Add Lyng string interpolation with docs/tests and refresh changelog

+added console support to lyng/jlyng CLI
+added unicode escapes
+created tetris console sample

.gitignore

@@ -21,3 +21,9 @@ xcuserdata
 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

.junie/guidelines.md

@@ -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.

AGENTS.md

@@ -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`.

CHANGELOG.md

@@ -1,119 +1,88 @@
-## Changelog
-
-### Unreleased
-
-- Language: Abstract Classes and Interfaces
-  - Support for `abstract` modifier on classes, methods, and variables.
-  - Introduced `interface` as a synonym for `abstract class`, supporting full state (constructors, fields, `init` blocks) and implementation by parts via MI.
-  - New `closed` modifier (antonym to `open`) to prevent overriding class members.
-  - Refined `override` logic: mandatory keyword when re-declaring members that exist in the ancestor chain (MRO).
-  - MI Satisfaction: Abstract requirements are automatically satisfied by matching concrete members found later in the C3 MRO chain without requiring explicit proxy methods.
-  - Integration: Updated highlighters (lynglib, lyngweb, IDEA plugin), IDEA completion, and Grazie grammar checking.
-  - Documentation: Updated `docs/OOP.md` with sections on "Abstract Classes and Members", "Interfaces", and "Overriding and Virtual Dispatch".
-
-- Language: Class properties with accessors
-  - Support for `val` (read-only) and `var` (read-write) properties in classes.
-  - Syntax: `val name [ : Type ] get() { body }` or `var name [ : Type ] get() { body } set(value) { body }`.
-  - Laconic Expression Shorthand: `val prop get() = expression` and `var prop get() = read set(v) = write`.
-  - Properties are pure accessors and do **not** have automatic backing fields.
-  - Validation: `var` properties must have both accessors; `val` must have only a getter.
-  - Integration: Updated TextMate grammar and IntelliJ plugin (highlighting + keywords).
-  - Documentation: New "Properties" section in `docs/OOP.md`.
-
-- Language: Restricted Setter Visibility
-  - Support for `private set` and `protected set` modifiers on `var` fields and properties.
-  - Allows members to be publicly readable but only writable from within the declaring class or its subclasses.
-  - Enforcement at runtime: throws `AccessException` on unauthorized writes.
-  - Supported only for declarations in class bodies (fields and properties).
-  - Documentation: New "Restricted Setter Visibility" section in `docs/OOP.md`.
-
-- Language: Late-initialized `val` fields in classes
-  - Support for declaring `val` without an immediate initializer in class bodies.
-  - Compulsory initialization: every late-init `val` must be assigned at least once within the class body or an `init` block.
-  - Write-once enforcement: assigning to a `val` is allowed only if its current value is `Unset`.
-  - Access protection: reading a late-init `val` before it is assigned returns the `Unset` singleton; using `Unset` for most operations throws an `UnsetException`.
-  - Extension properties do not support late-init.
-  - Documentation: New "Late-initialized `val` fields" and "The `Unset` singleton" sections in `docs/OOP.md`.
-
-- Docs: OOP improvements
-  - 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.
-  - 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.
-  - Fix: Property accessors (`get`, `set`, `private set`, `protected set`) are now correctly indented relative to the property declaration.
-  - Fix: Indentation now correctly carries over into blocks that start on extra‑indented lines (e.g., nested `if` statements or property accessor bodies).
-  - Fix: Formatting Markdown files no longer deletes content in `.lyng` code fences and works correctly with injected files (resolves clobbering, `StringIndexOutOfBoundsException`, and `nonempty text is not covered by block` errors).
+## 1.5.1 (2026-03-25)
 
-- CLI: Preserved legacy script invocation fast-paths:
-  - `lyng script.lyng [args...]` executes the script directly.
-  - `lyng -- -file.lyng [args...]` executes a script whose name begins with `-`.
+### Language
+- Added string interpolation:
+  - `"$name"` identifier interpolation.
+  - `"${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.
-  - Root command no longer prints help when a subcommand (e.g., `fmt`) is invoked.
+### Docs and AI references
+- 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.

LYNG_AI_SPEC.md

@@ -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.

README.md

@@ -1,6 +1,14 @@
-# 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:
 
@@ -17,37 +25,38 @@ 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]
-
-```
-  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.
+- 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.
 - 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
 
@@ -55,7 +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 {
     // ...
@@ -79,7 +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
@@ -95,9 +104,7 @@ Script is executed over some `Scope`. Create instance,
 add your specific vars and functions to it, and call:
 
 ```kotlin
-
-import com.sun.source.tree.Scope
-import new.sergeych.lyng.*
+import net.sergeych.lyng.*
 
 // simple function
 val scope = Script.newScope().apply {
@@ -145,6 +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/++.
@@ -164,7 +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:
@@ -176,6 +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?)
@@ -191,8 +205,19 @@ Ready features:
 - [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

archived/README.md

@@ -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.__

archived/proposals/delegates.lyng

@@ -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 } }
+
+

bin/deploy_all

@@ -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

bin/deploy_plugin

@@ -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

bin/deploy_site

@@ -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.
@@ -107,6 +116,8 @@ function refreshTextmateZip() {
   (cd editors && zip -rq ../distributables/lyng-textmate.zip .)
 }
 
+
+if [[ "$upload_only" == false ]]; 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"
@@ -125,9 +136,7 @@ if [[ $BUILD_RC -ne 0 ]]; then
     echo
     exit 100
   fi
-
-
-#exit 0
+fi
 
 # Prepare working dir
 ssh -p ${SSH_PORT} ${SSH_HOST} "
@@ -143,12 +152,15 @@ ssh -p ${SSH_PORT} ${SSH_HOST} "
   fi
 ";
 
+if [[ "$upload_only" == false ]]; then
   # sync files
   SRC=./site/build/dist/js/productionExecutable
   rsync -e "ssh -p ${SSH_PORT}" -avz -r -d --delete ${SRC}/* ${SSH_HOST}:${ROOT}/build/dist
   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
 

build.gradle.kts

@@ -35,3 +35,27 @@ tasks.register<Exec>("generateDocs") {
     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()
+        )
+    }
+}

bytecode_migration_plan.md

@@ -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)

docs/Array.md

@@ -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
-[List].
+Array therefore implements [Iterable] too. Well known implementations of `Array` are
+[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

docs/Buffer.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)

docs/BytecodeSpec.md

@@ -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.

docs/Collection.md

@@ -6,6 +6,13 @@ 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                                          |
 |------------------------|------------------------------------------------------|
 
@@ -17,3 +24,8 @@ See [List], [Set], [Iterable] and [Efficient Iterables in Kotlin Interop](Effici
 [Iterable]: Iterable.md
 [List]: List.md
 [Set]: Set.md
+[Map]: Map.md
+[ImmutableList]: ImmutableList.md
+[ImmutableSet]: ImmutableSet.md
+[ImmutableMap]: ImmutableMap.md
+[ObservableList]: ObservableList.md

docs/ImmutableList.md

@@ -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

docs/ImmutableMap.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

docs/ImmutableSet.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

docs/Iterable.md

@@ -108,8 +108,8 @@ You can also use flow variations that return a cold `Flow` instead of a `List`,
 Find the minimum or maximum value of a function applied to each element:
 
     val source = ["abc", "de", "fghi"]
-    assertEquals(2, source.minOf { it.length })
-    assertEquals(4, source.maxOf { it.length })
+    assertEquals(2, source.minOf { (it as String).length })
+    assertEquals(4, source.maxOf { (it as String).length })
     >>> void
 
 ## flatten and flatMap
@@ -147,12 +147,15 @@ Search for the first element that satisfies the given predicate:
 | 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 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 |
@@ -206,16 +209,20 @@ For high-performance Kotlin-side interop and custom iterable implementation deta
 
 ## 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

docs/List.md

@@ -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`:
 
@@ -179,6 +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  |
@@ -197,3 +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

docs/Map.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
@@ -176,3 +178,4 @@ Notes:
 - 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

docs/OOP.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:
@@ -71,14 +71,99 @@ object DefaultLogger : Logger("Default") {
 }
 ```
 
+## 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 `get()`/`set()` blocks:
+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
@@ -94,21 +179,17 @@ class Person(private var _age: Int) {
             if (value >= 0) _age = value
         }
 }
-
-val p = Person(15)
-assertEquals("Minor", p.ageCategory)
-p.age = 20
-assertEquals("Adult", p.ageCategory)
 ```
 
-### Laconic Expression Shorthand
+### Laconic Syntax (Optional Parentheses)
 
-For simple accessors and methods, you can use the `=` shorthand for a more elegant and laconic form:
+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) {
-    val area get() = π * radius * radius
-    val circumference get() = 2 * π * radius
+    // Laconic expression shorthand
+    val area get = π * radius * radius
+    val circumference get = 2 * π * radius
     
     fun diameter() = radius * 2
 }
@@ -117,15 +198,16 @@ fun median(a, b) = (a + b) / 2
 
 class Counter {
     private var _count = 0
-    var count get() = _count set(v) = _count = v
+    var count get = _count set(v) = _count = v
 }
 ```
 
 ### Key Rules
 
-- **`val` properties** must have a `get()` accessor and cannot have a `set()`.
-- **`var` properties** must have both `get()` and `set()` accessors.
+- **`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.
 
@@ -182,6 +264,19 @@ A delegate is any object that provides the following methods (all optional depen
 - `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
@@ -281,11 +376,10 @@ 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) {
-        // public method declaration:
-        fun length() { sqrt(d2()) }
-
         // private method:
         private fun d2() { x*x + y*y }
+        // public method declaration:
+        fun length() { sqrt(d2()) }
     }
     val p = Point(3,4)
     // private called from inside public: OK
@@ -372,7 +466,7 @@ 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.
 
 ## Abstract Classes and Members
 
@@ -489,6 +583,99 @@ class Critical {
 
 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:
 
 - Existing single‑inheritance code continues to work unchanged; its resolution order reduces to the single base.
@@ -572,6 +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:
@@ -694,23 +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). 
 
-```
-class A() {
-    protected fun ping() { "pong" }
+Protected members are not available from unrelated contexts:
+
+```lyng
+class Base {
+    abstract protected fun foo()
+    
+    fun bar() {
+        // Ancestor can see foo() because it's an override 
+        // of a member it defines (even as abstract):
+        foo()
     }
-class B() : A() {
-    fun call() { this@A.ping() }
 }
 
-val b = B()
-assertEquals("pong", b.call())
+class Derived : Base {
+    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
@@ -753,7 +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" )
@@ -764,24 +989,16 @@ 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:
-        private static var data = null
-
-        // the interface to access and change it:
-        static fun getData() { data }
-        static fun setData(value) { data = value }
+        static var data = "foo"
+        static fun getData() { Test.data }
     }
 
-    // no direct access:
-    assertThrows { Test.data }
-
-    // accessible with the interface:
-    assertEquals( null, Test.getData() )
-    Test.setData("fubar")
-    assertEquals("fubar", Test.getData() )
+    assertEquals( "foo", Test.getData() )
+    Test.data = "bar"
+    assertEquals("bar", Test.getData() )
     >>> void
 
 # Extending classes
@@ -790,23 +1007,11 @@ It sometimes happen that the class is missing some particular functionality that
 
 ## Extension methods
 
-For example, we want to create an extension method 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:
+For example, we want to create an extension method that would test if a value can be interpreted as an integer:
 
-        fun Object.isInteger() {
-            when(this) {
-                // already Int?
-                is Int -> true
-
-                // real, but with no declimal part?
-                is Real -> toInt() == this
-
-                // string with int or real reuusig code above
-                is String -> toReal().isInteger()
-                
-                // otherwise, no:
-                else -> false
-            }
-        }
+        fun Int.isInteger() { true }
+        fun Real.isInteger() { this.toInt() == this }
+        fun String.isInteger() { (this.toReal() as Real).isInteger() }
 
         // Let's test:
         assert( 12.isInteger() == true )
@@ -910,7 +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 ->

docs/ObservableList.md

@@ -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

docs/Range.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
-use finite ranges in loops and convert it to lists:
+Finite ranges are [Iterable] and can be used in loops and list conversions.
+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          |
-| end             |                              | Bool          |
+| step            | explicit iteration step      | Any?          |
+| 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

docs/Real.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 |
 |                 |                                                             |      |
 |                 |                                                             |      |
 |                 |                                                             |      |

docs/Regex.md

@@ -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 )
-    assertEquals( "abc123", result[0] )
-    assertEquals( "1", result[1] )
-    assertEquals( "2", result[2] )
-    assertEquals( "3", result[3] )
+    val match: RegexMatch = result as RegexMatch
+    assertEquals( 12 ..< 17, match.range )
+    assertEquals( "abc123", match[0] )
+    assertEquals( "1", match[1] )
+    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 )
-    assertEquals( "abc123", $~[0] )
-    assertEquals( "1", $~[1] )
-    assertEquals( "2", $~[2] )
-    assertEquals( "3", $~[3] )
+    val match2: RegexMatch = $~ as RegexMatch
+    assertEquals( 12 ..< 17, match2.range )
+    assertEquals( "abc123", match2[0] )
+    assertEquals( "1", match2[1] )
+    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
-

docs/Set.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
-    assertEquals( Set(1,4), Set(3, 1, 4) * Set(2, 4, 1) )
+    // or simple (intersection)
+    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

docs/advanced_topics.md

@@ -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")
-    assertEquals(registered["bar"](), "called foo2")
-    >>> void
+    val fooFn: Callable = registered["foo"] as Callable
+    val barFn: Callable = registered["bar"] as Callable
+    assertEquals(fooFn(), "called foo")
+    assertEquals(barFn(), "called foo2")
 
 [parallelism]: parallelism.md
 

docs/ai_language_reference.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.

docs/ai_notes_wasm_generation_bug.md

@@ -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.

docs/ai_stdlib_reference.md

@@ -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`).

docs/declaring_arguments.md

@@ -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")

docs/delegation.md

@@ -57,7 +57,8 @@ class lazy(val creator) : Delegate {
 
     override fun getValue(thisRef, name) {
         if (value == Unset) {
-            value = creator()
+            // calculate value using thisRef as this:
+            value = with(thisRef) creator()
         }
         value
     }
@@ -150,6 +151,24 @@ fun test() {
 }
 ```
 
+### 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:

docs/embedding.md

@@ -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 +65,74 @@ 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()`.
 
