Allow Object members on unknown types

AGENTS.md

@@ -7,8 +7,8 @@
 - 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/type_system_spec.md)
+## 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 member access requires explicit cast; remove `inspect` from Object and use `toInspectString()` instead.
+- Object members are always allowed even on unknown types; non-Object members require explicit casts. Remove `inspect` from Object and use `toInspectString()` instead.
 - 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.

LYNG_AI_SPEC.md

@@ -19,6 +19,7 @@ High-density specification for LLMs. Reference this for all Lyng code generation
 - **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.
@@ -37,6 +38,15 @@ High-density specification for LLMs. Reference this for all Lyng code generation
 - **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.
+- **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`.
 
 ## 3. Delegation (`by`)
 Unified model for `val`, `var`, and `fun`.
@@ -63,11 +73,11 @@ Delegate Methods:
 - **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 `Map()`.
+- **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`.
+- **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 |

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt

@@ -2027,10 +2027,14 @@ class BytecodeCompiler(
 
     private fun compileFieldRef(ref: FieldRef): CompiledValue? {
         val receiverClass = resolveReceiverClass(ref.target)
-            ?: throw BytecodeCompileException(
-                "Member access requires compile-time receiver type: ${ref.name}",
-                Pos.builtIn
-            )
+            ?: if (isAllowedObjectMember(ref.name)) {
+                Obj.rootObjectType
+            } else {
+                throw BytecodeCompileException(
+                    "Member access requires compile-time receiver type: ${ref.name}",
+                    Pos.builtIn
+                )
+            }
         val fieldId = receiverClass.instanceFieldIdMap()[ref.name]
         val methodId = receiverClass.instanceMethodIdMap(includeAbstract = true)[ref.name]
         val receiver = compileRefWithFallback(ref.target, null, Pos.builtIn) ?: return null

lynglib/stdlib/lyng/root.lyng

@@ -291,7 +291,7 @@ override fun List<T>.toString() {
     var result = "["
     for (item in this) {
         if (!first) result += ","
-        result += (item as Object).toString()
+        result += item.toString()
         first = false
     }
     result + "]"
@@ -311,7 +311,7 @@ fun List<T>.sort(): Void {
 fun Exception.printStackTrace(): Void {
     println(this)
     for( entry in stackTrace ) {
-        println("\tat "+(entry as Object).toString())
+        println("\tat "+entry.toString())
     }
 }
 

notes/ai_state.md

@@ -6,32 +6,16 @@ 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).
-- Fallbacks are forbidden and throw BytecodeFallbackException.
+- Runtime lookup opcodes (CALL_VIRTUAL/GET_FIELD/SET_FIELD) and fallback callsites are removed.
 
 Key recent changes
-- Added memberId storage and lookup on ObjClass/ObjInstance; compiler emits memberId ops.
-- Removed GET_THIS_MEMBER/SET_THIS_MEMBER usage from bytecode.
-- Added ObjIterable.iterator() abstract method to ensure methodId exists.
-- Bytecode compiler now throws if receiver type is unknown for member calls.
-- Added static receiver inference attempts (name/slot maps), but still failing for stdlib list usage.
-- Compiler now wraps function bodies into BytecodeStatement when possible.
-- VarDeclStatement now includes initializerObjClass (compile-time type hint).
+- 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.
+- Renamed BytecodeFallbackException to BytecodeCompileException.
 
-Known failing test
-- ScriptTest.testForInIterableUnknownTypeDisasm (jvmTest)
-  Failure: BytecodeFallbackException "Member call requires compile-time receiver type: add"
-  Location: stdlib root.lyng filter() -> "val result = []" then "result.add(item)"
-  Current debug shows LocalSlotRef(result) slotClass/nameClass/initClass all null.
-
-Likely cause
-- Initializer type inference for "val result = []" in stdlib is not reaching BytecodeCompiler:
-  - stdlib is generated at build time; initializer is wrapped in BytecodeStatement and losing ListLiteralRef info.
-  - Need a stable compile-time type hint from the compiler or a way to preserve list literal info.
-
-Potential fixes to pursue
-1) Preserve ObjRef for var initializers (e.g., store initializer ref/type in VarDeclStatement).
-2) When initializer is BytecodeStatement, use its CmdFunction to detect list/range literal usage.
-3) Ensure stdlib compilation sets initializerObjClass for list literals.
+Known failing tests
+- None (jvmTest passing).
 
 Files touched recently
 - notes/type_system_spec.md (spec updated)

notes/bytecode_callsite_fix.md

@@ -1,10 +1,11 @@
-# Bytecode call-site PIC + fallback gating
+# Bytecode call-site PIC + fallback gating (obsolete)
 
 Changes
 - Added method call PIC path in bytecode VM with new CALL_SLOT/CALL_VIRTUAL opcodes.
 - Fixed FieldRef property/delegate resolution to avoid bypassing ObjRecord delegation.
 - Prevent delegated ObjRecord mutation by returning a resolved copy.
 - Restricted bytecode call compilation to args that are ExpressionStatement (no splat/named/tail-block), fallback otherwise.
+- NOTE: PICs and fallback callsites have been removed; keep this for historical context only.
 
 Rationale
 - Fixes JVM test regressions and avoids premature evaluation of Statement args.

notes/new_lyng_type_system_spec.md

@@ -212,7 +212,7 @@ Type params are erased by default. Hidden `Class` args are only injected when a
 
 - Member access rules: If a variable is Object (dynamic), is member access a compile-time error, or allowed with fallback (which we are trying to remove)? If error, do we require explicit cast first?
 
-Compile time error unless it is an Object own method. Let's force rewriting existing code in favor of explicit casts. It will repay itself: I laready have a project on Lyng that suffers from implicit casts har to trace errors.
+Compile time error unless it is an Object own method. Object members are always allowed even on unknown types; non-Object members require explicit casts. This avoids runtime lookup while keeping common Object APIs available.
 
 No runtime lookups or fallbacks:
 - All symbol and member resolution must be done at compile time.