocInDeclarationFiles(file, info.target.containerName, info.target.name)
-            if (DEBUG_LOG) log.warn("[LYNG_DEBUG] QuickDoc: compileWithMini failed: ${t.message}")
+                    ?.let { info.copy(doc = it) } ?: info
-            null
+            } else {
                info
            }
            renderDocFromInfo(enriched)?.let { return it }
        }
        // Fallback: resolve references against merged MiniAst (including .lyng.d) when binder cannot
        run {
            val dotPos = DocLookupUtils.findDotLeft(text, idRange.startOffset)
            if (dotPos != null) {
                val receiverClass = DocLookupUtils.guessReceiverClassViaMini(mini, text, dotPos, imported, analysis.binding)
                    ?: DocLookupUtils.guessReceiverClass(text, dotPos, imported, mini)
                if (receiverClass != null) {
                    val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, receiverClass, ident, mini)
                    if (resolved != null) {
                        val owner = resolved.first
                        val member = resolved.second
                        val withDoc = if (member.doc == null) {
                            findDocInDeclarationFiles(file, owner, member.name)?.let { doc ->
                                when (member) {
                                    is MiniMemberFunDecl -> member.copy(doc = doc)
                                    is MiniMemberValDecl -> member.copy(doc = doc)
                                    is MiniMemberTypeAliasDecl -> member.copy(doc = doc)
                                    else -> member
                                }
                            } ?: member
                        } else {
                            member
                        }
                        return when (withDoc) {
                            is MiniMemberFunDecl -> renderMemberFunDoc(owner, withDoc)
                            is MiniMemberValDecl -> renderMemberValDoc(owner, withDoc)
                            is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, withDoc)
                            else -> null
                        }
                    }
                }
            } else {
                mini.declarations.firstOrNull { it.name == ident }?.let { decl ->
                    return renderDeclDoc(decl, text, mini, imported)
                }
            }
        val haveMini = mini != null
        if (mini == null) {
            // Ensure we have a dummy script object to avoid NPE in downstream helpers that expect a MiniScript
            mini = MiniScript(MiniRange(Pos(src, 1, 1), Pos(src, 1, 1)))
        }
        val source = src
        // Try resolve to: function param at position, function/class/val declaration at position
-        // 1) Check declarations whose name range contains offset
+        // 1) Use unified declaration detection
-        if (haveMini) for (d in mini.declarations) {
+        DocLookupUtils.findDeclarationAt(mini, offset, ident)?.let { (name, kind) ->
-            val s = source.offsetOf(d.nameStart)
+            if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: matched declaration '$name' kind=$kind")
-            val e = (s + d.name.length).coerceAtMost(text.length)
+            // Find the actual declaration object to render
-            if (offset in s until e) {
+            mini.declarations.forEach { d ->
-                if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: matched decl '${d.name}' kind=${d::class.simpleName}")
+                if (d.name == name) {
-                return renderDeclDoc(d)
+                    val s: Int = miniSource.offsetOf(d.nameStart)
                    if (s <= offset && s + d.name.length > offset) {
                        return renderDeclDoc(d, text, mini, imported)
                    }
                }
-        // 2) Check parameters of functions
+                // Handle members if it was a member
-        if (haveMini) for (fn in mini.declarations.filterIsInstance<MiniFunDecl>()) {
+                if (d is MiniClassDecl) {
-            for (p in fn.params) {
+                    d.members.forEach { m ->
-                val s = source.offsetOf(p.nameStart)
+                        if (m.name == name) {
-                val e = (s + p.name.length).coerceAtMost(text.length)
+                            val s: Int = miniSource.offsetOf(m.nameStart)
-                if (offset in s until e) {
+                            if (s <= offset && s + m.name.length > offset) {
-                    if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: matched param '${p.name}' in fun '${fn.name}'")
+                                return when (m) {
                                    is MiniMemberFunDecl -> renderMemberFunDoc(d.name, m)
                                    is MiniMemberValDecl -> renderMemberValDoc(d.name, m)
                                    is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(d.name, m)
                                    else -> null
                                }
                            }
                        }
                    }
                    d.ctorFields.forEach { cf ->
                        if (cf.name == name) {
                            val s: Int = miniSource.offsetOf(cf.nameStart)
                            if (s <= offset && s + cf.name.length > offset) {
                                // Render as a member val
                                val mv = MiniMemberValDecl(
                                    range = MiniRange(cf.nameStart, cf.nameStart), // dummy
                                    name = cf.name,
                                    mutable = cf.mutable,
                                    type = cf.type,
                                    initRange = null,
                                    doc = null,
                                    nameStart = cf.nameStart
                                )
                                return renderMemberValDoc(d.name, mv)
                            }
                        }
                    }
                    d.classFields.forEach { cf ->
                        if (cf.name == name) {
                            val s: Int = miniSource.offsetOf(cf.nameStart)
                            if (s <= offset && s + cf.name.length > offset) {
                                // Render as a member val
                                val mv = MiniMemberValDecl(
                                    range = MiniRange(cf.nameStart, cf.nameStart), // dummy
                                    name = cf.name,
                                    mutable = cf.mutable,
                                    type = cf.type,
                                    initRange = null,
                                    doc = null,
                                    nameStart = cf.nameStart
                                )
                                return renderMemberValDoc(d.name, mv)
                            }
                        }
                    }
                }
                if (d is MiniEnumDecl) {
                    if (d.entries.contains(name)) {
                        val s: Int = miniSource.offsetOf(d.range.start)
                        val e: Int = miniSource.offsetOf(d.range.end)
                        if (offset >= s && offset <= e) {
                            // For enum constant, we don't have detailed docs in MiniAst yet, but we can render a title
                            return renderTitle("enum constant ${d.name}.${name}")
                        }
                    }
                }
            }
            // Check parameters
            mini.declarations.filterIsInstance<MiniFunDecl>().forEach { fn ->
                fn.params.forEach { p ->
                    if (p.name == name) {
                        val s: Int = miniSource.offsetOf(p.nameStart)
                        if (s <= offset && s + p.name.length > offset) {
                            return renderParamDoc(fn, p)
                        }
                    }
                }
-        // 3) Member-context resolution first (dot immediately before identifier): handle literals and calls
+            }
        }
        // 3) usages in current file via Binder (resolves local variables, parameters, and classes)
        try {
            val binding = net.sergeych.lyng.binding.Binder.bind(text, mini)
            val ref = binding.references.firstOrNull { offset in it.start until it.end }
            if (ref != null) {
                val sym = binding.symbols.firstOrNull { it.id == ref.symbolId }
                if (sym != null) {
                    // Find local declaration that matches this symbol
                    var dsFound: MiniDecl? = null
                    mini.declarations.forEach { decl ->
                        if (decl.name == sym.name) {
                            val sOffset: Int = miniSource.offsetOf(decl.nameStart)
                            if (sOffset == sym.declStart) {
                                dsFound = decl
                            }
                        }
                    }
                    if (dsFound != null) return renderDeclDoc(dsFound, text, mini, imported)
                    // Check parameters
                    mini.declarations.filterIsInstance<MiniFunDecl>().forEach { fn ->
                        fn.params.forEach { p ->
                            if (p.name == sym.name) {
                                val sOffset: Int = miniSource.offsetOf(p.nameStart)
                                if (sOffset == sym.declStart) {
                                    return renderParamDoc(fn, p)
                                }
                            }
                        }
                    }
                    // Check class members (fields/functions)
                    mini.declarations.filterIsInstance<MiniClassDecl>().forEach { cls ->
                        cls.members.forEach { m ->
                            if (m.name == sym.name) {
                                val sOffset: Int = miniSource.offsetOf(m.nameStart)
                                if (sOffset == sym.declStart) {
                                    return when (m) {
                                        is MiniMemberFunDecl -> renderMemberFunDoc(cls.name, m)
                                        is MiniMemberValDecl -> renderMemberValDoc(cls.name, m)
                                        is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(cls.name, m)
                                        else -> null
                                    }
                                }
                            }
                        }
                        cls.ctorFields.forEach { cf ->
                            if (cf.name == sym.name) {
                                val sOffset: Int = miniSource.offsetOf(cf.nameStart)
                                if (sOffset == sym.declStart) {
                                    // Render as a member val
                                    val mv = MiniMemberValDecl(
                                        range = MiniRange(cf.nameStart, cf.nameStart), // dummy
                                        name = cf.name,
                                        mutable = cf.mutable,
                                        type = cf.type,
                                        initRange = null,
                                        doc = null,
                                        nameStart = cf.nameStart
                                    )
                                    return renderMemberValDoc(cls.name, mv)
                                }
                            }
                        }
                        cls.classFields.forEach { cf ->
                            if (cf.name == sym.name) {
                                val sOffset: Int = miniSource.offsetOf(cf.nameStart)
                                if (sOffset == sym.declStart) {
                                    // Render as a member val
                                    val mv = MiniMemberValDecl(
                                        range = MiniRange(cf.nameStart, cf.nameStart), // dummy
                                        name = cf.name,
                                        mutable = cf.mutable,
                                        type = cf.type,
                                        initRange = null,
                                        doc = null,
                                        nameStart = cf.nameStart
                                    )
                                    return renderMemberValDoc(cls.name, mv)
                                }
                            }
                        }
                    }
                }
            }
        } catch (e: Throwable) {
            if (DEBUG_LOG) log.warn("[LYNG_DEBUG] QuickDoc: local binder resolution failed: ${e.message}")
        }
        // 4) Member-context resolution first (dot immediately before identifier): handle literals and calls
        run {
            val dotPos = TextCtx.findDotLeft(text, idRange.startOffset)
                ?: TextCtx.findDotLeft(text, offset)
            if (dotPos != null) {
                // Build imported modules (MiniAst-derived if available, else lenient from text) and ensure stdlib is present
-                var importedModules = if (haveMini) DocLookupUtils.canonicalImportedModules(mini) else emptyList()
+                val importedModules = DocLookupUtils.canonicalImportedModules(mini, text)
                if (importedModules.isEmpty()) {
                    val fromText = extractImportsFromText(text)
                    importedModules = if (fromText.isEmpty()) listOf("lyng.stdlib") else fromText
                }
                if (!importedModules.contains("lyng.stdlib")) importedModules = importedModules + "lyng.stdlib"
                // Try literal and call-based receiver inference around the dot
                val i = TextCtx.prevNonWs(text, dotPos - 1)
@@ -154,15 +338,43 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                            } else null
                        } else null
                    }
-                    else -> DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules)
+                    else -> {
                        DocLookupUtils.guessReceiverClassViaMini(mini, text, dotPos, importedModules)
                            ?: DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules, mini)
                            ?: run {
                                // handle this@Type or as Type
                                val i2 = TextCtx.prevNonWs(text, dotPos - 1)
                                if (i2 >= 0) {
                                    val identRange = TextCtx.wordRangeAt(text, i2 + 1)
                                    if (identRange != null) {
                                        val id = text.substring(identRange.startOffset, identRange.endOffset)
                                        val k = TextCtx.prevNonWs(text, identRange.startOffset - 1)
                                        if (k >= 1 && text[k] == 's' && text[k - 1] == 'a' && (k - 1 == 0 || !text[k - 2].isLetterOrDigit())) {
                                            id
                                        } else if (k >= 0 && text[k] == '@') {
                                            val k2 = TextCtx.prevNonWs(text, k - 1)
                                            if (k2 >= 3 && text.substring(k2 - 3, k2 + 1) == "this") id else null
                                        } else null
                                    } else null
                                } else null
                            }
-                if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: memberCtx dotPos=${dotPos} chBeforeDot='${if (dotPos>0) text[dotPos-1] else ' '}' classGuess=${className} imports=${importedModules}")
+                    }
                }
                if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: memberCtx dotPos=${dotPos} chBeforeDot='${if (dotPos > 0) text[dotPos - 1] else ' '}' classGuess=${className} imports=${importedModules}")
                if (className != null) {
-                    DocLookupUtils.resolveMemberWithInheritance(importedModules, className, ident)?.let { (owner, member) ->
+                    val staticOnly = DocLookupUtils.isStaticReceiver(mini, text, dotPos, importedModules, analysis.binding)
                    DocLookupUtils.resolveMemberWithInheritance(importedModules, className, ident, mini, staticOnly = staticOnly)?.let { (owner, member) ->
                        if (DEBUG_INHERITANCE) log.info("[LYNG_DEBUG] QuickDoc: literal/call '$ident' resolved to $owner.${member.name}")
                        return when (member) {
                            is MiniMemberFunDecl -> renderMemberFunDoc(owner, member)
                            is MiniMemberValDecl -> renderMemberValDoc(owner, member)
                            is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, member)
                            is MiniInitDecl -> null
                            is MiniFunDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniValDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniClassDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniEnumDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniTypeAliasDecl -> renderDeclDoc(member, text, mini, importedModules)
                        }
                    }
                    log.info("[LYNG_DEBUG] QuickDoc: resolve failed for ${className}.${ident}")
@@ -171,21 +383,14 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        }
        // 4) As a fallback, if the caret is on an identifier text that matches any declaration name, show that
-        if (haveMini) mini.declarations.firstOrNull { it.name == ident }?.let {
+        mini.declarations.firstOrNull { it.name == ident }?.let {
            log.info("[LYNG_DEBUG] QuickDoc: fallback by name '${it.name}' kind=${it::class.simpleName}")
-            return renderDeclDoc(it)
+            return renderDeclDoc(it, text, mini, imported)
        }
        // 4) Consult BuiltinDocRegistry for imported modules (top-level and class members)
        // Canonicalize import names using ImportManager, as users may write shortened names (e.g., "io.fs")
-        var importedModules = if (haveMini) DocLookupUtils.canonicalImportedModules(mini) else emptyList()
+        var importedModules = DocLookupUtils.canonicalImportedModules(mini, text)
        // If MiniAst failed or captured no imports, try a lightweight textual import scan
        if (importedModules.isEmpty()) {
            val fromText = extractImportsFromText(text)
            if (fromText.isNotEmpty()) {
                importedModules = fromText
            }
        }
        // Always include stdlib as a fallback context
        if (!importedModules.contains("lyng.stdlib")) importedModules = importedModules + "lyng.stdlib"
        // 4a) try top-level decls
@@ -200,12 +405,14 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                if (arity != null && chosen.params.size != arity && matches.size > 1) {
                    return renderOverloads(ident, matches)
                }
-                return renderDeclDoc(chosen)
+                return renderDeclDoc(chosen, text, mini, imported)
            }
            // Also allow values/consts
-            docs.filterIsInstance<MiniValDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it) }
+            docs.filterIsInstance<MiniValDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it, text, mini, imported) }
-            // And classes
+            // And classes/enums
-            docs.filterIsInstance<MiniClassDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it) }
+            docs.filterIsInstance<MiniClassDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it, text, mini, imported) }
            docs.filterIsInstance<MiniEnumDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it, text, mini, imported) }
            docs.filterIsInstance<MiniTypeAliasDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it, text, mini, imported) }
        }
        // Defensive fallback: if nothing found and it's a well-known stdlib function, render minimal inline docs
        if (ident == "println" || ident == "print") {
@@ -213,17 +420,26 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                "Print values to the standard output and append a newline. Accepts any number of arguments." else
                "Print values to the standard output without a trailing newline. Accepts any number of arguments."