 ```kotlin
-// Read‑only constant
-scope.addConst("pi", ObjReal(3.14159))
+import net.sergeych.lyng.bridge.*
+import net.sergeych.lyng.obj.ObjInt
+import net.sergeych.lyng.obj.ObjString
 
-// Mutable variable: create or update
-scope.addOrUpdateItem("counter", ObjInt(0))
+val im = Script.defaultImportManager.copy()
+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
-scope.eval("counter = counter + 1")
+    val binder = module.globalBinder()
+
+    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)
+```
+
+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
@@ -103,12 +147,28 @@ 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") { ... }`.
 
+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.
@@ -122,6 +182,9 @@ 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)
 ```
 
@@ -153,6 +216,16 @@ myClass.addProperty(
     }
 )
 
+// 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)
 ```
 
@@ -164,6 +237,158 @@ 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.
@@ -224,6 +449,9 @@ 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
@@ -231,11 +459,19 @@ val im: ImportManager = scope.importManager
 
 // Register a package "my.tools"
 im.addPackage("my.tools") { module: ModuleScope ->
-    // Expose symbols inside the module scope
-    module.addConst("version", ObjString("1.0"))
-    module.addFn<ObjInt>("triple") {
-        val x = args.firstAndOnly() as ObjInt
-        ObjInt(x.value * 3)
+    module.eval(
+        """
+        extern val version: String
+        extern fun triple(x: Int): Int
+        """.trimIndent()
+    )
+    val binder = module.globalBinder()
+    binder.bindGlobalVar(
+        name = "version",
+        get = { "1.0" }
+    )
+    binder.bindGlobalFun1<Int>("triple") { x ->
+        ObjInt.of((x * 3).toLong())
     }
 }
 
@@ -286,6 +522,46 @@ 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.

docs/exceptions_handling.md

@@ -129,9 +129,11 @@ 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:
@@ -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` |
 | 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

docs/generics.md

@@ -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.

docs/idea_plugin.md

@@ -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

docs/json_and_kotlin_serialization.md

@@ -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
     

docs/lyng.io.console.md

@@ -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`.

docs/lyng.io.fs.md

@@ -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

docs/lyng.io.process.md

@@ -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`.

docs/lyng_d_files.md

@@ -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.

docs/lyngio.md

@@ -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) | ❌ | ❌ |

docs/math.md

@@ -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

docs/migrate_time_to_2_2.md

@@ -4,7 +4,7 @@
 
 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 an exptic decision to remove `Instant` and `Clock` from kotlinx.datetime and replace it with _yet experimental_ analogs in `kotlin.time`.
+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). 
 
@@ -12,14 +12,14 @@ Later JetBrains added serializers for their new `Instant` and `Clock` types, but
 
 ## Solution
 
-We hereby publish a new version of Lyng, 1.0.8-SNAPSHOT, which uses `ktlin.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. Still you might need to migrate your code to use `kotlinx.datetime` types.
+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, plase do:
+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 suh a brillant ideas from IDEA ideologspersons.
+This should solve the problem and hopefully we'll see no more such "brilliant" ideas from IDEA ideologspersons.
 
-Sorry for inconvenicence and send a ray of hate to JetBrains ;)
+Sorry for inconvenience and send a ray of hate to JetBrains ;)

docs/parallelism.md

@@ -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
-                delay(10)
+                val c = counter ?: 0
                 counter = c + 1
             }
         }
-    }.forEach { it.await() }
-    assertEquals(4, counter)
+    }.forEach { (it as Deferred).await() }
+    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
-2. Captured receiver instance/class members
-3. Closure ancestry locals + each frame’s `this` members (cycle‑safe)
-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)
+- **Captured locals are slots**: outer locals are resolved at compile time and captured as frame‑slot references, so they remain visible across suspension points.
+- **Members are statically resolved**: member access requires a statically known receiver type or an explicit cast (except `Object` members).
+- **No runtime fallbacks**: there is no dynamic name lookup or “search parent scopes” at runtime for missing symbols.
 
 Implications:
-- Outer locals (e.g., `counter`) stay visible across suspension points.
-- Global helpers like `delay(ms)` and `yield()` are available from inside closures.
-- If you write your own async helpers, execute user lambdas under `ClosureScope(callScope, capturedCreatorScope)` and avoid manual ancestry walking.
+- Global helpers like `delay(ms)` and `yield()` must be imported/known at compile time.
+- If you need dynamic access, use explicit helpers (e.g., `dynamic { ... }`) rather than relying on scope resolution.
 
-See also: [Scopes and Closures: resolution and safety](scopes_and_closures.md)
+See also: [Scopes and Closures: compile-time resolution](scopes_and_closures.md)

docs/perf_guide.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.

docs/return_statement.md

@@ -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`.

docs/samples/definitions.lyng.d

@@ -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
+}

docs/samples/fs_sample.lyng

@@ -1,7 +1,6 @@
 #!/bin/env lyng
 
 import lyng.io.fs
-import lyng.stdlib
 
 val files = Path("../..").list().toList()
 // most long is longest?

docs/samples/happy_numbers.lyng.bad

@@ -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( n2 in 0..9 )
-            for( n3 in 0..9 )
-                for( n4 in 0..9 )
-                    for( n5 in 0..9 )
-                        for( n6 in 0..9 )
+    for( n1 in 0..9 ) {
+        for( n2 in 0..9 ) {
+            for( n3 in 0..9 ) {
+                for( n4 in 0..9 ) {
+                    for( n5 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)
 }
-

docs/samples/operator_overloading.lyng

@@ -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)

docs/samples/sum.lyng

@@ -13,7 +13,6 @@ fun findSumLimit(f) {
             println("limit reached after "+n+" rounds")
             break sum
         }
-        n++
     }
     else {
         println("limit not reached")

docs/samples/type_nullability_checks.lyng

@@ -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))

docs/scopes_and_closures.md

@@ -1,95 +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
-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.
+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.
 
-## Resolution order in ClosureScope
-When evaluating an identifier `name` inside a closure, `ClosureScope.get(name)` resolves in this order:
+## Current rules (bytecode compiler)
+- **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
-2. Captured receiver (`closureScope.thisObj`) instance/class members
-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
+## Explicit dynamic access (opt-in only)
+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.
 
-This preserves intuitive visibility (locals → captured receiver → closure chain → caller members → caller chain → module/root) while preventing infinite recursion between scope types.
-
-## 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.
-
-## Practical Example: `cached`
-
-The `cached` function (defined in `lyng.stdlib`) is a classic example of using closures to maintain state. It wraps a builder into a zero-argument function that computes once and remembers the result:
-
-```lyng
-fun cached(builder) {
-    var calculated = false
-    var value = null
-    { // This lambda captures `calculated`, `value`, and `builder`
-        if( !calculated ) {
-            value = builder()
-            calculated = true
-        }
-        value
-    }
-}
-```
-
-Because Lyng now correctly isolates closures for each evaluation of a lambda literal, using `cached` inside a class instance works as expected: each instance maintains its own private `calculated` and `value` state, even if they share the same property declaration.
-
-## 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.
+## 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.

docs/serialization.md

@@ -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 )
-    assertEquals( 6, p.y )
-    >>> void
+    init {
+        // cachedValue can be recomputed here upon deserialization
+        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:
 

docs/time.md

@@ -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
-- `Duration` to represent amount of time not depending on the calendar, e.g. in absolute units (milliseconds, seconds,
-  hours, days)
+- `Instant` class for absolute time stamps with platform-dependent resolution.
+- `DateTime` class for calendar-aware points in time within a specific time zone.
+- `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
-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.
+Represent some moment of time not depending on the calendar. It is similar to `TIMESTAMP` in SQL or `Instant` in Kotlin.
 
-Instant is comparable to other Instant. Subtracting instants produce `Duration`, period in time that is not dependent on
-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:
+### Constructing and converting
 
     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:
-    val now = Instant()
+    // truncation:
+    val t4 = t3.truncateToMinute
+    assertEquals(t4.toRFC3339(), "2024-01-01T12:00:00Z")
     
-    // constructor with Instant instance makes a copy:
-    assertEquals( now, Instant(now) )
+    // to localized DateTime (uses system default TZ if not specified):
+    val dt = t3.toDateTime("+02:00")
+    assertEquals(dt.hour, 14)
 
-    // constructing from a number is trated as seconds since unix epoch:
-    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
+### 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                  |  
-| truncateToMillisecond: Instant | truncate new instance with to millisecond               |
+| truncateToMinute: Instant      | create new instance truncated to minute                 |
+| 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)
-: 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)
+## Calendar time: `DateTime`
 
-## 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 |
-| Instant.distantPast: Instant   | most distant instant in past                 |
-| Instant.distantFuture: Instant | most distant instant in future               |
+|----------------------------------|-----------------------------------------------|
+| year: Int                        | year component                                |
+| month: Int                       | month component (1..12)                       |
+| 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`.
 

docs/tutorial.md

@@ -8,12 +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)
 
@@ -32,6 +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() {
@@ -97,6 +107,23 @@ Singleton objects are declared using the `object` keyword. They define a class a
     
     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.
@@ -179,14 +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
-    assert( 25 == (x*=5) )
-    assert( 25 == x)
-    assert( 24 == (x-=1) )
-    assert( 12 == (x/=2) )
-    x
-    >>> 12
+    var x = null
+    x ?= 10
+    assertEquals(10, x)
+    x ?= 20
+    assertEquals(10, x)
 
 Notice the parentheses here: the assignment has low priority!
 
@@ -203,9 +229,8 @@ Naturally, assignment returns its value:
 rvalue means you cant assign the result if the assignment
 
     var x
-    assertThrows { (x = 11) = 5 }
-    void
-    >>> void
+    // compile-time error: can't assign to rvalue
+    (x = 11) = 5
 
 This also prevents chain assignments so use parentheses:
 
@@ -216,29 +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
-    assertThrows {  ref.field }
-    assertThrows {  ref.method() }
-    assertThrows {  ref.array[1] }
-    assertThrows {  ref[1] }
-    assertThrows {  ref() }
+    class Sample {
+        var field = 1
+        fun method() { 2 }
+        var list = [1, 2, 3]
+    }
+
+    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?[1] == null )
-    assert( ref?() == null )
+    assert( ref?.list?[1] == null )
+    assert( list?[1] == 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
@@ -283,8 +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)
-    val p = Point(1,2).also { it.x++ }
+    class Point(var x: Int, var y: Int)
+    val p: Point = Point(1,2).also { it.x++ }
     assertEquals(p.x, 2)
     >>> void
 
@@ -292,12 +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:
@@ -400,8 +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
@@ -409,6 +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) {
@@ -450,8 +659,9 @@ There are default parameters in Lyng:
 It is possible to define also vararg using ellipsis:
 
     fun sum(args...) {
-        var result = args[0]
-        for( i in 1 ..< args.size ) result += args[i]
+        val list = args as List
+        var result = list[0]
+        for( i in 1 ..< list.size ) result += list[i]
     }
     sum(10,20,30)
     >>> 60
@@ -544,6 +754,11 @@ 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)
@@ -554,6 +769,7 @@ See also: [Testing and Assertions](Testing.md)
         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
 
@@ -581,6 +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:
 
@@ -589,7 +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).
@@ -763,6 +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
 
@@ -823,6 +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
 
@@ -1037,8 +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) {
-        val x = if( candidate !is Int) candidate.toInt() else candidate
+    fun naive_is_prime(candidate: Int) {
+        val x = candidate
         var divisor = 1
         while( ++divisor < x/2 || divisor == 2 ) {
             if( x % divisor == 0 ) break false
@@ -1113,8 +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"]) {
-        letters += w.length
+    val words: List<String> = ["hello", "world"]
+    for( w in words) {
+        letters += (w as String).length
     }
     "total letters: "+letters
     >>> "total letters: 10"
@@ -1227,7 +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
@@ -1305,7 +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     |
 |--------|---------------------------------|---------------------|
@@ -1315,6 +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                   |                     |
@@ -1334,21 +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:
@@ -1360,6 +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
 
@@ -1437,22 +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(), lowercase() | change case to unicode upper                               |
 | 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                    |
@@ -1469,7 +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)                         |
 |                      |                                                            |
@@ -1519,7 +1801,7 @@ See [math functions](math.md). Other general purpose functions are:
 | flow {}                               | create flow sequence, see [parallelism]                    |
 | delay, launch, yield                  | see [parallelism]                                          |
 | 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. 
@@ -1535,6 +1817,7 @@ 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
 
@@ -1546,13 +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
 
@@ -1670,7 +1955,7 @@ 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.
 
