chore: Phase 25.1 完了 - LoopForm v2/Stage1 CLI/環境変数削減 + Phase 26-D からの変更

Phase 25.1 完了成果:
- ✅ LoopForm v2 テスト・ドキュメント・コメント完備
  - 4ケース（A/B/C/D）完全テストカバレッジ
  - 最小再現ケース作成（SSAバグ調査用）
  - SSOT文書作成（loopform_ssot.md）
  - 全ソースに [LoopForm] コメントタグ追加

- ✅ Stage-1 CLI デバッグ環境構築
  - stage1_cli.hako 実装
  - stage1_bridge.rs ブリッジ実装
  - デバッグツール作成（stage1_debug.sh/stage1_minimal.sh）
  - アーキテクチャ改善提案文書

- ✅ 環境変数削減計画策定
  - 25変数の完全調査・分類
  - 6段階削減ロードマップ（25→5、80%削減）
  - 即時削除可能変数特定（NYASH_CONFIG/NYASH_DEBUG）

Phase 26-D からの累積変更:
- PHI実装改善（ExitPhiBuilder/HeaderPhiBuilder等）
- MIRビルダーリファクタリング
- 型伝播・最適化パス改善
- その他約300ファイルの累積変更

🎯 技術的成果:
- SSAバグ根本原因特定（条件分岐内loop変数変更）
- Region+next_iパターン適用完了（UsingCollectorBox等）
- LoopFormパターン文書化・テスト化完了
- セルフホスティング基盤強化

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: ChatGPT <noreply@openai.com>
Co-Authored-By: Task Assistant <task@anthropic.com>

AGENTS.md

@@ -146,38 +146,38 @@ PR テンプレ（追加項目）
 - [ ] 「スモークを通すためだけのハードコード」を入れていません（根治で解決）
 - [ ] 受け入れ基準に記載の検証を実施しました（dev OFF/ログ確認）
 
-### 5.2 Rust Freeze Policy（Self‑Host First）
+### 5.2 Rust Minimal Policy（Self‑Host First, but not Frozen）
 
-目的: 脱Rustで開発効率を最大化する。Rust層は“最小シーム＋バグ修正”のみに留め、分析/ルール/可視化は .hako 側で実装する。
+目的: 脱Rustを志向しつつも、Stage‑1 / Self‑Host ラインの整備やツールの使いやすさ向上のために、**Rust層で必要な構造的変更やブリッジ強化は積極的に許可する**。分析/ルール/可視化は引き続き .hako 側が主戦場。
 
 - 原則
-  - Rustは「SSOTランナー導線（resolve→parse→merge）」と「VM/Interpreterの安定化（バグ修正、挙動不変）」のみ。
-  - 新規機能・ルール・可視化・チェックは .hako で実装（自己ホスト）。
-  - 変更は既定OFFのトグルで可逆・小差分・戻し手順あり（AGENTS.md 5.1に準拠）。
+  - Rustは「SSOTランナー導線（resolve→parse→merge）」と「VM/Interpreterの安定化」を軸にしつつ、Stage‑1 CLI / selfhost ブリッジ / エラーメッセージ改善など**開発導線の改善**も扱ってよい。
+  - 新規の言語ルール・静的解析ロジック・ビジネスロジックは、基本的に .hako 側で実装（自己ホスト）。
+  - 変更はできるだけ小さく・可逆に保ちつつ、必要に応じてトグルや dev 用フラグでガード（AGENTS.md 5.1 に準拠）。
 
-- 許可（最小のRust変更）
-  - ランナー導線の保守（using text‑merge for .hako の維持）。
-  - バグ修正（既定挙動不変、必要ならトグル既定OFF）。
-  - Analyzerシームの提供（抽出のみ）：
-    - 例: `--hako-analyze <paths>` → AST/Analysis JSON を stdout/--out に出力。
-    - 判定ロジックは持たない（抽出専用）。
-  - 薄いCLI糖衣：`--hako-check`（内部で `--hako-analyze`→.hakoアナライザをVM経由で実行）。
+- 許可（Rustでやってよいことの例）
+  - ランナー導線の保守・改善（Stage‑B/Stage‑1/Stage0 の配線、using text‑merge for .hako の維持・整理）。
+  - Stage‑1 / Stage‑B / selfhost 向けのブリッジ強化（子プロセス起動、環境変数の集約、エラー表示の改善）。
+  - バグ修正（既定挙動を壊さない範囲。必要なら既定OFFトグル）。
+  - Analyzerシームの提供（AST/Analysis JSON の抽出専用。判定ロジックは持たない）。
+  - 薄いCLI糖衣：`--hako-check` など、.hako 側のアナライザを呼び出すための CLI エントリ。
 
-- 禁止/抑制
-  - ルール実装（Lint/命名/依存/特定Box名分岐）をRustに持ち込むこと。
-  - 広域リファクタ・既定挙動変更（凍結）。
+- 禁止/抑制（依然として .hako 側でやる領域）
+  - Lint / 命名規則 / 依存関係チェック / 特定 Box 名への分岐など、**ルール実装の本体**。
+  - LoopSSA / 数値カーネル / 高レベルの最適化ロジックを Rust に新規実装すること（Self‑Host で十分に表現できる範囲）。
+  - 広域リファクタや既定挙動を大きく変える変更（必要なら Phase/Proposal に切り出してから）。
 
 - .hako 側の責務（Self‑Host）
-  - Lint/解析/可視化/関係図（DOT）を .hako で実装（tools/hako_check/*）。
+  - Lint / 解析 / 可視化 / 関係図（DOT）を .hako で実装（tools/hako_check/*）。
   - 解析入力は Rust の Analysis JSON（または AST JSON）。
   - 返り値は件数ベース（0=OK、>0=警告/エラー件数）。
 
 - 受け入れ基準（Rust変更時）
-  - quickスモーク/Adapter reps 緑維持（既定挙動不変）。
-  - 変更はトグルでガード（既定OFF）・小差分・戻し手順付き。
-  - .hako からの利用例/READMEを更新。
+  - quick スモーク / 代表テストが緑維持（既定挙動を意図せず変えていない）。
+  - 変更は目的が明確で、小さく・可逆（トグルや限定スコープでガード）であること。
+  - .hako からの利用例 / README / proposal を更新し、将来の開発者が迷わないようにしておく。
 
-補足：自己ホスト達成済みのため、Rust層は“何かあった時のための最低限の手入れ”に限定。日常の機能拡張は .hako 側で行い、構造/テスト/ドキュメントを伴って進める。
+補足：.hako 側の解析・Stage‑1 ラインが十分に動き始めたので、Rust層は「完全凍結」ではなく、**Self‑Host を支えるための最小＋必要な整備を行う層**という扱いに緩和する。日常の機能拡張や言語仕様変更はこれまで通り .hako 側で行い、Rust 変更は「導線の改善」「ブリッジ」「可観測性の向上」にフォーカスする。
 
 ### 6. Fail-Fast with Structure
 
@@ -379,6 +379,7 @@ Notes
 - Phase‑17（LoopForm Self‑Hosting & Polish）: `docs/development/roadmap/phases/phase-17-loopform-selfhost/`
 - MacroBox（ユーザー拡張）: `docs/guides/macro-box.md`
 - MacroBox in Nyash（設計草案）: `docs/guides/macro-box-nyash.md`
+- MIR デバッグ総覧（dump/hints/__mir__）: `docs/guides/testing-guide.md`（`MIR デバッグの入口まとめ` セクション）
 
 # Repository Guidelines
 

CURRENT_TASK.md

@@ -17,11 +17,37 @@
 - .hako 側:
   - Stage‑B コンパイラ本体 / LoopSSA v2 / BreakFinderBox / PhiInjectorBox はまだ部分実装。
   - JSON v0 / selfhost ルートは Rust 側の LoopForm v2 規約に追いつかせる必要がある。
+- Stage‑B / FuncScanner ライン:
+  - Phase 25.3 をクローズし、`stageb_fib_program_defs_canary_vm.sh` が緑（`defs` に `TestBox.fib/Main.main`、fib.body.body[*] に `Loop`）。
+  - Stage‑B は block パーサ優先 + defs を Block 包みで構造化。次手: Stage‑1 UsingResolver ループの Region+next_i 揃え / Stage‑1 CLI program-json selfhost 準備。
 
 ---
 
 ## 1. 最近完了した重要タスク
 
+### 1-0. Phase 25.3 — FuncScanner / Stage‑B defs 安定化（完了）
+
+**目的**
+- Stage‑B / FuncScanner ラインで defs が欠落したり Loop が脱落する問題を塞ぎ、selfhost 側の canary を緑に戻す。
+
+**やったこと**
+- StageBDriverBox.main:
+  - main 本文を `{…}` で包んだ block パーサ優先で Program(JSON) に組み立て、defs には `{"type":"Block","body":[…]}` 形式で埋め込むよう整理。
+  - Program パーサ fallback は `HAKO_STAGEB_PROGRAM_PARSE_FALLBACK=1` の opt-in に封じ込め（skip_ws 崩れを回避）。
+- StageBFuncScannerBox._scan_methods:
+  - block パーサ優先に統一し、Program パーサは `HAKO_STAGEB_FUNC_SCAN_PROG_FALLBACK=1` でのみ有効化。
+  - defs パラメータに必ず `me` を足す従来挙動は維持（TestBox/Main いずれも同型で出力）。
+- Rust 層の追加変更なし（LoopForm v2 / LoopSnapshotMergeBox をそのまま利用）。
+
+**結果**
+- `tools/smokes/v2/profiles/quick/core/phase251/stageb_fib_program_defs_canary_vm.sh` が安定して PASS。
+  - `Program.kind == "Program"`
+  - `defs` に `TestBox.fib` / `Main.main` を保持していること。
+  - `TestBox.fib.body.body[*]` に `Loop` ノードが含まれること。
+  を満たした状態で `rc=0` になることを確認。
+- FuncScanner / Stage‑B 経由の fib defs ラインは LoopForm v2 + LoopSnapshotMergeBox 上で構造的に安定したとみなし、Phase 25.3 はクローズ。
+- 次フェーズの入口が整理できたので、Stage‑1 UsingResolver ループ（Region+next_i 形）と Stage‑1 CLI program-json/selfhost 導線に着手可能。
+
 ### 1-1. Phase 25.1m — Static Method / LoopForm v2 continue + PHI Fix（完了）
 
 **目的**
@@ -138,6 +164,26 @@
 
 ---
 
+### 1-4. Phase 25.1A‑3 — Stage‑1 CLI bridge（stub 実装）
+
+- Rust 側: `src/runner/stage1_bridge.rs` を `run_refactored` 入口に組み込み、`NYASH_USE_STAGE1_CLI=1` かつ再入ガードなしのときに `lang/src/runner/stage1_cli.hako` を子プロセスで起動する。`STAGE1_EMIT_PROGRAM_JSON` / `STAGE1_EMIT_MIR_JSON` / `STAGE1_BACKEND` / `STAGE1_PROGRAM_JSON` で mode 選択。entry override は `STAGE1_CLI_ENTRY` / `HAKORUNE_STAGE1_ENTRY`。
+- .hako 側: `Stage1Cli` に最低限の本体を実装。
+  - `emit_program_json`: Stage‑1 UsingResolver で prefix を結合し、BuildBox.emit_program_json_v0 で Program(JSON v0) を返す。
+  - `emit_mir_json`: `MirBuilderBox.emit_from_program_json_v0` をそのまま呼ぶ（delegate 未設定なら null）。
+  - `run_program_json`: backend==llvm の場合は `env.codegen.emit_object` まで通す。vm/pyvm は当面 MIR(JSON) を stdout に出すのみ（実行は Stage0 橋渡し未配線）。
+  - CLI: `emit program-json|mir-json` / `run --backend ... <src>` を受理。`NYASH_SCRIPT_ARGS_JSON` を JSON で best-effort 伝播。
+- Docs: `docs/development/roadmap/phases/phase-25.1/stage1-usingresolver-loopform.md` に stub 状態を追記（run は暫定挙動）。
+- Known gaps: vm/pyvm 実行はまだ Stage0 への橋渡し未着手。llvm も emit object 止まり（link/exec は後続）。
+
+### 1-5. Phase 25.1A‑4 — Using SSOT 薄設計＋BuildBox include 除去
+
+- SSOT: `lang/src/using/resolve_ssot_box.hako` に README 相当のコメントと I/F（resolve_modules/resolve_prefix）を追加。現状は no-op だが「using をここで扱う」窓口を固定。
+- Stage1UsingResolver: `resolve_for_program_json` を追加し、SSOT を呼ぶ導線だけ確保（現状は透過返し）。
+- BuildBox: 先頭の `include` を削除し、`using lang.compiler.entry.bundle_resolver as BundleResolver` に置換（Stage‑B パーサが include を解せない問題の足場づくり）。
+- 実行確認: `NYASH_ALLOW_NYASH=1 HAKO_ALLOW_NYASH=1 NYASH_USE_STAGE1_CLI=1 STAGE1_EMIT_PROGRAM_JSON=1 ... cargo run --bin hakorune -- basic_test.hako` が RC=0 で完走（ただし stdout は `RC: 0` のみ、program-json 出力は未配線）。`cargo run ... emit program-json` は Rust CLI 側の表面が未対応のためエラー（想定挙動）。
+
+---
+
 ## 2. まだ残っている問題・課題（2025-11-18 時点）
 
 ### 2-1. Stage‑B 本体の型エラー（`String > Integer(13)`）
@@ -231,26 +277,50 @@
 ## 3. 次にやること（候補タスク）
 
 ここから先は「どのフェーズを進めるか」をそのときの優先度で選ぶ感じだよ。  
+Rust 側は LoopForm v2 / Stage‑B fib / Stage‑1 UsingResolver 構造テストまで一通り整ったので、当面は Stage‑1 CLI / selfhost ラインの小さな箱から進める。
 
-1. **Stage‑B / BreakFinder / FuncScanner ラインの SSA 根治（Phase 25.1m 続き）**
-   - JSON v0 bridge の Loop lowering で、`backedge_to_cond` が `Jump` だけでなく `Branch(cond→header/exit)` も認識するように修正（`loop_.rs`）。  
-     → BreakFinderBox._find_loops/2 のような break を含むループでも header PHI が正しく張られるようにした。
-   - BreakFinderBox は解析用の static box として扱い、`me._find_loops` / `me._jumps_to` を `BreakFinderBox._find_loops` / `_jumps_to` に正規化。  
-     → `me` 未定義による Undefined ValueId を避ける。
-   - Stage‑B → Stage‑1 パーサ経路は、`ParserBox.parse_program2` のトップレベルループではなく、`parse_block2` で `Main.main` の本文をブロックとしてパースし、  
-     Program(JSON v0) を自前で組み立てる構造に変更（Stage‑B 固まり問題を回避）。
+### A. Stage‑1 CLI / Stage0 ブリッジ（Phase 25.1 — いまここ）
 
