Fixed:
- Environment::set now properly searches ancestor chain before creating new binding
- Added exists_in_chain_locked() helper for explicit existence checking
- Simple {} blocks now correctly update outer scope variables
Verified Working:
- local x = 10; { x = 42 }; print(x) → prints 42 ✅
Still Broken:
- else blocks don't update outer scope variables
- local x = 10; if flag { x = 99 } else { x = 42 }; print(x) → prints 10 ❌
Root Cause Identified:
- Issue is in MIR Builder (compile-time), not Environment (runtime)
- src/mir/builder/if_form.rs:108 resets variable_map before else block
- PHI generation at merge doesn't use else_var_map_end correctly
- MIR shows: phi [%32, bb1], [%1, bb2] where %1 is original value, not else value
Next: Fix else block variable merging in if_form.rs
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
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