 ## Extension members
@@ -1685,7 +1970,7 @@ You can add new methods and properties to existing classes without modifying the
 
 ### Extension properties
 
-    val Int.isEven = this % 2 == 0
+    val Int.isEven get() = this % 2 == 0
     4.isEven
     >>> true
 

docs/wasm_generation_bug.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.

docs/whats_new.md

@@ -1,6 +1,7 @@
 # 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
 
@@ -24,6 +25,9 @@ class Person(private var _age: Int) {
 ### 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
@@ -98,13 +102,47 @@ Singleton objects are declared using the `object` keyword. They provide a conven
 
 ```lyng
 object Config {
-    val version = "1.2.3"
+    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.
 
@@ -123,6 +161,70 @@ var name by Observable("initial") { n, old, new ->
 
 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
@@ -138,3 +240,15 @@ lyng fmt --check MyFile.lyng     # Check if file needs formatting
 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.

docs/whats_new_1_3.md

@@ -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`

docs/whats_new_1_5.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)

editors/lyng-textmate/syntaxes/lyng.tmLanguage.json

@@ -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}_]*)\\.)?([\\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)\\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|interface|val|var|import|package|constructor|property|abstract|override|open|closed|extern|private|protected|static|get|set)\\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)" } ] },
+    "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|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(?:@[\\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": ":" } ] }

examples/tetris_console.lyng

@@ -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))
+    }
+}

gradle.properties

@@ -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

gradle/libs.versions.toml

@@ -1,10 +1,12 @@
 [versions]
 agp = "8.5.2"
 clikt = "5.0.3"
+mordant = "3.0.2"
 kotlin = "2.3.0"
 android-minSdk = "24"
 android-compileSdk = "34"
 kotlinx-coroutines = "1.10.2"
+kotlinx-datetime = "0.6.1"
 mp_bintools = "0.3.2"
 firebaseCrashlyticsBuildtools = "3.0.3"
 okioVersion = "3.10.2"
@@ -13,9 +15,12 @@ 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" }
 firebase-crashlytics-buildtools = { group = "com.google.firebase", name = "firebase-crashlytics-buildtools", version.ref = "firebaseCrashlyticsBuildtools" }
 okio = { module = "com.squareup.okio:okio", version.ref = "okioVersion" }

lyng-idea/build.gradle.kts

@@ -17,7 +17,7 @@
 
 plugins {
     kotlin("jvm")
-    id("org.jetbrains.intellij") version "1.17.3"
+    id("org.jetbrains.intellij") version "1.17.4"
 }
 
 group = "net.sergeych.lyng"
@@ -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

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/LyngFileTypeFactory.kt

@@ -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"))
+    }
+}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/actions/RunLyngScriptAction.kt

@@ -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
+    }
+}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/annotators/LyngExternalAnnotator.kt

@@ -25,320 +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.miniast.*
+import net.sergeych.lyng.idea.util.LyngAstManager
+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 Result(val modStamp: Long, val spans: List<Span>, val error: Error? = null,
-                      val spellIdentifiers: List<IntRange> = emptyList(),
-                      val spellComments: List<IntRange> = emptyList(),
-                      val spellStrings: List<IntRange> = emptyList())
+    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 diagnostics: List<Diag> = 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 prev = if (cached != null && cached.modStamp == doc.modificationStamp) cached.spans else null
-        return Input(doc.text, doc.modificationStamp, prev)
+        val combinedStamp = LyngAstManager.getCombinedStamp(file)
+
+        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 sink = MiniAstBuilder()
-        val source = Source("<ide>", text)
-        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)
-        }
+        val analysis = LyngAstManager.getAnalysis(collectedInfo.file)
+            ?: return Result(collectedInfo.modStamp, collectedInfo.previousSpans ?: emptyList())
+        val mini = analysis.mini
+
         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)
-            putRange(s, (s + name.length).coerceAtMost(text.length), key)
-        }
-        fun putMiniRange(r: MiniRange, key: com.intellij.openapi.editor.colors.TextAttributesKey) {
-            val s = source.offsetOf(r.start)
-            val e = source.offsetOf(r.end)
-            putRange(s, e, key)
+
+        fun keyForKind(kind: LyngSemanticKind): com.intellij.openapi.editor.colors.TextAttributesKey? = when (kind) {
+            LyngSemanticKind.Function -> LyngHighlighterColors.FUNCTION
+            LyngSemanticKind.Class, LyngSemanticKind.Enum, LyngSemanticKind.TypeAlias -> LyngHighlighterColors.TYPE
+            LyngSemanticKind.Value -> LyngHighlighterColors.VALUE
+            LyngSemanticKind.Variable -> LyngHighlighterColors.VARIABLE
+            LyngSemanticKind.Parameter -> LyngHighlighterColors.PARAMETER
+            LyngSemanticKind.TypeRef -> LyngHighlighterColors.TYPE
+            LyngSemanticKind.EnumConstant -> LyngHighlighterColors.ENUM_CONSTANT
         }
 
-        // Declarations
-        for (d in mini.declarations) {
-            when (d) {
-                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
-                )
-                is MiniEnumDecl -> putName(d.nameStart, d.name, LyngHighlighterColors.TYPE)
-            }
+        // Semantic highlights from shared tooling
+        LyngLanguageTools.semanticHighlights(analysis).forEach { span ->
+            keyForKind(span.kind)?.let { putRange(span.range.start, span.range.endExclusive, it) }
         }
 
         // Imports: each segment as namespace/path
-        for (imp in mini.imports) {
-            for (seg in imp.segments) putMiniRange(seg.range, LyngHighlighterColors.NAMESPACE)
+        mini?.imports?.forEach { imp ->
+            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)
+                    val end = analysis.source.offsetOf(seg.range.end)
+                    putRange(start, end, LyngHighlighterColors.NAMESPACE)
                 }
-
-        // Parameters
-        for (fn in mini.declarations.filterIsInstance<MiniFunDecl>()) {
-            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) }
-                    addTypeSegments(d.receiver)
-                }
-                is MiniValDecl -> {
-                    addTypeSegments(d.type)
-                    addTypeSegments(d.receiver)
-                }
-                is MiniClassDecl -> {
-                    d.ctorFields.forEach { addTypeSegments(it.type) }
-                    d.classFields.forEach { addTypeSegments(it.type) }
-                }
-                is MiniEnumDecl -> {}
             }
         }
 
-        ProgressManager.checkCanceled()
-
-        // 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.Parameter -> LyngHighlighterColors.PARAMETER
-                SymbolKind.Value -> LyngHighlighterColors.VALUE
-                SymbolKind.Variable -> 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)
+        // Add annotation/label coloring using token highlighter
         run {
-            val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
-            for (s in tokens) if (s.kind == HighlightKind.Label) {
+            analysis.lexicalHighlights.forEach { s ->
+                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 }
-                    if (lexeme != null && lexeme.startsWith("@")) {
+                        val lexeme = try {
+                            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
-        val idRanges = mutableSetOf<IntRange>()
-        try {
-            val binding = Binder.bind(text, mini)
-            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)
+        analysis.diagnostics.forEach { d ->
+            val range = d.range ?: return@forEach
+            val severity = if (d.severity == LyngDiagnosticSeverity.Warning) HighlightSeverity.WARNING else HighlightSeverity.ERROR
+            diags += Diag(range.start, range.endExclusive, d.message, severity)
         }
-            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,
-            spellIdentifiers = idRanges.toList(),
-            spellComments = commentRanges,
-            spellStrings = stringRanges)
+        return Result(collectedInfo.modStamp, out, diags)
     }
 
+
     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 currentStamp = doc?.modificationStamp
+        val combinedStamp = LyngAstManager.getCombinedStamp(file)
         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 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") }
-        }
+        val doc = file.viewProvider.document
 
         for (s in result.spans) {
             holder.newSilentAnnotation(HighlightSeverity.INFORMATION)
@@ -347,13 +164,12 @@ class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, Lyn
                 .create()
         }
 
-        // Show syntax error if present
-        val err = result.error
-        if (err != null) {
-            val start = err.start.coerceIn(0, (doc?.textLength ?: 0))
-            val end = err.end.coerceIn(start, (doc?.textLength ?: start))
+        // Show errors and warnings
+        result.diagnostics.forEach { d ->
+            val start = d.start.coerceIn(0, (doc?.textLength ?: 0))
+            val end = d.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()
             }
@@ -364,30 +180,15 @@ class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, Lyn
         private val CACHE_KEY: Key<Result> = Key.create("LYNG_SEMANTIC_CACHE")
     }
 
-    /**
-     * Make the error highlight a bit wider than a single character so it is easier to see and click.
-     * Strategy:
-     *  - If the offset points inside an identifier-like token (letters/digits/underscore), expand to the full token.
-     *  - Otherwise select a small range starting at the offset with a minimum width, but not crossing the line end.
-     */
-    private fun expandErrorRange(text: String, rawStart: Int): Pair<Int, Int> {
-        if (text.isEmpty()) return 0 to 0
-        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
+    private fun prevNonWs(text: String, idxExclusive: Int): Int {
+        var i = idxExclusive - 1
+        while (i >= 0) {
+            val ch = text[i]
+            if (ch != ' ' && ch != '\t' && ch != '\n' && ch != '\r') return i
+            i--
+        }
+        return -1
     }
 
-        // 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
-    }
+    
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/completion/LyngCompletionContributor.kt

@@ -30,7 +30,6 @@ import com.intellij.patterns.PlatformPatterns
 import com.intellij.psi.PsiFile
 import com.intellij.util.ProcessingContext
 import kotlinx.coroutines.runBlocking
-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
@@ -97,13 +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
-            val mini = LyngAstManager.getMiniAst(file)
-            val binding = LyngAstManager.getBinding(file)
+            // Build analysis (cached) for both global and member contexts to enable local class/val inference
+            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()
@@ -117,11 +117,12 @@ 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 =
@@ -136,7 +137,7 @@ class LyngCompletionContributor : CompletionContributor() {
 
                 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)")
@@ -144,11 +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) {
@@ -166,19 +162,25 @@ class LyngCompletionContributor : CompletionContributor() {
                         .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")
@@ -191,33 +193,51 @@ class LyngCompletionContributor : CompletionContributor() {
                         ?: DocLookupUtils.guessReturnClassAcrossKnownCallees(text, memberDotPos, imported, mini)
                         ?: DocLookupUtils.guessReceiverClass(text, memberDotPos, imported, mini)
                 if (!inferredClass.isNullOrBlank()) {
-                    val ext = BuiltinDocRegistry.extensionMemberNamesFor(inferredClass)
-                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Post-engine extension check for $inferredClass: ${'$'}{ext}")
+                    val ext = DocLookupUtils.collectExtensionMemberNames(imported, inferredClass, mini)
+                    if (DEBUG_COMPLETION) log.info("[LYNG_DEBUG] Post-engine extension check for $inferredClass: ${ext}")
                     for (name in ext) {
                         if (existing.contains(name)) continue
                         val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, inferredClass, name, mini)
                         if (resolved != null) {
-                            when (val member = resolved.second) {
+                            val m = resolved.second
+                            val builder = when (m) {
                                 is MiniMemberFunDecl -> {
-                                    val params = member.params.joinToString(", ") { it.name }
-                                    val ret = typeOf(member.returnType)
-                                    val builder = LookupElementBuilder.create(name)
+                                    val params = m.params.joinToString(", ") { it.name }
+                                    val ret = typeOf(m.returnType)
+                                    LookupElementBuilder.create(name)
                                         .withIcon(AllIcons.Nodes.Method)
-                                        .withTailText("(${ '$' }params)", true)
+                                        .withTailText("($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)
-                                        .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
-                                        .withTypeText(typeOf(member.type), true)
