Root cause: toString/stringify/str were being rewritten to Global/Method calls
with class inference, causing Main.toString/0 to be called for primitives.
Fix (Box-First + Legacy Deletion):
1. ✅ MIR Builder - toString normalization (special.rs)
- ALWAYS emit BoxCall with method_id=0 for toString/stringify/str
- Do NOT rewrite to Global(Class.str/0) or Method calls
- DELETED 70+ lines of complex class inference logic
- Primitive guard with method name filter (known.rs)
2. ✅ JSON Serializer - method_id output (mir_json_emit.rs)
- Include method_id field in BoxCall JSON for LLVM
3. ✅ LLVM Backend - universal slot #0 support
- Extract method_id from JSON (instruction_lower.py)
- Box primitives via nyash.box.from_i64 (boxcall.py)
- Invoke toString via plugin system with method_id=0
- ⚠️ TODO: Add nyash.integer.tostring_h to kernel
Test Results:
✅ VM: local x = 1; print(x.toString()) → "1" (PASS)
✅ VM: array_length test (boxed Integer) → PASS
⚠️ LLVM: Compiles successfully, needs kernel function
SSOT: slot_registry - toString is ALWAYS universal slot #0
Legacy Deleted:
- special.rs: Complex class inference rewrite (~70 lines)
- special.rs: Unique suffix fallback for toString
- special.rs: Main box special handling
Files changed:
- src/mir/builder/rewrite/special.rs (try_early_str_like_to_dst)
- src/mir/builder/rewrite/known.rs (primitive guards x4)
- src/runner/mir_json_emit.rs (method_id serialization x2)
- src/llvm_py/builders/instruction_lower.py (method_id extraction)
- src/llvm_py/instructions/boxcall.py (slot #0 handler)
- docs/reference/language/quick-reference.md (toString SSOT)
🎊 Generated with Claude Code
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>