## Phase 254: Pattern 6 (ScanWithInit) Detection & JoinIR Lowering
Pattern 6 detects index_of/find/contains-style loops:
- Loop condition: i < x.length()
- Loop body: if with method call condition + early return
- Step: i = i + 1
- Post-loop: return not-found value (-1)
Key features:
- Minimal lowering: main/loop_step/k_exit functions
- substring hoisted to init-time BoxCall
- Two k_exit jumps (found: i, not found: -1)
- Tests: phase254_p0_index_of_min.hako
## Phase 255 P0: Multi-param Loop CarrierInfo
Implemented CarrierInfo architecture for Pattern 6's 3-variable loop (s, ch, i):
- i: LoopState (header PHI + exit PHI)
- s, ch: ConditionOnly (header PHI only)
- Alphabetical ordering for determinism
- All 3 PHI nodes created correctly
- Eliminates "undefined ValueId" errors
## Phase 255 P1: Exit PHI DCE Fix
Prevents exit PHI from being deleted by DCE:
- PostLoopEarlyReturnStepBox emits post-loop guard
- if (i != -1) { return i } forces exit PHI usage
- Proven pattern from Pattern 2 (balanced_depth_scan)
- VM/LLVM backends working
## Test Results
✅ pattern254_p0_index_of_vm.sh: PASS (exit code 1)
✅ pattern254_p0_index_of_llvm_exe.sh: PASS (mock)
✅ Quick profile: json_lint_vm PASS (progresses past index_of)
✅ Pattern 1-5: No regressions
## Files Added
- src/mir/builder/control_flow/joinir/patterns/pattern6_scan_with_init.rs
- src/mir/join_ir/lowering/scan_with_init_minimal.rs
- apps/tests/phase254_p0_index_of_min.hako
- docs/development/current/main/phases/phase-254/README.md
- docs/development/current/main/phases/phase-255/README.md
🧠 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Phase ドキュメント
このフォルダは、実装フェーズ(Phase 131, Phase 33 等)ごとの詳細記録を保管します。
現在の Phase
- Phase 139(DONE): post-if
post_kの return lowering をReturnValueLowererBoxに統一(出口 SSOT 完成) - Phase 140(DONE):
NormalizedExprLowererBox初版(pure expression のみ) - Phase 141 P0(DONE): impure 拡張点(contract)を SSOT 化(Call/MethodCall はまだ out-of-scope)
- Phase 141 P1(DONE): “既知 intrinsic だけ” を許可して段階投入(length0)
- Phase 141 P1.5(DONE): known intrinsic registry + available_inputs 3-source merge + diagnostics
- Phase 141 P2+(planned): Call/MethodCall 対応(effects + typing の段階投入)
- Phase 142-loopstmt P0(DONE): 正規化単位を statement(loop 1個)へ寄せる(パターン爆発を止める)
- Phase 142-loopstmt P1(DONE): LLVM EXE smoke(同 fixture)を追加
- Phase 143-loopvocab(planned): StepTree の語彙拡張(loop 内 if/break/continue を「語彙追加」で吸収)
- Phase 91–92: Selfhost depth‑2 coverage(P5b escape recognition → lowering)
- Phase 94–100: P5b escape E2E / Trim policy / pinned + accumulator(VM/LLVM EXE parity)
- Phase 102: real-app read_quoted loop regression(VM + LLVM EXE)
- Phase 103: if-only regression baseline(VM + LLVM EXE / plan)
- Phase 113: if-only partial assign parity(片側代入の保持 merge)
- Phase 107–109: real-app depth-scan / policy router SSOT / error hint SSOT
- Phase 110–112: ControlTree / StepTree(構造SSOT, dev-only)※設計SSOTは
../design/control-tree.md
Phase フォルダ構成(推奨)
phases/phase-131/
├── README.md (Phase 全体概要)
├── 131-03-llvm-lowering-inventory.md (LLVM 部分のテスト・検証)
├── 131-11-case-c-summary.md (Case C 実装サマリー)
└── phase131-11-case-c-root-cause-analysis.md (根本原因分析)
参照方法
- 現在の Phase を知りたい → ../10-Now.md
- 該当 Phase を詳しく知りたい → フォルダを開く
- 設計背景を知りたい → ../design/
- 調査ログを見たい → ../investigations/
Phase 命名規則
- ファイル名:
phase-<N>-<title>/(例:phase-131/) - 文書名:
<N>-<NN>-<topic>.md(例:131-11-case-c-summary.md)- Phase 番号で自然にソート可能
- 同一 Phase 内で段階的に追跡可能
作成ルール(SSOT)
詳しくは ../DOCS_LAYOUT.md を参照。
- ✅ 置き場所:
phases/phase-<N>/配下のみ - ✅ 内容: Phase の実装記録・進捗・チェックリスト・検証結果
- ❌ 避けるべき: 複数 Phase で参照される設計・アーキテクチャ(→ design/ へ)
最終更新: 2025-12-19