            val title = "function $ident(values)"
-            return "<div class='doc-title'>${htmlEscape(title)}</div>" + styledMarkdown(htmlEscape(fallback))
+            return renderTitle(title) + styledMarkdown(htmlEscape(fallback))
        }
        // 4b) try class members like ClassName.member with inheritance fallback
        val lhs = previousWordBefore(text, idRange.startOffset)
        if (lhs != null && hasDotBetween(text, lhs.endOffset, idRange.startOffset)) {
            val className = text.substring(lhs.startOffset, lhs.endOffset)
-            DocLookupUtils.resolveMemberWithInheritance(importedModules, className, ident)?.let { (owner, member) ->
+            val dotPos = findDotLeft(text, idRange.startOffset)
            val staticOnly = dotPos?.let { DocLookupUtils.isStaticReceiver(mini, text, it, importedModules, analysis.binding) } ?: false
            DocLookupUtils.resolveMemberWithInheritance(importedModules, className, ident, mini, staticOnly = staticOnly)?.let { (owner, member) ->
                if (DEBUG_INHERITANCE) log.info("[LYNG_DEBUG] Inheritance resolved $className.$ident to $owner.${member.name}")
                return when (member) {
                    is MiniMemberFunDecl -> renderMemberFunDoc(owner, member)
                    is MiniMemberValDecl -> renderMemberValDoc(owner, member)
                    is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, member)
                    is MiniInitDecl -> null
                    is MiniFunDecl -> renderDeclDoc(member, text, mini, importedModules)
                    is MiniValDecl -> renderDeclDoc(member, text, mini, importedModules)
                    is MiniClassDecl -> renderDeclDoc(member, text, mini, importedModules)
                    is MiniEnumDecl -> renderDeclDoc(member, text, mini, importedModules)
                    is MiniTypeAliasDecl -> renderDeclDoc(member, text, mini, importedModules)
                }
            }
        } else {
@@ -234,14 +450,22 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
            if (dotPos != null) {
                val guessed = when {
                    looksLikeListLiteralBefore(text, dotPos) -> "List"
-                    else -> DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules)
+                    else -> DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules, mini)
                }
                if (guessed != null) {
-                    DocLookupUtils.resolveMemberWithInheritance(importedModules, guessed, ident)?.let { (owner, member) ->
+                    val staticOnly = DocLookupUtils.isStaticReceiver(mini, text, dotPos, importedModules, analysis.binding)
                    DocLookupUtils.resolveMemberWithInheritance(importedModules, guessed, ident, mini, staticOnly = staticOnly)?.let { (owner, member) ->
                        if (DEBUG_INHERITANCE) log.info("[LYNG_DEBUG] Heuristic '$guessed.$ident' resolved via inheritance to $owner.${member.name}")
                        return when (member) {
                            is MiniMemberFunDecl -> renderMemberFunDoc(owner, member)
                            is MiniMemberValDecl -> renderMemberValDoc(owner, member)
                            is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, member)
                            is MiniInitDecl -> null
                            is MiniFunDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniValDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniClassDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniEnumDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniTypeAliasDecl -> renderDeclDoc(member, text, mini, importedModules)
                        }
                    }
                } else {
@@ -249,18 +473,26 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                    run {
                        val candidates = listOf("String", "Iterable", "Iterator", "List", "Collection", "Array", "Dict", "Regex")
                        for (c in candidates) {
-                            DocLookupUtils.resolveMemberWithInheritance(importedModules, c, ident)?.let { (owner, member) ->
+                            val staticOnly = DocLookupUtils.isStaticReceiver(mini, text, dotPos, importedModules, analysis.binding)
                            DocLookupUtils.resolveMemberWithInheritance(importedModules, c, ident, mini, staticOnly = staticOnly)?.let { (owner, member) ->
                                if (DEBUG_INHERITANCE) log.info("[LYNG_DEBUG] Candidate '$c.$ident' resolved via inheritance to $owner.${member.name}")
                                return when (member) {
                                    is MiniMemberFunDecl -> renderMemberFunDoc(owner, member)
                                    is MiniMemberValDecl -> renderMemberValDoc(owner, member)
                                    is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, member)
                                    is MiniInitDecl -> null
                                    is MiniFunDecl -> renderDeclDoc(member, text, mini, importedModules)
                                    is MiniValDecl -> renderDeclDoc(member, text, mini, importedModules)
                                    is MiniClassDecl -> renderDeclDoc(member, text, mini, importedModules)
                                    is MiniEnumDecl -> renderDeclDoc(member, text, mini, importedModules)
                                    is MiniTypeAliasDecl -> renderDeclDoc(member, text, mini, importedModules)
                                }
                            }
                        }
                    }
                    // As a last resort try aggregated String members (extensions from stdlib text)
                    run {
-                        val classes = DocLookupUtils.aggregateClasses(importedModules)
+                        val classes = DocLookupUtils.aggregateClasses(importedModules, mini)
                        val stringCls = classes["String"]
                        val m = stringCls?.members?.firstOrNull { it.name == ident }
                        if (m != null) {
@@ -268,15 +500,24 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                            return when (m) {
                                is MiniMemberFunDecl -> renderMemberFunDoc("String", m)
                                is MiniMemberValDecl -> renderMemberValDoc("String", m)
                                is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc("String", m)
                                is MiniInitDecl -> null
                            }
                        }
                    }
                    // Search across classes; prefer Iterable, then Iterator, then List for common ops
-                    DocLookupUtils.findMemberAcrossClasses(importedModules, ident)?.let { (owner, member) ->
+                    DocLookupUtils.findMemberAcrossClasses(importedModules, ident, mini)?.let { (owner, member) ->
                        if (DEBUG_INHERITANCE) log.info("[LYNG_DEBUG] Cross-class '$ident' resolved to $owner.${member.name}")
                        return when (member) {
                            is MiniMemberFunDecl -> renderMemberFunDoc(owner, member)
                            is MiniMemberValDecl -> renderMemberValDoc(owner, member)
                            is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(owner, member)
                            is MiniInitDecl -> null
                            is MiniFunDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniValDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniClassDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniEnumDecl -> renderDeclDoc(member, text, mini, importedModules)
                            is MiniTypeAliasDecl -> renderDeclDoc(member, text, mini, importedModules)
                        }
                    }
                }
@@ -287,49 +528,44 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        return null
    }
    /**
     * Very lenient import extractor for cases when MiniAst is unavailable.
     * Looks for lines like `import xxx.yyy` and returns canonical module names
     * (prefixing with `lyng.` if missing).
     */
    private fun extractImportsFromText(text: String): List<String> {
        val result = LinkedHashSet<String>()
        val re = Regex("(?m)^\\s*import\\s+([a-zA-Z_][a-zA-Z0-9_]*(?:\\.[a-zA-Z_][a-zA-Z0-9_]*)*)")
        re.findAll(text).forEach { m ->
            val raw = m.groupValues.getOrNull(1)?.trim().orEmpty()
            if (raw.isNotEmpty()) {
                val canon = if (raw.startsWith("lyng.")) raw else "lyng.$raw"
                result.add(canon)
            }
        }
        return result.toList()
    }
    // External docs registrars discovery via reflection to avoid hard dependencies on optional modules
    private val externalDocsLoaded: Boolean by lazy { tryLoadExternalDocs() }
    private fun ensureExternalDocsRegistered() { @Suppress("UNUSED_EXPRESSION") externalDocsLoaded }
    private fun tryLoadExternalDocs(): Boolean {
-        return try {
+        var anyLoaded = false
        try {
            // Try known registrars; ignore failures if module is absent
            val cls = Class.forName("net.sergeych.lyngio.docs.FsBuiltinDocs")
            val m = cls.getMethod("ensure")
            m.invoke(null)
            log.info("[LYNG_DEBUG] QuickDoc: external docs loaded: net.sergeych.lyngio.docs.FsBuiltinDocs.ensure() OK")
-            true
+            anyLoaded = true
-        } catch (_: Throwable) {
+        } catch (_: Throwable) {}
        try {
            val cls = Class.forName("net.sergeych.lyngio.docs.ProcessBuiltinDocs")
            val m = cls.getMethod("ensure")
            m.invoke(null)
            log.info("[LYNG_DEBUG] QuickDoc: external docs loaded: net.sergeych.lyngio.docs.ProcessBuiltinDocs.ensure() OK")
            anyLoaded = true
        } catch (_: Throwable) {}
        if (!anyLoaded) {
            // Seed a minimal plugin-local fallback so Path docs still work without lyngio
            val seeded = try {
                FsDocsFallback.ensureOnce()
                ProcessDocsFallback.ensureOnce()
                true
            } catch (_: Throwable) { false }
            if (seeded) {
-                log.info("[LYNG_DEBUG] QuickDoc: external docs NOT found; seeded plugin fallback for lyng.io.fs")
+                log.info("[LYNG_DEBUG] QuickDoc: external docs NOT found; seeded plugin fallbacks")
            } else {
                log.info("[LYNG_DEBUG] QuickDoc: external docs NOT found (lyngio absent on classpath)")
            }
-            seeded
+            return seeded
        }
        return true
    }
    override fun getCustomDocumentationElement(
@@ -343,25 +579,105 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        return contextElement ?: file.findElementAt(targetOffset)
    }
-    private fun renderDeclDoc(d: MiniDecl): String {
+    private fun renderDeclDoc(d: MiniDecl, text: String, mini: MiniScript, imported: List<String>): String {
        val title = when (d) {
            is MiniFunDecl -> "function ${d.name}${signatureOf(d)}"
            is MiniClassDecl -> "class ${d.name}"
-            is MiniValDecl -> if (d.mutable) "var ${d.name}${typeOf(d.type)}" else "val ${d.name}${typeOf(d.type)}"
+            is MiniEnumDecl -> "enum ${d.name} { ${d.entries.joinToString(", ")} }"
-            else -> d.name
+            is MiniTypeAliasDecl -> "type ${d.name}${typeAliasSuffix(d)}"
            is MiniValDecl -> {
                val t = d.type ?: DocLookupUtils.inferTypeRefForVal(d, text, imported, mini)
                val typeStr = if (t == null) ": Object?" else typeOf(t)
                if (d.mutable) "var ${d.name}${typeStr}" else "val ${d.name}${typeStr}"
            }
        }
        // Show full detailed documentation, not just the summary
        val raw = d.doc?.raw
        val doc: String? = if (raw.isNullOrBlank()) null else MarkdownRenderer.render(raw)
        val sb = StringBuilder()
-        sb.append("<div class='doc-title'>").append(htmlEscape(title)).append("</div>")
+        sb.append(renderTitle(title))
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc!!))