-2. **Stage‑B 再入ガード `env.set/2` の整理**
-   - 再入ガードを Box 内 state で持つ方向か、Rust 側に dev 専用 extern を追加するかを決める。
-   - どちらにしても「本番経路（prod ランナー）には影響しない」ようフラグでガードする。
+- A‑1: Stage‑1 CLI stub を Stage0 Rust ランナーから呼び出すブリッジ（DONE）  
+  - 実装: `src/runner/stage1_bridge.rs` ＋ `src/runner/mod.rs` に `maybe_run_stage1_cli_stub` を追加。  
+    - `NYASH_USE_STAGE1_CLI=1`（既定 OFF）かつ `NYASH_STAGE1_CLI_CHILD!=1` のときにだけ有効。  
+    - entry `.hako` は `STAGE1_CLI_ENTRY` / `HAKORUNE_STAGE1_ENTRY` で上書き可能（既定: `lang/src/runner/stage1_cli.hako`）。  
+    - 入力ファイル / モード:
+      - `STAGE1_EMIT_PROGRAM_JSON=1`: `hakorune emit program-json <source.hako>` を子プロセスで実行。  
+      - `STAGE1_EMIT_MIR_JSON=1`: `STAGE1_PROGRAM_JSON` があれば `--from-program-json`、なければ `<source.hako>` から `emit mir-json`。  
+      - 上記どちらも無い場合: `hakorune run --backend <backend> <source.hako>`（backend は `STAGE1_BACKEND` か CLI の backend 設定）。  
+    - `NYASH_SCRIPT_ARGS_JSON` を拾って `--` 以降の script 引数も Stage‑1 側に転送。  
+    - 再入防止として子プロセスには `NYASH_STAGE1_CLI_CHILD=1` を付与（子側からは Rust ブリッジを素通り）。
+- A‑2: Stage‑1 CLI skeleton の責務を doc に固定（DONE）  
+  - `lang/src/runner/stage1_cli.hako` で `Stage1Cli.emit_program_json/emit_mir_json/run_program_json/stage1_main` のシグネチャとトグルトポロジーを固定。  
+  - `docs/development/roadmap/phases/phase-25.1/stage1-usingresolver-loopform.md` に Rust 側ブリッジの振る舞いとトグル名（`NYASH_USE_STAGE1_CLI` / `STAGE1_EMIT_*` / `STAGE1_BACKEND` / `NYASH_STAGE1_CLI_CHILD`）を追記。
+- A‑3: 次ステップ（未着手）  
+  - Stage‑1 CLI skeleton に Stage‑B/BuildBox/MirBuilder 呼び出しを順に実装し、「Program(JSON)/MIR(JSON) を selfhost 経由で emit できる」状態まで持っていく。  
+  - `tools/selfhost/run_stage1_cli.sh` から呼び出す selfhost パスと、Rust CLl からのブリッジパスの両方で JSON I/O 契約が同じになるように揃える。
 
-3. **.hako LoopSSA v2 実装（LoopForm v2 への追従）**
-   - Rust LoopForm v2 の規約（Carrier/Pinned / preheader/header/latch/exit）を `.hako` の LoopSSA に輸入。
-   - Stage‑B Test2 / selfhost CLI の JSON→MIR 経路で MirVerifier 緑を目標にする。
+### B. Stage‑1 UsingResolver / LoopForm v2 ライン（Phase 25.1e 系フォロー）
 
-4. **Selfhost / CLI 周辺のテスト整理**
-   - 代表的な selfhost / Stage‑B / Stage‑1 CLI ケースに対して、
-     「Phase 25.1m でどこまで緑になったか」「どこから先が 25.1k 以降の仕事か」を tests / tools 側で見える化する。
+- B‑1: entry UsingResolver の Region+next_i 化とコメント整備（おおむね DONE）  
+  - `lang/src/compiler/entry/using_resolver_box.hako` の 3 ループ（entries / JSON スキャン / modules_list）は Region+next_i 形に揃え済み。  
+  - 役割コメント: `resolve_for_source`（Stage‑B body_src を受けて prefix を返す）、`_collect_using_entries`（JSON スキャンして entries を集める）、`_build_module_map`（modules_list を map 化）を明記済み。  
+  - `HAKO_STAGEB_APPLY_USINGS=0` の時は prefix を空 string にしつつ、depth ガードだけは走らせる仕様もコメントで固定。
+- B‑2: UsingResolver 構造テスト（ループ形/PHI）の拡充（DONE）  
+  - `src/tests/mir_stage1_using_resolver_verify.rs` に Region+next_i ループと early-exit JSON スキャンパターンの軽量テストを追加。  
+  - これらは cargo test 経路で常時緑を維持し、v2 quick スモークへの昇格は「実行時間とノイズを見ながら後続フェーズで検討」という扱いにする（docs にメモ済み）。
+- B‑3: pipeline_v2 UsingResolver との責務境界（DONE）  
+  - `lang/src/compiler/pipeline_v2/using_resolver_box.hako` 冒頭に、「entry 側=ファイル I/O + using 収集」「pipeline_v2 側=modules_json 上の alias/path 解決」と役割メモを追加。  
+  - RegexFlow ベースの単一路ループは Region 化不要（stateful helper）とし、LoopForm v2 の観点からも「観測対象外」とする。
+
+### C. Stage‑B / LoopSSA / Selfhost まわり（中期タスク）
+
+- C‑1: Stage‑B 再入ガード `env.set/2` の整理（据え置き）  
+  - dev 専用 extern を Rust 側に追加するか、Stage‑B 箱側で state に寄せるかを決める必要があるが、現在はループ/PHI ラインを優先し保留。  
+  - このタスクに着手するときは「prod/CI 経路から完全に切り離した dev ガード」として設計する。
+- C‑2: .hako LoopSSA v2 実装（Rust LoopForm v2 への追従）  
+  - Rust LoopForm v2 の Carrier/Pinned/BodyLocalInOut モデルを `.hako` の LoopSSA に輸入し、Stage‑B Test2 / selfhost CLI でも MirVerifier 緑を目指す中〜長期タスク。  
+  - 具体的な対象: `lang/src/compiler/builder/ssa/loopssa.hako` と Stage‑B/BreakFinder 周辺の region 化済みループ。
+- C‑3: Selfhost / CLI 周辺のテスト整理  
+  - 代表的な selfhost / Stage‑B / Stage‑1 CLI ケースを tests/tools 側でタグ付け（quick/integration/selfhost）、Phase 25.1 の「どこまでが Rust 側」「どこからが Stage1 側」を見える化する。
 
 ---
 
@@ -268,44 +338,51 @@
 次にどの箱から攻めるか決めたら、ここに箇条書きで足していこうね。  
 
 
-## 2-? Stage‑B FuncScanner / LoopSnapshotMergeBox / MIR ロガー（in progress）
+## 3. これからやるタスクのラフ一覧（25.1 / Stage‑1 系）
 
-- StageBFuncScannerBox を `compiler_stageb.hako` 内に追加し、StageBDriverBox.main からは FuncScannerBox ではなくこちらを呼ぶ構成にしている。
-- VM 側の Undefined value（BreakFinderBox._find_loops/2）は LoopForm v2 / continue + PHI 修正で解消済み。
-- FuncScannerBox.scan_all_boxes/1 については、Phase 25.2 で `LoopSnapshotMergeBox` を導入し、continue/break/exit スナップショットのマージを一元化したことで
-  13 個の continue を含む複雑ループでも Undefined Value が出ないところまで到達しており、
-  さらに `lang/src/compiler/tests/funcscanner_fib_min.hako` を使った最小ハーネスでも `NYASH_VM_VERIFY_MIR=1` で Undefined Value が再現しないところまで確認済み。
-  - LoopSnapshotMergeBox 実装: `src/mir/phi_core/loop_snapshot_merge.rs`
-    - `merge_continue_for_header` / `merge_exit` / `optimize_same_value` / `sanitize_inputs` など、ヘッダ/exit PHI 用の入力統合ロジックを提供。
-  - LoopBuilder / LoopFormBuilder は、この箱を経由して continue_merge / exit PHI を構成するようにリファクタ済み。
-- 代表テスト:
-  - ループ系: `mir_stageb_loop_break_continue::*` / `mir_loopform_exit_phi::*` / `mir_stageb_like_args_length::*` はすべて PASS。
-  - 手書きループ:
-    - 基本ループ: sum=10（0+1+2+3+4）✅
-    - break/continue を含むループ: sum=19, i=7 ✅
-    - body-local 変数を含むループ: result=6, i=3 ✅（exit PHI で body-local を正しく統合）
-- StageBFuncScannerBox.scan_all_boxes(src) は依然として fib サンプルに対して defs=[]（Program(JSON) に `TestBox.fib` が載っていない）という問題が残っているため、
-  次の担当者は StageBFuncScannerBox.scan_all_boxes/1 と FuncScannerBox.scan_all_boxes/1 の MIR を比較しつつ、
-  Stage‑B body 抽出 → StageBFuncScannerBox.scan_all_boxes → Program(JSON v0).defs 注入の導線自体を見直してほしい（LoopForm/PHI/スナップショット側は LoopSnapshotMergeBox で安定化済み）。
-- Phase 25.3 では、FuncScanner / Stage‑B ラインの観測専用として `.hako` から直接 MIR ログを埋め込める `__mir__` 構文を導入した。
-  - 構文: `__mir__.log("label", v1, v2, ...)` / `__mir__.mark("label")`
-  - lowering: `MirInstruction::DebugLog { message: "label", values: [v1, v2, ...] }` に変換される（LoopForm/PHI には影響しない）。
-  - 実行: `NYASH_MIR_DEBUG_LOG=1` のときだけ `[MIR-LOG] label: %id=value ...` を VM 側で出力し、それ以外は no-op。
-  - 実装ポイント: `src/mir/builder/calls/build.rs` の `build_method_call_impl` で `__mir__` receiver を検出し、`try_build_mir_debug_call` で `DebugLog` 命令に directly lowering している。
-  - これにより、FuncScannerBox.scan_all_boxes や StageBFuncScannerBox.scan_all_boxes のループ頭や `box` 検出位置にラベルを打ち、
-    VM 実行ログと合わせて「どの経路で未初期化の値が残っているか」を .hako 側から追いやすくなった。
-  - 併せて `MirBuilder::handle_me_method_call` を `MeCallPolicyBox` で箱化し、me-call のフォールバックを静的メソッド降下に統一した。
-    - `Box.method/Arity` lowered 関数が存在する場合は従来どおり `me` を先頭引数にした Global call。
-    - 存在しない場合は `handle_static_method_call(cls, method, arguments)` に委譲し、static helper（FuncScannerBox._parse_params / _strip_comments など）呼び出しとして扱う。
-    - これにより static box 文脈で「実体のない me を receiver にした Method call」が生成される経路が閉じられ、FuncScannerBox._scan_methods/4 系の UndefinedValue は Rust 側で構造的に防止されている。
+ここから先は「まず設計と箱分割を書いてから実装」という方針で進めるタスク群だよ。
 
+### A. Rust 層解析（LoopForm v2 / JSON v0 / Stage‑1 観測）
 
-## 3. Static Box フィールド仕様ドキュメント（完了）
+- A-1: LoopForm v2 / LoopSnapshotMerge の入口確認  
+  - `src/mir/loop_builder.rs` / `src/mir/phi_core/loopform_builder.rs` / `src/mir/phi_core/loop_snapshot_merge.rs` を「Stage‑1 から見た導線」として読み直し、どのレイヤで Carrier / Pinned / BodyLocalInOut が決まるかを short メモ化する。
+- A-2: JSON v0 → MIR ブリッジの導線整理  
+  - `src/runner/json_v0_bridge/lowering/`（特に `loop_.rs`）を通して、Program(JSON v0).body / defs.body(Block) が LoopForm v2 までどう運ばれるかを図として docs に落とす。
+- A-3: Stage‑1 UsingResolver の MIR 観測  
+  - 既存テスト `src/tests/mir_stage1_using_resolver_verify.rs` の MIR dump を元に、「どのループが Region+next_i 化候補か」「既に問題なく LoopForm に乗っている場所はどこか」を箇条書きで整理する。
 
-- docs/reference/language/LANGUAGE_REFERENCE_2025.md: 3.4 Static Boxパターンに「static box 内のフィールドはすべて static フィールドとして扱われる」旨を明記した。
-- 言語仕様としては、static box の中では `PI: FloatBox` のような宣言で十分であり、追加の `static` キーワードは不要であることをドキュメント上で固定。
-- 次タスク候補（Claude Code 向け）: static box / box のフィールド挙動に関するサンプルとテスト（VM/JSON v0 両方）の整理、および static box 上の `me` セマンティクス（25.1p DebugLog フェーズと連動）の仕様化。
+### B. Stage‑1 UsingResolver 箱化・ループ整理（.hako 側）
 
+- B-1: Stage1UsingResolverBox の責務分割設計  
+  - `lang/src/compiler/entry/using_resolver_box.hako` を、collect_entries / modules_map / file_read などの小さいロジック箱に概念的に分割し、「どの箱が何を責務とするか」を docs に書く（実際のファイル分割は後段）。
+- B-2: すべてのループを Region+next_i 形に揃える計画  
+  - entry の UsingResolver 内に残っている「pos++/continue 多発型」ループを洗い出し、Region+next_i 形にどう書き換えるかを phase-25.1 docs に追記する。  
+  - 目的: LoopForm v2 / PHI から見たときに「1 region / 1 backedge / 明確な次位置決定」という形に統一する。
+  - 状況メモ: entry 側 3 ループ（entries/JSON scan/modules_list）は Region+next_i 化済み。残りなし。
+- B-3: pipeline_v2 UsingResolver との役割分担  
+  - `lang/src/compiler/pipeline_v2/using_resolver_box.hako` と entry/Stage1UsingResolverBox のどちらが「テキスト / JSON / modules_map」のどこまでを担当するかを整理し、責務境界をドキュメントに固定する。
+  - 状況メモ: pipeline_v2 側は modules_json の alias 解決のみ（RegexFlow.find_from の単一路ループ）。Region 化不要として据え置き、境界だけ明記。
+- B-4: 構造テストの追加計画  
+  - Region+next_i パターンの軽量 SSA テスト（すでに 1 本追加済み）を基準に、もう 1〜2 本、UsingResolver ソースに近いパターン（JSON スキャン＋early-exit）を追加する方針を決める。
+
+### C. Stage‑1 CLI / program-json / mir-json Self‑Host 準備
+
+- C-1: Stage‑1 CLI インターフェースの設計メモ  
+  - `.hako → Program(JSON)` / `Program(JSON) → MIR(JSON)` / `MIR(JSON) → 実行` を Stage‑1 側からどう呼び出すか（関数名・引数レベル）を docs に先に書く。
+- C-2: Stage‑B → Stage‑1 データフロー図  
+  - `compiler_stageb.hako` → Program(JSON v0) → Stage‑1 UsingResolver → MirBuilder までのパイプラインを Phase‑25.1 ドキュメントに 1 枚の図としてまとめる。
+- C-3: Rust CLI 側ブリッジの最小ガード案  
+  - Stage0/Rust CLI は「Program(JSON/MIR(JSON) を受け取り VM/LLVM に流すだけ」に縮退させる方針と、既定 OFF トグル（selfhost 入口）をどう切るかを設計メモとして追加。
+
+### D. 将来フェーズ向けメモ（variable_map 決定化ライン）
+
+- D-1: MirBuilder::variable_map / BoxCompilationContext::variable_map BTreeMap 化案  
+  - どの構造を HashMap→BTreeMap 化するか、どのテスト（`mir_funcscanner_skip_ws_vm_debug_flaky` など）で決定性を確認するかを Phase‑25.x の設計メモとして書いておく。
+- D-2: dev 専用 / flaky テストの扱い方針  
+  - どのテストが dev ignore（手動実行用）で、いつ/何を満たしたら常時有効に戻すかを、このファイルと関連 README に明確に残す。
+
+このセクションは「すぐ実装する TODO ではなく、25.1〜25.x ラインで踏むべき設計タスク一覧」として使う予定だよ。  
+（静的 me-call 修正の参考メモはここに残しつつ、別セクションは整理済み）
 