+                                    LookupElementBuilder.create(name)
+                                        .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
+                                        .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)
-                                }
-                                is MiniInitDecl -> {}
-                            }
                         } else {
                             // Fallback: emit simple method name without detailed types
                             val builder = LookupElementBuilder.create(name)
@@ -233,7 +253,7 @@ 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")
@@ -276,6 +296,9 @@ class LyngCompletionContributor : CompletionContributor() {
                 }
                 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)
         }
@@ -353,6 +376,7 @@ 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
                         }
                     }
@@ -389,17 +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
-                    // 2) Else any method
-                    // 3) Else the first variant
+                    // 1) Prefer a method with return type AND parameters
+                    // 2) Prefer a method with parameters
+                    // 3) Prefer a method with return type
+                    // 4) Else any method
+                    // 5) Else the first variant
                     val rep =
-                        list.asSequence()
-                            .filterIsInstance<MiniMemberFunDecl>()
+                        list.asSequence().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()
@@ -416,8 +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
@@ -427,16 +460,30 @@ class LyngCompletionContributor : CompletionContributor() {
                             val builder = LookupElementBuilder.create(name)
                                 .withIcon(icon)
                                 .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(inheritedMap)
+            emitGroup(directMap, 100.0)
+            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.
@@ -458,30 +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)
-                                    .withIcon(AllIcons.Nodes.Field)
+                                LookupElementBuilder.create(name)
+                                    .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)
-                            }
-                            is MiniInitDecl -> {}
-                        }
                     } else {
                         // Synthetic fallback: method without detailed params/types to improve UX in absence of docs
                         val isProperty = name in setOf("size", "length")
@@ -494,7 +558,7 @@ class LyngCompletionContributor : CompletionContributor() {
                                 .withTailText("()", true)
                                 .withInsertHandler(ParenInsertHandler)
                         }
-                        emit(builder)
+                        emit(PrioritizedLookupElement.withPriority(builder, 50.0))
                         already.add(name)
                     }
                 }
@@ -508,90 +572,64 @@ class LyngCompletionContributor : CompletionContributor() {
                 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 ret = typeOf(member.returnType)
-                                val builder = LookupElementBuilder.create(name)
+                                val params = m.params.joinToString(", ") { it.name }
+                                val ret = typeOf(m.returnType)
+                                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)
-                                    .withIcon(if (member.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
-                                    .withTypeText(typeOf(member.type), true)
-                                emit(builder)
+                                LookupElementBuilder.create(name)
+                                    .withIcon(if (m.mutable) AllIcons.Nodes.Variable else AllIcons.Nodes.Field)
+                                    .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(PrioritizedLookupElement.withPriority(builder, 50.0))
                         already.add(name)
                         continue
                     }
-                            is MiniInitDecl -> {}
-                        }
-                    }
                     // 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 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("^\\s*import\\s+([a-zA-Z_][a-zA-Z0-9_]*(?:\\.[a-zA-Z_][a-zA-Z0-9_]*)*)", RegexOption.MULTILINE)
-            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) {
-                null -> ""
-                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}"
-            }
+            val s = DocLookupUtils.typeOf(t)
+            return if (s.isEmpty()) "" else ": $s"
         }
     }
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/docs/LyngDocumentationProvider.kt

@@ -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
@@ -69,61 +68,117 @@ 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 partial AST.
-        val sink = MiniAstBuilder()
-        val provider = IdeLenientImportProvider.create()
-        val src = Source("<ide>", text)
-        val mini = try {
-            runBlocking { Compiler.compileWithMini(src, provider, sink) }
-            sink.build()
-        } catch (t: Throwable) {
-            if (DEBUG_LOG) log.warn("[LYNG_DEBUG] QuickDoc: compileWithMini produced partial AST: ${t.message}")
-            sink.build()
-        } ?: MiniScript(MiniRange(Pos(src, 1, 1), Pos(src, 1, 1)))
-        val source = src
+        // 1. Get merged mini-AST from Manager (handles local + .lyng.d merged declarations)
+        val analysis = LyngAstManager.getAnalysis(file) ?: return null
+        val mini = analysis.mini ?: return null
+        val miniSource = mini.range.start.source
+        val imported = analysis.importedModules.ifEmpty { DocLookupUtils.canonicalImportedModules(mini, text) }
+
+        // Single-source quick doc lookup
+        LyngLanguageTools.docAt(analysis, offset)?.let { info ->
+            val enriched = if (info.doc == null) {
+                findDocInDeclarationFiles(file, info.target.containerName, info.target.name)
+                    ?.let { info.copy(doc = it) } ?: info
+            } 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)
+                }
+            }
+        }
 
         // Try resolve to: function param at position, function/class/val declaration at position
         // 1) Use unified declaration detection
         DocLookupUtils.findDeclarationAt(mini, offset, ident)?.let { (name, kind) ->
             if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: matched declaration '$name' kind=$kind")
             // Find the actual declaration object to render
-            for (d in mini.declarations) {
-                if (d.name == name && source.offsetOf(d.nameStart) <= offset && source.offsetOf(d.nameStart) + d.name.length > offset) {
-                    return renderDeclDoc(d)
+            mini.declarations.forEach { d ->
+                if (d.name == name) {
+                    val s: Int = miniSource.offsetOf(d.nameStart)
+                    if (s <= offset && s + d.name.length > offset) {
+                        return renderDeclDoc(d, text, mini, imported)
+                    }
                 }
                 // Handle members if it was a member
                 if (d is MiniClassDecl) {
-                    for (m in d.members) {
-                        if (m.name == name && source.offsetOf(m.nameStart) <= offset && source.offsetOf(m.nameStart) + m.name.length > offset) {
+                    d.members.forEach { m ->
+                        if (m.name == name) {
+                            val s: Int = miniSource.offsetOf(m.nameStart)
+                            if (s <= offset && s + m.name.length > offset) {
                                 return when (m) {
                                     is MiniMemberFunDecl -> renderMemberFunDoc(d.name, m)
                                     is MiniMemberValDecl -> renderMemberValDoc(d.name, m)
-                                is MiniInitDecl -> null
+                                    is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(d.name, m)
+                                    else -> null
                                 }
                             }
                         }
-                    for (cf in d.ctorFields) {
-                        if (cf.name == name && source.offsetOf(cf.nameStart) <= offset && source.offsetOf(cf.nameStart) + cf.name.length > offset) {
+                    }
+                    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)
                             }
                         }
-                    for (cf in d.classFields) {
-                        if (cf.name == name && source.offsetOf(cf.nameStart) <= offset && source.offsetOf(cf.nameStart) + cf.name.length > offset) {
+                    }
+                    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
                                 )
@@ -131,22 +186,30 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                             }
                         }
                     }
+                }
                 if (d is MiniEnumDecl) {
-                    if (d.entries.contains(name) && offset >= source.offsetOf(d.range.start) && offset <= source.offsetOf(d.range.end)) {
+                    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 "<div class='doc-title'>enum constant ${d.name}.${name}</div>"
+                            return renderTitle("enum constant ${d.name}.${name}")
+                        }
                     }
                 }
             }
             // Check parameters
-            for (fn in mini.declarations.filterIsInstance<MiniFunDecl>()) {
-                for (p in fn.params) {
-                    if (p.name == name && source.offsetOf(p.nameStart) <= offset && source.offsetOf(p.nameStart) + p.name.length > offset) {
+            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) usages in current file via Binder (resolves local variables, parameters, and classes)
         try {
@@ -156,58 +219,73 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                 val sym = binding.symbols.firstOrNull { it.id == ref.symbolId }
                 if (sym != null) {
                     // Find local declaration that matches this symbol
-                    val ds = mini.declarations.firstOrNull { decl ->
-                        val s = source.offsetOf(decl.nameStart)
-                        decl.name == sym.name && s == sym.declStart
+                    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 (ds != null) return renderDeclDoc(ds)
+                        }
+                    }
+                    if (dsFound != null) return renderDeclDoc(dsFound, text, mini, imported)
 
                     // Check parameters
-                    for (fn in mini.declarations.filterIsInstance<MiniFunDecl>()) {
-                        for (p in fn.params) {
-                            val s = source.offsetOf(p.nameStart)
-                            if (p.name == sym.name && s == sym.declStart) {
+                    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)
-                    for (cls in mini.declarations.filterIsInstance<MiniClassDecl>()) {
-                        for (m in cls.members) {
-                            val s = source.offsetOf(m.nameStart)
-                            if (m.name == sym.name && s == sym.declStart) {
+                    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 MiniInitDecl -> null
+                                        is MiniMemberTypeAliasDecl -> renderMemberTypeAliasDoc(cls.name, m)
+                                        else -> null
                                     }
                                 }
                             }
-                        for (cf in cls.ctorFields) {
-                            val s = source.offsetOf(cf.nameStart)
-                            if (cf.name == sym.name && s == sym.declStart) {
+                        }
+                        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)
                                 }
                             }
-                        for (cf in cls.classFields) {
-                            val s = source.offsetOf(cf.nameStart)
-                            if (cf.name == sym.name && s == sym.declStart) {
+                        }
+                        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
                                     )
@@ -217,6 +295,7 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                         }
                     }
                 }
+            }
         } catch (e: Throwable) {
             if (DEBUG_LOG) log.warn("[LYNG_DEBUG] QuickDoc: local binder resolution failed: ${e.message}")
         }
@@ -260,9 +339,9 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                         } else null
                     }
                     else -> {
-                        val guessed = DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules)
-                        if (guessed != null) guessed
-                        else {
+                        DocLookupUtils.guessReceiverClassViaMini(mini, text, dotPos, importedModules)
+                            ?: DocLookupUtils.guessClassFromCallBefore(text, dotPos, importedModules, mini)
+                            ?: run {
                                 // handle this@Type or as Type
                                 val i2 = TextCtx.prevNonWs(text, dotPos - 1)
                                 if (i2 >= 0) {
@@ -283,12 +362,19 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
                 }
                 if (DEBUG_LOG) log.info("[LYNG_DEBUG] QuickDoc: memberCtx dotPos=${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}")
@@ -299,7 +385,7 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
         // 4) As a fallback, if the caret is on an identifier text that matches any declaration name, show that
         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)