+        sb.append(renderDocBody(d.doc))
        return sb.toString()
    }
    private fun renderDocFromInfo(info: LyngSymbolInfo): String? {
        val kind = when (info.target.kind) {
            net.sergeych.lyng.binding.SymbolKind.Function -> "function"
            net.sergeych.lyng.binding.SymbolKind.Class -> "class"
            net.sergeych.lyng.binding.SymbolKind.Enum -> "enum"
            net.sergeych.lyng.binding.SymbolKind.TypeAlias -> "type"
            net.sergeych.lyng.binding.SymbolKind.Value -> "val"
            net.sergeych.lyng.binding.SymbolKind.Variable -> "var"
            net.sergeych.lyng.binding.SymbolKind.Parameter -> "parameter"
        }
        val title = info.signature ?: "$kind ${info.target.name}"
        if (title.isBlank() && info.doc == null) return null
        val sb = StringBuilder()
        sb.append(renderTitle(title))
        sb.append(renderDocBody(info.doc))
        return sb.toString()
    }
    private fun findDocInDeclarationFiles(file: PsiFile, container: String?, name: String): MiniDoc? {
        val declFiles = LyngAstManager.getDeclarationFiles(file)
        if (declFiles.isEmpty()) return null
        fun findInMini(mini: MiniScript): MiniDoc? {
            if (container == null) {
                mini.declarations.firstOrNull { it.name == name }?.let { return it.doc }
                return null
            }
            val cls = mini.declarations.filterIsInstance<MiniClassDecl>().firstOrNull { it.name == container } ?: return null
            cls.members.firstOrNull { it.name == name }?.let { return it.doc }
            cls.ctorFields.firstOrNull { it.name == name }?.let { return null }
            cls.classFields.firstOrNull { it.name == name }?.let { return null }
            return null
        }
        for (df in declFiles) {
            val mini = LyngAstManager.getMiniAst(df)
                ?: run {
                    try {
                        val res = runBlocking {
                            LyngLanguageTools.analyze(df.text, df.name)
                        }
                        res.mini
                    } catch (_: Throwable) {
                        null
                    }
                }
            if (mini != null) {
                val doc = findInMini(mini)
                if (doc != null) return doc
            }
            // Text fallback: parse preceding doc comment for the symbol
            val parsed = parseDocFromText(df.text, name)
            if (parsed != null) return parsed
        }
        return null
    }
    private fun parseDocFromText(text: String, name: String): MiniDoc? {
        if (text.isBlank()) return null
        val pattern = Regex("/\\*\\*([\\s\\S]*?)\\*/\\s*(?:public|private|protected|static|abstract|extern|open|closed|override\\s+)*\\s*(?:fun|val|var|class|interface|enum|type)\\s+$name\\b")
        val m = pattern.find(text) ?: return null
        val raw = m.groupValues.getOrNull(1)?.trim() ?: return null
        if (raw.isBlank()) return null
        val src = net.sergeych.lyng.Source("<doc>", raw)
        return MiniDoc.parse(MiniRange(src.startPos, src.startPos), raw.lines())
    }
    private fun renderParamDoc(fn: MiniFunDecl, p: MiniParam): String {
        val title = "parameter ${p.name}${typeOf(p.type)} in ${fn.name}${signatureOf(fn)}"
-        return "<div class='doc-title'>${htmlEscape(title)}</div>"
+        val sb = StringBuilder()
        sb.append(renderTitle(title))
        // Find matching @param tag
        fn.doc?.tags?.get("param")?.forEach { tag ->
            val parts = tag.split(Regex("\\s+"), 2)
            if (parts.getOrNull(0) == p.name && parts.size > 1) {
                sb.append(styledMarkdown(MarkdownRenderer.render(parts[1])))
            }
        }
        return sb.toString()
    }
    private fun renderMemberFunDoc(className: String, m: MiniMemberFunDecl): String {
@@ -372,37 +688,45 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        val ret = typeOf(m.returnType)
        val staticStr = if (m.isStatic) "static " else ""
        val title = "${staticStr}method $className.${m.name}(${params})${ret}"
        val raw = m.doc?.raw
        val doc: String? = if (raw.isNullOrBlank()) null else MarkdownRenderer.render(raw)
        val sb = StringBuilder()
-        sb.append("<div class='doc-title'>").append(htmlEscape(title)).append("</div>")
+        sb.append(renderTitle(title))
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc!!))
+        sb.append(renderDocBody(m.doc))
        return sb.toString()
    }
    private fun renderMemberValDoc(className: String, m: MiniMemberValDecl): String {
-        val ts = typeOf(m.type)
+        val ts = if (m.type == null) ": Object?" else typeOf(m.type)
        val kind = if (m.mutable) "var" else "val"
        val staticStr = if (m.isStatic) "static " else ""
        val title = "${staticStr}${kind} $className.${m.name}${ts}"
        val raw = m.doc?.raw
        val doc: String? = if (raw.isNullOrBlank()) null else MarkdownRenderer.render(raw)
        val sb = StringBuilder()
-        sb.append("<div class='doc-title'>").append(htmlEscape(title)).append("</div>")
+        sb.append(renderTitle(title))
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc!!))
+        sb.append(renderDocBody(m.doc))
        return sb.toString()
    }
-    private fun typeOf(t: MiniTypeRef?): String = when (t) {
+    private fun renderMemberTypeAliasDoc(className: String, m: MiniMemberTypeAliasDecl): String {
-        is MiniTypeName -> ": ${t.segments.joinToString(".") { it.name }}${if (t.nullable) "?" else ""}"
+        val tp = if (m.typeParams.isEmpty()) "" else "<" + m.typeParams.joinToString(", ") + ">"
-        is MiniGenericType -> {
+        val body = typeOf(m.target)
-            val base = typeOf(t.base).removePrefix(": ")
+        val rhs = if (body.isBlank()) "" else " = ${body.removePrefix(": ")}"
-            val args = t.args.joinToString(", ") { typeOf(it).removePrefix(": ") }
+        val staticStr = if (m.isStatic) "static " else ""
-            ": ${base}<${args}>${if (t.nullable) "?" else ""}"
+        val title = "${staticStr}type $className.${m.name}$tp$rhs"
        val sb = StringBuilder()
        sb.append(renderTitle(title))
        sb.append(renderDocBody(m.doc))
        return sb.toString()
    }
-        is MiniFunctionType -> ": (..) -> ..${if (t.nullable) "?" else ""}"
+
-        is MiniTypeVar -> ": ${t.name}${if (t.nullable) "?" else ""}"
+    private fun typeAliasSuffix(d: MiniTypeAliasDecl): String {
-        null -> ""
+        val tp = if (d.typeParams.isEmpty()) "" else "<" + d.typeParams.joinToString(", ") + ">"
        val body = typeOf(d.target)
        val rhs = if (body.isBlank()) "" else " = ${body.removePrefix(": ")}"
        return "$tp$rhs"
    }
    private fun typeOf(t: MiniTypeRef?): String {
        val s = DocLookupUtils.typeOf(t)
        return if (s.isEmpty()) (if (t == null) ": Object?" else "") else ": $s"
    }
    private fun signatureOf(fn: MiniFunDecl): String {
@@ -414,6 +738,10 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        return "(${params})${ret}"
    }
    private fun renderTitle(title: String): String {
        return "<div class='doc-title' style='margin-bottom: 0.8em;'>${htmlEscape(title)}</div>"
    }
    private fun htmlEscape(s: String): String = buildString(s.length) {
        for (ch in s) append(
            when (ch) {
@@ -480,7 +808,7 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
    private fun renderOverloads(name: String, overloads: List<MiniFunDecl>): String {
        val sb = StringBuilder()
-        sb.append("<div class='doc-title'>Overloads for ").append(htmlEscape(name)).append("</div>")
+        sb.append(renderTitle("Overloads for $name"))
        sb.append("<ul>")
        overloads.forEach { fn ->
            sb.append("<li><code>")
@@ -502,11 +830,64 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
        return if (e > s) TextRange(s, e) else null
    }
    private fun renderDocBody(doc: MiniDoc?): String {
        if (doc == null) return ""
        val sb = StringBuilder()
        if (doc.raw.isNotBlank()) {
            sb.append(styledMarkdown(MarkdownRenderer.render(doc.raw)))
        }
        if (doc.tags.isNotEmpty()) {
            sb.append(renderTags(doc.tags))
        }
        return sb.toString()
    }
    private fun renderTags(tags: Map<String, List<String>>): String {
        if (tags.isEmpty()) return ""
        val sb = StringBuilder()
        sb.append("<table class='sections'>")
        fun section(title: String, list: List<String>, isKeyValue: Boolean = false) {
            if (list.isEmpty()) return
            sb.append("<tr><td valign='top' class='section'><p>").append(htmlEscape(title)).append(":</p></td><td valign='top'>")
            list.forEachIndexed { index, item ->
                if (index > 0) sb.append("<p>")
                if (isKeyValue) {
                    val parts = item.split(Regex("\\s+"), 2)
                    sb.append("<code>").append(htmlEscape(parts[0])).append("</code>")
                    if (parts.size > 1) {
                        sb.append(" — ").append(MarkdownRenderer.render(parts[1]).removePrefix("<p>").removeSuffix("</p>"))
                    }
                } else {
                    sb.append(MarkdownRenderer.render(item).removePrefix("<p>").removeSuffix("</p>"))
                }
            }
            sb.append("</td></tr>")
        }
        section("Parameters", tags["param"] ?: emptyList(), isKeyValue = true)
        section("Returns", tags["return"] ?: emptyList())
        section("Throws", tags["throws"] ?: emptyList(), isKeyValue = true)
        tags.forEach { (name, list) ->
            if (name !in listOf("param", "return", "throws")) {
                section(name.replaceFirstChar { if (it.isLowerCase()) it.titlecase() else it.toString() }, list)
            }
        }
        sb.append("</table>")
        return sb.toString()
    }
    private fun previousWordBefore(text: String, offset: Int): TextRange? {
-        // skip spaces and dots to the left, but stop after hitting a non-identifier or dot boundary
+        // skip spaces and the dot to the left, but stop after hitting a non-identifier boundary
        var i = (offset - 1).coerceAtLeast(0)
-        // first, move left past spaces
+        // skip trailing spaces
-        while (i > 0 && text[i].isWhitespace()) i--
+        while (i >= 0 && text[i].isWhitespace()) i--
        // skip the dot if present
        if (i >= 0 && text[i] == '.') i--
        // skip spaces before the dot
        while (i >= 0 && text[i].isWhitespace()) i--
        // remember position to check for dot between words
        val end = i + 1
        // now find the start of the identifier
@@ -0,0 +1,69 @@
 /*
 * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 /*
 * Minimal fallback docs seeding for `lyng.io.process` used only inside the IDEA plugin
 * when external docs module (lyngio) is not present on the classpath.