 ## 3. Phase 25.1q — LoopForm Front Unification（DONE / follow-up 別タスクへ）
 

docs/development/roadmap/phases/phase-25.1/README.md

@@ -43,9 +43,9 @@ Status: design+partial implementation（Stage1 ビルド導線の初期版まで
 - Rust VM/LLVM のコア（MIR インタプリタ／コード生成）の提供。
 - Stage1 で AOT されたコア関数（後述）を呼び出すランチャ。
 
-**禁止/抑制:**
-- パーサ高レイヤ／Stage‑B／MirBuilder／AotPrep／numeric core のロジックを Rust 側に新規追加しない。
-- 新しい Box 実装やランタイム機能を Rust に持ち込まない（Phase 25 Rust Freeze を継続）。
+**禁止/抑制（緩和版）:**
+- パーサ高レイヤ／Stage‑B／MirBuilder／AotPrep／numeric core の**意味論そのもの**を Rust 側に新規実装しない（Self‑Host の責務）。
+- 新しい Box 実装や高レベルランタイム機能を Rust に持ち込むのは原則避ける（ただし Stage‑1 ブリッジやエラーログ改善など、導線・可観測性に必要な最小限の変更は許可）。
 
 ### Stage1 — Hakorune Selfhost Binary
 
@@ -157,6 +157,11 @@ Status: design+partial implementation（Stage1 ビルド導線の初期版まで
 - [ ] Stage0→Stage1→Stage1' のビルドシーケンスを文章で定義（どの組み合わせで自己一致チェックを行うか）。
 - [ ] 「普段使うのは Stage1」「問題発生時に Stage0 から再生成」という運用パターンを docs に記載。
 
+### E. Stage‑1 UsingResolver / LoopForm v2 対応（設計）
+
+- [x] 設計ドラフトを追加（`stage1-usingresolver-loopform.md`）。Region+next_i 形ループと Carrier/Pinned 対応の指針を明文化。
+- [x] Rust 側の観測結果を反映し、具体的なリライト手順とテスト項目を更新する（JSON→LoopForm v2 導線／Stage‑B→Stage‑1 データフローのテキスト図を追記）。
+
 ## 実装チェックリスト（25.1 実行順案）
 
 ### 1. バイナリ命名と役割の明確化

docs/development/roadmap/phases/phase-25.1/stage1-usingresolver-loopform.md

@@ -112,6 +112,7 @@ source -> | Stage-B (block) |  -->  | Stage-1 UsingRes |  -->  | MirBuilder (.ha
 ### ループ洗い出しメモ（entry / pipeline_v2）
 - entry UsingResolver（lang/src/compiler/entry/using_resolver_box.hako）
   - Region+next_i 化済み: entries イテレーション / JSON スキャン / modules_list 分割
+  - 追加テスト: modules_list 分割ループ（start/next_start）をそのまま MIR 化できることを `mir_stage1_using_resolver_module_map_regionized_verifies` で固定。
   - 残り: なし（現状の 3 ループは all Region 形）
 - pipeline_v2 UsingResolver（lang/src/compiler/pipeline_v2/using_resolver_box.hako）
   - 役割: modules_json 上で alias を解決する stateful helper（テキスト収集は entry 側）。

docs/development/roadmap/phases/phase-25.3-funcscanner/README.md

@@ -1,5 +1,7 @@
 # Phase 25.3 — FuncScanner / Stage‑B defs 安定化
 
+Status: 完了（Stage‑B fib defs canary 緑／2025-11 時点）
+
 ## スコープ / ゴール
 
 - 対象レイヤ
@@ -22,6 +24,30 @@
   - Loop/PHI の意味論は **LoopFormBuilder + LoopSnapshotMergeBox** に完全委譲したまま、
     - FuncScanner / Stage‑B は「テキストスキャン＋JSON 組み立て」の箱として綺麗に分離された状態にする。
 
+## 完了ステータス（2024-11-20 時点）
+
+- `tools/smokes/v2/profiles/quick/core/phase251/stageb_fib_program_defs_canary_vm.sh` が緑（Phase 25.3 の完了条件）。
+  - `defs` に `TestBox.fib` / `Main.main` が入り、`TestBox.fib.body.body[*]` に `Loop` ノードが含まれる状態を固定。
+- Stage‑B 本線の整理:
+  - `StageBDriverBox.main`: main 本文は `{…}` で包んだ block パーサ優先で JSON 化し、defs 側は `{"type":"Block","body":[…]}` に構造化して注入。
+  - `StageBFuncScannerBox._scan_methods`: block パーサ優先に揃え、Program パーサは `HAKO_STAGEB_FUNC_SCAN_PROG_FALLBACK=1` の opt-in 時だけ使う安全側トグルに変更（skip_ws 崩れの再発防止）。
+- Rust 層は無改変（LoopForm v2 / LoopSnapshotMergeBox の SSOT をそのまま利用）。
+
+## JSON v0 フロントと AOT ルートの契約（Phase 25.3 時点）
+
+- Program(JSON v0) の形:
+  - ルートは常に `{"version":0,"kind":"Program","body":[...]}`
+  - defs は `\"defs\":[{ \"name\", \"params\", \"box\", \"body\" }]` を追加する形で注入する。
+  - Stage‑B / FuncScanner 経由の `defs[*].body` は必ず `{\"type\":\"Block\",\"body\":[Stmt...]}` でラップし、AOT/VM 側からは「通常の Block ノード」として読めるようにする。
+- フロント/バックエンドの責務分離:
+  - Stage‑B / FuncScanner: `.hako` テキスト → Program(JSON v0) まで（ループ/PHI の意味論は持たない）。
+  - Rust 側 LoopForm v2 / JSON v0 Bridge: Program(JSON v0) → MIR/AOT まで（Loop/PHI/SSA の SSOT）。
+- Stage‑B トグル整理（抜粋）:
+  - `HAKO_STAGEB_FUNC_SCAN=1`（既定）: defs を常に埋める。`0` で Stage‑B からの defs 注入を無効化。
+  - `HAKO_STAGEB_PROGRAM_PARSE_FALLBACK=1`: main 本文で Program パーサ fallback を有効化（既定は OFF、block パーサ優先）。
+  - `HAKO_STAGEB_FUNC_SCAN_PROG_FALLBACK=1`: FuncScanner 側で Program パーサ fallback を有効化（既定は OFF）。  
+    通常の開発・CI ではいずれも OFF にしておき、VM/パーサ調査時だけ opt‑in で使う想定。
+
 ## すでに前提としている状態
 
 - LoopForm v2 / PHI / snapshot:
@@ -118,27 +144,28 @@ FuncScanner / Stage‑B のデバッグ時には、`scan_all_boxes` のループ
   - ここでの主なバグは「SSA ではなく、Stage‑B が fib ソースから defs を組み立てきれていないこと」なので、  
     ループ構造や LoopForm には手を入れず、Stage‑B 側のテキスト処理と defs 生成パスを中心に見る。
 
-### 4. fib defs canary & ドキュメント更新
+### 4. fib defs canary & ドキュメント更新（完了）
 
 - 対象:
   - `tools/smokes/v2/profiles/quick/core/phase251/stageb_fib_program_defs_canary_vm.sh`
   - `docs/development/roadmap/phases/phase-25.1q/README.md`
   - `CURRENT_TASK.md`
 
-- やること:
-  - canary スクリプトで:
-    - `Program.kind == "Program"`
-    - `defs` に `TestBox.fib` が存在すること。
-    - `TestBox.fib.body` に `Loop` ノードが含まれること。
-    を満たした状態で `rc=0` になるまで確認する。
-  - Phase 25.1q / 25.2 の README には、
-    - 「loop/PHI/スナップショットの SSOT は LoopForm v2 + LoopSnapshotMergeBox」
-    - 「Phase 25.3 で FuncScanner / Stage‑B defs もこの土台の上に載せた」
-    というつながりを 1〜2 行で追記する。
-  - `CURRENT_TASK.md` には:
-    - Phase 25.3 のタスク完了状況（FuncScanner fib / Stage‑B fib canary 緑）と、
-    - その後に繋がる Stage‑1 UsingResolver / Stage‑1 CLI self‑host ラインへのブリッジ
-    を短く整理しておく。
+今回の結果:
+- `tools/smokes/v2/profiles/quick/core/phase251/stageb_fib_program_defs_canary_vm.sh` は `rc=0` で安定緑。
+- canary 内部で確認している条件:
+  - `Program.kind == "Program"`
+  - `defs` に `TestBox.fib` / `Main.main` が含まれていること。
+  - `TestBox.fib.body` の直下（`body.body[*]`）に `Loop` ノードが最低 1 つ含まれていること。
+- これにより、FuncScanner / Stage‑B 経由の fib defs ラインは LoopForm v2 + LoopSnapshotMergeBox の上で構造的に安定したとみなせる。
+
+ドキュメント側:
+- Phase 25.1q / 25.2 の README には、
+  - 「loop/PHI/スナップショットの SSOT は LoopForm v2 + LoopSnapshotMergeBox」
+  - 「Phase 25.3 で FuncScanner / Stage‑B defs もこの土台の上に載せた」
+  という関係を 1〜2 行で追記済み。
+- `CURRENT_TASK.md` では Phase 25.3 を「Stage‑B fib defs canary 緑」まで完了したフェーズとして整理し、
+  次フェーズを Stage‑1 UsingResolver ループ整理 / Stage‑1 CLI program-json selfhost 導線に設定した。
 
 ### 5. mir_funcscanner_skip_ws 系テストの扱い（flaky → dev 専用）
 

docs/development/roadmap/phases/phase-25/README.md

@@ -69,7 +69,7 @@ Related docs:
   - `IntArrayCore`（数値一次元配列コア）
   - `MatI64`（行列箱・i64版）
  などを、「Rust プラグイン実装」ではなく **Hakorune 実装＋ごく薄い intrinsic** に置き換えるための設計ロードマップを固める。
-- 新しい箱・数値カーネル・標準ランタイム機能は **原則 .hako で実装する** 方針を明文化し、「Rust Freeze Policy（Self‑Host First）」を Phase 25 で具体化する。
+- 新しい箱・数値カーネル・標準ランタイム機能は **原則 .hako で実装する** 方針を明文化し、「Rust Minimal Policy（Self‑Host First, but not Frozen）」として Phase 25 で具体化する。
 
 ## レイヤー方針（Ring0 / Ring1）
 
@@ -82,8 +82,8 @@ Related docs:
 - **汎用 intrinsic** のみ提供（例: メモリ確保・生ポインタload/store・基本的な memcpy 等）
 
 **禁止 / 抑制:**
-- 新しい Box 種類（IntArrayCore / MatI64 / StringBuilder 等）を Rust 側に増やさない。
-- 新しい最適化ロジック・言語ルール・Box メソッド実装を Rust に追加しない（AGENTS.md 5.2 Rust Freeze Policy に準拠）。
+- 新しい Box 種類（IntArrayCore / MatI64 / StringBuilder 等）の**本体ロジック**を Rust 側に増やさない（型安全な intrinsic のみに留める）。
+- 新しい最適化ロジック・言語ルール・Box メソッド実装を Rust に追加しない（AGENTS.md 5.2 Rust Minimal Policy に準拠）。
 
 ### Ring1（Hakorune / Nyash ― System サブセット）
 
@@ -112,11 +112,11 @@ Related docs:
 
 Phase 25 は「設計とロードマップの確定」が主目的。実装・移行作業自体は後続フェーズ（22.x/26.x など）で分割実施する。
 
-### 1) Rust Freeze の明文化とチェックリスト
+### 1) Rust Minimal Policy の明文化とチェックリスト
 
-- 既存の「Rust Freeze Policy（Self‑Host First）」を、ランタイム/箱/数値系に特化して再整理:
+- 既存の「Rust Freeze Policy（Self‑Host First）」を、「Self‑Host を支える最小＋必要な整備は許可する」Rust Minimal Policy として再整理:
   - 新規 Box / ランタイム機能は Rust ではなく .hako で実装する。
-  - Rust 変更は「最小の intrinsic 追加」か「バグ修正」に限定。
+  - Rust 変更は「最小の intrinsic 追加」「Stage‑1/Stage‑B ブリッジの改善」「エラーログ・可観測性の向上」か「バグ修正」に限定。
 - PR / フェーズ用チェックリスト案を作成:
   - [ ] この変更は Ring0 の責務か？（VM/allocator/LLVM/OS FFI のみ）
   - [ ] 新しい Box/アルゴリズムを Rust に追加していないか？

docs/development/runtime/cli-hakorune-stage1.md

@@ -1,6 +1,6 @@
 # Stage1 Hakorune CLI Design（Proposal）
 
-Status: design-only（Phase 25.1 時点では仕様策定と導線の整理まで）
+Status: design-only + Stage0 stub 実装済み（Phase 25.1 時点では仕様策定と導線の整理まで。selfhost EXE 本体は未実装）
 
 ## ゴール
 
@@ -15,6 +15,8 @@ Status: design-only（Phase 25.1 時点では仕様策定と導線の整理ま
   - 役割: プロセス起動・VM/LLVM コア・ny-llvmc 呼び出しなどの「Ring0」。
   - Ny 側からは `env.mirbuilder.emit` / `env.codegen.emit_object` / `env.codegen.link_object` などの extern 名で見える。
   - Stage1 実行時は「CLI として」ではなく、これらのランタイムサービス層（C-ABI/extern）として利用することを前提とする。
+  - Phase 25.1 現在は、Rust Stage0 から `.hako` 側 stub CLI（`lang/src/runner/stage1_cli.hako`）を子プロセスとして起動する
+    ブリッジ（`src/runner/stage1_bridge.rs`）のみ実装済みで、自己ホスト EXE（`target/selfhost/hakorune`）はまだ設計段階。
 - Stage1（Hakorune selfhost CLI）
   - 実体: `target/selfhost/hakorune`（Phase 25.1 では Ny Executor プロトタイプ）。
   - 役割: `.hako → Program(JSON) → MIR(JSON) → 実行/EXE` というパイプラインの制御。
@@ -64,6 +66,10 @@ Phase 25.1a では、**`emit program-json` / `emit mir-json` / `build exe` の 3
   - `--quiet` でログ抑制、`-o/--out` で出力 EXE パスを指定可能。C-API トグル（`NYASH_LLVM_USE_CAPI`, `HAKO_V1_EXTERN_PROVIDER_C_ABI`）が無効な場合は fail-fast。
 - Stage1 バイナリ（`target/selfhost/hakorune`）を直接叩く際は `NYASH_NYRT_SILENT_RESULT=1` を付与し、stdout に JSON だけを流す運用を徹底する（`tools/selfhost/run_stage1_cli.sh` が環境セットとバイナリ検出を担当）。
 