@@ -319,13 +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/enums
-            docs.filterIsInstance<MiniClassDecl>().firstOrNull { it.name == ident }?.let { return renderDeclDoc(it) }
-            docs.filterIsInstance<MiniEnumDecl>().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") {
@@ -333,18 +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 {
@@ -355,15 +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 {
@@ -371,19 +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) {
@@ -391,17 +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)
                         }
                     }
                 }
@@ -417,25 +533,39 @@ class LyngDocumentationProvider : AbstractDocumentationProvider() {
     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
-        } catch (_: Throwable) {
+            anyLoaded = true
+        } 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(
@@ -449,25 +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 MiniEnumDecl -> "enum ${d.name} { ${d.entries.joinToString(", ")} }"
-            is MiniValDecl -> if (d.mutable) "var ${d.name}${typeOf(d.type)}" else "val ${d.name}${typeOf(d.type)}"
+            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>")
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc))
+        sb.append(renderTitle(title))
+        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 {
@@ -478,37 +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>")
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc))
+        sb.append(renderTitle(title))
+        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>")
-        if (!doc.isNullOrBlank()) sb.append(styledMarkdown(doc))
+        sb.append(renderTitle(title))
+        sb.append(renderDocBody(m.doc))
         return sb.toString()
     }
 
-    private fun typeOf(t: MiniTypeRef?): String = when (t) {
-        is MiniTypeName -> ": ${t.segments.joinToString(".") { it.name }}${if (t.nullable) "?" else ""}"
-        is MiniGenericType -> {
-            val base = typeOf(t.base).removePrefix(": ")
-            val args = t.args.joinToString(", ") { typeOf(it).removePrefix(": ") }
-            ": ${base}<${args}>${if (t.nullable) "?" else ""}"
+    private fun renderMemberTypeAliasDoc(className: String, m: MiniMemberTypeAliasDecl): String {
+        val tp = if (m.typeParams.isEmpty()) "" else "<" + m.typeParams.joinToString(", ") + ">"
+        val body = typeOf(m.target)
+        val rhs = if (body.isBlank()) "" else " = ${body.removePrefix(": ")}"
+        val staticStr = if (m.isStatic) "static " else ""
+        val title = "${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 ""}"
-        null -> ""
+
+    private fun typeAliasSuffix(d: MiniTypeAliasDecl): String {
+        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 {
@@ -520,6 +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) {
@@ -586,7 +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>")
@@ -608,11 +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
-        while (i > 0 && text[i].isWhitespace()) i--
+        // skip trailing spaces
+        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

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/docs/ProcessDocsFallback.kt

@@ -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
+        }
+    }
+}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/AddToLyngDictionaryFix.kt

@@ -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)
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/EnglishDictionary.kt

@@ -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
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/LyngGrazieAnnotator.kt

@@ -1,609 +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","interface","enum","type","import","package","return","if","else","when","while","for","try","catch","finally","true","false","null",
-            "abstract","closed","override",
-            // 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]
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/LyngGrazieStrategy.kt

@@ -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)
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/LyngTextExtractor.kt

@@ -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.spell.LyngSpellIndex
+import net.sergeych.lyng.idea.psi.LyngElementTypes
 
 /**
- * Provides Grazie with extractable text for Lyng PSI elements.
- * We return text for identifiers, comments, and (optionally) string literals.
- * printf-like specifiers are filtered by the Grammar strategy via stealth ranges.
+ * Simplified TextExtractor for Lyng.
+ * Designates areas for Natural Languages (Grazie) to check.
  */
 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) }
-
-        // 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) {
+        val 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 (domain == TextDomain.LITERALS && !allowedDomains.contains(TextDomain.LITERALS) && settings.grazieTreatLiteralsAsComments) {
-            domain = TextDomain.COMMENTS
-        }
-        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
-        }
+        if (!allowedDomains.contains(domain)) return null
+        
+        return TextContent.psiFragment(domain, element)
     }
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/ReplaceWordFix.kt

@@ -1,86 +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.command.WriteCommandAction
-import com.intellij.openapi.editor.CaretModel
-import com.intellij.openapi.editor.Document
-import com.intellij.openapi.editor.Editor
-import com.intellij.openapi.project.Project
-import com.intellij.openapi.util.TextRange
-import com.intellij.psi.PsiFile
-
-/**
- * Lightweight quick-fix to replace a misspelled word (subrange) with a suggested alternative.
- * Works without the legacy Spell Checker. The replacement is applied directly to the file text.
- */
-class ReplaceWordFix(
-    private val range: TextRange,
-    private val original: String,
-    private val replacementRaw: String
-) : IntentionAction {
-
-    override fun getText(): String = "Replace '$original' with '$replacementRaw'"
-    override fun getFamilyName(): String = "Lyng Spelling"
-    override fun isAvailable(project: Project, editor: Editor?, file: PsiFile?): Boolean =
-        editor != null && file != null && range.startOffset in 0..range.endOffset
-
-    override fun startInWriteAction(): Boolean = true
-
-    override fun invoke(project: Project, editor: Editor?, file: PsiFile?) {
-        if (editor == null) return
-        val doc: Document = editor.document
-        val safeRange = range.constrainTo(doc)
-        val current = doc.getText(safeRange)
-        // Preserve basic case style based on the original token
-        val replacement = adaptCaseStyle(current, replacementRaw)
-        WriteCommandAction.runWriteCommandAction(project, "Replace word", null, Runnable {
-            doc.replaceString(safeRange.startOffset, safeRange.endOffset, replacement)
-        }, file)
-        // Move caret to end of replacement for convenience
-        try {
-            val caret: CaretModel = editor.caretModel
-            caret.moveToOffset(safeRange.startOffset + replacement.length)
-        } catch (_: Throwable) {}
-        // Restart daemon to refresh highlights
-        if (file != null) DaemonCodeAnalyzer.getInstance(project).restart(file)
-    }
-
-    private fun TextRange.constrainTo(doc: Document): TextRange {
-        val start = startOffset.coerceIn(0, doc.textLength)
-        val end = endOffset.coerceIn(start, doc.textLength)
-        return TextRange(start, end)
-    }
-
-    private fun adaptCaseStyle(sample: String, suggestion: String): String {
-        if (suggestion.isEmpty()) return suggestion
-        return when {
-            sample.all { it.isUpperCase() } -> suggestion.uppercase()
-            // PascalCase / Capitalized single word
-            sample.firstOrNull()?.isUpperCase() == true && sample.drop(1).any { it.isLowerCase() } ->
-                suggestion.replaceFirstChar { if (it.isLowerCase()) it.titlecase() else it.toString() }
-            // snake_case -> lower
-            sample.contains('_') -> suggestion.lowercase()
-            // camelCase -> lower first
-            sample.firstOrNull()?.isLowerCase() == true && sample.any { it.isUpperCase() } ->
-                suggestion.replaceFirstChar { it.lowercase() }
-            else -> suggestion
-        }
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/grazie/TechDictionary.kt

@@ -1,77 +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
-
-/**
- * Lightweight technical/Lyng vocabulary dictionary.
- * Loaded from classpath resources; supports .txt and .txt.gz. Merged with EnglishDictionary.
- */
-object TechDictionary {
-    private val log = Logger.getInstance(TechDictionary::class.java)
-    @Volatile private var loaded = false
-    @Volatile private var words: Set<String> = emptySet()
-
-    private fun ensureLoaded() {
-        if (loaded) return
-        synchronized(this) {
-            if (loaded) return
-            val candidates = listOf(
-                "/dictionaries/tech-lyng.txt.gz",
-                "/dictionaries/tech-lyng.txt"
-            )
-            val merged = HashSet<String>(8_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 n = 0
-                    reader.useLines { seq -> seq.forEach { line ->
-                        val w = line.trim()
-                        if (w.isNotEmpty() && !w.startsWith("#")) { merged += w.lowercase(); n++ }
-                    } }
-                    log.info("TechDictionary: loaded $n words from $res (total=${merged.size})")
-                } catch (t: Throwable) {
-                    log.info("TechDictionary: failed to load $res: ${t.javaClass.simpleName}: ${t.message}")
-                }
-            }
-            if (merged.isEmpty()) {
-                merged += setOf(
-                    // minimal Lyng/tech seeding to avoid empty dictionary
-                    "lyng","miniast","binder","printf","specifier","specifiers","regex","token","tokens",
-                    "identifier","identifiers","keyword","keywords","comment","comments","string","strings",
-                    "literal","literals","formatting","formatter","grazie","typo","typos","dictionary","dictionaries"
-                )
-                log.info("TechDictionary: using minimal built-in set (${merged.size})")
-            }
-            words = merged
-            loaded = true
-        }
-    }
-
-    fun allWords(): Set<String> {
-        ensureLoaded()
-        return words
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngColorSettingsPage.kt

@@ -43,10 +43,15 @@ class LyngColorSettingsPage : ColorSettingsPage {
         }
         
         var counter = 0
+        outer@ while (counter < 10) {
+          if (counter == 5) return@outer
           counter = counter + 1
+        }
     """.trimIndent()
 
-    override fun getAdditionalHighlightingTagToDescriptorMap(): MutableMap<String, TextAttributesKey>? = null
+    override fun getAdditionalHighlightingTagToDescriptorMap(): MutableMap<String, TextAttributesKey> = mutableMapOf(
+        "label" to LyngHighlighterColors.LABEL
+    )
 
     override fun getAttributeDescriptors(): Array<AttributesDescriptor> = arrayOf(
         AttributesDescriptor("Keyword", LyngHighlighterColors.KEYWORD),
@@ -58,6 +63,7 @@ class LyngColorSettingsPage : ColorSettingsPage {
         AttributesDescriptor("Punctuation", LyngHighlighterColors.PUNCT),
         // Semantic
         AttributesDescriptor("Annotation (semantic)", LyngHighlighterColors.ANNOTATION),
+        AttributesDescriptor("Label (semantic)", LyngHighlighterColors.LABEL),
         AttributesDescriptor("Variable (semantic)", LyngHighlighterColors.VARIABLE),
         AttributesDescriptor("Value (semantic)", LyngHighlighterColors.VALUE),
         AttributesDescriptor("Function (semantic)", LyngHighlighterColors.FUNCTION),

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngHighlighterColors.kt

@@ -82,4 +82,9 @@ object LyngHighlighterColors {
     val ENUM_CONSTANT: TextAttributesKey = TextAttributesKey.createTextAttributesKey(
         "LYNG_ENUM_CONSTANT", DefaultLanguageHighlighterColors.STATIC_FIELD
     )
+
+    // Labels (label@ or @label used as exit target)
+    val LABEL: TextAttributesKey = TextAttributesKey.createTextAttributesKey(
+        "LYNG_LABEL", DefaultLanguageHighlighterColors.LABEL
+    )
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngLexer.kt

@@ -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.
@@ -33,10 +33,10 @@ class LyngLexer : LexerBase() {
 
     private val keywords = setOf(
         "fun", "val", "var", "class", "interface", "type", "import", "as",
-        "abstract", "closed", "override",
+        "abstract", "closed", "override", "static", "extern", "open", "private", "protected",
         "if", "else", "for", "while", "return", "true", "false", "null",
-        "when", "in", "is", "break", "continue", "try", "catch", "finally",
-        "get", "set"
+        "when", "in", "is", "break", "continue", "try", "catch", "finally", "void",
+        "get", "set", "object", "enum", "init", "by", "step", "property", "constructor"
     )
 
     override fun start(buffer: CharSequence, startOffset: Int, endOffset: Int, initialState: Int) {
@@ -101,8 +101,9 @@ class LyngLexer : LexerBase() {
             return
         }
 
-        // String "..." with simple escape handling
-        if (ch == '"') {
+        // String "..." or '...' with simple escape handling
+        if (ch == '"' || ch == '\'') {
+            val quote = ch
             i++
             while (i < endOffset) {
                 val c = buffer[i]
@@ -110,7 +111,7 @@ class LyngLexer : LexerBase() {
                     i += 2
                     continue
                 }
-                if (c == '"') { i++; break }
+                if (c == quote) { i++; break }
                 i++
             }
             myTokenEnd = i
@@ -120,12 +121,39 @@ class LyngLexer : LexerBase() {
 
         // Number
         if (ch.isDigit()) {
+            // Check for hex: 0x...
+            if (ch == '0' && i + 1 < endOffset && buffer[i + 1] == 'x') {
+                i += 2
+                while (i < endOffset && (buffer[i].isDigit() || buffer[i] in 'a'..'f' || buffer[i] in 'A'..'F')) i++