 */
 package net.sergeych.lyng.idea.docs
 import net.sergeych.lyng.miniast.BuiltinDocRegistry
 import net.sergeych.lyng.miniast.ParamDoc
 import net.sergeych.lyng.miniast.type
 internal object ProcessDocsFallback {
    @Volatile
    private var seeded = false
    fun ensureOnce(): Boolean {
        if (seeded) return true
        synchronized(this) {
            if (seeded) return true
            BuiltinDocRegistry.module("lyng.io.process") {
                classDoc(name = "Process", doc = "Process execution and control.") {
                    method(
                        name = "execute",
                        doc = "Execute a process with arguments.",
                        params = listOf(ParamDoc("executable", type("lyng.String")), ParamDoc("args", type("lyng.List"))),
                        returns = type("RunningProcess"),
                        isStatic = true
                    )
                    method(
                        name = "shell",
                        doc = "Execute a command via system shell.",
                        params = listOf(ParamDoc("command", type("lyng.String"))),
                        returns = type("RunningProcess"),
                        isStatic = true
                    )
                }
                classDoc(name = "RunningProcess", doc = "Handle to a running process.") {
                    method(name = "stdout", doc = "Get standard output stream as a Flow of lines.", returns = type("lyng.Flow"))
                    method(name = "stderr", doc = "Get standard error stream as a Flow of lines.", returns = type("lyng.Flow"))
                    method(name = "waitFor", doc = "Wait for the process to exit.", returns = type("lyng.Int"))
                    method(name = "signal", doc = "Send a signal to the process.", params = listOf(ParamDoc("signal", type("lyng.String"))))
                    method(name = "destroy", doc = "Forcefully terminate the process.")
                }
                valDoc(name = "Process", doc = "Process execution and control.", type = type("Process"))
                valDoc(name = "RunningProcess", doc = "Handle to a running process.", type = type("RunningProcess"))
            }
            seeded = true
            return true
        }
    }
 }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -35,6 +35,8 @@ import com.intellij.psi.codeStyle.CodeStyleManager
 import net.sergeych.lyng.format.LyngFormatConfig
 import net.sergeych.lyng.format.LyngFormatter
 import net.sergeych.lyng.idea.LyngLanguage
 import net.sergeych.lyng.idea.util.FormattingUtils.computeDesiredIndent
 import net.sergeych.lyng.idea.util.FormattingUtils.findFirstNonWs
 class LyngEnterHandler : EnterHandlerDelegate {
    private val log = Logger.getInstance(LyngEnterHandler::class.java)
@@ -80,16 +82,39 @@ class LyngEnterHandler : EnterHandlerDelegate {
            val trimmed = prevText.trimStart()
            // consider only code part before // comment
            val code = trimmed.substringBefore("//").trim()
-            if (code == "}") {
+            if (code == "}" || code == "*/") {
-                // Previously we reindented the enclosed block on Enter after a lone '}'.
+                // Adjust indent for the previous line if it's a block or comment closer
-                // Per new behavior, this action is now bound to typing '}' instead.
+                val prevStart = doc.getLineStartOffset(prevLine)
-                // Keep Enter flow limited to indenting the new line only.
+                if (file.context == null) {
                    try {
                        CodeStyleManager.getInstance(project).adjustLineIndent(file, prevStart)
                    } catch (e: Exception) {
                        log.warn("Failed to adjust line indent for previous line: ${e.message}")
                    }
                }
                // Fallback for previous line: manual application
                val desiredPrev = computeDesiredIndent(project, doc, prevLine)
                val lineStartPrev = doc.getLineStartOffset(prevLine)
                val lineEndPrev = doc.getLineEndOffset(prevLine)
                val firstNonWsPrev = findFirstNonWs(doc, lineStartPrev, lineEndPrev)
                val currentIndentLenPrev = firstNonWsPrev - lineStartPrev
                if (doc.getText(TextRange(lineStartPrev, lineStartPrev + currentIndentLenPrev)) != desiredPrev) {
                    WriteCommandAction.runWriteCommandAction(project) {
                        doc.replaceString(lineStartPrev, lineStartPrev + currentIndentLenPrev, desiredPrev)
                    }
                }
            }
        }
        // Adjust indent for the current (new) line
        val currentStart = doc.getLineStartOffsetSafe(currentLine)
-        val csm = CodeStyleManager.getInstance(project)
+        if (file.context == null) {
-        csm.adjustLineIndent(file, currentStart)
+            try {
                CodeStyleManager.getInstance(project).adjustLineIndent(file, currentStart)
            } catch (e: Exception) {
                log.warn("Failed to adjust line indent for current line: ${e.message}")
            }
        }
        // Fallback: if the platform didn't physically insert indentation, compute it from our formatter and apply
        val lineStart = doc.getLineStartOffset(currentLine)
@@ -159,35 +184,6 @@ class LyngEnterHandler : EnterHandlerDelegate {
        caret.moveToOffset(target)
    }
    private fun computeDesiredIndent(project: Project, doc: Document, line: Int): String {
        val options = CodeStyle.getIndentOptions(project, doc)
        val start = 0
        val end = doc.getLineEndOffset(line)
        val snippet = doc.getText(TextRange(start, end))
        val isBlankLine = doc.getLineText(line).trim().isEmpty()
        val snippetForCalc = if (isBlankLine) snippet + "x" else snippet
        val cfg = LyngFormatConfig(
            indentSize = options.INDENT_SIZE.coerceAtLeast(1),
            useTabs = options.USE_TAB_CHARACTER,
            continuationIndentSize = options.CONTINUATION_INDENT_SIZE.coerceAtLeast(options.INDENT_SIZE.coerceAtLeast(1)),
        )
        val formatted = LyngFormatter.reindent(snippetForCalc, cfg)
        val lastNl = formatted.lastIndexOf('\n')
        val lastLine = if (lastNl >= 0) formatted.substring(lastNl + 1) else formatted
        val wsLen = lastLine.indexOfFirst { it != ' ' && it != '\t' }.let { if (it < 0) lastLine.length else it }
        return lastLine.substring(0, wsLen)
    }
    private fun findFirstNonWs(doc: Document, start: Int, end: Int): Int {
        var i = start
        val text = doc.charsSequence
        while (i < end) {
            val ch = text[i]
            if (ch != ' ' && ch != '\t') break
            i++
        }
        return i
    }
    private fun Document.safeLineNumber(offset: Int): Int =
        getLineNumber(offset.coerceIn(0, textLength))
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -32,14 +32,16 @@ import net.sergeych.lyng.format.LyngFormatConfig
 import net.sergeych.lyng.format.LyngFormatter
 import net.sergeych.lyng.idea.LyngLanguage
 import net.sergeych.lyng.idea.settings.LyngFormatterSettings
 import net.sergeych.lyng.idea.util.FormattingUtils.computeDesiredIndent
 import net.sergeych.lyng.idea.util.FormattingUtils.findFirstNonWs
 class LyngTypedHandler : TypedHandlerDelegate() {
    private val log = Logger.getInstance(LyngTypedHandler::class.java)
    override fun charTyped(c: Char, project: Project, editor: Editor, file: PsiFile): Result {
        if (file.language != LyngLanguage) return Result.CONTINUE
        if (c != '}') return Result.CONTINUE
        if (c == '}') {
            val doc = editor.document
            PsiDocumentManager.getInstance(project).commitDocument(doc)
@@ -56,7 +58,40 @@ class LyngTypedHandler : TypedHandlerDelegate() {
                }
                // After block reindent, adjust line indent to what platform thinks (no-op in many cases)
                val lineStart = doc.getLineStartOffset(line)
                if (file.context == null) {
                    try {
                        CodeStyleManager.getInstance(project).adjustLineIndent(file, lineStart)
                    } catch (e: Exception) {
                        log.warn("Failed to adjust line indent for current line: ${e.message}")
                    }
                }
            }
        } else if (c == '/') {
            val doc = editor.document
            val offset = editor.caretModel.offset
            if (offset >= 2 && doc.getText(TextRange(offset - 2, offset)) == "*/") {
                PsiDocumentManager.getInstance(project).commitDocument(doc)
                val line = doc.getLineNumber(offset - 1)
                val lineStart = doc.getLineStartOffset(line)
                if (file.context == null) {
                    try {
                        CodeStyleManager.getInstance(project).adjustLineIndent(file, lineStart)
                    } catch (e: Exception) {
                        log.warn("Failed to adjust line indent for comment: ${e.message}")
                    }
                }
                // Manual application fallback
                val desired = computeDesiredIndent(project, doc, line)
                val lineEnd = doc.getLineEndOffset(line)
                val firstNonWs = findFirstNonWs(doc, lineStart, lineEnd)
                val currentIndentLen = firstNonWs - lineStart
                if (doc.getText(TextRange(lineStart, lineStart + currentIndentLen)) != desired) {
                    WriteCommandAction.runWriteCommandAction(project) {
                        doc.replaceString(lineStart, lineStart + currentIndentLen, desired)
                    }
                }
            }
        }
        return Result.CONTINUE
    }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -42,7 +42,7 @@ private class LineBlocksRootBlock(
    private val file: PsiFile,
    private val settings: CodeStyleSettings
 ) : Block {
-    override fun getTextRange(): TextRange = file.textRange
+    override fun getTextRange(): TextRange = TextRange(0, file.textLength)
    override fun getSubBlocks(): List<Block> = emptyList()
@@ -52,7 +52,7 @@ private class LineBlocksRootBlock(
    override fun getSpacing(child1: Block?, child2: Block): Spacing? = null
    override fun getChildAttributes(newChildIndex: Int): ChildAttributes = ChildAttributes(Indent.getNoneIndent(), null)
    override fun isIncomplete(): Boolean = false
-    override fun isLeaf(): Boolean = false
+    override fun isLeaf(): Boolean = true
 }
 // Intentionally no sub-blocks/spacing: indentation is handled by PreFormatProcessor + LineIndentProvider
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -24,9 +24,8 @@ import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiDocumentManager
 import com.intellij.psi.codeStyle.CommonCodeStyleSettings.IndentOptions
 import com.intellij.psi.codeStyle.lineIndent.LineIndentProvider
 import net.sergeych.lyng.format.LyngFormatConfig
 import net.sergeych.lyng.format.LyngFormatter
 import net.sergeych.lyng.idea.LyngLanguage
 import net.sergeych.lyng.idea.util.FormattingUtils
 /**
 * Lightweight indentation provider for Lyng.
@@ -45,8 +44,7 @@ class LyngLineIndentProvider : LineIndentProvider {
        val options = CodeStyle.getIndentOptions(project, doc)
        val line = doc.getLineNumberSafe(offset)
-        val indent = computeDesiredIndentFromCore(doc, line, options)
+        return FormattingUtils.computeDesiredIndent(project, doc, line)
        return indent
    }
    override fun isSuitableFor(language: Language?): Boolean = language == null || language == LyngLanguage
@@ -79,25 +77,4 @@ class LyngLineIndentProvider : LineIndentProvider {
        return spaces / size
    }
    private fun computeDesiredIndentFromCore(doc: Document, line: Int, options: IndentOptions): String {
        // Build a minimal text consisting of all previous lines and the current line.
        // Special case: when the current line is blank (newly created by Enter), compute the
        // indent as if there was a non-whitespace character at line start (append a sentinel).
        val start = 0
        val end = doc.getLineEndOffset(line)
        val snippet = doc.getText(TextRange(start, end))
        val isBlankLine = doc.getLineText(line).trim().isEmpty()
        val snippetForCalc = if (isBlankLine) snippet + "x" else snippet
        val cfg = LyngFormatConfig(
            indentSize = options.INDENT_SIZE.coerceAtLeast(1),
            useTabs = options.USE_TAB_CHARACTER,
            continuationIndentSize = options.CONTINUATION_INDENT_SIZE.coerceAtLeast(options.INDENT_SIZE.coerceAtLeast(1)),
        )
        val formatted = LyngFormatter.reindent(snippetForCalc, cfg)
        // Grab the last line's leading whitespace as the indent for the current line
        val lastNl = formatted.lastIndexOf('\n')
        val lastLine = if (lastNl >= 0) formatted.substring(lastNl + 1) else formatted
        val wsLen = lastLine.indexOfFirst { it != ' ' && it != '\t' }.let { if (it < 0) lastLine.length else it }
        return lastLine.substring(0, wsLen)
    }
 }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -44,25 +44,67 @@ class LyngPreFormatProcessor : PreFormatProcessor {
        // When both spacing and wrapping are OFF, still fix indentation for the whole file to
        // guarantee visible changes on Reformat Code.
        val runFullFileIndent = !settings.enableSpacing && !settings.enableWrapping
        // Maintain a working range and a modification flag to avoid stale offsets after replacements
        var modified = false
        fun fullRange(): TextRange = TextRange(0, doc.textLength)
        var workingRange: TextRange = range.intersection(fullRange()) ?: fullRange()
-        val startLine = if (runFullFileIndent) 0 else doc.getLineNumber(workingRange.startOffset)
+        val docW = doc as? com.intellij.injected.editor.DocumentWindow
-        val endLine = if (runFullFileIndent) (doc.lineCount - 1).coerceAtLeast(0)
+        // The host range of the entire injected fragment (or the whole file if not injected).