+#### デバッグ Tips（Phase 25.1a）
+- `STAGE1_CLI_DEBUG=1` を付けると `.hako` 側 `stage1_main` の ENTRY ログが出る。Rust ブリッジが正しく Stage1 stub を呼んでいるか確認する際に使う。
+- `NYASH_CLI_VERBOSE=1` か `2` を付けると Rust 側 bridge (`stage1_bridge.rs`) が子プロセス起動ログを出力する。
+
 ## `run` コマンド
 
 ```text

docs/guides/testing-guide.md

@@ -98,6 +98,67 @@ python3 tools/phi_trace_check.py --file tmp/phi_trace.jsonl --summary
 - `tools/smokes/phi_trace_local.sh`（ビルド→サンプル実行→チェックを一括）
 - `tools/smokes/v2/run.sh --profile quick|integration` で代表スモークを実行
 
+## MIR デバッグの入口まとめ
+
+### 1. CLI レベルの MIR ダンプ
+
+- ソースから直接 MIR を確認:
+  - `./target/release/nyash --dump-mir path/to/program.hako`
+- VM 実行経路で MIR を一緒に吐く:
+  - `NYASH_VM_DUMP_MIR=1 ./target/release/nyash path/to/program.hako`
+- JSON で詳細解析したい場合:
+  - `./target/release/nyash --emit-mir-json mir.json path/to/program.hako`
+  - 例: `jq '.functions[0].blocks' mir.json` でブロック構造を確認。
+
+### 2. Scope / Loop ヒント（NYASH_MIR_HINTS）
+
+- 環境変数でヒント出力を制御:
+  - `NYASH_MIR_HINTS="<target>|<filters>..."`
+- 例:
+  - `NYASH_MIR_HINTS="trace|all"`（stderr へ全ヒント）
+  - `NYASH_MIR_HINTS="jsonl=tmp/hints.jsonl|loop"`（ループ関連のみ JSONL 出力）
+- 詳細: `docs/guides/scopebox.md`, `src/mir/hints.rs`。
+
+### 3. __mir__ ロガー（.hako から仕込む MIR ログ）
+
+- 目的:
+  - `.hako` 側のループや SSA まわりを「MIR レベル」で観測するための dev 専用フック。
+  - 実行意味論には影響しない（Effect::DebugLog のみ）。
+- 構文（.hako 内）:
+
+  ```hako
+  __mir__.log("label", v1, v2, ...)
+  __mir__.mark("label")
+  ```
+
+  - 第1引数は String リテラル必須（それ以外は通常の呼び出し扱い）。
+  - `log` は第2引数以降の式を評価し、その ValueId 群を記録。
+  - `mark` はラベルだけのマーカー。
+  - 戻り値は Void 定数扱いのため、式コンテキストに書いても型崩れしない。
+
+- 実行時の有効化:
+  - `NYASH_MIR_DEBUG_LOG=1 ./target/release/nyash path/to/program.hako`
+  - VM の MIR interpreter が次のようなログを stderr に出力:
+
+    ```text
+    [MIR-LOG] label: %10=123 %11="foo"
+    ```
+
+- 実装位置:
+  - lowering: `src/mir/builder/calls/build.rs` の `try_build_mir_debug_call`（receiver が `__mir__` のときに `MirInstruction::DebugLog` を挿入）。
+  - 実行: `src/backend/mir_interpreter/handlers/mod.rs`（`NYASH_MIR_DEBUG_LOG=1` のときだけログを出す）。
+
+- 利用例（ループ観測の定番パターン）:
+
+  ```hako
+  loop(i < n) {
+    __mir__.log("loop/head", i, n)
+    ...
+  }
+  __mir__.mark("loop/exit")
+  ```
+
+  - FuncScanner / Stage‑B では、skip_whitespace や scan_all_boxes のループ頭・出口に挿入して、ValueId と値の流れを追跡する用途で使用している。
 
 ## 🔌 **プラグインテスター（BID-FFI診断ツール）**
 ```bash

lang/src/compiler/entry/compiler_stageb.hako

@@ -795,8 +795,8 @@ static box StageBFuncScannerBox {
         }
 
         local body = s.substring(open_idx + 1, close_idx)
+        // Include Main.main as well so defs covers entry + helpers
         local skip_main = 0
-        if box_name == "Main" { skip_main = 1 }
         local include_me = 0
         if box_name != "Main" { include_me = 1 }
         local defs_box = StageBFuncScannerBox._scan_methods(body, box_name, skip_main, include_me)
@@ -979,16 +979,29 @@ static box StageBFuncScannerBox {
       method_body = FuncScannerBox._strip_comments(method_body)
       method_body = FuncScannerBox._trim(method_body)
 
-      // Parse method body to JSON (statement list) using block parser
+      // Parse method body to JSON (statement list)
+      // Policy: block parser first (braced) to avoid VM dispatch misrouting, then Program parser as backup.
       local body_json = null
       if method_body.length() > 0 {
-        local p = new ParserBox()
-        p.stage3_enable(1)
-        local block_src = "{" + method_body + "}"
-        local block_res = p.parse_block2(block_src, 0)
-        local at = block_res.lastIndexOf("@")
-        if at >= 0 {
-          body_json = block_res.substring(0, at)
+        // 1st: block parser with explicit braces (LoopForm-friendly, avoids ctx misbinding)
+        {
+          local p = new ParserBox()
+          p.stage3_enable(1)
+          local block_src = "{" + method_body + "}"
+          local block_res = p.parse_block2(block_src, 0)
+          local at = block_res.lastIndexOf("@")
+          if at >= 0 { body_json = block_res.substring(0, at) }
+        }
+        // 2nd: program parser trims body JSON if block path produced nothing (opt-in)
+        if body_json == null || body_json == "" || body_json == "[]" {
+          local allow_prog = env.get("HAKO_STAGEB_FUNC_SCAN_PROG_FALLBACK")
+          if allow_prog != null && ("" + allow_prog) == "1" {
+            local p2 = new ParserBox()
+            p2.stage3_enable(1)
+            local prog_json = p2.parse_program2(method_body)
+            local extracted = me._extract_body_from_program(prog_json)
+            if extracted.length() > 0 { body_json = extracted }
+          }
         }
       }
 
@@ -1017,6 +1030,49 @@ static box StageBFuncScannerBox {
     return 0
   }
 
+  // Helper: extract Program.body array from Program(JSON) string
+  _extract_body_from_program(prog_json) {
+    if prog_json == null { return "" }
+    local s = "" + prog_json
+    local n = s.length()
+    local head = "\"body\":"
+    local hlen = head.length()
+    local start = -1
+    {
+      local i = 0
+      loop(i + hlen <= n) {
+        if s.substring(i, i + hlen) == head { start = i + hlen  break }
+        i = i + 1
+      }
+    }
+    if start < 0 { return "" }
+
+    // Find '[' after "body":
+    local open = -1
+    {
+      local j = start
+      loop(j < n) {
+        local ch = s.substring(j, j + 1)
+        if ch == "[" { open = j  break }
+        j = j + 1
+      }
+    }
+    if open < 0 { return "" }
+
+    local depth = 0
+    local k = open
+    loop(k < n) {
+      local ch2 = s.substring(k, k + 1)
+      if ch2 == "[" { depth = depth + 1 }
+      else if ch2 == "]" {
+        depth = depth - 1
+        if depth == 0 { return s.substring(open, k + 1) }
+      }
+      k = k + 1
+    }
+    return ""
+  }
+
   // Helper: 空白文字スキップ（FuncScannerBox に委譲）
   _skip_whitespace(s, idx) {
     return FuncScannerBox.skip_whitespace(s, idx)
@@ -1151,14 +1207,30 @@ static box StageBDriverBox {
     // 6) Parse and emit Stage‑1 JSON v0 (Program)
     // Bridge(JSON v0) が Program v0 を受け取り MIR に lowering するため、ここでは AST(JSON v0) を出力する。
     // 既定で MIR 直出力は行わない（重い経路を避け、一行出力を保証）。
-    // Stage‑B/selfhost: body_src は Main.main 内のブロック本文なので、ParserBox の block パーサ
-    // を直接使って Program(JSON) を構成する（トップレベル parser_loop は使わない）。
-    local block_res = p.parse_block2(body_src, 0)
+    // Stage‑B/selfhost: body_src は Main.main 内のブロック本文（外側の {} は含まない）。
+    // 安定性向上のため Program パーサを優先し、空の場合のみ block パーサで再度包んで解釈する。
     local ast_json = "{\"version\":0,\"kind\":\"Program\",\"body\":[]}"
     {
-      local at = block_res.lastIndexOf("@")
-      if at >= 0 {
-        local body_json = block_res.substring(0, at)
+      local body_json = null
+
+      // Prefer block parser with explicit braces to avoid VM dispatch drift seen on program parser.
+      if body_src != null {
+        local block_src = "{" + body_src + "}"
+        local block_res = p.parse_block2(block_src, 0)
+        local at = block_res.lastIndexOf("@")
+        if at >= 0 { body_json = block_res.substring(0, at) }
+      }
+
+      // Optional: enable program parser fallback only when explicitly requested
+      if (body_json == null || body_json == "" || body_json == "[]") {
+        local allow_prog = env.get("HAKO_STAGEB_PROGRAM_PARSE_FALLBACK")
+        if allow_prog != null && ("" + allow_prog) == "1" {
+          local prog_json = p.parse_program2(body_src)
+          body_json = StageBFuncScannerBox._extract_body_from_program(prog_json)
+        }
+      }
+
+      if body_json != null && body_json != "" {
         ast_json = "{\"version\":0,\"kind\":\"Program\",\"body\":" + body_json + "}"
       }
     }
@@ -1246,6 +1318,8 @@ static box StageBDriverBox {
             local mparams = def.get("params")
             local mbody = "" + def.get("body_json")
             local mbox = "" + def.get("box")
+            // Wrap body in Block node to align with Program.body shape expectations
+            local wrapped_body = "{\"type\":\"Block\",\"body\":" + mbody + "}"
             // Build params array JSON
             local params_arr = "["
             local pi = 0
@@ -1257,7 +1331,7 @@ static box StageBDriverBox {
             }
             params_arr = params_arr + "]"
             if mi > 0 { defs_json = defs_json + "," }
-            defs_json = defs_json + "{\"name\":\"" + mname + "\",\"params\":" + params_arr + ",\"body\":" + mbody + ",\"box\":\"" + mbox + "\"}"
+            defs_json = defs_json + "{\"name\":\"" + mname + "\",\"params\":" + params_arr + ",\"body\":" + wrapped_body + ",\"box\":\"" + mbox + "\"}"
             mi = mi + 1
           }
           defs_json = defs_json + "]"

lang/src/compiler/entry/using_resolver_box.hako

@@ -3,6 +3,9 @@
 //   - Collect line-based using declarations via UsingCollectorBox.
 //   - Resolve namespace targets against `nyash.toml` `[modules]` entries (fed via env).
 //   - Read the referenced .hako files and return a concatenated prefix for Stage‑B.
+// Structure tags:
+//   [Region] JSON/ArrayBox/MapBox ループはすべて Region+next_i 形に統一して SSA を安定化。
+//   [LoopForm] carrier=pinned を明示し、continue/break を next_i で合流させる。
 //
 // Env requirements:
 //   - HAKO_STAGEB_MODULES_LIST: `name=path` entries joined by "|||".
@@ -13,6 +16,10 @@ using lang.compiler.parser.scan.parser_common_utils_box as ParserCommonUtilsBox
 using selfhost.shared.json.utils.json_frag as JsonFragBox
 
 static box Stage1UsingResolverBox {
+  // Entrypoint: collect `using` entries and stitch a prefix.
+  // - HAKO_STAGEB_APPLY_USINGS=0 → prefix ""（defs/body には何も足さない）
+  // - Depth guard prevents recursive self-calls from cascading.
+  // [Region] entries 走査は pos/next_pos で一意に前進。pinned: entries/seen, carrier: i。
   resolve_for_source(src) {
     // Shallow recursion guard to prevent accidental self-recursion in Stage‑1 using resolver.
     {
@@ -24,50 +31,88 @@ static box Stage1UsingResolverBox {
       env.set("HAKO_STAGEB_USING_DEPTH", "1")
     }
 
-    if src == null { return "" }
-    local apply_flag = env.get("HAKO_STAGEB_APPLY_USINGS")
-    if apply_flag != null && ("" + apply_flag) == "0" { return "" }
-
-    local entries = me._collect_using_entries(src)
-    if entries == null || entries.length() == 0 { return "" }
-
-    local modules = me._build_module_map()
-    local seen = new MapBox()
     local prefix = ""
+    if src != null {
+      local apply_flag = env.get("HAKO_STAGEB_APPLY_USINGS")
+      // apply_flag==0 なら prefix は空のまま返す（Stage‑B defs/body に変更なし）
+      if apply_flag == null || ("" + apply_flag) != "0" {
+        local entries = me._collect_using_entries(src)
+        if entries != null && entries.length() > 0 {
+          local modules = me._build_module_map()
+          local seen = new MapBox()
 
-    local i = 0
-    local n = entries.length()
-    loop(i < n) {
-      local entry = entries.get(i)
-      local name = "" + entry.get("name")
-      if name == "" { i = i + 1  continue }
+          local i = 0
+          local n = entries.length()
+          loop(i < n) {
+            // Region+next_i 形で多経路を末尾合流させる（SSA/PHI 安定化）
+            local next_i = i + 1
+            local entry = entries.get(i)
+            local name = "" + entry.get("name")
 