+                myTokenEnd = i
+                myTokenType = LyngTokenTypes.NUMBER
+                return
+            }
+
+            // Decimal or integer
             i++
             var hasDot = false
+            var hasE = false
             while (i < endOffset) {
                 val c = buffer[i]
-                if (c.isDigit()) { i++; continue }
-                if (c == '.' && !hasDot) { hasDot = true; i++; continue }
+                if (c.isDigit() || c == '_') {
+                    i++
+                    continue
+                }
+                if (c == '.' && !hasDot && !hasE) {
+                    // Check if it's a fractional part (must be followed by a digit)
+                    if (i + 1 < endOffset && buffer[i + 1].isDigit()) {
+                        hasDot = true
+                        i++
+                        continue
+                    }
+                }
+                if ((c == 'e' || c == 'E') && !hasE) {
+                    hasE = true
+                    i++
+                    if (i < endOffset && (buffer[i] == '+' || buffer[i] == '-')) i++
+                    continue
+                }
                 break
             }
             myTokenEnd = i
@@ -133,10 +161,24 @@ class LyngLexer : LexerBase() {
             return
         }
 
-        // Identifier / keyword
+        // Labels / Annotations: @label or label@
+        if (ch == '@') {
+            i++
+            while (i < endOffset && (buffer[i].isIdentifierPart())) i++
+            myTokenEnd = i
+            myTokenType = LyngTokenTypes.LABEL
+            return
+        }
+
         if (ch.isIdentifierStart()) {
             i++
             while (i < endOffset && buffer[i].isIdentifierPart()) i++
+            if (i < endOffset && buffer[i] == '@') {
+                i++
+                myTokenEnd = i
+                myTokenType = LyngTokenTypes.LABEL
+                return
+            }
             myTokenEnd = i
             val text = buffer.subSequence(myTokenStart, myTokenEnd).toString()
             myTokenType = if (text in keywords) LyngTokenTypes.KEYWORD else LyngTokenTypes.IDENTIFIER
@@ -146,6 +188,35 @@ class LyngLexer : LexerBase() {
         // Punctuation
         if (isPunct(ch)) {
             i++
+            // Handle common multi-char operators for better highlighting
+            when (ch) {
+                '.' -> {
+                    if (i < endOffset && buffer[i] == '.') {
+                        i++
+                        if (i < endOffset && (buffer[i] == '.' || buffer[i] == '<')) i++
+                    }
+                }
+                '=' -> {
+                    if (i < endOffset && (buffer[i] == '=' || buffer[i] == '>' || buffer[i] == '~')) {
+                        i++
+                        if (buffer[i - 1] == '=' && i < endOffset && buffer[i] == '=') i++
+                    }
+                }
+                '+', '-', '*', '/', '%', '!', '<', '>', '&', '|', '?', ':', '^' -> {
+                    if (i < endOffset) {
+                        val next = buffer[i]
+                        if (next == '=' || next == ch) {
+                            i++
+                            if (ch == '<' && next == '=' && i < endOffset && buffer[i] == '>') i++
+                            if (ch == '!' && next == '=' && i < endOffset && buffer[i] == '=') i++
+                        } else if (ch == '?' && (next == '.' || next == '[' || next == '(' || next == '{' || next == ':' || next == '?')) {
+                            i++
+                        } else if (ch == '-' && next == '>') {
+                            i++
+                        }
+                    }
+                }
+            }
             myTokenEnd = i
             myTokenType = LyngTokenTypes.PUNCT
             return
@@ -160,5 +231,5 @@ class LyngLexer : LexerBase() {
     private fun Char.isDigit(): Boolean = this in '0'..'9'
     private fun Char.isIdentifierStart(): Boolean = this == '_' || this.isLetter()
     private fun Char.isIdentifierPart(): Boolean = this.isIdentifierStart() || this.isDigit()
-    private fun isPunct(c: Char): Boolean = c in setOf('(', ')', '{', '}', '[', ']', '.', ',', ';', ':', '+', '-', '*', '/', '%', '=', '<', '>', '!', '?', '&', '|', '^', '~')
+    private fun isPunct(c: Char): Boolean = c in setOf('(', ')', '{', '}', '[', ']', '.', ',', ';', ':', '+', '-', '*', '/', '%', '=', '<', '>', '!', '?', '&', '|', '^', '~', '@')
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngSyntaxHighlighter.kt

@@ -33,6 +33,7 @@ class LyngSyntaxHighlighter : SyntaxHighlighter {
         LyngTokenTypes.BLOCK_COMMENT -> pack(LyngHighlighterColors.BLOCK_COMMENT)
         LyngTokenTypes.PUNCT -> pack(LyngHighlighterColors.PUNCT)
         LyngTokenTypes.IDENTIFIER -> pack(LyngHighlighterColors.IDENTIFIER)
+        LyngTokenTypes.LABEL -> pack(LyngHighlighterColors.LABEL)
         else -> emptyArray()
     }
 

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngTokenTypes.kt

@@ -29,6 +29,7 @@ object LyngTokenTypes {
     val NUMBER = LyngTokenType("NUMBER")
     val KEYWORD = LyngTokenType("KEYWORD")
     val IDENTIFIER = LyngTokenType("IDENTIFIER")
+    val LABEL = LyngTokenType("LABEL")
     val PUNCT = LyngTokenType("PUNCT")
     val BAD_CHAR = LyngTokenType("BAD_CHAR")
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/navigation/LyngGotoDeclarationHandler.kt

@@ -20,13 +20,14 @@ package net.sergeych.lyng.idea.navigation
 import com.intellij.codeInsight.navigation.actions.GotoDeclarationHandler
 import com.intellij.openapi.editor.Editor
 import com.intellij.psi.PsiElement
+import net.sergeych.lyng.idea.LyngLanguage
 
 /**
  * Ensures Ctrl+B (Go to Definition) works on Lyng identifiers by resolving through LyngPsiReference.
  */
 class LyngGotoDeclarationHandler : GotoDeclarationHandler {
     override fun getGotoDeclarationTargets(sourceElement: PsiElement?, offset: Int, editor: Editor?): Array<PsiElement>? {
-        if (sourceElement == null) return null
+        if (sourceElement == null || sourceElement.language != LyngLanguage) return null
         
         val allTargets = mutableListOf<PsiElement>()
 

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/navigation/LyngPsiReference.kt

@@ -20,12 +20,18 @@ package net.sergeych.lyng.idea.navigation
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.*
+import com.intellij.psi.search.FileTypeIndex
 import com.intellij.psi.search.FilenameIndex
 import com.intellij.psi.search.GlobalSearchScope
+import kotlinx.coroutines.runBlocking
 import net.sergeych.lyng.highlight.offsetOf
+import net.sergeych.lyng.idea.LyngFileType
 import net.sergeych.lyng.idea.util.LyngAstManager
 import net.sergeych.lyng.idea.util.TextCtx
 import net.sergeych.lyng.miniast.*
+import net.sergeych.lyng.tools.IdeLenientImportProvider
+import net.sergeych.lyng.tools.LyngAnalysisRequest
+import net.sergeych.lyng.tools.LyngLanguageTools
 
 class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiElement>(element, TextRange(0, element.textLength)) {
 
@@ -36,25 +42,29 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
         val name = element.text ?: ""
         val results = mutableListOf<ResolveResult>()
 
-        val mini = LyngAstManager.getMiniAst(file) ?: return emptyArray()
-        val binding = LyngAstManager.getBinding(file)
+        val analysis = LyngAstManager.getAnalysis(file) ?: return emptyArray()
+        val mini = analysis.mini ?: return emptyArray()
+        val binding = analysis.binding
+        val imported = analysis.importedModules.toSet()
+        val currentPackage = getPackageName(file)
+        val allowedPackages = if (currentPackage != null) imported + currentPackage else imported
 
         // 1. Member resolution (obj.member)
         val dotPos = TextCtx.findDotLeft(text, offset)
         if (dotPos != null) {
-            val imported = DocLookupUtils.canonicalImportedModules(mini, text)
-            val receiverClass = DocLookupUtils.guessReceiverClassViaMini(mini, text, dotPos, imported, binding)
-                ?: DocLookupUtils.guessReceiverClass(text, dotPos, imported, mini)
+            val receiverClass = DocLookupUtils.guessReceiverClassViaMini(mini, text, dotPos, imported.toList(), binding)
+                ?: DocLookupUtils.guessReceiverClass(text, dotPos, imported.toList(), mini)
+            val staticOnly = DocLookupUtils.isStaticReceiver(mini, text, dotPos, imported.toList(), binding)
             
             if (receiverClass != null) {
-                val resolved = DocLookupUtils.resolveMemberWithInheritance(imported, receiverClass, name, mini)
+                val resolved = DocLookupUtils.resolveMemberWithInheritance(imported.toList(), receiverClass, name, mini, staticOnly = staticOnly)
                 if (resolved != null) {
                     val owner = resolved.first
                     val member = resolved.second
                     
                     // We need to find the actual PSI element for this member
                     val targetFile = findFileForClass(file.project, owner) ?: file
-                    val targetMini = LyngAstManager.getMiniAst(targetFile)
+                    val targetMini = loadMini(targetFile)
                     if (targetMini != null) {
                         val targetSrc = targetMini.range.start.source
                         val off = targetSrc.offsetOf(member.nameStart)
@@ -62,7 +72,13 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
                             val kind = when(member) {
                                 is MiniMemberFunDecl -> "Function"
                                 is MiniMemberValDecl -> if (member.mutable) "Variable" else "Value"
+                                is MiniMemberTypeAliasDecl -> "TypeAlias"
                                 is MiniInitDecl -> "Initializer"
+                                is MiniFunDecl -> "Function"
+                                is MiniValDecl -> if (member.mutable) "Variable" else "Value"
+                                is MiniClassDecl -> "Class"
+                                is MiniEnumDecl -> "Enum"
+                                is MiniTypeAliasDecl -> "TypeAlias"
                             }
                             results.add(PsiElementResolveResult(LyngDeclarationElement(it, member.name, kind)))
                         }
@@ -71,7 +87,7 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
             }
             // If we couldn't resolve exactly, we might still want to search globally but ONLY for members
             if (results.isEmpty()) {
-                results.addAll(resolveGlobally(file.project, name, membersOnly = true))
+                results.addAll(resolveGlobally(file.project, name, membersOnly = true, allowedPackages = allowedPackages))
             }
         } else {
             // 2. Local resolution via Binder
@@ -90,7 +106,7 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
             // 3. Global project scan
             // Only search globally if we haven't found a strong local match
             if (results.isEmpty()) {
-                results.addAll(resolveGlobally(file.project, name))
+                results.addAll(resolveGlobally(file.project, name, allowedPackages = allowedPackages))
             }
         }
 
@@ -113,30 +129,53 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
     }
 
     private fun findFileForClass(project: Project, className: String): PsiFile? {
-        val psiManager = PsiManager.getInstance(project)
-        
         // 1. Try file with matching name first (optimization)
-        val matchingFiles = FilenameIndex.getFilesByName(project, "$className.lyng", GlobalSearchScope.projectScope(project))
+        val scope = GlobalSearchScope.projectScope(project)
+        val psiManager = PsiManager.getInstance(project)
+        val matchingFiles = FileTypeIndex.getFiles(LyngFileType, scope)
+            .asSequence()
+            .filter { it.name == "$className.lyng" }
+            .mapNotNull { psiManager.findFile(it) }
+            .toList()
+        val matchingDeclFiles = FileTypeIndex.getFiles(LyngFileType, scope)
+            .asSequence()
+            .filter { it.name == "$className.lyng.d" }
+            .mapNotNull { psiManager.findFile(it) }
+            .toList()
         for (file in matchingFiles) {
-            val mini = LyngAstManager.getMiniAst(file) ?: continue
-            if (mini.declarations.any { (it is MiniClassDecl && it.name == className) || (it is MiniEnumDecl && it.name == className) }) {
+            val mini = loadMini(file) ?: continue
+            if (mini.declarations.any { isLocalDecl(mini, it) && ((it is MiniClassDecl && it.name == className) || (it is MiniEnumDecl && it.name == className)) }) {
+                return file
+            }
+        }
+        for (file in matchingDeclFiles) {
+            val mini = loadMini(file) ?: continue
+            if (mini.declarations.any { isLocalDecl(mini, it) && ((it is MiniClassDecl && it.name == className) || (it is MiniEnumDecl && it.name == className)) }) {
                 return file
             }
         }
 
         // 2. Fallback to full project scan
-        val allFiles = FilenameIndex.getAllFilesByExt(project, "lyng", GlobalSearchScope.projectScope(project))
-        for (vFile in allFiles) {
-            val file = psiManager.findFile(vFile) ?: continue
-            if (matchingFiles.contains(file)) continue // already checked
-            val mini = LyngAstManager.getMiniAst(file) ?: continue
-            if (mini.declarations.any { (it is MiniClassDecl && it.name == className) || (it is MiniEnumDecl && it.name == className) }) {
+        for (file in collectLyngFiles(project)) {
+            if (matchingFiles.contains(file) || matchingDeclFiles.contains(file)) continue // already checked
+            val mini = loadMini(file) ?: continue
+            if (mini.declarations.any { isLocalDecl(mini, it) && ((it is MiniClassDecl && it.name == className) || (it is MiniEnumDecl && it.name == className)) }) {
                 return file
             }
         }
         return null
     }
 
+    private fun getPackageName(file: PsiFile): String? {
+        val mini = loadMini(file) ?: return null
+        return try {
+            val pkg = mini.range.start.source.extractPackageName()
