better docs/AI instructions/readme

AGENTS.md

@@ -13,6 +13,7 @@
 - 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

LYNG_AI_SPEC.md

@@ -4,6 +4,7 @@ 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.
@@ -13,6 +14,7 @@ High-density specification for LLMs. Reference this for all Lyng code generation
         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).
@@ -44,9 +46,21 @@ High-density specification for LLMs. Reference this for all Lyng code generation
 - **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.
-- **Inference**: List/map literals infer union element types; empty list is `List<Object>`, empty map is `{:}`.
-- **Generics**: Bounds with `T: A & B` or `T: A | B`; variance uses `out`/`in`.
+- **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`.

README.md

@@ -32,9 +32,9 @@ class A {
     enum E* { One, Two }
 }
 val ab = A.B()
-assertEquals(ab.x, null)
-assertEquals(A.Inner.foo, "bar")
-assertEquals(A.One, A.E.One)
+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)

docs/parallelism.md

@@ -223,17 +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. **Current frame locals and arguments**: Variables defined within the current closure execution.
-2. **Captured lexical ancestry**: Outer local variables captured at the site where the closure was defined (the "lexical environment").
-3. **Captured receiver members**: If the closure was defined within a class or explicitly bound to an object, it checks members of that object (`this`), following MRO and respecting visibility.
-4. **Caller environment**: Falls back to the calling context (e.g., the caller's `this` or local variables).
-5. **Global/Module fallbacks**: Final check for module-level constants and global functions.
+- **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/scopes_and_closures.md

@@ -1,94 +1,18 @@
-# Scopes and Closures: resolution and safety
+# Scopes and Closures: compile-time resolution
 
-Attention to AI: name lookup is ibsolete and must not be used with bytecode compiler
+Attention to AI: name lookup in runtime `Scope` is legacy. The bytecode compiler uses **compile-time name/member resolution only**.
 
-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.
+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.
 
-## 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.
+## 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.
 
-## Resolution order in ClosureScope
-When evaluating an identifier `name` inside a closure, `ClosureScope.get(name)` resolves in this order:
+## 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.
 
-1. **Current frame locals and arguments**: Variables defined within the current closure execution.
-2. **Captured lexical ancestry**: Outer local variables captured at the site where the closure was defined (the "lexical environment").
-3. **Captured receiver members**: If the closure was defined within a class or explicitly bound to an object, it checks members of that object (`this`). This includes both instance fields/methods and class-level static members, following the MRO (C3) and respecting visibility rules (private members are only visible if the closure was defined in their class).
-4. **Caller environment**: If not found lexically, it falls back to the calling context (e.g., the DSL's `this` or the caller's local variables).
-5. **Global/Module fallbacks**: Final check for module-level constants and global functions.
-
-This ensures that closures primarily interact with their defining environment (lexical capture) while still being able to participate in DSL-style calling contexts.
-
-## 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/whats_new_1_5.md

@@ -22,7 +22,7 @@ The API is fixed and will be kept with further Lyng core changes. It is now the
 
 - **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). No type erasure: in a generic function you can, for example, check `A in T`, where T is the generic type.
+- **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

notes/ai_state.md

@@ -1,37 +1,20 @@
 AI State (for session restart)
 
-Project: /home/sergeych/dev/ling_lib
+Project: /home/sergeych/dev/lyng
 Module focus: :lynglib
 
 Current focus
 - Enforce compile-time name/member resolution only; no runtime scope lookup or fallback.
-- Bytecode uses memberId-based ops (CALL_MEMBER_SLOT/GET_MEMBER_SLOT/SET_MEMBER_SLOT).
-- Runtime lookup opcodes (CALL_VIRTUAL/GET_FIELD/SET_FIELD) and fallback callsites are removed.
-- Use FrameSlotRef for captures and only materialize Scope for Kotlin interop; use frame.ip -> pos mapping for diagnostics.
+- Closures capture frame slots directly; materialize `Scope` only for Kotlin interop or explicit dynamic helpers.
+- Object members are allowed on unknown types; other members require a statically known receiver type or explicit cast.
+- Type system is Kotlin-style: `T` non-null, `T?` nullable, `!!` asserts non-null; `void` is a singleton of class `Void`.
+- Type expressions: unions/intersections with bounds, declaration-site variance (`in`/`out`), and structural equality.
 
 Key recent changes
-- Removed method callsite PICs and fallback opcodes; bytecode now relies on compile-time member ids only.
-- Operator dispatch emits memberId calls when known; falls back to Obj opcodes for allowed built-ins without name lookup.
-- Object members are allowed on unknown types; other members still require a statically known receiver type.
-- Added frame.ip -> pos mapping; call-site ops restore pos after args to keep stack traces accurate.
-- Loop var overrides now take precedence in slot resolution to keep loop locals in frame slots.
-- LocalSlotRef now falls back to name lookup when slot plans are missing (closure safety).
+- Updated AI helper docs to reflect static typing, type expressions, and compile-time-only name resolution.
 
 Known failing tests
-- None (jvmTest passing).
-
-Files touched recently
-- notes/type_system_spec.md (spec updated)
-- AGENTS.md (type inference reminders)
-- lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt
-- lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
-- lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt
+- Not checked in this session.
 
 Last test run
-- ./gradlew :lynglib:jvmTest
-
-Spec decisions (notes/type_system_spec.md)
-- Nullability: Kotlin-style, T non-null, T? nullable, !! asserts non-null.
-- void is singleton of class Void (syntax sugar).
-- Untyped params default to Object (non-null); syntax sugar: fun foo(x?) and class X(a,b?).
-- Object member access requires explicit cast; remove inspect, use toInspectString().
+- Not checked in this session.