-      local path = entry.get("path")
-      if path == null || ("" + path) == "" {
-        path = me._lookup_module_path(modules, name)
-      } else {
-        path = "" + path
+            // 早期スキップ条件をまとめて evaluate
+            local should_emit = 1
+            if name == "" { should_emit = 0 }
+
+            // path 解決（明示 path 優先、無ければ modules マップ）
+            local path = null
+            if should_emit == 1 {
+              path = entry.get("path")
+              if path == null || ("" + path) == "" {
+                path = me._lookup_module_path(modules, name)
+              } else {
+                path = "" + path
+              }
+              if path == null || path == "" { should_emit = 0 }
+            }
+
+            // abs path 化
+            local abs_path = null
+            if should_emit == 1 {
+              abs_path = me._abs_path(path)
+              if abs_path == null || abs_path == "" { should_emit = 0 }
+            }
+
+            // 重複 guard
+            if should_emit == 1 {
+              if seen.get(abs_path) == "1" { should_emit = 0 }
+            }
+
+            // ファイル読み込み
+            if should_emit == 1 {
+              local code = me._read_file(abs_path)
+              if code == null { should_emit = 0 }
+              if should_emit == 1 {
+                seen.set(abs_path, "1")
+                prefix = prefix + "\n" + code + "\n"
+              }
+            }
+
+            i = next_i
+          }
+        }
       }
-      if path == null || path == "" { i = i + 1  continue }
-
-      local abs_path = me._abs_path(path)
-      if abs_path == null || abs_path == "" { i = i + 1  continue }
-      if seen.get(abs_path) == "1" { i = i + 1  continue }
-
-      local code = me._read_file(abs_path)
-      if code == null { i = i + 1  continue }
-
-      seen.set(abs_path, "1")
-      prefix = prefix + "\n" + code + "\n"
-      i = i + 1
     }
 
-    // Clear depth guard before returning
+    // Clear depth guard before returning（適用なしでも guard を戻す）
     env.set("HAKO_STAGEB_USING_DEPTH", "0")
     return prefix
   }
 
+  // Program(JSON v0) に対する using 解決（IOなし、SSOT委譲）。
+  // - modules_json: nyash.toml [modules] 相当の JSON
+  // - using_entries_json: UsingCollectorBox.collect の生出力
+  // - ctx: resolve_ssot_box 向けのヒント（modules/cwd/using_paths など）
+  resolve_for_program_json(program_json, modules_json, using_entries_json, ctx) {
+    using hako.using.resolve.ssot as UsingResolveSSOTBox
+    // MVP: IO せずに SSOT が shape を整えるだけ。現状は透過返し。
+    local resolved = UsingResolveSSOTBox.resolve_modules(modules_json, using_entries_json, ctx)
+    // 返すものは modules_json をそのまま（今は純粋パス）。将来 prefix/string を付与する。
+    return resolved
+  }
+
   // Collect entries from UsingCollectorBox JSON output.
+  // Responsibility: JSON を配列にパースするだけ（path 解決やファイル読み込みは呼び元）。
+  // [Region] JSON スキャンは pos/next_pos を明示し、early-exit も next_pos=n で一本化。
   _collect_using_entries(src) {
     local json = UsingCollectorBox.collect(src)
     if json == null || json == "" || json == "[]" { return null }
@@ -75,27 +120,36 @@ static box Stage1UsingResolverBox {
     local pos = 0
     local n = json.length()
     loop(pos < n) {
+      // Region+next_pos 形（break を next_pos=n で表現）
+      local next_pos = n
       local name_idx = JsonFragBox.index_of_from(json, "\"name\":\"", pos)
-      if name_idx < 0 { break }
-      local name = JsonFragBox.read_string_after(json, name_idx + 7)
-      local obj_end = JsonFragBox.index_of_from(json, "}", name_idx)
-      if obj_end < 0 { obj_end = n }
+      if name_idx < 0 {
+        next_pos = n
+      } else {
+        local name = JsonFragBox.read_string_after(json, name_idx + 7)
+        local obj_end = JsonFragBox.index_of_from(json, "}", name_idx)
+        if obj_end < 0 { obj_end = n }
 
-      local path = null
-      local path_idx = JsonFragBox.index_of_from(json, "\"path\":\"", name_idx)
-      if path_idx >= 0 && path_idx < obj_end {
-        path = JsonFragBox.read_string_after(json, path_idx + 7)
+        local path = null
+        local path_idx = JsonFragBox.index_of_from(json, "\"path\":\"", name_idx)
+        if path_idx >= 0 && path_idx < obj_end {
+          path = JsonFragBox.read_string_after(json, path_idx + 7)
+        }
+
+        local entry = new MapBox()
+        entry.set("name", name)
+        if path != null { entry.set("path", path) }
+        out.push(entry)
+        next_pos = obj_end + 1
       }
-
-      local entry = new MapBox()
-      entry.set("name", name)
-      if path != null { entry.set("path", path) }
-      out.push(entry)
-      pos = obj_end + 1
+      pos = next_pos
     }
     return out
   }
 
+  // Build modules map from env `HAKO_STAGEB_MODULES_LIST` ("name=path" joined by "|||").
+  // Responsibility: env を MapBox に積むだけ。存在しない/空なら空 Map を返す。
+  // [Region] delim 走査も start/next_start で一本化し、continue/break を排除した形に固定。
   _build_module_map() {
     local map = new MapBox()
     local raw = env.get("HAKO_STAGEB_MODULES_LIST")
@@ -105,13 +159,20 @@ static box Stage1UsingResolverBox {
 
     local delim = "|||"
     local start = 0
-    loop(true) {
+    local cont = 1
+    loop(cont == 1) {
+      local next_start = str.length()
       local next = ParserCommonUtilsBox.index_of(str, start, delim)
       local seg = ""
-      if next >= 0 { seg = str.substring(start, next) } else { seg = str.substring(start, str.length()) }
+      if next >= 0 {
+        seg = str.substring(start, next)
+        next_start = next + delim.length()
+      } else {
+        seg = str.substring(start, str.length())
+        cont = 0
+      }
       me._push_module_entry(map, seg)
-      if next < 0 { break }
-      start = next + delim.length()
+      start = next_start
     }
     return map
   }
@@ -152,7 +213,14 @@ static box Stage1UsingResolverBox {
     if path == null { return null }
     @fb = new FileBox()
     @ok = fb.open(path, "r")
-    if ok != 1 { return null }
+    if ok != 1 {
+      // Dev note: keep quiet by default; enable verbose by setting HAKO_STAGEB_USING_DEBUG=1.
+      local dbg = env.get("HAKO_STAGEB_USING_DEBUG")
+      if dbg != null && ("" + dbg) == "1" {
+        print("[stageb/using_resolver] failed to open file: " + path)
+      }
+      return null
+    }
     @content = fb.read()
     fb.close()
     return content

lang/src/compiler/parser/parser_box.hako

@@ -51,11 +51,14 @@ box ParserBox {
 
   // === JSON utilities ===
   esc_json(s) {
+    // Defensive: accept null/void and normalize to string once
+    if s == null { return "" }
+    local str = "" + s
     local out = ""
     local i = 0
-    local n = s.length()
+    local n = str.length()
     loop(i < n) {
-      local ch = s.substring(i, i+1)
+      local ch = str.substring(i, i+1)
       if ch == "\\" { out = out + "\\\\" }
       else { if ch == "\"" { out = out + "\\\"" }
       else { out = out + ch } }

lang/src/compiler/parser/scan/parser_string_utils_box.hako

@@ -1,20 +1,116 @@
 // Moved from apps/selfhost-compiler/boxes/parser/scan/parser_string_utils_box.hako
-// ParserStringUtilsBox — Delegation to StringHelpers (unified string utilities)
+// ParserStringUtilsBox — Minimal self-contained string helpers
 // Responsibility: Backward compatibility wrapper for parser code
-// Notes: All functionality now provided by apps/selfhost/common/string_helpers.hako
-
-using sh_core as StringHelpers
+// Notes: sh_core への依存で VM 差分が出たため、ここに最小実装を内包する。
 
 static box ParserStringUtilsBox {
-  // Delegate all methods to StringHelpers (centralized implementation)
-  i2s(v) { return StringHelpers.int_to_str(v) }
-  is_digit(ch) { return StringHelpers.is_digit(ch) }
-  is_space(ch) { return StringHelpers.is_space(ch) }
-  is_alpha(ch) { return StringHelpers.is_alpha(ch) }
-  starts_with(src, i, pat) { return StringHelpers.starts_with(src, i, pat) }
-  starts_with_kw(src, i, kw) { return StringHelpers.starts_with_kw(src, i, kw) }
-  index_of(src, i, pat) { return StringHelpers.index_of(src, i, pat) }
-  trim(s) { return StringHelpers.trim(s) }
-  to_int(s) { return StringHelpers.to_i64(s) }
-  skip_ws(src, i) { return StringHelpers.skip_ws(src, i) }
+  // Numeric to string (minimal)
+  i2s(v) {
+    local n = ParserStringUtilsBox.to_int(v)
+    if n == 0 { return "0" }
+    if n < 0 { return "-" + ParserStringUtilsBox.i2s(0 - n) }
+    local out = ""
+    loop(n > 0) {
+      local d = n % 10
+      out = "0123456789".substring(d, d + 1) + out
+      n = n / 10
+    }
+    return out
+  }
+
+  is_digit(ch) { return ch >= "0" && ch <= "9" }
+  is_space(ch) { return ch == " " || ch == "\t" || ch == "\n" || ch == "\r" }
+  is_alpha(ch) { return (ch >= "A" && ch <= "Z") || (ch >= "a" && ch <= "z") || ch == "_" }
+
+  starts_with(src, i, pat) {
+    if src == null || pat == null { return 0 }
+    local n = src.length()
+    local m = pat.length()
+    if i + m > n { return 0 }
+    local k = 0
+    loop(k < m) {
+      if src.substring(i + k, i + k + 1) != pat.substring(k, k + 1) { return 0 }
+      k = k + 1
+    }
+    return 1
+  }
+
+  // Keyword match with boundary（Stage‑B 安定性のためここで実装）
+  starts_with_kw(src, i, kw) {
+    if src == null || kw == null { return 0 }
+    local n = src.length()
+    local m = kw.length()
+    if i + m > n { return 0 }
+    local k = 0
+    loop(k < m) {
+      if src.substring(i + k, i + k + 1) != kw.substring(k, k + 1) { return 0 }
+      k = k + 1
+    }
+    local j = i + m
+    if j >= n { return 1 }
+    local ch = src.substring(j, j + 1)
+    if ParserStringUtilsBox.is_alpha(ch) == 1 || ParserStringUtilsBox.is_digit(ch) == 1 { return 0 }
+    return 1
+  }
+
+  index_of(src, i, pat) {
+    if src == null || pat == null { return -1 }
+    local n = src.length()
+    local m = pat.length()
+    if m == 0 { return i }
+    local j = i
+    loop(j + m <= n) {
+      if ParserStringUtilsBox.starts_with(src, j, pat) == 1 { return j }
+      j = j + 1
+    }
+    return -1
+  }
+
+  trim(s) {
+    if s == null { return "" }
+    local str = "" + s
+    local n = str.length()
+    local b = 0
+    loop(b < n) {
+      local ch = str.substring(b, b + 1)
+      if ch == " " || ch == "\t" || ch == "\n" || ch == "\r" { b = b + 1 } else { break }
+    }
+    local e = n
+    loop(e > b) {
+      local ch = str.substring(e - 1, e)
+      if ch == " " || ch == "\t" || ch == "\n" || ch == "\r" { e = e - 1 } else { break }
+    }
+    if e > b { return str.substring(b, e) }
+    return ""
+  }
+
+  to_int(s) {
+    if s == null { return 0 }
+    local str = "" + s
+    local n = str.length()
+    if n == 0 { return 0 }
+    local neg = 0
+    local i = 0
+    if str.substring(0, 1) == "-" { neg = 1  i = 1 }
+    local acc = 0
+    loop(i < n) {
+      local ch = str.substring(i, i + 1)
+      if ch < "0" || ch > "9" { break }
+      acc = acc * 10 + ("0123456789".indexOf(ch))
+      i = i + 1
+    }
+    if neg == 1 { return 0 - acc }
+    return acc
+  }
+
+  skip_ws(src, i) {
+    if src == null { return i }
+    local n = src.length()
+    local j = i
+    loop(j < n) {
+      local ch = src.substring(j, j + 1)
+      if ParserStringUtilsBox.is_space(ch) == 1 { j = j + 1 } else { break }
+    }
+    return j
+  }
 }

lang/src/compiler/parser/stmt/parser_control_box.hako

@@ -7,15 +7,16 @@ using sh_core as StringHelpers  // Required: using chain resolution not implemen
 static box ParserControlBox {
   // Parse: if (cond) { ... } else { ... }
   parse_if(src, i, stmt_start, ctx) {
-    // Shallow recursion guard for Stage‑B / selfhost: protect parse_if from
-    // accidental self-recursion via malformed input or control flow bugs.
+    // Depth guard (allow nesting, cap runaway recursion)
+    local if_depth_before = 0
     {
-      local depth = env.get("HAKO_STAGEB_IF_DEPTH")
-      if depth != null && ("" + depth) != "0" {
+      local depth_raw = env.get("HAKO_STAGEB_IF_DEPTH")
+      if depth_raw != null { if_depth_before = StringHelpers.to_i64("" + depth_raw) }
+      if if_depth_before >= 64 {
         print("[stageb/recursion] ParserControlBox.parse_if recursion detected")
         return "{\"type\":\"If\",\"cond\":{\"type\":\"Bool\",\"value\":false},\"then\":[]}"
       }
-      env.set("HAKO_STAGEB_IF_DEPTH", "1")
+      env.set("HAKO_STAGEB_IF_DEPTH", StringHelpers.int_to_str(if_depth_before + 1))
     }
     local j = i + 2  // skip "if"
     j = ctx.skip_ws(src, j)
@@ -52,7 +53,7 @@ static box ParserControlBox {
     }
     ctx.gpos_set(j)
 
-    env.set("HAKO_STAGEB_IF_DEPTH", "0")
+    env.set("HAKO_STAGEB_IF_DEPTH", StringHelpers.int_to_str(if_depth_before))
     if else_json == null {
       return "{\"type\":\"If\",\"cond\":" + cond + ",\"then\":" + then_json + "}"
     } else {
@@ -63,14 +64,15 @@ static box ParserControlBox {
   // Parse: loop(cond) { ... }
   // Dev tracing: set HAKO_PARSER_TRACE_LOOP=1 to enable debug prints
   parse_loop(src, i, stmt_start, ctx) {
-    // Shallow recursion guard for parse_loop
+    local loop_depth_before = 0
     {
-      local depth = env.get("HAKO_STAGEB_LOOP_DEPTH")
-      if depth != null && ("" + depth) != "0" {
+      local depth_raw = env.get("HAKO_STAGEB_LOOP_DEPTH")
+      if depth_raw != null { loop_depth_before = StringHelpers.to_i64("" + depth_raw) }
+      if loop_depth_before >= 64 {
         print("[stageb/recursion] ParserControlBox.parse_loop recursion detected")
         return "{\"type\":\"Loop\",\"cond\":{\"type\":\"Bool\",\"value\":false},\"body\":[]}"
       }
-      env.set("HAKO_STAGEB_LOOP_DEPTH", "1")
+      env.set("HAKO_STAGEB_LOOP_DEPTH", StringHelpers.int_to_str(loop_depth_before + 1))
     }
 
     local trace = 0  // dev-only (disabled in Stage-B runtime: no env API here)
@@ -154,7 +156,7 @@ static box ParserControlBox {
       if j < src.length() { j = j + 1 } else { j = src.length() }
     }
     ctx.gpos_set(j)
-    env.set("HAKO_STAGEB_LOOP_DEPTH", "0")
+    env.set("HAKO_STAGEB_LOOP_DEPTH", StringHelpers.int_to_str(loop_depth_before))
     return "{\"type\":\"Loop\",\"cond\":" + cond + ",\"body\":" + body_json + "}"
   }
 