+            if (pkg.startsWith("lyng.")) pkg else "lyng.$pkg"
+        } catch (e: Exception) {
+            null
+        }
+    }
+
     override fun resolve(): PsiElement? {
         val results = multiResolve(false)
         if (results.isEmpty()) return null
@@ -150,14 +189,21 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
         return target
     }
 
-    private fun resolveGlobally(project: Project, name: String, membersOnly: Boolean = false): List<ResolveResult> {
+    private fun resolveGlobally(project: Project, name: String, membersOnly: Boolean = false, allowedPackages: Set<String>? = null): List<ResolveResult> {
         val results = mutableListOf<ResolveResult>()
-        val files = FilenameIndex.getAllFilesByExt(project, "lyng", GlobalSearchScope.projectScope(project))
         val psiManager = PsiManager.getInstance(project)
 
-        for (vFile in files) {
-            val file = psiManager.findFile(vFile) ?: continue
-            val mini = LyngAstManager.getMiniAst(file) ?: continue
+        for (file in collectLyngFiles(project)) {
+            
+            // Filter by package if requested
+            if (allowedPackages != null) {
+                val pkg = getPackageName(file)
+                if (pkg == null) {
+                    if (!file.name.endsWith(".lyng.d")) continue
+                } else if (pkg !in allowedPackages) continue
+            }
+
+            val mini = loadMini(file) ?: continue
             val src = mini.range.start.source
 
             fun addIfMatch(dName: String, nameStart: net.sergeych.lyng.Pos, dKind: String) {
@@ -170,12 +216,14 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
             }
 
             for (d in mini.declarations) {
+                if (!isLocalDecl(mini, d)) continue
                 if (!membersOnly) {
                     val dKind = when(d) {
                         is net.sergeych.lyng.miniast.MiniFunDecl -> "Function"
                         is net.sergeych.lyng.miniast.MiniClassDecl -> "Class"
                         is net.sergeych.lyng.miniast.MiniEnumDecl -> "Enum"
                         is net.sergeych.lyng.miniast.MiniValDecl -> if (d.mutable) "Variable" else "Value"
+                        is net.sergeych.lyng.miniast.MiniTypeAliasDecl -> "TypeAlias"
                     }
                     addIfMatch(d.name, d.nameStart, dKind)
                 }
@@ -188,9 +236,11 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
                 }
                 
                 for (m in members) {
+                    if (m.range.start.source != src) continue
                     val mKind = when(m) {
                         is net.sergeych.lyng.miniast.MiniMemberFunDecl -> "Function"
                         is net.sergeych.lyng.miniast.MiniMemberValDecl -> if (m.mutable) "Variable" else "Value"
+                        is net.sergeych.lyng.miniast.MiniMemberTypeAliasDecl -> "TypeAlias"
                         is net.sergeych.lyng.miniast.MiniInitDecl -> "Initializer"
                     }
                     addIfMatch(m.name, m.nameStart, mKind)
@@ -200,5 +250,42 @@ class LyngPsiReference(element: PsiElement) : PsiPolyVariantReferenceBase<PsiEle
         return results
     }
 
+    private fun collectLyngFiles(project: Project): List<PsiFile> {
+        val scope = GlobalSearchScope.projectScope(project)
+        val psiManager = PsiManager.getInstance(project)
+        val out = LinkedHashSet<PsiFile>()
+
+        val lyngFiles = FilenameIndex.getAllFilesByExt(project, "lyng", scope)
+        for (vFile in lyngFiles) {
+            psiManager.findFile(vFile)?.let { out.add(it) }
+        }
+
+        // Include declaration files (*.lyng.d) which are indexed as extension "d".
+        val dFiles = FilenameIndex.getAllFilesByExt(project, "d", scope)
+        for (vFile in dFiles) {
+            if (!vFile.name.endsWith(".lyng.d")) continue
+            psiManager.findFile(vFile)?.let { out.add(it) }
+        }
+
+        return out.toList()
+    }
+
+    private fun loadMini(file: PsiFile): MiniScript? {
+        LyngAstManager.getMiniAst(file)?.let { return it }
+        return try {
+            val provider = IdeLenientImportProvider.create()
+            runBlocking {
+                LyngLanguageTools.analyze(
+                    LyngAnalysisRequest(text = file.text, fileName = file.name, importProvider = provider)
+                )
+            }.mini
+        } catch (_: Throwable) {
+            null
+        }
+    }
+
+    private fun isLocalDecl(mini: MiniScript, decl: MiniDecl): Boolean =
+        decl.range.start.source == mini.range.start.source
+
     override fun getVariants(): Array<Any> = emptyArray()
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/psi/LyngElementTypes.kt

@@ -0,0 +1,27 @@
+/*
+ * 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.psi
+
+import com.intellij.psi.tree.IElementType
+import net.sergeych.lyng.idea.LyngLanguage
+
+object LyngElementTypes {
+    val NAME_IDENTIFIER = IElementType("NAME_IDENTIFIER", LyngLanguage)
+    val PARAMETER_NAME = IElementType("PARAMETER_NAME", LyngLanguage)
+    val ENUM_CONSTANT_NAME = IElementType("ENUM_CONSTANT_NAME", LyngLanguage)
+}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/psi/LyngParserDefinition.kt

@@ -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.
@@ -45,7 +45,68 @@ class LyngParserDefinition : ParserDefinition {
 
     override fun createParser(project: Project?): PsiParser = PsiParser { root, builder ->
         val mark: PsiBuilder.Marker = builder.mark()
-        while (!builder.eof()) builder.advanceLexer()
+        var lastKeyword: String? = null
+        var inEnum = false
+        var inParams = false
+        var parenDepth = 0
+        var braceDepth = 0
+
+        while (!builder.eof()) {
+            val type = builder.tokenType
+            val text = builder.tokenText
+
+            when (type) {
+                LyngTokenTypes.KEYWORD -> {
+                    lastKeyword = text
+                    if (text == "enum") inEnum = true
+                }
+                LyngTokenTypes.PUNCT -> {
+                    if (text == "(") {
+                        parenDepth++
+                        if (lastKeyword == "fun" || lastKeyword == "constructor" || lastKeyword == "init") inParams = true
+                    } else if (text == ")") {
+                        parenDepth--
+                        if (parenDepth == 0) inParams = false
+                    } else if (text == "{") {
+                        braceDepth++
+                    } else if (text == "}") {
+                        braceDepth--
+                        if (braceDepth == 0) inEnum = false
+                    }
+                    if (text != ".") lastKeyword = null
+                }
+                LyngTokenTypes.IDENTIFIER -> {
+                    val m = builder.mark()
+                    builder.advanceLexer()
+                    val nextType = builder.tokenType
+                    val isQualified = nextType == LyngTokenTypes.PUNCT && builder.tokenText == "."
+                    
+                    if (!isQualified) {
+                        when {
+                            lastKeyword in setOf("fun", "val", "var", "class", "enum", "object", "interface", "type", "property") -> {
+                                m.done(LyngElementTypes.NAME_IDENTIFIER)
+                            }
+                            inParams && parenDepth > 0 -> {
+                                m.done(LyngElementTypes.PARAMETER_NAME)
+                            }
+                            inEnum && braceDepth > 0 && parenDepth == 0 -> {
+                                m.done(LyngElementTypes.ENUM_CONSTANT_NAME)
+                            }
+                            else -> m.drop()
+                        }
+                    } else {
+                        m.drop()
+                    }
+                    lastKeyword = null
+                    continue
+                }
+                LyngTokenTypes.WHITESPACE, LyngTokenTypes.LINE_COMMENT, LyngTokenTypes.BLOCK_COMMENT -> {
+                    // keep lastKeyword
+                }
+                else -> lastKeyword = null
+            }
+            builder.advanceLexer()
+        }
         mark.done(root)
         builder.treeBuilt
     }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/settings/LyngFormatterSettings.kt

@@ -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.
@@ -32,24 +32,6 @@ class LyngFormatterSettings(private val project: Project) : PersistentStateCompo
         var reindentClosedBlockOnEnter: Boolean = true,
         var reindentPastedBlocks: Boolean = true,
         var normalizeBlockCommentIndent: Boolean = false,
-        var spellCheckStringLiterals: Boolean = true,
-        // When Grazie/Natural Languages is present, prefer it for comments and literals (avoid legacy duplicates)
-        var preferGrazieForCommentsAndLiterals: Boolean = true,
-        // When Grazie is available, also check identifiers via Grazie.
-        // Default OFF because Grazie typically doesn't flag code identifiers; legacy Spellchecker is better for code.
-        var grazieChecksIdentifiers: Boolean = false,
-        // Grazie-only fallback: treat identifiers as comments domain so Grazie applies spelling rules
-        var grazieTreatIdentifiersAsComments: Boolean = true,
-        // Grazie-only fallback: treat string literals as comments domain when LITERALS domain is not requested
-        var grazieTreatLiteralsAsComments: Boolean = true,
-        // Debug helper: show the exact ranges we feed to Grazie/legacy as weak warnings
-        var debugShowSpellFeed: Boolean = false,
-        // Visuals: render Lyng typos using the standard Typo green underline styling
-        var showTyposWithGreenUnderline: Boolean = true,
-        // Enable lightweight quick-fixes (Replace..., Add to dictionary) without legacy Spell Checker
-        var offerLyngTypoQuickFixes: Boolean = true,
-        // Per-project learned words (do not flag again)
-        var learnedWords: MutableSet<String> = mutableSetOf(),
         // Experimental: enable Lyng autocompletion (can be disabled if needed)
         var enableLyngCompletionExperimental: Boolean = true,
     )
@@ -82,42 +64,6 @@ class LyngFormatterSettings(private val project: Project) : PersistentStateCompo
         get() = myState.normalizeBlockCommentIndent
         set(value) { myState.normalizeBlockCommentIndent = value }
 
-    var spellCheckStringLiterals: Boolean
-        get() = myState.spellCheckStringLiterals
-        set(value) { myState.spellCheckStringLiterals = value }
-
-    var preferGrazieForCommentsAndLiterals: Boolean
-        get() = myState.preferGrazieForCommentsAndLiterals
-        set(value) { myState.preferGrazieForCommentsAndLiterals = value }
-
-    var grazieChecksIdentifiers: Boolean
-        get() = myState.grazieChecksIdentifiers
-        set(value) { myState.grazieChecksIdentifiers = value }
-
-    var grazieTreatIdentifiersAsComments: Boolean
-        get() = myState.grazieTreatIdentifiersAsComments
-        set(value) { myState.grazieTreatIdentifiersAsComments = value }
-
-    var grazieTreatLiteralsAsComments: Boolean
-        get() = myState.grazieTreatLiteralsAsComments
-        set(value) { myState.grazieTreatLiteralsAsComments = value }
-
-    var debugShowSpellFeed: Boolean
-        get() = myState.debugShowSpellFeed
-        set(value) { myState.debugShowSpellFeed = value }
-
-    var showTyposWithGreenUnderline: Boolean
-        get() = myState.showTyposWithGreenUnderline
-        set(value) { myState.showTyposWithGreenUnderline = value }
-
-    var offerLyngTypoQuickFixes: Boolean
-        get() = myState.offerLyngTypoQuickFixes
-        set(value) { myState.offerLyngTypoQuickFixes = value }
-
-    var learnedWords: MutableSet<String>
-        get() = myState.learnedWords
-        set(value) { myState.learnedWords = value }
-
     var enableLyngCompletionExperimental: Boolean
         get() = myState.enableLyngCompletionExperimental
         set(value) { myState.enableLyngCompletionExperimental = value }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/settings/LyngFormatterSettingsConfigurable.kt

@@ -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.
@@ -30,14 +30,6 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
     private var reindentClosedBlockCb: JCheckBox? = null
     private var reindentPasteCb: JCheckBox? = null
     private var normalizeBlockCommentIndentCb: JCheckBox? = null
-    private var spellCheckLiteralsCb: JCheckBox? = null
-    private var preferGrazieCommentsLiteralsCb: JCheckBox? = null
-    private var grazieChecksIdentifiersCb: JCheckBox? = null
-    private var grazieIdsAsCommentsCb: JCheckBox? = null
-    private var grazieLiteralsAsCommentsCb: JCheckBox? = null
-    private var debugShowSpellFeedCb: JCheckBox? = null
-    private var showTyposGreenCb: JCheckBox? = null
-    private var offerQuickFixesCb: JCheckBox? = null
     private var enableCompletionCb: JCheckBox? = null
 
     override fun getDisplayName(): String = "Lyng Formatter"
@@ -50,14 +42,6 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
         reindentClosedBlockCb = JCheckBox("Reindent enclosed block on Enter after '}'")
         reindentPasteCb = JCheckBox("Reindent pasted blocks (align pasted code to current indent)")
         normalizeBlockCommentIndentCb = JCheckBox("Normalize block comment indentation [experimental]")
-        spellCheckLiteralsCb = JCheckBox("Spell check string literals (skip % specifiers like %s, %d, %-12s)")
-        preferGrazieCommentsLiteralsCb = JCheckBox("Prefer Natural Languages/Grazie for comments and string literals (avoid duplicates)")
-        grazieChecksIdentifiersCb = JCheckBox("Check identifiers via Natural Languages/Grazie when available")
-        grazieIdsAsCommentsCb = JCheckBox("Natural Languages/Grazie: treat identifiers as comments (forces spelling checks in 2024.3)")
-        grazieLiteralsAsCommentsCb = JCheckBox("Natural Languages/Grazie: treat string literals as comments when literals are not processed")
-        debugShowSpellFeedCb = JCheckBox("Debug: show spell-feed ranges (weak warnings)")
-        showTyposGreenCb = JCheckBox("Show Lyng typos with green underline (TYPO styling)")
-        offerQuickFixesCb = JCheckBox("Offer Lyng typo quick fixes (Replace…, Add to dictionary) without Spell Checker")