-        else doc.getLineNumber(workingRange.endOffset.coerceAtMost(doc.textLength))
+        fun currentHostRange(): TextRange = if (docW != null) {
            TextRange(docW.injectedToHost(0), docW.injectedToHost(doc.textLength))
        } else {
            file.textRange
        }
        // The range in 'doc' coordinate system (local 0..len for injections, host offsets for normal files).
        fun currentLocalRange(): TextRange = if (docW != null) {
            TextRange(0, doc.textLength)
        } else {
            file.textRange
        }
        val clr = currentLocalRange()
        val chr = currentHostRange()
        // Convert the input range to the coordinate system of 'doc'
        var workingRangeLocal: TextRange = if (docW != null) {
            val hostIntersection = range.intersection(chr)
            if (hostIntersection != null) {
                try {
                    val start = docW.hostToInjected(hostIntersection.startOffset)
                    val end = docW.hostToInjected(hostIntersection.endOffset)
                    TextRange(start.coerceAtMost(end), end.coerceAtLeast(start))
                } catch (e: Exception) {
                    clr
                }
            } else {
                range.intersection(clr) ?: clr
            }
        } else {
            range.intersection(clr) ?: clr
        }
        val startLine = if (runFullFileIndent) {
            doc.getLineNumber(currentLocalRange().startOffset)
        } else {
            doc.getLineNumber(workingRangeLocal.startOffset)
        }
        val endLine = if (runFullFileIndent) {
            if (clr.endOffset <= clr.startOffset) doc.getLineNumber(clr.startOffset)
            else doc.getLineNumber(clr.endOffset)
        } else {
            doc.getLineNumber(workingRangeLocal.endOffset.coerceAtMost(doc.textLength))
        }
        fun codePart(s: String): String {
            val idx = s.indexOf("//")
            return if (idx >= 0) s.substring(0, idx) else s
        }
-        // Pre-scan to compute balances up to startLine
+        // Pre-scan to compute balances up to startLine.
        val fragmentStartLine = doc.getLineNumber(currentLocalRange().startOffset)
        var blockLevel = 0
        var parenBalance = 0
        var bracketBalance = 0
-        for (ln in 0 until startLine) {
+        for (ln in fragmentStartLine until startLine) {
            val text = doc.getText(TextRange(doc.getLineStartOffset(ln), doc.getLineEndOffset(ln)))
            for (ch in codePart(text)) when (ch) {
                '{' -> blockLevel++
@@ -80,7 +122,13 @@ class LyngPreFormatProcessor : PreFormatProcessor {
            val lineStart = doc.getLineStartOffset(line)
            // adjustLineIndent delegates to our LineIndentProvider which computes
            // indentation from scratch; this is safe and idempotent
            if (file.context == null) {
                try {
                    CodeStyleManager.getInstance(project).adjustLineIndent(file, lineStart)
                } catch (e: Exception) {
                    // Log as debug because this can be called many times during reformat
                }
            }
            // After indentation, update block/paren/bracket balances using the current line text
            val lineEnd = doc.getLineEndOffset(line)
@@ -103,15 +151,14 @@ class LyngPreFormatProcessor : PreFormatProcessor {
                useTabs = options.USE_TAB_CHARACTER,
                continuationIndentSize = options.CONTINUATION_INDENT_SIZE.coerceAtLeast(options.INDENT_SIZE.coerceAtLeast(1)),
            )
-            val full = fullRange()
+            val r = if (runFullFileIndent) currentLocalRange() else workingRangeLocal.intersection(currentLocalRange()) ?: currentLocalRange()
            val r = if (runFullFileIndent) full else workingRange.intersection(full) ?: full
            val text = doc.getText(r)
            val formatted = LyngFormatter.reindent(text, cfg)
            if (formatted != text) {
                doc.replaceString(r.startOffset, r.endOffset, formatted)
                modified = true
                psiDoc.commitDocument(doc)
-                workingRange = fullRange()
+                workingRangeLocal = currentLocalRange()
            }
        }
@@ -124,14 +171,14 @@ class LyngPreFormatProcessor : PreFormatProcessor {
                applySpacing = true,
                applyWrapping = false,
            )
-            val safe = workingRange.intersection(fullRange()) ?: fullRange()
+            val r = if (runFullFileIndent) currentLocalRange() else workingRangeLocal.intersection(currentLocalRange()) ?: currentLocalRange()
-            val text = doc.getText(safe)
+            val text = doc.getText(r)
            val formatted = LyngFormatter.format(text, cfg)
            if (formatted != text) {
-                doc.replaceString(safe.startOffset, safe.endOffset, formatted)
+                doc.replaceString(r.startOffset, r.endOffset, formatted)
                modified = true
                psiDoc.commitDocument(doc)
-                workingRange = fullRange()
+                workingRangeLocal = currentLocalRange()
            }
        }
        // Optionally apply wrapping (after spacing) when enabled
@@ -143,17 +190,19 @@ class LyngPreFormatProcessor : PreFormatProcessor {
                applySpacing = settings.enableSpacing,
                applyWrapping = true,
            )
-            val safe2 = workingRange.intersection(fullRange()) ?: fullRange()
+            val r = if (runFullFileIndent) currentLocalRange() else workingRangeLocal.intersection(currentLocalRange()) ?: currentLocalRange()
-            val text2 = doc.getText(safe2)
+            val text = doc.getText(r)
-            val wrapped = LyngFormatter.format(text2, cfg)
+            val wrapped = LyngFormatter.format(text, cfg)
-            if (wrapped != text2) {
+            if (wrapped != text) {
-                doc.replaceString(safe2.startOffset, safe2.endOffset, wrapped)
+                doc.replaceString(r.startOffset, r.endOffset, wrapped)
                modified = true
                psiDoc.commitDocument(doc)
-                workingRange = fullRange()
+                workingRangeLocal = currentLocalRange()
            }
        }
-        // Return a safe range for the formatter to continue with, preventing stale offsets
+        // Return a safe range for the formatter to continue with, preventing stale offsets.
-        return if (modified) fullRange() else (range.intersection(fullRange()) ?: fullRange())
+        // For injected files, ALWAYS return a range in local coordinates.
        val finalRange = currentLocalRange()
        return if (modified) finalRange else (range.intersection(finalRange) ?: finalRange)
    }
 }
@@ -1,43 +0,0 @@
 /*
 * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 package net.sergeych.lyng.idea.grazie
 import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer
 import com.intellij.codeInsight.intention.IntentionAction
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiFile
 import net.sergeych.lyng.idea.settings.LyngFormatterSettings
 /**
 * Lightweight quick-fix that adds a word to the per-project Lyng dictionary.
 */
 class AddToLyngDictionaryFix(private val word: String) : IntentionAction {
    override fun getText(): String = "Add '$word' to Lyng dictionary"
    override fun getFamilyName(): String = "Lyng Spelling"
    override fun isAvailable(project: Project, editor: Editor?, file: PsiFile?): Boolean = word.isNotBlank()
    override fun startInWriteAction(): Boolean = true
    override fun invoke(project: Project, editor: Editor?, file: PsiFile?) {
        val settings = LyngFormatterSettings.getInstance(project)
        val learned = settings.learnedWords
        learned.add(word.lowercase())
        settings.learnedWords = learned
        // Restart daemon to refresh highlights
        if (file != null) DaemonCodeAnalyzer.getInstance(project).restart(file)
    }
 }
@@ -1,83 +0,0 @@
 /*
 * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 package net.sergeych.lyng.idea.grazie
 import com.intellij.openapi.diagnostic.Logger
 import java.io.BufferedReader
 import java.io.InputStreamReader
 import java.util.zip.GZIPInputStream
 /**
 * Very simple English dictionary loader for offline suggestions on IC-243.
 * It loads a word list from classpath resources. Supports plain text (one word per line)
 * and gzipped text if the resource ends with .gz.
 */
 object EnglishDictionary {
    private val log = Logger.getInstance(EnglishDictionary::class.java)
    @Volatile private var loaded = false
    @Volatile private var words: Set<String> = emptySet()
    /**
     * Load dictionary from bundled resources (once).
     * If multiple candidates exist, the first found is used.
     */
    private fun ensureLoaded() {
        if (loaded) return
        synchronized(this) {
            if (loaded) return
            val candidates = listOf(
                // preferred large bundles first (add en-basic.txt.gz ~3–5MB here)
                "/dictionaries/en-basic.txt.gz",
                "/dictionaries/en-large.txt.gz",
                // plain text fallbacks
                "/dictionaries/en-basic.txt",
                "/dictionaries/en-large.txt",
            )
            val merged = HashSet<String>(128_000)
            for (res in candidates) {
                try {
                    val stream = javaClass.getResourceAsStream(res) ?: continue
                    val reader = if (res.endsWith(".gz"))
                        BufferedReader(InputStreamReader(GZIPInputStream(stream)))
                    else
                        BufferedReader(InputStreamReader(stream))
                    var loadedCount = 0
                    reader.useLines { seq -> seq.forEach { line ->
                        val w = line.trim()
                        if (w.isNotEmpty() && !w.startsWith("#")) { merged += w.lowercase(); loadedCount++ }
                    } }
                    log.info("EnglishDictionary: loaded $loadedCount words from $res (total=${merged.size})")
                } catch (t: Throwable) {
                    log.info("EnglishDictionary: failed to load $res: ${t.javaClass.simpleName}: ${t.message}")
                }
            }
            if (merged.isEmpty()) {
                // Fallback minimal set
                merged += setOf("comment","comments","error","errors","found","file","not","word","words","count","value","name","class","function","string")
                log.info("EnglishDictionary: using minimal built-in set (${merged.size})")
            }
            words = merged
            loaded = true
        }
    }
    fun allWords(): Set<String> {
        ensureLoaded()
        return words
    }
 }
@@ -1,608 +0,0 @@
 /*
 * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 /*
 * Grazie-backed annotator for Lyng files.
 *
 * It consumes the MiniAst-driven LyngSpellIndex and, when Grazie is present,
 * tries to run Grazie checks on the extracted TextContent. Results are painted
 * as warnings in the editor. If the Grazie API changes, we use reflection and
 * fail softly with INFO logs (no errors shown to users).