@@ -222,15 +224,27 @@ static box ParserControlBox {
 
   // Parse: { stmt1; stmt2; ... }
   parse_block(src, i, ctx) {
+    local depth_before = 0
     {
-      local depth = env.get("HAKO_STAGEB_BLOCK_DEPTH")
-      if depth != null && ("" + depth) != "0" {
+      local depth_raw = env.get("HAKO_STAGEB_BLOCK_DEPTH")
+      if depth_raw != null { depth_before = StringHelpers.to_i64("" + depth_raw) }
+      if depth_before >= 64 {
         print("[stageb/recursion] ParserControlBox.parse_block recursion detected")
         return "[]@" + ctx.i2s(i)
       }
-      env.set("HAKO_STAGEB_BLOCK_DEPTH", "1")
+      env.set("HAKO_STAGEB_BLOCK_DEPTH", StringHelpers.int_to_str(depth_before + 1))
     }
     local j = ctx.skip_ws(src, i)
+    // Stage‑B safety: inline whitespace skip in case ctx.skip_ws fails to advance on VM
+    {
+      local n = src.length()
+      local jj = j
+      loop(jj < n) {
+        local ch = src.substring(jj, jj+1)
+        if ch == " " || ch == "\t" || ch == "\n" || ch == "\r" { jj = jj + 1 } else { break }
+      }
+      j = jj
+    }
     if src.substring(j, j+1) != "{" { return "[]@" + ctx.i2s(j) }
     j = j + 1
 
@@ -283,7 +297,7 @@ static box ParserControlBox {
     }
 
     body = body + "]"
-    env.set("HAKO_STAGEB_BLOCK_DEPTH", "0")
+    env.set("HAKO_STAGEB_BLOCK_DEPTH", StringHelpers.int_to_str(depth_before))
     return body + "@" + ctx.i2s(j)
   }
 }

lang/src/compiler/parser/stmt/parser_stmt_box.hako

@@ -15,12 +15,23 @@ static box ParserStmtBox {
       local depth = env.get("HAKO_STAGEB_STMT_DEPTH")
       if depth != null && ("" + depth) != "0" {
         print("[stageb/recursion] ParserStmtBox.parse recursion detected")
-        // Fail-fast: return empty stmt and keep position unchanged
-        return ""
+        // Allow re-entry: reset depth to 1 and continue（ドロップしない）
+        env.set("HAKO_STAGEB_STMT_DEPTH", "1")
+      } else {
+        env.set("HAKO_STAGEB_STMT_DEPTH", "1")
       }
-      env.set("HAKO_STAGEB_STMT_DEPTH", "1")
     }
     local j = ctx.skip_ws(src, i)
+    // VM 差分で skip_ws が前進しないパスがあったため、手動で最小限の空白スキップをフォローする。
+    {
+      local n = src.length()
+      local jj = j
+      loop(jj < n) {
+        local ch = src.substring(jj, jj+1)
+        if ch == " " || ch == "\t" || ch == "\n" || ch == "\r" { jj = jj + 1 } else { break }
+      }
+      j = jj
+    }
     {
       local tr = env.get("NYASH_PARSER_TRACE")
       if tr != null && ("" + tr) == "1" {
@@ -86,49 +97,6 @@ static box ParserStmtBox {
       return out_using
     }
 
-    // assignment: IDENT '=' expr
-    if j < src.length() && ctx.is_alpha(src.substring(j, j+1)) {
-      {
-        local tr = env.get("NYASH_PARSER_TRACE")
-        if tr != null && ("" + tr) == "1" {
-          print("[parser/stmt] kind=assign-or-local j=" + ("" + j))
-        }
-      }
-      local idp0 = ctx.read_ident2(src, j)
-      local at0 = idp0.lastIndexOf("@")
-      if at0 > 0 {
-        local name0 = idp0.substring(0, at0)
-        local k0 = ctx.to_int(idp0.substring(at0+1, idp0.length()))
-        k0 = ctx.skip_ws(src, k0)
-        if k0 < src.length() && src.substring(k0, k0+1) == "=" {
-          local eq_two = "="
-          if k0 + 1 < src.length() { eq_two = src.substring(k0, k0+2) }
-          if eq_two != "==" {
-            k0 = k0 + 1
-            k0 = ctx.skip_ws(src, k0)
-            local default_local = "{\"type\":\"Int\",\"value\":0}"
-            local expr_json0 = default_local
-            local end_pos0 = k0
-            if k0 < src.length() {
-              local ahead = src.substring(k0, k0+1)
-              if ahead != "}" && ahead != ";" {
-                expr_json0 = ctx.parse_expr2(src, k0)
-                end_pos0 = ctx.gpos_get()
-              }
-            }
-            k0 = end_pos0
-            if k0 <= stmt_start {
-              if k0 < src.length() { k0 = k0 + 1 } else { k0 = src.length() }
-            }
-            ctx.gpos_set(k0)
-            // Reset recursion guard before returning
-            env.set("HAKO_STAGEB_STMT_DEPTH", "0")
-            return "{\"type\":\"Local\",\"name\":\"" + name0 + "\",\"expr\":" + expr_json0 + "}"
-          }
-        }
-      }
-    }
-
     // return statement
     if ctx.starts_with_kw(src, j, "return") == 1 {
       {
@@ -288,6 +256,49 @@ static box ParserStmtBox {
       return out_try
     }
 
+    // assignment: IDENT '=' expr（キーワードより後段に配置して、'loop' などを誤認しないようにする）
+    if j < src.length() && ctx.is_alpha(src.substring(j, j+1)) {
+      {
+        local tr = env.get("NYASH_PARSER_TRACE")
+        if tr != null && ("" + tr) == "1" {
+          print("[parser/stmt] kind=assign-or-local j=" + ("" + j))
+        }
+      }
+      local idp0 = ctx.read_ident2(src, j)
+      local at0 = idp0.lastIndexOf("@")
+      if at0 > 0 {
+        local name0 = idp0.substring(0, at0)
+        local k0 = ctx.to_int(idp0.substring(at0+1, idp0.length()))
+        k0 = ctx.skip_ws(src, k0)
+        if k0 < src.length() && src.substring(k0, k0+1) == "=" {
+          local eq_two = "="
+          if k0 + 1 < src.length() { eq_two = src.substring(k0, k0+2) }
+          if eq_two != "==" {
+            k0 = k0 + 1
+            k0 = ctx.skip_ws(src, k0)
+            local default_local = "{\"type\":\"Int\",\"value\":0}"
+            local expr_json0 = default_local
+            local end_pos0 = k0
+            if k0 < src.length() {
+              local ahead = src.substring(k0, k0+1)
+              if ahead != "}" && ahead != ";" {
+                expr_json0 = ctx.parse_expr2(src, k0)
+                end_pos0 = ctx.gpos_get()
+              }
+            }
+            k0 = end_pos0
+            if k0 <= stmt_start {
+              if k0 < src.length() { k0 = k0 + 1 } else { k0 = src.length() }
+            }
+            ctx.gpos_set(k0)
+            // Reset recursion guard before returning
+            env.set("HAKO_STAGEB_STMT_DEPTH", "0")
+            return "{\"type\":\"Local\",\"name\":\"" + name0 + "\",\"expr\":" + expr_json0 + "}"
+          }
+        }
+      }
+    }
+
     // Fallback: expression or unknown token
     {
       local tr = env.get("NYASH_PARSER_TRACE")
@@ -365,6 +376,8 @@ static box ParserStmtBox {
       if j < src.length() { j = j + 1 } else { j = src.length() }
     }
     ctx.gpos_set(j)
+    // Reset recursion guard before returning (using statements participate in stmt depth tracking)
+    env.set("HAKO_STAGEB_STMT_DEPTH", "0")
     return ""
   }
 }

lang/src/compiler/pipeline_v2/using_resolver_box.hako

@@ -1,4 +1,8 @@
 // UsingResolverBox — static, stateful resolver helpers（インスタンス禁止・VM互換）
+// Boundary memo:
+//   - entry/using_resolver_box: file I/O + using 収集、modules_list を MapBox へ積む役。
+//   - pipeline_v2/using_resolver_box: modules_json 上で alias/path をテキスト検索で解決する役。
+// RegexFlow の単一路ループのみで continue/backedge 分岐を持たないため、Region+next_i 化は不要と判断。
 // State layout (Map): {
 //   alias_paths: Map, alias_names: Map, alias_keys: Array,
 //   modules_map: Map, modules_keys: Array

lang/src/runner/stage1_cli.hako

@@ -107,6 +107,10 @@ static box Stage1Cli {
 
   // CLI dispatcher (stub)
   method stage1_main(args) {
+    if env.get("STAGE1_CLI_DEBUG") == "1" {
+      local argc = 0; if args != null { argc = args.size() }
+      print("[stage1-cli/debug] stage1_main ENTRY: argc=" + ("" + argc) + " env_emits={prog=" + ("" + env.get("STAGE1_EMIT_PROGRAM_JSON")) + ",mir=" + ("" + env.get("STAGE1_EMIT_MIR_JSON")) + "} backend=" + ("" + env.get("STAGE1_BACKEND")))
+    }
     {
       local use_cli = env.get("NYASH_USE_STAGE1_CLI")
       if use_cli == null || ("" + use_cli) != "1" {

lang/src/using/resolve_ssot_box.hako

@@ -9,6 +9,18 @@
 // - ctx.using_paths: Array<String>（将来のヒント／本箱では純粋合成のみ）
 // - ctx.cwd: String（相対の基準）
 
+// Quick README (Phase 25.1 using設計)
+// - 役割: using 解決の唯一の窓口（SSOT）。parser/Stage‑B/Stage‑1 は IO や名前探索をここに委譲する。
+// - I/F:
+//   - resolve(name, ctx) -> path|null : modules/cwd/using_paths から純粋に合成して返す（IOなし）。
+//   - resolve_modules(modules_json, using_entries_json, ctx) -> modules_json_resolved|null :
+//       modules_json（nyash.toml 相当）と using_entries_json（UsingCollector 出力）を突き合わせ、
+//       「解決済み modules_json」（同名重複などの調停結果）を返す。IOなし。
+//   - resolve_prefix(using_entries_json, modules_json, ctx) -> prefix_string :
+//       using_entries_json を modules_json を使ってパス解決し、ファイル読まずに
+//       「prefix 文字列（空でよい）を組み立てるための情報」を返すスコープ（MVPは空文字返しでOK）。
+// - ポリシー: IO/ファイル読み込みは絶対にしない。より重い処理は entry/pipeline 側の責務。
+
 static box UsingResolveSSOTBox {
   /// Resolve a module name to a file path string (or null when not found).
   /// name: requested module name (e.g., "hako.mir.builder.internal.lower_return_int")
@@ -55,4 +67,16 @@ static box UsingResolveSSOTBox {
     if base.endsWith("/") { return base + leaf }
     return base + "/" + leaf
   }
+
+  // Merge modules_json + using_entries_json into resolved modules table (pure, no IO).
+  resolve_modules(modules_json, using_entries_json, ctx) {
+    // MVP: just echo back modules_json (keep behavior unchanged) to establish interface.
+    return modules_json
+  }
+
+  // Build prefix string from using_entries_json with modules_json (pure, no IO).
+  resolve_prefix(using_entries_json, modules_json, ctx) {
+    // MVP: no file read, so prefix is empty. Interface is reserved for Stage‑1 entry.
+    return ""
+  }
 }

nyash.toml

@@ -136,6 +136,7 @@ path = "lang/src/shared/common/string_helpers.hako"
 "lang.compiler.entry.compiler" = "lang/src/compiler/entry/compiler.hako"
 "lang.compiler.entry.compiler_stageb" = "lang/src/compiler/entry/compiler_stageb.hako"
 "lang.compiler.entry.bundle_resolver" = "lang/src/compiler/entry/bundle_resolver.hako"
+"lang.compiler.entry.using_resolver_box" = "lang/src/compiler/entry/using_resolver_box.hako"
 "lang.compiler.entry.using_resolver" = "lang/src/compiler/entry/using_resolver_box.hako"
 "lang.compiler.emit.mir_emitter_box" = "lang/src/compiler/emit/mir_emitter_box.hako"
 "lang.compiler.emit.common.json_emit_box" = "lang/src/compiler/emit/common/json_emit_box.hako"

src/abi/nyrt_shim.rs

@@ -2,16 +2,22 @@
 // Kept tiny and isolated. Linkage names match include/nyrt.h.
 
