Root Cause:
- Else blocks were not propagating variable assignments to outer scope
- Bug 1 (if_form.rs): PHI materialization happened before variable_map reset,
causing PHI nodes to be lost
- Bug 2 (phi.rs): Variable merge didn't check if else branch modified variables
Changes:
- src/mir/builder/if_form.rs:93-127
- Reordered: reset variable_map BEFORE materializing PHI nodes
- Now matches then-branch pattern (reset → materialize → execute)
- Applied to both "else" and "no else" branches for consistency
- src/mir/builder/phi.rs:137-154
- Added else_modified_var check to detect variable modifications
- Use modified value from else_var_map_end_opt when available
- Fall back to pre-if value only when truly not modified
Test Results:
✅ Simple block: { x=42 } → 42
✅ If block: if 1 { x=42 } → 42
✅ Else block: if 0 { x=99 } else { x=42 } → 42 (FIXED!)
✅ Stage-B body extraction: "return 42" correctly extracted (was null)
Impact:
- Else block variable assignments now work correctly
- Stage-B compiler body extraction restored
- Selfhost builder path can now function
- Foundation for Phase 21.x progress
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Unify standard method calls to emit_unified_call; route via RouterPolicy and apply rewrite::{special,known} at a single entry.\n- Stabilize emit-time invariants: LocalSSA finalize + BlockSchedule PHI→Copy→Call ordering; metadata propagation on copies.\n- Known rewrite default ON (userbox only, strict guards) with opt-out flag NYASH_REWRITE_KNOWN_DEFAULT=0.\n- Expand TypeAnnotation whitelist (is_digit_char/is_hex_digit_char/is_alpha_char/Map.has).\n- Docs: unified-method-resolution design note; Quick Reference normalization note; selfhosting/quickstart.\n- Tools: add tools/selfhost_smoke.sh (dev-only).\n- Keep behavior unchanged for Unknown/core/user-instance via BoxCall fallback; all tests green (quick/integration).
- Fix condition_fn resolution: Value call path + dev safety + stub injection
- VM bridge: handle Method::birth via BoxCall; ArrayBox push/get/length/set direct bridge
- Receiver safety: pin receiver in method_call_handlers to avoid undefined use across blocks
- Local vars: materialize on declaration (use init ValueId; void for uninit)
- Prefer legacy BoxCall for Array/Map/String/user boxes in emit_box_or_plugin_call (stability-first)
- Test runner: update LLVM hint to llvmlite harness (remove LLVM_SYS_180_PREFIX guidance)
- Docs/roadmap: update CURRENT_TASK with unified default-ON + guards
Note: NYASH_DEV_BIRTH_INJECT_BUILTINS=1 can re-enable builtin birth() injection during migration.
- Update CLAUDE.md: peek式 → match式, peek構文 → match構文
- Update LANGUAGE_REFERENCE_2025.md: Peek式 → Match式
- Fix default pattern: else → _ (underscore)
- Resolve confusion causing JSON development Claude to use incorrect syntax
This fixes the root cause where new AI developers were referencing outdated
'peek' syntax examples and getting parse errors, forcing them to rewrite
with 'if' statements instead of using the correct 'match' syntax.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Decision recorded in CURRENT_TASK: replace with (no compat alias)
- EBNF: add match_expr/pattern/guard; note legacy peek removal
- Guides/Reference: update examples and wording (null-coalesce/safe-access sugar via match)
## Summary
Documented the "init block vs fields-at-top" design discussion as a valuable example of AI-human collaboration in language design.
## Changes
### Paper G (AI Collaboration)
- Added field-declaration-design.md documenting the entire discussion flow
- Showcased how complex init block proposal evolved to simple "fields at top" rule
- Demonstrates AI's tendency toward complexity vs human intuition for simplicity
### Paper H (AI Practical Patterns)
- Added Pattern #17: "Gradual Refinement Pattern" (段階的洗練型)
- Documents the process: Complex AI proposal → Detailed analysis → Human insight → Convergence
- Field declaration design as a typical example
### Paper K (Explosive Incidents)
- Added Incident #046: "init block vs fields-at-top incident"
- Updated total count to 46 incidents
- Shows how a single human comment redirected entire design approach
## Design Decision
After analysis, decided that BoxIndex should remain a compiler-internal structure, not a core Box:
- Core Boxes: User-instantiable runtime values (String, Integer, Array, Map)
- Compiler internals: BoxIndex for name resolution (compile-time only)
- Clear separation of concerns between language features and compiler tools
## Philosophy
This discussion exemplifies key principles:
- The best design needs no explanation
- Constraints provide clarity, not limitation
- "Everything is Box" doesn't mean "compiler internals are Boxes"
- AI tends toward theoretical completeness; humans toward practical simplicity
🐱 Sometimes the simplest answer is right in front of us\!
Parser improvements:
- Added expression statement fallback in parse_statement() for flexible syntax
- Fixed ternary operator to use PeekExpr instead of If AST (better lowering)
- Added peek_token() check to avoid ?/?: operator conflicts
LLVM Python improvements:
- Added optional ESC_JSON_FIX environment flag for string concatenation
- Improved PHI generation with better default handling
- Enhanced substring tracking for esc_json pattern
Documentation updates:
- Updated language guide with peek expression examples
- Added box theory diagrams to Phase 15 planning
- Clarified peek vs when syntax differences
These changes enable cleaner parser implementation for self-hosting,
especially for handling digit conversion with peek expressions instead
of 19-line if-else chains.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