 */
 package net.sergeych.lyng.idea.grazie
 import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer
 import com.intellij.grazie.text.TextContent
 import com.intellij.grazie.text.TextContent.TextDomain
 import com.intellij.ide.plugins.PluginManagerCore
 import com.intellij.lang.annotation.AnnotationHolder
 import com.intellij.lang.annotation.ExternalAnnotator
 import com.intellij.lang.annotation.HighlightSeverity
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.editor.Document
 import com.intellij.openapi.editor.colors.TextAttributesKey
 import com.intellij.openapi.project.DumbAware
 import com.intellij.openapi.util.Key
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiFile
 import net.sergeych.lyng.idea.settings.LyngFormatterSettings
 import net.sergeych.lyng.idea.spell.LyngSpellIndex
 class LyngGrazieAnnotator : ExternalAnnotator<LyngGrazieAnnotator.Input, LyngGrazieAnnotator.Result>(), DumbAware {
    private val log = Logger.getInstance(LyngGrazieAnnotator::class.java)
    companion object {
        // Cache GrammarChecker availability to avoid repeated reflection + noisy logs
        @Volatile
        private var grammarCheckerAvailable: Boolean? = null
        @Volatile
        private var grammarCheckerMissingLogged: Boolean = false
        private fun isGrammarCheckerKnownMissing(): Boolean = (grammarCheckerAvailable == false)
        private fun markGrammarCheckerMissingOnce(log: Logger, message: String) {
            if (!grammarCheckerMissingLogged) {
                // Downgrade to debug to reduce log noise across projects/sessions
                log.debug(message)
                grammarCheckerMissingLogged = true
            }
        }
        private val RETRY_KEY: Key<Long> = Key.create("LYNG_GRAZIE_ANN_RETRY_STAMP")
    }
    data class Input(val modStamp: Long)
    data class Finding(val range: TextRange, val message: String)
    data class Result(val modStamp: Long, val findings: List<Finding>)
    override fun collectInformation(file: PsiFile): Input? {
        val doc: Document = file.viewProvider.document ?: return null
        // Only require Grazie presence; index readiness is checked in apply with a retry.
        val grazie = isGrazieInstalled()
        if (!grazie) {
            log.info("LyngGrazieAnnotator.collectInformation: skip (grazie=false) file='${file.name}'")
            return null
        }
        log.info("LyngGrazieAnnotator.collectInformation: file='${file.name}', modStamp=${doc.modificationStamp}")
        return Input(doc.modificationStamp)
    }
    override fun doAnnotate(collectedInfo: Input?): Result? {
        // All heavy lifting is done in apply where we have the file context
        return collectedInfo?.let { Result(it.modStamp, emptyList()) }
    }
    override fun apply(file: PsiFile, annotationResult: Result?, holder: AnnotationHolder) {
        if (annotationResult == null || !isGrazieInstalled()) return
        val doc = file.viewProvider.document ?: return
        val idx = LyngSpellIndex.getUpToDate(file) ?: run {
            log.info("LyngGrazieAnnotator.apply: index not ready for '${file.name}', scheduling one-shot restart")
            scheduleOneShotRestart(file, annotationResult.modStamp)
            return
        }
        val settings = LyngFormatterSettings.getInstance(file.project)
        // Build TextContent fragments for comments/strings/identifiers according to settings
        val fragments = mutableListOf<Pair<TextContent, TextRange>>()
        try {
            fun addFragments(ranges: List<TextRange>, domain: TextDomain) {
                for (r in ranges) {
                    val local = rangeToTextContent(file, domain, r) ?: continue
                    fragments += local to r
                }
            }
            // Comments always via COMMENTS
            addFragments(idx.comments, TextDomain.COMMENTS)
            // Strings: LITERALS if requested, else COMMENTS if fallback enabled
            if (settings.spellCheckStringLiterals) {
                val domain = if (settings.grazieTreatLiteralsAsComments) TextDomain.COMMENTS else TextDomain.LITERALS
                addFragments(idx.strings, domain)
            }
            // Identifiers via COMMENTS to force painting in 243 unless user disables fallback
            val idsDomain = if (settings.grazieTreatIdentifiersAsComments) TextDomain.COMMENTS else TextDomain.DOCUMENTATION
            addFragments(idx.identifiers, idsDomain)
            log.info(
                "LyngGrazieAnnotator.apply: file='${file.name}', idxCounts ids=${idx.identifiers.size}, comments=${idx.comments.size}, strings=${idx.strings.size}, builtFragments=${fragments.size}"
            )
        } catch (e: Throwable) {
            log.info("LyngGrazieAnnotator: failed to build TextContent fragments: ${e.javaClass.simpleName}: ${e.message}")
            return
        }
        if (fragments.isEmpty()) return
        val findings = mutableListOf<Finding>()
        var totalReturned = 0
        var chosenEntry: String? = null
        for ((content, hostRange) in fragments) {
            try {
                val (typos, entryNote) = runGrazieChecksWithTracing(file, content)
                if (chosenEntry == null) chosenEntry = entryNote
                if (typos != null) {
                    totalReturned += typos.size
                    for (t in typos) {
                        val rel = extractRangeFromTypo(t) ?: continue
                        // Map relative range inside fragment to host file range
                        val abs = TextRange(hostRange.startOffset + rel.startOffset, hostRange.startOffset + rel.endOffset)
                        findings += Finding(abs, extractMessageFromTypo(t) ?: "Spelling/Grammar")
                    }
                }
            } catch (e: Throwable) {
                log.info("LyngGrazieAnnotator: Grazie check failed: ${e.javaClass.simpleName}: ${e.message}")
            }
        }
        log.info("LyngGrazieAnnotator.apply: used=${chosenEntry ?: "<none>"}, totalFindings=$totalReturned, painting=${findings.size}")
        // IMPORTANT: Do NOT fallback to the tiny bundled vocabulary on modern IDEs.
        // If Grazie/Natural Languages processing returned nothing, we simply exit here
        // to avoid low‑quality results from the legacy dictionary.
        if (findings.isEmpty()) return
        for (f in findings) {
            val ab = holder.newAnnotation(HighlightSeverity.INFORMATION, f.message).range(f.range)
            applyTypoStyleIfRequested(file, ab)
            ab.create()
        }
    }
    private fun scheduleOneShotRestart(file: PsiFile, modStamp: Long) {
        try {
            val last = file.getUserData(RETRY_KEY)
            if (last == modStamp) {
                log.info("LyngGrazieAnnotator.restart: already retried for modStamp=$modStamp, skip")
                return
            }
            file.putUserData(RETRY_KEY, modStamp)
            ApplicationManager.getApplication().invokeLater({
                try {
                    DaemonCodeAnalyzer.getInstance(file.project).restart(file)
                    log.info("LyngGrazieAnnotator.restart: daemon restarted for '${file.name}'")
                } catch (e: Throwable) {
                    log.info("LyngGrazieAnnotator.restart failed: ${e.javaClass.simpleName}: ${e.message}")
                }
            })
        } catch (e: Throwable) {
            log.info("LyngGrazieAnnotator.scheduleOneShotRestart failed: ${e.javaClass.simpleName}: ${e.message}")
        }
    }
    private fun isGrazieInstalled(): Boolean {
        return PluginManagerCore.isPluginInstalled(com.intellij.openapi.extensions.PluginId.getId("com.intellij.grazie")) ||
                PluginManagerCore.isPluginInstalled(com.intellij.openapi.extensions.PluginId.getId("tanvd.grazi"))
    }
    private fun rangeToTextContent(file: PsiFile, domain: TextDomain, range: TextRange): TextContent? {
        // Build TextContent via reflection: prefer psiFragment(domain, element)
        return try {
            // Try to find an element that fully covers the target range
            var element = file.findElementAt(range.startOffset) ?: return null
            val start = range.startOffset
            val end = range.endOffset
            while (element.parent != null && (element.textRange.startOffset > start || element.textRange.endOffset < end)) {
                element = element.parent
            }
            if (element.textRange.startOffset > start || element.textRange.endOffset < end) return null
            // In many cases, the element may not span the whole range; use file + range via suitable factory
            val methods = TextContent::class.java.methods.filter { it.name == "psiFragment" }
            val byElementDomain = methods.firstOrNull { it.parameterCount == 2 && it.parameterTypes[0].name.endsWith("PsiElement") }
            if (byElementDomain != null) {
                @Suppress("UNCHECKED_CAST")
                return (byElementDomain.invoke(null, element, domain) as? TextContent)?.let { tc ->
                    val relStart = start - element.textRange.startOffset
                    val relEnd = end - element.textRange.startOffset
                    if (relStart < 0 || relEnd > tc.length || relStart >= relEnd) return null
                    tc.subText(TextRange(relStart, relEnd))
                }
            }
            val byDomainElement = methods.firstOrNull { it.parameterCount == 2 && it.parameterTypes[0].name.endsWith("TextDomain") }
            if (byDomainElement != null) {
                @Suppress("UNCHECKED_CAST")
                return (byDomainElement.invoke(null, domain, element) as? TextContent)?.let { tc ->
                    val relStart = start - element.textRange.startOffset
                    val relEnd = end - element.textRange.startOffset
                    if (relStart < 0 || relEnd > tc.length || relStart >= relEnd) return null
                    tc.subText(TextRange(relStart, relEnd))
                }
            }
            null
        } catch (e: Throwable) {
            log.info("LyngGrazieAnnotator: rangeToTextContent failed: ${e.javaClass.simpleName}: ${e.message}")
            null
        }
    }
    private fun runGrazieChecksWithTracing(file: PsiFile, content: TextContent): Pair<Collection<Any>?, String?> {
        // Try known entry points via reflection to avoid hard dependencies on Grazie internals
        if (isGrammarCheckerKnownMissing()) return null to null
        try {
            // 1) Static GrammarChecker.check(TextContent)
            val checkerCls = try {
                Class.forName("com.intellij.grazie.grammar.GrammarChecker").also { grammarCheckerAvailable = true }
            } catch (t: Throwable) {
                grammarCheckerAvailable = false
                markGrammarCheckerMissingOnce(log, "LyngGrazieAnnotator: GrammarChecker class not found: ${t.javaClass.simpleName}: ${t.message}")
                null
            }
            if (checkerCls != null) {
                // Diagnostic: list available 'check' methods once
                runCatching {
                    val checks = checkerCls.methods.filter { it.name == "check" }
                    val sig = checks.joinToString { m ->
                        val params = m.parameterTypes.joinToString(prefix = "(", postfix = ")") { it.simpleName }
                        "${m.name}$params static=${java.lang.reflect.Modifier.isStatic(m.modifiers)}"
                    }
                    log.info("LyngGrazieAnnotator: GrammarChecker.check candidates: ${if (sig.isEmpty()) "<none>" else sig}")
                }
                checkerCls.methods.firstOrNull { it.name == "check" && it.parameterCount == 1 && it.parameterTypes[0].name.endsWith("TextContent") }?.let { m ->
                    @Suppress("UNCHECKED_CAST")
                    val res = m.invoke(null, content) as? Collection<Any>
                    return res to "GrammarChecker.check(TextContent) static"
                }
                // 2) GrammarChecker.getInstance().check(TextContent)
                val getInstance = checkerCls.methods.firstOrNull { it.name == "getInstance" && it.parameterCount == 0 }
                val inst = getInstance?.invoke(null)
                if (inst != null) {
                    val m = checkerCls.methods.firstOrNull { it.name == "check" && it.parameterCount == 1 && it.parameterTypes[0].name.endsWith("TextContent") }
                    if (m != null) {
                        @Suppress("UNCHECKED_CAST")
                        val res = m.invoke(inst, content) as? Collection<Any>
                        return res to "GrammarChecker.getInstance().check(TextContent)"
                    }
                }
                // 3) GrammarChecker.getDefault().check(TextContent)
                val getDefault = checkerCls.methods.firstOrNull { it.name == "getDefault" && it.parameterCount == 0 }
                val def = getDefault?.invoke(null)
                if (def != null) {
                    val m = checkerCls.methods.firstOrNull { it.name == "check" && it.parameterCount == 1 && it.parameterTypes[0].name.endsWith("TextContent") }
                    if (m != null) {
                        @Suppress("UNCHECKED_CAST")
                        val res = m.invoke(def, content) as? Collection<Any>
                        return res to "GrammarChecker.getDefault().check(TextContent)"
                    }
                }
                // 4) Service from project/application: GrammarChecker as a service
                runCatching {
                    val app = com.intellij.openapi.application.ApplicationManager.getApplication()
                    val getService = app::class.java.methods.firstOrNull { it.name == "getService" && it.parameterCount == 1 }
                    val svc = getService?.invoke(app, checkerCls)
                    if (svc != null) {
                        val m = checkerCls.methods.firstOrNull { it.name == "check" && it.parameterCount == 1 && it.parameterTypes[0].name.endsWith("TextContent") }
                        if (m != null) {
                            @Suppress("UNCHECKED_CAST")
                            val res = m.invoke(svc, content) as? Collection<Any>
                            if (res != null) return res to "Application.getService(GrammarChecker).check(TextContent)"
                        }
                    }
                }
                runCatching {
                    val getService = file.project::class.java.methods.firstOrNull { it.name == "getService" && it.parameterCount == 1 }
                    val svc = getService?.invoke(file.project, checkerCls)
                    if (svc != null) {
                        val m = checkerCls.methods.firstOrNull { it.name == "check" && it.parameterCount == 1 && it.parameterTypes[0].name.endsWith("TextContent") }
                        if (m != null) {
                            @Suppress("UNCHECKED_CAST")
                            val res = m.invoke(svc, content) as? Collection<Any>
                            if (res != null) return res to "Project.getService(GrammarChecker).check(TextContent)"
                        }
                    }
                }
            }
            // 5) Fallback: search any public method named check that accepts TextContent in any Grazie class (static)
            val candidateClasses = listOf(
                "com.intellij.grazie.grammar.GrammarChecker",
                "com.intellij.grazie.grammar.GrammarRunner",