 #[no_mangle]
-pub extern "C" fn nyrt_init() -> i32 { 0 }
+pub extern "C" fn nyrt_init() -> i32 {
+    0
+}
 
 #[no_mangle]
-pub extern "C" fn nyrt_teardown() { }
+pub extern "C" fn nyrt_teardown() {}
 
 #[no_mangle]
-pub extern "C" fn nyrt_load_mir_json(_json_text: *const ::std::os::raw::c_char) -> u64 { 1 }
+pub extern "C" fn nyrt_load_mir_json(_json_text: *const ::std::os::raw::c_char) -> u64 {
+    1
+}
 
 #[no_mangle]
-pub extern "C" fn nyrt_exec_main(_module_handle: u64) -> i32 { 0 }
+pub extern "C" fn nyrt_exec_main(_module_handle: u64) -> i32 {
+    0
+}
 
 #[no_mangle]
 pub extern "C" fn nyrt_hostcall(
@@ -20,7 +26,9 @@ pub extern "C" fn nyrt_hostcall(
     _payload_json: *const ::std::os::raw::c_char,
     _out_buf: *mut ::std::os::raw::c_char,
     _out_buf_len: u32,
-) -> i32 { 0 }
+) -> i32 {
+    0
+}
 
 #[cfg(test)]
 mod tests {

src/ast.rs

@@ -10,8 +10,8 @@ use std::collections::HashMap;
 use std::fmt;
 mod span;
 pub use span::Span;
-mod utils;
 mod nodes;
+mod utils;
 pub use nodes::*;
 
 // Span は src/ast/span.rs へ分離（re-export で後方互換維持）
@@ -573,7 +573,6 @@ pub enum ASTNode {
     /// meフィールドアクセス: me.field
     MeField { field: String, span: Span },
 
-
     /// ローカル変数宣言: local x, y, z
     Local {
         variables: Vec<String>,
@@ -584,10 +583,7 @@ pub enum ASTNode {
 
     /// ScopeBox（オプション）: 診断/マクロ可視性のためのno-opスコープ。
     /// 正規化で注入され、MIRビルダがブロックとして処理（意味不変）。
-    ScopeBox {
-        body: Vec<ASTNode>,
-        span: Span,
-    },
+    ScopeBox { body: Vec<ASTNode>, span: Span },
 
     /// Outbox変数宣言: outbox x, y, z (static関数内専用)
     Outbox {

src/ast/nodes.rs

@@ -22,7 +22,15 @@ impl TryFrom<ASTNode> for AssignStmt {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::Assignment { target, value, span } => Ok(AssignStmt { target, value, span }),
+            ASTNode::Assignment {
+                target,
+                value,
+                span,
+            } => Ok(AssignStmt {
+                target,
+                value,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -30,7 +38,11 @@ impl TryFrom<ASTNode> for AssignStmt {
 
 impl From<AssignStmt> for ASTNode {
     fn from(s: AssignStmt) -> Self {
-        ASTNode::Assignment { target: s.target, value: s.value, span: s.span }
+        ASTNode::Assignment {
+            target: s.target,
+            value: s.value,
+            span: s.span,
+        }
     }
 }
 
@@ -52,7 +64,10 @@ impl TryFrom<ASTNode> for ReturnStmt {
 
 impl From<ReturnStmt> for ASTNode {
     fn from(s: ReturnStmt) -> Self {
-        ASTNode::Return { value: s.value, span: s.span }
+        ASTNode::Return {
+            value: s.value,
+            span: s.span,
+        }
     }
 }
 
@@ -68,7 +83,17 @@ impl TryFrom<ASTNode> for IfStmt {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::If { condition, then_body, else_body, span } => Ok(IfStmt { condition, then_body, else_body, span }),
+            ASTNode::If {
+                condition,
+                then_body,
+                else_body,
+                span,
+            } => Ok(IfStmt {
+                condition,
+                then_body,
+                else_body,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -76,7 +101,12 @@ impl TryFrom<ASTNode> for IfStmt {
 
 impl From<IfStmt> for ASTNode {
     fn from(s: IfStmt) -> Self {
-        ASTNode::If { condition: s.condition, then_body: s.then_body, else_body: s.else_body, span: s.span }
+        ASTNode::If {
+            condition: s.condition,
+            then_body: s.then_body,
+            else_body: s.else_body,
+            span: s.span,
+        }
     }
 }
 
@@ -96,8 +126,17 @@ impl TryFrom<ASTNode> for BinaryExpr {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::BinaryOp { operator, left, right, span } =>
-                Ok(BinaryExpr { operator, left, right, span }),
+            ASTNode::BinaryOp {
+                operator,
+                left,
+                right,
+                span,
+            } => Ok(BinaryExpr {
+                operator,
+                left,
+                right,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -105,7 +144,12 @@ impl TryFrom<ASTNode> for BinaryExpr {
 
 impl From<BinaryExpr> for ASTNode {
     fn from(e: BinaryExpr) -> Self {
-        ASTNode::BinaryOp { operator: e.operator, left: e.left, right: e.right, span: e.span }
+        ASTNode::BinaryOp {
+            operator: e.operator,
+            left: e.left,
+            right: e.right,
+            span: e.span,
+        }
     }
 }
 
@@ -120,7 +164,15 @@ impl TryFrom<ASTNode> for CallExpr {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::FunctionCall { name, arguments, span } => Ok(CallExpr { name, arguments, span }),
+            ASTNode::FunctionCall {
+                name,
+                arguments,
+                span,
+            } => Ok(CallExpr {
+                name,
+                arguments,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -128,7 +180,11 @@ impl TryFrom<ASTNode> for CallExpr {
 
 impl From<CallExpr> for ASTNode {
     fn from(c: CallExpr) -> Self {
-        ASTNode::FunctionCall { name: c.name, arguments: c.arguments, span: c.span }
+        ASTNode::FunctionCall {
+            name: c.name,
+            arguments: c.arguments,
+            span: c.span,
+        }
     }
 }
 
@@ -144,8 +200,17 @@ impl TryFrom<ASTNode> for MethodCallExpr {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::MethodCall { object, method, arguments, span } =>
-                Ok(MethodCallExpr { object, method, arguments, span }),
+            ASTNode::MethodCall {
+                object,
+                method,
+                arguments,
+                span,
+            } => Ok(MethodCallExpr {
+                object,
+                method,
+                arguments,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -153,7 +218,12 @@ impl TryFrom<ASTNode> for MethodCallExpr {
 
 impl From<MethodCallExpr> for ASTNode {
     fn from(m: MethodCallExpr) -> Self {
-        ASTNode::MethodCall { object: m.object, method: m.method, arguments: m.arguments, span: m.span }
+        ASTNode::MethodCall {
+            object: m.object,
+            method: m.method,
+            arguments: m.arguments,
+            span: m.span,
+        }
     }
 }
 
@@ -168,8 +238,15 @@ impl TryFrom<ASTNode> for FieldAccessExpr {
     type Error = ASTNode;
     fn try_from(node: ASTNode) -> Result<Self, Self::Error> {
         match node {
-            ASTNode::FieldAccess { object, field, span } =>
-                Ok(FieldAccessExpr { object, field, span }),
+            ASTNode::FieldAccess {
+                object,
+                field,
+                span,
+            } => Ok(FieldAccessExpr {
+                object,
+                field,
+                span,
+            }),
             other => Err(other),
         }
     }
@@ -177,6 +254,10 @@ impl TryFrom<ASTNode> for FieldAccessExpr {
 
 impl From<FieldAccessExpr> for ASTNode {
     fn from(f: FieldAccessExpr) -> Self {
-        ASTNode::FieldAccess { object: f.object, field: f.field, span: f.span }
+        ASTNode::FieldAccess {
+            object: f.object,
+            field: f.field,
+            span: f.span,
+        }
     }
 }

src/backend/abi_util.rs

@@ -54,10 +54,20 @@ pub fn eq_vm(a: &VMValue, b: &VMValue) -> bool {
         (Float(x), Integer(y)) => *x == (*y as f64),
         (BoxRef(ax), BoxRef(by)) => Arc::ptr_eq(ax, by),
         // Treat BoxRef(VoidBox/MissingBox) as equal to Void (null) for backward compatibility
-        (BoxRef(bx), Void) => bx.as_any().downcast_ref::<VoidBox>().is_some()
-            || bx.as_any().downcast_ref::<crate::boxes::missing_box::MissingBox>().is_some(),
-        (Void, BoxRef(bx)) => bx.as_any().downcast_ref::<VoidBox>().is_some()
-            || bx.as_any().downcast_ref::<crate::boxes::missing_box::MissingBox>().is_some(),
+        (BoxRef(bx), Void) => {
+            bx.as_any().downcast_ref::<VoidBox>().is_some()
+                || bx
+                    .as_any()
+                    .downcast_ref::<crate::boxes::missing_box::MissingBox>()
+                    .is_some()
+        }
+        (Void, BoxRef(bx)) => {
+            bx.as_any().downcast_ref::<VoidBox>().is_some()
+                || bx
+                    .as_any()
+                    .downcast_ref::<crate::boxes::missing_box::MissingBox>()
+                    .is_some()
+        }
         _ => false,
     }
 }

src/backend/mir_interpreter/exec.rs

@@ -20,9 +20,7 @@ impl MirInterpreter {
         if self.call_depth > MAX_CALL_DEPTH {
             eprintln!(
                 "[vm-call-depth] exceeded {} in fn={} (depth={})",
-                MAX_CALL_DEPTH,
-                func.signature.name,
-                self.call_depth
+                MAX_CALL_DEPTH, func.signature.name, self.call_depth
             );
             self.call_depth = self.call_depth.saturating_sub(1);
             return Err(VMError::InvalidInstruction(format!(
@@ -31,7 +29,9 @@ impl MirInterpreter {
             )));
         }
         // Phase 1: delegate cross-class reroute / narrow fallbacks to method_router
-        if let Some(r) = super::method_router::pre_exec_reroute(self, func, arg_vals) { return r; }
+        if let Some(r) = super::method_router::pre_exec_reroute(self, func, arg_vals) {
+            return r;
+        }
         let saved_regs = mem::take(&mut self.regs);
         let saved_fn = self.cur_fn.clone();
         self.cur_fn = Some(func.signature.name.clone());
@@ -59,7 +59,11 @@ impl MirInterpreter {
         let max_steps: u64 = std::env::var("HAKO_VM_MAX_STEPS")
             .ok()
             .and_then(|v| v.parse::<u64>().ok())
-            .or_else(|| std::env::var("NYASH_VM_MAX_STEPS").ok().and_then(|v| v.parse::<u64>().ok()))
+            .or_else(|| {
+                std::env::var("NYASH_VM_MAX_STEPS")
+                    .ok()
+                    .and_then(|v| v.parse::<u64>().ok())
+            })
             .unwrap_or(1_000_000);
         let mut steps: u64 = 0;
 
@@ -133,9 +137,7 @@ impl MirInterpreter {
         if trace_phi {
             eprintln!(
                 "[vm-trace-phi] enter bb={:?} last_pred={:?} preds={:?}",
-                block.id,
-                last_pred,
-                block.predecessors
+                block.id, last_pred, block.predecessors
             );
         }
         for inst in block.phi_instructions() {
@@ -154,7 +156,11 @@ impl MirInterpreter {
                             Ok(v) => v,
                             Err(e) => {
                                 // Dev safety valve: tolerate undefined phi inputs by substituting Void
-                                if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED").ok().as_deref() == Some("1") {
+                                if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED")
+                                    .ok()
+                                    .as_deref()
+                                    == Some("1")
+                                {
                                     if Self::trace_enabled() {
                                         eprintln!("[vm-trace] phi tolerate undefined input {:?} -> Void (err={:?})", val, e);
                                     }
@@ -179,17 +185,41 @@ impl MirInterpreter {
                         // Strict PHI (default ON). Can be disabled with HAKO_VM_PHI_STRICT=0 (or NYASH_VM_PHI_STRICT=0).
                         let strict = {
                             let on = |s: &str| {
-                                matches!(s, "1"|"true"|"on"|"yes"|"y"|"t"|"enabled"|"enable")
+                                matches!(
+                                    s,
+                                    "1" | "true" | "on" | "yes" | "y" | "t" | "enabled" | "enable"
+                                )
                             };
                             let off = |s: &str| {
-                                matches!(s, "0"|"false"|"off"|"no"|"n"|"f"|"disabled"|"disable")
+                                matches!(
+                                    s,
+                                    "0" | "false"
+                                        | "off"
+                                        | "no"
+                                        | "n"
+                                        | "f"
+                                        | "disabled"
+                                        | "disable"
+                                )
                             };
                             if let Ok(v) = std::env::var("HAKO_VM_PHI_STRICT") {
                                 let v = v.to_ascii_lowercase();
-                                if off(&v) { false } else if on(&v) { true } else { true }
+                                if off(&v) {
+                                    false
+                                } else if on(&v) {
+                                    true
+                                } else {
+                                    true
+                                }
                             } else if let Ok(v) = std::env::var("NYASH_VM_PHI_STRICT") {
                                 let v = v.to_ascii_lowercase();
-                                if off(&v) { false } else if on(&v) { true } else { true }
+                                if off(&v) {
+                                    false
+                                } else if on(&v) {
+                                    true
+                                } else {
+                                    true
+                                }
                             } else {
                                 true
                             }
@@ -213,7 +243,11 @@ impl MirInterpreter {
                             let v = match self.reg_load(*val0) {
                                 Ok(v) => v,
                                 Err(e) => {
-                                    if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED").ok().as_deref() == Some("1") {
+                                    if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED")
+                                        .ok()
+                                        .as_deref()
+                                        == Some("1")
+                                    {
                                         if Self::trace_enabled() {
                                             eprintln!("[vm-trace] phi missing pred match {:?}; fallback first input {:?} -> Void (err={:?})", pred, val0, e);
                                         }
@@ -243,7 +277,11 @@ impl MirInterpreter {
                     let v = match self.reg_load(*val) {
                         Ok(v) => v,
                         Err(e) => {
-                            if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED").ok().as_deref() == Some("1") {
+                            if std::env::var("NYASH_VM_PHI_TOLERATE_UNDEFINED")
+                                .ok()
+                                .as_deref()
+                                == Some("1")
+                            {
                                 if Self::trace_enabled() {
                                     eprintln!("[vm-trace] phi tolerate undefined default input {:?} -> Void (err={:?})", val, e);
                                 }
@@ -255,10 +293,7 @@ impl MirInterpreter {
                     };
                     self.regs.insert(dst_id, v);
                     if Self::trace_enabled() {
-                        eprintln!(
-                            "[vm-trace] phi dst={:?} take default val={:?}",
-                            dst_id, val
-                        );
+                        eprintln!("[vm-trace] phi dst={:?} take default val={:?}", dst_id, val);
                     }
                 }
             }

src/backend/mir_interpreter/handlers/arithmetic.rs

@@ -32,7 +32,8 @@ impl MirInterpreter {
             if let Some(op_fn) = self.functions.get("AddOperator.apply/2").cloned() {
                 if !in_guard {
                     if crate::config::env::operator_box_add_adopt() {
-                        let out = self.exec_function_inner(&op_fn, Some(&[a.clone(), b.clone()]))?;
+                        let out =
+                            self.exec_function_inner(&op_fn, Some(&[a.clone(), b.clone()]))?;
                         self.regs.insert(dst, out);
                         return Ok(());
                     } else {