         enableCompletionCb = JCheckBox("Enable Lyng autocompletion (experimental)")
 
         // Tooltips / short help
@@ -66,27 +50,12 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
         reindentClosedBlockCb?.toolTipText = "On Enter after a closing '}', reindent the just-closed {…} block using formatter rules."
         reindentPasteCb?.toolTipText = "When caret is in leading whitespace, reindent the pasted text and align it to the caret's indent."
         normalizeBlockCommentIndentCb?.toolTipText = "Experimental: normalize indentation inside /* … */ comments (code is not modified)."
-        preferGrazieCommentsLiteralsCb?.toolTipText = "When ON and Natural Languages/Grazie is installed, comments and string literals are checked by Grazie. Turn OFF to force legacy Spellchecker to check them."
-        grazieChecksIdentifiersCb?.toolTipText = "When ON and Natural Languages/Grazie is installed, identifiers (non-keywords) are checked by Grazie too."
-        grazieIdsAsCommentsCb?.toolTipText = "Grazie-only fallback: route identifiers as COMMENTS domain so Grazie applies spelling in 2024.3."
-        grazieLiteralsAsCommentsCb?.toolTipText = "Grazie-only fallback: when Grammar doesn't process literals, route strings as COMMENTS so they are checked."
-        debugShowSpellFeedCb?.toolTipText = "Show the exact ranges we feed to spellcheckers (ids/comments/strings) as weak warnings."
-        showTyposGreenCb?.toolTipText = "Render Lyng typos using the platform's green TYPO underline instead of generic warnings."
-        offerQuickFixesCb?.toolTipText = "Provide lightweight Replace… and Add to dictionary quick-fixes without requiring the legacy Spell Checker."
         enableCompletionCb?.toolTipText = "Turn on/off the lightweight Lyng code completion (BASIC)."
         p.add(spacingCb)
         p.add(wrappingCb)
         p.add(reindentClosedBlockCb)
         p.add(reindentPasteCb)
         p.add(normalizeBlockCommentIndentCb)
-        p.add(spellCheckLiteralsCb)
-        p.add(preferGrazieCommentsLiteralsCb)
-        p.add(grazieChecksIdentifiersCb)
-        p.add(grazieIdsAsCommentsCb)
-        p.add(grazieLiteralsAsCommentsCb)
-        p.add(debugShowSpellFeedCb)
-        p.add(showTyposGreenCb)
-        p.add(offerQuickFixesCb)
         p.add(enableCompletionCb)
         panel = p
         reset()
@@ -100,14 +69,6 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
                 reindentClosedBlockCb?.isSelected != s.reindentClosedBlockOnEnter ||
                 reindentPasteCb?.isSelected != s.reindentPastedBlocks ||
                 normalizeBlockCommentIndentCb?.isSelected != s.normalizeBlockCommentIndent ||
-                spellCheckLiteralsCb?.isSelected != s.spellCheckStringLiterals ||
-                preferGrazieCommentsLiteralsCb?.isSelected != s.preferGrazieForCommentsAndLiterals ||
-                grazieChecksIdentifiersCb?.isSelected != s.grazieChecksIdentifiers ||
-                grazieIdsAsCommentsCb?.isSelected != s.grazieTreatIdentifiersAsComments ||
-                grazieLiteralsAsCommentsCb?.isSelected != s.grazieTreatLiteralsAsComments ||
-                debugShowSpellFeedCb?.isSelected != s.debugShowSpellFeed ||
-                showTyposGreenCb?.isSelected != s.showTyposWithGreenUnderline ||
-                offerQuickFixesCb?.isSelected != s.offerLyngTypoQuickFixes ||
                 enableCompletionCb?.isSelected != s.enableLyngCompletionExperimental
     }
 
@@ -118,14 +79,6 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
         s.reindentClosedBlockOnEnter = reindentClosedBlockCb?.isSelected == true
         s.reindentPastedBlocks = reindentPasteCb?.isSelected == true
         s.normalizeBlockCommentIndent = normalizeBlockCommentIndentCb?.isSelected == true
-        s.spellCheckStringLiterals = spellCheckLiteralsCb?.isSelected == true
-        s.preferGrazieForCommentsAndLiterals = preferGrazieCommentsLiteralsCb?.isSelected == true
-        s.grazieChecksIdentifiers = grazieChecksIdentifiersCb?.isSelected == true
-        s.grazieTreatIdentifiersAsComments = grazieIdsAsCommentsCb?.isSelected == true
-        s.grazieTreatLiteralsAsComments = grazieLiteralsAsCommentsCb?.isSelected == true
-        s.debugShowSpellFeed = debugShowSpellFeedCb?.isSelected == true
-        s.showTyposWithGreenUnderline = showTyposGreenCb?.isSelected == true
-        s.offerLyngTypoQuickFixes = offerQuickFixesCb?.isSelected == true
         s.enableLyngCompletionExperimental = enableCompletionCb?.isSelected == true
     }
 
@@ -136,14 +89,6 @@ class LyngFormatterSettingsConfigurable(private val project: Project) : Configur
         reindentClosedBlockCb?.isSelected = s.reindentClosedBlockOnEnter
         reindentPasteCb?.isSelected = s.reindentPastedBlocks
         normalizeBlockCommentIndentCb?.isSelected = s.normalizeBlockCommentIndent
-        spellCheckLiteralsCb?.isSelected = s.spellCheckStringLiterals
-        preferGrazieCommentsLiteralsCb?.isSelected = s.preferGrazieForCommentsAndLiterals
-        grazieChecksIdentifiersCb?.isSelected = s.grazieChecksIdentifiers
-        grazieIdsAsCommentsCb?.isSelected = s.grazieTreatIdentifiersAsComments
-        grazieLiteralsAsCommentsCb?.isSelected = s.grazieTreatLiteralsAsComments
-        debugShowSpellFeedCb?.isSelected = s.debugShowSpellFeed
-        showTyposGreenCb?.isSelected = s.showTyposWithGreenUnderline
-        offerQuickFixesCb?.isSelected = s.offerLyngTypoQuickFixes
         enableCompletionCb?.isSelected = s.enableLyngCompletionExperimental
     }
 }

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/spell/LyngSpellIndex.kt

@@ -1,50 +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.spell
-
-import com.intellij.openapi.diagnostic.Logger
-import com.intellij.openapi.util.Key
-import com.intellij.openapi.util.TextRange
-import com.intellij.psi.PsiFile
-
-/**
- * Per-file cached spellcheck index built from MiniAst-based highlighting and the lynglib highlighter.
- * It exposes identifier, comment, and string literal ranges. Strategies should suspend until data is ready.
- */
-object LyngSpellIndex {
-    private val LOG = Logger.getInstance(LyngSpellIndex::class.java)
-
-    data class Data(
-        val modStamp: Long,
-        val identifiers: List<TextRange>,
-        val comments: List<TextRange>,
-        val strings: List<TextRange>,
-    )
-
-    private val KEY: Key<Data> = Key.create("LYNG_SPELL_INDEX")
-
-    fun getUpToDate(file: PsiFile): Data? {
-        val doc = file.viewProvider.document ?: return null
-        val d = file.getUserData(KEY) ?: return null
-        return if (d.modStamp == doc.modificationStamp) d else null
-    }
-
-    fun store(file: PsiFile, data: Data) {
-        file.putUserData(KEY, data)
-        LOG.info("LyngSpellIndex built: ids=${data.identifiers.size}, comments=${data.comments.size}, strings=${data.strings.size}")
-    }
-}

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/spell/LyngSpellcheckingStrategy.kt

@@ -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.
@@ -16,140 +16,26 @@
  */
 package net.sergeych.lyng.idea.spell
 
-// Avoid Tokenizers helper to keep compatibility; implement our own tokenizers
-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 com.intellij.spellchecker.inspections.PlainTextSplitter
 import com.intellij.spellchecker.tokenizer.SpellcheckingStrategy
-import com.intellij.spellchecker.tokenizer.TokenConsumer
 import com.intellij.spellchecker.tokenizer.Tokenizer
-import net.sergeych.lyng.idea.settings.LyngFormatterSettings
+import net.sergeych.lyng.idea.highlight.LyngTokenTypes
+import net.sergeych.lyng.idea.psi.LyngElementTypes
 
 /**
- * Spellchecking strategy for Lyng:
- * - Identifiers: checked as identifiers
- * - Comments: checked as plain text
- * - Keywords: skipped
- * - String literals: optional (controlled by settings), and we exclude printf-style format specifiers like
- *   %s, %d, %-12s, %0.2f, etc.
+ * Standard IntelliJ spellchecking strategy for Lyng.
+ * Uses the simplified PSI structure to identify declarations.
  */
 class LyngSpellcheckingStrategy : SpellcheckingStrategy() {
-
-    private val log = Logger.getInstance(LyngSpellcheckingStrategy::class.java)
-    @Volatile private var loggedOnce = false
-
-    private fun grazieInstalled(): Boolean {
-        // Support both historical and bundled IDs
-        return PluginManagerCore.isPluginInstalled(PluginId.getId("com.intellij.grazie")) ||
-                PluginManagerCore.isPluginInstalled(PluginId.getId("tanvd.grazi"))
-    }
-
-    private fun grazieApiAvailable(): Boolean = try {
-        // If this class is absent (as in IC-243), third-party plugins can't run Grazie programmatically
-        Class.forName("com.intellij.grazie.grammar.GrammarChecker")
-        true
-    } catch (_: Throwable) { false }
-
-    override fun getTokenizer(element: PsiElement): Tokenizer<*> {
-        val hasGrazie = grazieInstalled()
-        val hasGrazieApi = grazieApiAvailable()
-        val settings = LyngFormatterSettings.getInstance(element.project)
-        if (!loggedOnce) {
-            loggedOnce = true
-            log.info("LyngSpellcheckingStrategy activated: hasGrazie=$hasGrazie, grazieApi=$hasGrazieApi, preferGrazieForCommentsAndLiterals=${settings.preferGrazieForCommentsAndLiterals}, spellCheckStringLiterals=${settings.spellCheckStringLiterals}, grazieChecksIdentifiers=${settings.grazieChecksIdentifiers}")
-        }
-
-        val file = element.containingFile ?: return EMPTY_TOKENIZER
-        val index = LyngSpellIndex.getUpToDate(file) ?: run {
-            // Suspend legacy spellcheck until MiniAst-based index is ready
-            return EMPTY_TOKENIZER
-        }
-        val elRange = element.textRange ?: return EMPTY_TOKENIZER
-
-        fun overlaps(list: List<TextRange>) = list.any { it.intersects(elRange) }
-
-        // Decide responsibility per settings
-        // If Grazie is present but its public API is not available (IC-243), do NOT delegate to it.
-        val preferGrazie = hasGrazie && hasGrazieApi && settings.preferGrazieForCommentsAndLiterals
-        val grazieIds = hasGrazie && hasGrazieApi && settings.grazieChecksIdentifiers
-
-        // Identifiers: only if range is within identifiers index and not delegated to Grazie
-        if (overlaps(index.identifiers) && !grazieIds) return IDENTIFIER_TOKENIZER
-
-        // Comments: only if not delegated to Grazie and overlapping indexed comments
-        if (!preferGrazie && overlaps(index.comments)) return COMMENT_TEXT_TOKENIZER
-
-        // Strings: only if not delegated to Grazie, literals checking enabled, and overlapping indexed strings
-        if (!preferGrazie && settings.spellCheckStringLiterals && overlaps(index.strings)) return STRING_WITH_PRINTF_EXCLUDES
-
-        return EMPTY_TOKENIZER
-    }
-
-    private object EMPTY_TOKENIZER : Tokenizer<PsiElement>() {
-        override fun tokenize(element: PsiElement, consumer: TokenConsumer) {}
-    }
-
-    private object IDENTIFIER_TOKENIZER : Tokenizer<PsiElement>() {
-        private val splitter = PlainTextSplitter.getInstance()
-        override fun tokenize(element: PsiElement, consumer: TokenConsumer) {
-            val text = element.text
-            if (text.isNullOrEmpty()) return
-            consumer.consumeToken(element, text, false, 0, TextRange(0, text.length), splitter)
-        }
-    }
-
-    private object COMMENT_TEXT_TOKENIZER : Tokenizer<PsiElement>() {
-        private val splitter = PlainTextSplitter.getInstance()
-        override fun tokenize(element: PsiElement, consumer: TokenConsumer) {
-            val text = element.text
-            if (text.isNullOrEmpty()) return
-            consumer.consumeToken(element, text, false, 0, TextRange(0, text.length), splitter)
-        }
-    }
-
-    private object STRING_WITH_PRINTF_EXCLUDES : Tokenizer<PsiElement>() {
-        private val splitter = PlainTextSplitter.getInstance()
-
-        // Regex for printf-style specifiers: %[flags][width][.precision][length]type
-        // This is intentionally permissive to skip common cases like %s, %d, %-12s, %08x, %.2f, %%
-        private val SPEC = Regex("%(?:[-+ #0]*(?:\\d+)?(?:\\.\\d+)?[a-zA-Z%])")
-
-        override fun tokenize(element: PsiElement, consumer: TokenConsumer) {
-            // Check project settings whether literals should be spell-checked
-            val settings = LyngFormatterSettings.getInstance(element.project)
-            if (!settings.spellCheckStringLiterals) return
-
-            val text = element.text
-            if (text.isEmpty()) return
-
-            // Try to strip surrounding quotes (simple lexer token for Lyng strings)
-            var startOffsetInElement = 0
-            var endOffsetInElement = text.length
-            if (text.length >= 2 && (text.first() == '"' && text.last() == '"' || text.first() == '\'' && text.last() == '\'')) {
-                startOffsetInElement = 1
-                endOffsetInElement = text.length - 1
-            }
-            if (endOffsetInElement <= startOffsetInElement) return
-
-            val content = text.substring(startOffsetInElement, endOffsetInElement)
-
-            var last = 0
-            for (m in SPEC.findAll(content)) {
-                val ms = m.range.first
-                val me = m.range.last + 1
-                if (ms > last) {
-                    val range = TextRange(startOffsetInElement + last, startOffsetInElement + ms)
-                    consumer.consumeToken(element, text, false, 0, range, splitter)
-                }
-                last = me
-            }
-            if (last < content.length) {
-                val range = TextRange(startOffsetInElement + last, startOffsetInElement + content.length)
-                consumer.consumeToken(element, text, false, 0, range, splitter)
-            }
+    override fun getTokenizer(element: PsiElement?): Tokenizer<*> {
+        val type = element?.node?.elementType
+        return when (type) {
+            LyngTokenTypes.LINE_COMMENT, LyngTokenTypes.BLOCK_COMMENT -> TEXT_TOKENIZER
+            LyngTokenTypes.STRING -> TEXT_TOKENIZER
+            LyngElementTypes.NAME_IDENTIFIER,
+            LyngElementTypes.PARAMETER_NAME,
+            LyngElementTypes.ENUM_CONSTANT_NAME -> TEXT_TOKENIZER
+            else -> super.getTokenizer(element)
         }
     }
 }