                "com.intellij.grazie.grammar.Grammar" // historical names
            )
            for (cn in candidateClasses) {
                val cls = try { Class.forName(cn) } catch (_: Throwable) { continue }
                val m = cls.methods.firstOrNull { it.name == "check" && it.parameterTypes.any { p -> p.name.endsWith("TextContent") } }
                if (m != null) {
                    val args = arrayOfNulls<Any>(m.parameterCount)
                    // place content to the first TextContent parameter; others left null (common defaults)
                    for (i in 0 until m.parameterCount) if (m.parameterTypes[i].name.endsWith("TextContent")) { args[i] = content; break }
                    @Suppress("UNCHECKED_CAST")
                    val res = m.invoke(null, *args) as? Collection<Any>
                    if (res != null) return res to "$cn.${m.name}(TextContent)"
                }
            }
            // 6) Kotlin top-level function: GrammarCheckerKt.check(TextContent)
            runCatching {
                val kt = Class.forName("com.intellij.grazie.grammar.GrammarCheckerKt")
                val m = kt.methods.firstOrNull { it.name == "check" && it.parameterTypes.any { p -> p.name.endsWith("TextContent") } }
                if (m != null) {
                    val args = arrayOfNulls<Any>(m.parameterCount)
                    for (i in 0 until m.parameterCount) if (m.parameterTypes[i].name.endsWith("TextContent")) { args[i] = content; break }
                    @Suppress("UNCHECKED_CAST")
                    val res = m.invoke(null, *args) as? Collection<Any>
                    if (res != null) return res to "GrammarCheckerKt.check(TextContent)"
                }
            }
        } catch (e: Throwable) {
            log.info("LyngGrazieAnnotator: runGrazieChecks reflection failed: ${e.javaClass.simpleName}: ${e.message}")
        }
        return null to null
    }
    private fun extractRangeFromTypo(typo: Any): TextRange? {
        // Try to get a relative range from returned Grazie issue/typo via common accessors
        return try {
            // Common getters
            val m1 = typo.javaClass.methods.firstOrNull { it.name == "getRange" && it.parameterCount == 0 }
            val r1 = if (m1 != null) m1.invoke(typo) else null
            when (r1) {
                is TextRange -> return r1
                is IntRange -> return TextRange(r1.first, r1.last + 1)
            }
            val m2 = typo.javaClass.methods.firstOrNull { it.name == "getHighlightRange" && it.parameterCount == 0 }
            val r2 = if (m2 != null) m2.invoke(typo) else null
            when (r2) {
                is TextRange -> return r2
                is IntRange -> return TextRange(r2.first, r2.last + 1)
            }
            // Separate from/to ints
            val fromM = typo.javaClass.methods.firstOrNull { it.name == "getFrom" && it.parameterCount == 0 && it.returnType == Int::class.javaPrimitiveType }
            val toM = typo.javaClass.methods.firstOrNull { it.name == "getTo" && it.parameterCount == 0 && it.returnType == Int::class.javaPrimitiveType }
            if (fromM != null && toM != null) {
                val s = (fromM.invoke(typo) as? Int) ?: return null
                val e = (toM.invoke(typo) as? Int) ?: return null
                if (e > s) return TextRange(s, e)
            }
            null
        } catch (_: Throwable) { null }
    }
    private fun extractMessageFromTypo(typo: Any): String? {
        return try {
            val m = typo.javaClass.methods.firstOrNull { it.name == "getMessage" && it.parameterCount == 0 }
            (m?.invoke(typo) as? String)
        } catch (_: Throwable) { null }
    }
    // Fallback that uses legacy SpellCheckerManager (if present) via reflection to validate words in fragments.
    // Returns number of warnings painted.
    private fun fallbackWithLegacySpellcheckerIfAvailable(
        file: PsiFile,
        fragments: List<Pair<TextContent, TextRange>>,
        holder: AnnotationHolder
    ): Int {
        return try {
            val mgrCls = Class.forName("com.intellij.spellchecker.SpellCheckerManager")
            val getInstance = mgrCls.methods.firstOrNull { it.name == "getInstance" && it.parameterCount == 1 }
            val isCorrect = mgrCls.methods.firstOrNull { it.name == "isCorrect" && it.parameterCount == 1 && it.parameterTypes[0] == String::class.java }
            if (getInstance == null || isCorrect == null) {
                // No legacy spellchecker API available — fall back to naive painter
                return naiveFallbackPaint(file, fragments, holder)
            }
            val mgr = getInstance.invoke(null, file.project)
            if (mgr == null) {
                // Legacy manager not present for this project — use naive fallback
                return naiveFallbackPaint(file, fragments, holder)
            }
            var painted = 0
            val docText = file.viewProvider.document?.text ?: return 0
            val tokenRegex = Regex("[A-Za-z][A-Za-z0-9_']{2,}")
            for ((content, hostRange) in fragments) {
                val text = try { docText.substring(hostRange.startOffset, hostRange.endOffset) } catch (_: Throwable) { null } ?: continue
                var seen = 0
                var flagged = 0
                for (m in tokenRegex.findAll(text)) {
                    val token = m.value
                    if ('%' in token) continue // skip printf fragments defensively
                    // Split snake_case and camelCase within the token
                    val parts = splitIdentifier(token)
                    for (part in parts) {
                        if (part.length <= 2) continue
                        if (isAllowedWord(part)) continue
                        // Quick allowlist for very common words to reduce noise if dictionaries differ
                        val ok = try { isCorrect.invoke(mgr, part) as? Boolean } catch (_: Throwable) { null }
                        if (ok == false) {
                            // Map part back to original token occurrence within this hostRange
                            val localStart = m.range.first + token.indexOf(part)
                            val localEnd = localStart + part.length
                            val abs = TextRange(hostRange.startOffset + localStart, hostRange.startOffset + localEnd)
                            paintTypoAnnotation(file, holder, abs, part)
                            painted++
                            flagged++
                        }
                        seen++
                    }
                }
                log.info("LyngGrazieAnnotator.fallback: fragment words=$seen, flagged=$flagged")
            }
            painted
        } catch (_: Throwable) {
            // If legacy manager is not available, fall back to a very naive heuristic (no external deps)
            return naiveFallbackPaint(file, fragments, holder)
        }
    }
    private fun naiveFallbackPaint(
        file: PsiFile,
        fragments: List<Pair<TextContent, TextRange>>,
        holder: AnnotationHolder
    ): Int {
        var painted = 0
        val docText = file.viewProvider.document?.text
        val tokenRegex = Regex("[A-Za-z][A-Za-z0-9_']{2,}")
        val baseWords = setOf(
            // small, common vocabulary to catch near-miss typos in typical code/comments
            "comment","comments","error","errors","found","file","not","word","words","count","value","name","class","function","string"
        )
        for ((content, hostRange) in fragments) {
            val text: String? = docText?.let { dt ->
                try { dt.substring(hostRange.startOffset, hostRange.endOffset) } catch (_: Throwable) { null }
            }
            if (text.isNullOrBlank()) continue
            var seen = 0
            var flagged = 0
            for (m in tokenRegex.findAll(text)) {
                val token = m.value
                if ('%' in token) continue
                val parts = splitIdentifier(token)
                for (part in parts) {
                    seen++
                    val lower = part.lowercase()
                    if (lower.length <= 2 || isAllowedWord(part)) continue
                    // Heuristic: no vowels OR 3 repeated chars OR ends with unlikely double consonants
                    val noVowel = lower.none { it in "aeiouy" }
                    val triple = Regex("(.)\\1\\1").containsMatchIn(lower)
                    val dblCons = Regex("[bcdfghjklmnpqrstvwxyz]{2}$").containsMatchIn(lower)
                    var looksWrong = noVowel || triple || dblCons
                    // Additional: low vowel ratio for length>=4
                    if (!looksWrong && lower.length >= 4) {
                        val vowels = lower.count { it in "aeiouy" }
                        val ratio = if (lower.isNotEmpty()) vowels.toDouble() / lower.length else 1.0
                        if (ratio < 0.25) looksWrong = true
                    }
                    // Additional: near-miss to a small base vocabulary (edit distance 1, or 2 for words >=6)
                    if (!looksWrong) {
                        for (bw in baseWords) {
                            val d = editDistance(lower, bw)
                            if (d == 1 || (d == 2 && lower.length >= 6)) { looksWrong = true; break }
                        }
                    }
                    if (looksWrong) {
                        val localStart = m.range.first + token.indexOf(part)
                        val localEnd = localStart + part.length
                        val abs = TextRange(hostRange.startOffset + localStart, hostRange.startOffset + localEnd)
                        paintTypoAnnotation(file, holder, abs, part)
                        painted++
                        flagged++
                    }
                }
            }
            log.info("LyngGrazieAnnotator.fallback(naive): fragment words=$seen, flagged=$flagged")
        }
        return painted
    }
    private fun paintTypoAnnotation(file: PsiFile, holder: AnnotationHolder, range: TextRange, word: String) {
        val settings = LyngFormatterSettings.getInstance(file.project)
        val ab = holder.newAnnotation(HighlightSeverity.INFORMATION, "Possible typo")
            .range(range)
        applyTypoStyleIfRequested(file, ab)
        if (settings.offerLyngTypoQuickFixes) {
            // Offer lightweight fixes; for 243 provide Add-to-dictionary always
            ab.withFix(net.sergeych.lyng.idea.grazie.AddToLyngDictionaryFix(word))
            // Offer "Replace with…" candidates (top 7)
            val cands = suggestReplacements(file, word).take(7)
            for (c in cands) {
                ab.withFix(net.sergeych.lyng.idea.grazie.ReplaceWordFix(range, word, c))
            }
        }
        ab.create()
    }
    private fun applyTypoStyleIfRequested(file: PsiFile, ab: com.intellij.lang.annotation.AnnotationBuilder) {
        val settings = LyngFormatterSettings.getInstance(file.project)
        if (!settings.showTyposWithGreenUnderline) return
        // Use the standard TYPO text attributes key used by the platform
        val TYPO: TextAttributesKey = TextAttributesKey.createTextAttributesKey("TYPO")
        try {
            ab.textAttributes(TYPO)
        } catch (_: Throwable) {
            // some IDEs may not allow setting attributes on INFORMATION; ignore gracefully
        }
    }
    private fun suggestReplacements(file: PsiFile, word: String): List<String> {
        val lower = word.lowercase()
        val fromProject = collectProjectWords(file)
        val fromTech = TechDictionary.allWords()
        val fromEnglish = EnglishDictionary.allWords()
        // Merge with priority: project (p=0), tech (p=1), english (p=2)
        val all = LinkedHashSet<String>()
        all.addAll(fromProject)
        all.addAll(fromTech)
        all.addAll(fromEnglish)
        data class Cand(val w: String, val d: Int, val p: Int)
        val cands = ArrayList<Cand>(32)
        for (w in all) {
            if (w == lower) continue
            if (kotlin.math.abs(w.length - lower.length) > 2) continue
            val d = editDistance(lower, w)
            val p = when {
                w in fromProject -> 0
                w in fromTech -> 1
                else -> 2
            }
            cands += Cand(w, d, p)
        }
        cands.sortWith(compareBy<Cand> { it.d }.thenBy { it.p }.thenBy { it.w })
        // Return a larger pool so callers can choose desired display count
        return cands.take(16).map { it.w }
    }
    private fun collectProjectWords(file: PsiFile): Set<String> {
        // Simple approach: use current file text; can be extended to project scanning later
        val text = file.viewProvider.document?.text ?: return emptySet()
        val out = LinkedHashSet<String>()
        val tokenRegex = Regex("[A-Za-z][A-Za-z0-9_']{2,}")
        for (m in tokenRegex.findAll(text)) {
            val parts = splitIdentifier(m.value)
            parts.forEach { out += it.lowercase() }
        }
        // Include learned words
        val settings = LyngFormatterSettings.getInstance(file.project)
        out.addAll(settings.learnedWords.map { it.lowercase() })
        return out
    }
    private fun splitIdentifier(token: String): List<String> {
        // Split on underscores and camelCase boundaries
        val unders = token.split('_').filter { it.isNotBlank() }
        val out = mutableListOf<String>()
        val camelBoundary = Regex("(?<=[a-z])(?=[A-Z])")
        for (u in unders) out += u.split(camelBoundary).filter { it.isNotBlank() }
        return out
    }
    private fun isAllowedWord(w: String): Boolean {
        val s = w.lowercase()
        return s in setOf(
            // common code words / language keywords to avoid noise
            "val","var","fun","class","enum","type","import","package","return","if","else","when","while","for","try","catch","finally","true","false","null",
            // very common English words
            "the","and","or","not","with","from","into","this","that","file","found","count","name","value","object"
        )
    }
    private fun editDistance(a: String, b: String): Int {
        if (a == b) return 0
        if (a.isEmpty()) return b.length
        if (b.isEmpty()) return a.length
        val dp = IntArray(b.length + 1) { it }
        for (i in 1..a.length) {
            var prev = dp[0]
            dp[0] = i
            for (j in 1..b.length) {
                val temp = dp[j]
                dp[j] = minOf(
                    dp[j] + 1,                // deletion
                    dp[j - 1] + 1,            // insertion
                    prev + if (a[i - 1] == b[j - 1]) 0 else 1 // substitution
                )
                prev = temp
            }
        }
        return dp[b.length]
    }
 }
@@ -1,139 +0,0 @@
 /*
 * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
 package net.sergeych.lyng.idea.grazie
 import com.intellij.grazie.grammar.strategy.GrammarCheckingStrategy
 import com.intellij.grazie.grammar.strategy.GrammarCheckingStrategy.TextDomain
 import com.intellij.ide.plugins.PluginManagerCore
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.extensions.PluginId
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiElement
 import net.sergeych.lyng.idea.highlight.LyngTokenTypes
 import net.sergeych.lyng.idea.settings.LyngFormatterSettings
 import net.sergeych.lyng.idea.spell.LyngSpellIndex
 /**
 * Grazie/Natural Languages strategy for Lyng.
 *
 * - Comments: checked as natural language (TextDomain.COMMENTS)
 * - String literals: optionally checked (setting), skipping printf-like specifiers via stealth ranges (TextDomain.LITERALS)
 * - Identifiers (non-keywords): checked under TextDomain.CODE so "Process code" controls apply
 * - Keywords: skipped
 */
 class LyngGrazieStrategy : GrammarCheckingStrategy {
    private val log = Logger.getInstance(LyngGrazieStrategy::class.java)
    @Volatile private var loggedOnce = false
    @Volatile private var loggedFirstMatch = false
    private val seenTypes: MutableSet<String> = java.util.Collections.synchronizedSet(mutableSetOf())
    private fun legacySpellcheckerInstalled(): Boolean =
        PluginManagerCore.isPluginInstalled(PluginId.getId("com.intellij.spellchecker"))
    // Regex for printf-style specifiers: %[flags][width][.precision][length]type
    private val spec = Regex("%(?:[-+ #0]*(?:\\d+)?(?:\\.\\d+)?[a-zA-Z%])")
    override fun isMyContextRoot(element: PsiElement): Boolean {
        val type = element.node?.elementType
        val settings = LyngFormatterSettings.getInstance(element.project)
        val legacyPresent = legacySpellcheckerInstalled()
        if (type != null && seenTypes.size < 10) {
            val name = type.toString()
            if (seenTypes.add(name)) {
                log.info("LyngGrazieStrategy: saw PSI type=$name")
            }
        }
        if (!loggedOnce) {
            loggedOnce = true
            log.info("LyngGrazieStrategy activated: legacyPresent=$legacyPresent, preferGrazieForCommentsAndLiterals=${settings.preferGrazieForCommentsAndLiterals}, spellCheckStringLiterals=${settings.spellCheckStringLiterals}, grazieChecksIdentifiers=${settings.grazieChecksIdentifiers}")
        }
        val file = element.containingFile ?: return false
        val index = LyngSpellIndex.getUpToDate(file) ?: return false // Suspend until ready
        // To ensure Grazie asks TextExtractor for all leafs, accept any Lyng element once index is ready.
        // The extractor will decide per-range/domain what to actually provide.
        if (!loggedFirstMatch) {
            loggedFirstMatch = true
            log.info("LyngGrazieStrategy: enabling Grazie on all Lyng elements (index ready)")
        }
        return true
    }
    override fun getContextRootTextDomain(root: PsiElement): TextDomain {
        val type = root.node?.elementType
        val settings = LyngFormatterSettings.getInstance(root.project)
        val file = root.containingFile
        val index = if (file != null) LyngSpellIndex.getUpToDate(file) else null
        val r = root.textRange
        fun overlaps(list: List<TextRange>): Boolean = r != null && list.any { it.intersects(r) }
        return when (type) {
            LyngTokenTypes.LINE_COMMENT, LyngTokenTypes.BLOCK_COMMENT -> TextDomain.COMMENTS
            LyngTokenTypes.STRING -> if (settings.grazieTreatLiteralsAsComments) TextDomain.COMMENTS else TextDomain.LITERALS
            LyngTokenTypes.IDENTIFIER -> {
                // For Grazie-only reliability in 243, route identifiers via COMMENTS when configured
                if (settings.grazieTreatIdentifiersAsComments && index != null && r != null && overlaps(index.identifiers))
                    TextDomain.COMMENTS
                else TextDomain.PLAIN_TEXT
            }
            else -> TextDomain.PLAIN_TEXT
        }
    }
    // Note: do not override getLanguageSupport to keep compatibility with 243 API
    override fun getStealthyRanges(root: PsiElement, text: CharSequence): java.util.LinkedHashSet<IntRange> {
        val result = LinkedHashSet<IntRange>()
        val type = root.node?.elementType
        if (type == LyngTokenTypes.STRING) {
            if (!shouldCheckLiterals(root)) {
                // Hide the entire string when literals checking is disabled by settings
                result += (0 until text.length)
                return result
            }
            // Hide printf-like specifiers in strings
            val (start, end) = stripQuotesBounds(text)
            if (end > start) {
                val content = text.subSequence(start, end)
                for (m in spec.findAll(content)) {
                    val ms = start + m.range.first
                    val me = start + m.range.last
                    result += (ms..me)
                }
                if (result.isNotEmpty()) {
                    log.debug("LyngGrazieStrategy: hidden ${result.size} printf specifier ranges in string literal")
                }
            }
        }
        return result
    }
    override fun isEnabledByDefault(): Boolean = true
    private fun shouldCheckLiterals(root: PsiElement): Boolean =
        LyngFormatterSettings.getInstance(root.project).spellCheckStringLiterals
    private fun stripQuotesBounds(text: CharSequence): Pair<Int, Int> {
        if (text.length < 2) return 0 to text.length
        val first = text.first()
        val last = text.last()
        return if ((first == '"' && last == '"') || (first == '\'' && last == '\''))
            1 to (text.length - 1) else (0 to text.length)
    }
 }
@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -19,86 +19,29 @@ package net.sergeych.lyng.idea.grazie
 import com.intellij.grazie.text.TextContent
 import com.intellij.grazie.text.TextContent.TextDomain
 import com.intellij.grazie.text.TextExtractor
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.psi.PsiElement
 import net.sergeych.lyng.idea.highlight.LyngTokenTypes
-import net.sergeych.lyng.idea.settings.LyngFormatterSettings
+import net.sergeych.lyng.idea.psi.LyngElementTypes
 import net.sergeych.lyng.idea.spell.LyngSpellIndex
 /**
- * Provides Grazie with extractable text for Lyng PSI elements.
+ * Simplified TextExtractor for Lyng.
- * We return text for identifiers, comments, and (optionally) string literals.
+ * Designates areas for Natural Languages (Grazie) to check.
 * printf-like specifiers are filtered by the Grammar strategy via stealth ranges.
 */
 class LyngTextExtractor : TextExtractor() {
    private val log = Logger.getInstance(LyngTextExtractor::class.java)
    @Volatile private var loggedOnce = false
    private val seen: MutableSet<String> = java.util.Collections.synchronizedSet(mutableSetOf())
    override fun buildTextContent(element: PsiElement, allowedDomains: Set<TextDomain>): TextContent? {
        val type = element.node?.elementType ?: return null
        if (!loggedOnce) {
            loggedOnce = true
            log.info("LyngTextExtractor active; allowedDomains=${allowedDomains.joinToString()}")
        }
        val settings = LyngFormatterSettings.getInstance(element.project)
        val file = element.containingFile
        val index = if (file != null) LyngSpellIndex.getUpToDate(file) else null
        val r = element.textRange
-        fun overlaps(list: List<com.intellij.openapi.util.TextRange>): Boolean = r != null && list.any { it.intersects(r) }
+        val domain = when (type) {
        // Decide target domain by intersection with our MiniAst-driven index; prefer comments > strings > identifiers
        var domain: TextDomain? = null
        if (index != null && r != null) {
            if (overlaps(index.comments)) domain = TextDomain.COMMENTS
            else if (overlaps(index.strings) && settings.spellCheckStringLiterals) domain = TextDomain.LITERALS
            else if (overlaps(index.identifiers)) domain = if (settings.grazieTreatIdentifiersAsComments) TextDomain.COMMENTS else TextDomain.DOCUMENTATION
        } else {
            // Fallback to token type if index is not ready (rare timing), mostly for comments
            domain = when (type) {
            LyngTokenTypes.LINE_COMMENT, LyngTokenTypes.BLOCK_COMMENT -> TextDomain.COMMENTS
-                else -> null
+            LyngTokenTypes.STRING -> TextDomain.LITERALS
            LyngElementTypes.NAME_IDENTIFIER,
            LyngElementTypes.PARAMETER_NAME,
            LyngElementTypes.ENUM_CONSTANT_NAME -> TextDomain.COMMENTS
            else -> return null
        }
        }
        if (domain == null) return null
-        // If literals aren't requested but fallback is enabled, route strings as COMMENTS
+        if (!allowedDomains.contains(domain)) return null
-        if (domain == TextDomain.LITERALS && !allowedDomains.contains(TextDomain.LITERALS) && settings.grazieTreatLiteralsAsComments) {
+        
-            domain = TextDomain.COMMENTS
+        return TextContent.psiFragment(domain, element)
        }
        if (!allowedDomains.contains(domain)) {
            if (seen.add("deny-${domain.name}")) {
                log.info("LyngTextExtractor: domain ${domain.name} not in allowedDomains; skipping")
            }
            return null
        }
        return try {
            // Try common factory names across versions
            val methods = TextContent::class.java.methods.filter { it.name == "psiFragment" }
            val built: TextContent? = when {
                // Try psiFragment(PsiElement, TextDomain)
                methods.any { it.parameterCount == 2 && it.parameterTypes[0].name.contains("PsiElement") } -> {
                    val m = methods.first { it.parameterCount == 2 && it.parameterTypes[0].name.contains("PsiElement") }
                    @Suppress("UNCHECKED_CAST")
                    (m.invoke(null, element, domain) as? TextContent)?.also {
                        if (seen.add("ok-${domain.name}")) log.info("LyngTextExtractor: provided ${domain.name} for ${type} via psiFragment(element, domain)")
                    }
                }
                // Try psiFragment(TextDomain, PsiElement)
                methods.any { it.parameterCount == 2 && it.parameterTypes[0].name.endsWith("TextDomain") } -> {
                    val m = methods.first { it.parameterCount == 2 && it.parameterTypes[0].name.endsWith("TextDomain") }
                    @Suppress("UNCHECKED_CAST")
                    (m.invoke(null, domain, element) as? TextContent)?.also {
                        if (seen.add("ok-${domain.name}")) log.info("LyngTextExtractor: provided ${domain.name} for ${type} via psiFragment(domain, element)")
                    }
                }
                else -> null
            }
            built
        } catch (e: Throwable) {
            log.info("LyngTextExtractor: failed to build TextContent: ${e.javaClass.simpleName}: ${e.message}")
            null
        }
    }
 }
		`@@ -0,0 +1,4 @@`
							`# Obsolete files`


							`__Do not rely on contents of the files in this directory. They are kept for historical reference only and may not be up-to-date or relevant.__`