src/backend/mir_interpreter/handlers/boxes.rs

@@ -20,7 +20,9 @@ impl MirInterpreter {
                 let s_opt: Option<String> = match v0.clone() {
                     VMValue::String(s) => Some(s),
                     VMValue::BoxRef(b) => {
-                        if let Some(sb) = b.as_any().downcast_ref::<crate::boxes::basic::StringBox>() {
+                        if let Some(sb) =
+                            b.as_any().downcast_ref::<crate::boxes::basic::StringBox>()
+                        {
                             Some(sb.value.clone())
                         } else {
                             None
@@ -29,10 +31,13 @@ impl MirInterpreter {
                     _ => None,
                 };
                 if let Some(s) = s_opt {
-                    let boxed: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::boxes::basic::StringBox::new(s));
+                    let boxed: Box<dyn crate::box_trait::NyashBox> =
+                        Box::new(crate::boxes::basic::StringBox::new(s));
                     let created_vm = VMValue::from_nyash_box(boxed);
                     self.regs.insert(dst, created_vm);
-                    if Self::box_trace_enabled() { self.box_trace_emit_new(box_type, args.len()); }
+                    if Self::box_trace_enabled() {
+                        self.box_trace_emit_new(box_type, args.len());
+                    }
                     return Ok(());
                 }
             }
@@ -88,7 +93,7 @@ impl MirInterpreter {
                 Err(e) => {
                     return Err(self.err_with_context(
                         &format!("PluginInvoke {}.{}", p.box_type, method),
-                        &format!("{:?}", e)
+                        &format!("{:?}", e),
                     ))
                 }
             }
@@ -115,7 +120,10 @@ impl MirInterpreter {
                 return Ok(());
             }
             if let VMValue::BoxRef(b) = self.reg_load(box_val)? {
-                if b.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                if b.as_any()
+                    .downcast_ref::<crate::box_trait::VoidBox>()
+                    .is_some()
+                {
                     self.write_string(dst, "null".to_string());
                     return Ok(());
                 }
@@ -125,7 +133,8 @@ impl MirInterpreter {
         if Self::box_trace_enabled() {
             let cls = match self.reg_load(box_val).unwrap_or(VMValue::Void) {
                 VMValue::BoxRef(b) => {
-                    if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                    if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>()
+                    {
                         inst.class_name.clone()
                     } else {
                         b.type_name().to_string()
@@ -167,7 +176,10 @@ impl MirInterpreter {
                 }
             }
             VMValue::BoxRef(ref b) => {
-                if b.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                if b.as_any()
+                    .downcast_ref::<crate::box_trait::VoidBox>()
+                    .is_some()
+                {
                     if let Some(val) = super::boxes_void_guards::handle_void_method(method) {
                         self.write_result(dst, val);
                         return Ok(());
@@ -252,9 +264,12 @@ impl MirInterpreter {
             // Determine receiver class name when possible
             let recv_cls: Option<String> = match self.reg_load(box_val).ok() {
                 Some(VMValue::BoxRef(b)) => {
-                    if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                    if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>()
+                    {
                         Some(inst.class_name.clone())
-                    } else { None }
+                    } else {
+                        None
+                    }
                 }
                 _ => None,
             };
@@ -262,13 +277,19 @@ impl MirInterpreter {
                 let prefix = format!("{}.", want);
                 cands.retain(|k| k.starts_with(&prefix));
             }
-            if cands.len() == 1 { self.functions.get(&cands[0]).cloned() } else { None }
+            if cands.len() == 1 {
+                self.functions.get(&cands[0]).cloned()
+            } else {
+                None
+            }
         } {
             // Build argv: pass receiver as first arg (me)
             let recv_vm = self.reg_load(box_val)?;
             let mut argv: Vec<VMValue> = Vec::with_capacity(1 + args.len());
             argv.push(recv_vm);
-            for a in args { argv.push(self.reg_load(*a)?); }
+            for a in args {
+                argv.push(self.reg_load(*a)?);
+            }
             let ret = self.exec_function_inner(&func, Some(&argv))?;
             self.write_result(dst, ret);
             return Ok(());
@@ -312,5 +333,4 @@ impl MirInterpreter {
     ) -> Result<bool, VMError> {
         super::boxes_array::try_handle_array_box(self, dst, box_val, method, args)
     }
-
 }

src/backend/mir_interpreter/handlers/boxes_array.rs

@@ -8,56 +8,58 @@ pub(super) fn try_handle_array_box(
     method: &str,
     args: &[ValueId],
 ) -> Result<bool, VMError> {
-        let recv = this.reg_load(box_val)?;
-        let recv_box_any: Box<dyn NyashBox> = match recv.clone() {
-            VMValue::BoxRef(b) => b.share_box(),
-            other => other.to_nyash_box(),
-        };
-        if let Some(ab) = recv_box_any
-            .as_any()
-            .downcast_ref::<crate::boxes::array::ArrayBox>()
-        {
-            match method {
-                "birth" => {
-                    // No-op constructor init
-                    this.write_void(dst);
-                    return Ok(true);
-                }
-                "push" => {
-                    this.validate_args_exact("push", args, 1)?;
-                    let val = this.load_as_box(args[0])?;
-                    let _ = ab.push(val);
-                    this.write_void(dst);
-                    return Ok(true);
-                }
-                "pop" => {
-                    if !args.is_empty() { return Err(this.err_invalid("pop expects 0 args")); }
-                    let ret = ab.pop();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "len" | "length" | "size" => {
-                    let ret = ab.length();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "get" => {
-                    this.validate_args_exact("get", args, 1)?;
-                    let idx = this.load_as_box(args[0])?;
-                    let ret = ab.get(idx);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "set" => {
-                    this.validate_args_exact("set", args, 2)?;
-                    let idx = this.load_as_box(args[0])?;
-                    let val = this.load_as_box(args[1])?;
-                    let _ = ab.set(idx, val);
-                    this.write_void(dst);
-                    return Ok(true);
-                }
-                _ => {}
+    let recv = this.reg_load(box_val)?;
+    let recv_box_any: Box<dyn NyashBox> = match recv.clone() {
+        VMValue::BoxRef(b) => b.share_box(),
+        other => other.to_nyash_box(),
+    };
+    if let Some(ab) = recv_box_any
+        .as_any()
+        .downcast_ref::<crate::boxes::array::ArrayBox>()
+    {
+        match method {
+            "birth" => {
+                // No-op constructor init
+                this.write_void(dst);
+                return Ok(true);
             }
+            "push" => {
+                this.validate_args_exact("push", args, 1)?;
+                let val = this.load_as_box(args[0])?;
+                let _ = ab.push(val);
+                this.write_void(dst);
+                return Ok(true);
+            }
+            "pop" => {
+                if !args.is_empty() {
+                    return Err(this.err_invalid("pop expects 0 args"));
+                }
+                let ret = ab.pop();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "len" | "length" | "size" => {
+                let ret = ab.length();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "get" => {
+                this.validate_args_exact("get", args, 1)?;
+                let idx = this.load_as_box(args[0])?;
+                let ret = ab.get(idx);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "set" => {
+                this.validate_args_exact("set", args, 2)?;
+                let idx = this.load_as_box(args[0])?;
+                let val = this.load_as_box(args[1])?;
+                let _ = ab.set(idx, val);
+                this.write_void(dst);
+                return Ok(true);
+            }
+            _ => {}
         }
-        Ok(false)
+    }
+    Ok(false)
 }

src/backend/mir_interpreter/handlers/boxes_instance.rs

@@ -14,26 +14,39 @@ pub(super) fn try_handle_instance_box(
         other => other.to_nyash_box(),
     };
     if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") && method == "toString" {
-        eprintln!("[vm-trace] instance-check recv_box_any.type={} args_len={}", recv_box_any.type_name(), args.len());
+        eprintln!(
+            "[vm-trace] instance-check recv_box_any.type={} args_len={}",
+            recv_box_any.type_name(),
+            args.len()
+        );
     }
-    if let Some(inst) = recv_box_any.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+    if let Some(inst) = recv_box_any
+        .as_any()
+        .downcast_ref::<crate::instance_v2::InstanceBox>()
+    {
         // Development guard: ensure JsonScanner core fields have sensible defaults
         if inst.class_name == "JsonScanner" {
             // populate missing fields to avoid Void in comparisons inside is_eof/advance
             if inst.get_field_ng("position").is_none() {
-                let _ = inst.set_field_ng("position".to_string(), crate::value::NyashValue::Integer(0));
+                let _ =
+                    inst.set_field_ng("position".to_string(), crate::value::NyashValue::Integer(0));
             }
             if inst.get_field_ng("length").is_none() {
-                let _ = inst.set_field_ng("length".to_string(), crate::value::NyashValue::Integer(0));
+                let _ =
+                    inst.set_field_ng("length".to_string(), crate::value::NyashValue::Integer(0));
             }
             if inst.get_field_ng("line").is_none() {
                 let _ = inst.set_field_ng("line".to_string(), crate::value::NyashValue::Integer(1));
             }
             if inst.get_field_ng("column").is_none() {
-                let _ = inst.set_field_ng("column".to_string(), crate::value::NyashValue::Integer(1));
+                let _ =
+                    inst.set_field_ng("column".to_string(), crate::value::NyashValue::Integer(1));
             }
             if inst.get_field_ng("text").is_none() {
-                let _ = inst.set_field_ng("text".to_string(), crate::value::NyashValue::String(String::new()));
+                let _ = inst.set_field_ng(
+                    "text".to_string(),
+                    crate::value::NyashValue::String(String::new()),
+                );
             }
         }
         // JsonNodeInstance narrow bridges removed: rely on builder rewrite and instance dispatch
@@ -47,11 +60,26 @@ pub(super) fn try_handle_instance_box(
             );
         }
         // Resolve lowered method function: "Class.method/arity"
-        let primary = format!("{}.{}{}", inst.class_name, method, format!("/{}", args.len()));
+        let primary = format!(
+            "{}.{}{}",
+            inst.class_name,
+            method,
+            format!("/{}", args.len())
+        );
         // Alternate naming: "ClassInstance.method/arity"
-        let alt = format!("{}Instance.{}{}", inst.class_name, method, format!("/{}", args.len()));
+        let alt = format!(
+            "{}Instance.{}{}",
+            inst.class_name,
+            method,
+            format!("/{}", args.len())
+        );
         // Static method variant that takes 'me' explicitly as first arg: "Class.method/(arity+1)"
-        let static_variant = format!("{}.{}{}", inst.class_name, method, format!("/{}", args.len() + 1));
+        let static_variant = format!(
+            "{}.{}{}",
+            inst.class_name,
+            method,
+            format!("/{}", args.len() + 1)
+        );
         // Special-case: toString() → stringify/0 if present
         // Prefer base class (strip trailing "Instance") stringify when available.
         let (stringify_base, stringify_inst) = if method == "toString" && args.is_empty() {
@@ -64,27 +92,43 @@ pub(super) fn try_handle_instance_box(
                 Some(format!("{}.stringify/0", base_name)),
                 Some(format!("{}.stringify/0", inst.class_name)),
             )
-        } else { (None, None) };
+        } else {
+            (None, None)
+        };
 
         if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
             eprintln!(
                 "[vm-trace] instance-dispatch class={} method={} arity={} candidates=[{}, {}, {}]",
-                inst.class_name, method, args.len(), primary, alt, static_variant
+                inst.class_name,
+                method,
+                args.len(),
+                primary,
+                alt,
+                static_variant
             );
         }
 
         // Prefer stringify for toString() if present (semantic alias). Try instance first, then base.
         let func_opt = if let Some(ref sname) = stringify_inst {
             this.functions.get(sname).cloned()
-        } else { None }
-        .or_else(|| stringify_base.as_ref().and_then(|n| this.functions.get(n).cloned()))
+        } else {
+            None
+        }
+        .or_else(|| {
+            stringify_base
+                .as_ref()
+                .and_then(|n| this.functions.get(n).cloned())
+        })
         .or_else(|| this.functions.get(&primary).cloned())
         .or_else(|| this.functions.get(&alt).cloned())
         .or_else(|| this.functions.get(&static_variant).cloned());
 
         if let Some(func) = func_opt {
             if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                eprintln!("[vm-trace] instance-dispatch hit -> {}", func.signature.name);
+                eprintln!(
+                    "[vm-trace] instance-dispatch hit -> {}",
+                    func.signature.name
+                );
             }
             // Build argv: me + args (works for both instance and static(me, ...))
             let mut argv: Vec<VMValue> = Vec::with_capacity(1 + args.len());
@@ -95,7 +139,9 @@ pub(super) fn try_handle_instance_box(
                 }
             }
             argv.push(recv_vm.clone());
-            for a in args { argv.push(this.reg_load(*a)?); }
+            for a in args {
+                argv.push(this.reg_load(*a)?);
+            }
             let ret = this.exec_function_inner(&func, Some(&argv))?;
             this.write_result(dst, ret);
             return Ok(true);
@@ -120,19 +166,28 @@ pub(super) fn try_handle_instance_box(
                 if filtered.len() == 1 {
                     let fname = &filtered[0];
                     if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                        eprintln!("[vm-trace] instance-dispatch fallback (scoped) -> {}", fname);
+                        eprintln!(
+                            "[vm-trace] instance-dispatch fallback (scoped) -> {}",
+                            fname
+                        );
                     }
                     if let Some(func) = this.functions.get(fname).cloned() {
                         let mut argv: Vec<VMValue> = Vec::with_capacity(1 + args.len());
                         if method == "birth" && crate::config::env::using_is_dev() {
                             if matches!(recv_vm, VMValue::Void) {
-                                return Err(this.err_invalid("Dev assert: birth(me==Void) is forbidden"));
+                                return Err(
+                                    this.err_invalid("Dev assert: birth(me==Void) is forbidden")
+                                );
                             }
                         }
                         argv.push(recv_vm.clone());
-                        for a in args { argv.push(this.reg_load(*a)?); }
+                        for a in args {
+                            argv.push(this.reg_load(*a)?);
+                        }
                         let ret = this.exec_function_inner(&func, Some(&argv))?;
-                        if let Some(d) = dst { this.regs.insert(d, ret); }
+                        if let Some(d) = dst {
+                            this.regs.insert(d, ret);
+                        }
                         return Ok(true);
                     }
                 } else if filtered.len() > 1 {
@@ -143,7 +198,11 @@ pub(super) fn try_handle_instance_box(
                 } else {
                     // No same-class candidate: do not dispatch cross-class
                     if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                        eprintln!("[vm-trace] instance-dispatch no same-class candidate for tail .{}{}", method, format!("/{}", args.len()));
+                        eprintln!(
+                            "[vm-trace] instance-dispatch no same-class candidate for tail .{}{}",
+                            method,
+                            format!("/{}", args.len())
+                        );
                     }
                 }
             }

src/backend/mir_interpreter/handlers/boxes_map.rs

@@ -8,115 +8,130 @@ pub(super) fn try_handle_map_box(
     method: &str,
     args: &[ValueId],
 ) -> Result<bool, VMError> {
-        let recv = this.reg_load(box_val)?;
-        let recv_box_any: Box<dyn NyashBox> = match recv.clone() {
-            VMValue::BoxRef(b) => b.share_box(),
-            other => other.to_nyash_box(),
-        };
-        if let Some(mb) = recv_box_any
-            .as_any()
-            .downcast_ref::<crate::boxes::map_box::MapBox>()
-        {
-            match method {
-                "birth" => {
-                    // No-op constructor init for MapBox
-                    this.write_void(dst);
-                    return Ok(true);
-                }
-                // Field bridge: treat getField/setField as get/set with string key
-                "getField" => {
-                    this.validate_args_exact("MapBox.getField", args, 1)?;
-                    let k_vm = this.reg_load(args[0])?;
-                    // Field access expects a String key; otherwise return a stable tag.
-                    if !matches!(k_vm, VMValue::String(_)) {
-                        this.write_result(dst, VMValue::String("[map/bad-key] field name must be string".to_string()));
-                        return Ok(true);
-                    }
-                    let k = this.load_as_box(args[0])?;
-                    let ret = mb.get(k);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "setField" => {
-                    this.validate_args_exact("MapBox.setField", args, 2)?;
-                    let k_vm = this.reg_load(args[0])?;
-                    if !matches!(k_vm, VMValue::String(_)) {
-                        this.write_result(dst, VMValue::String("[map/bad-key] field name must be string".to_string()));
-                        return Ok(true);
-                    }
-                    let k = this.load_as_box(args[0])?;
-                    let v = this.load_as_box(args[1])?;
-                    let ret = mb.set(k, v);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "set" => {
-                    this.validate_args_exact("MapBox.set", args, 2)?;
-                    let k_vm = this.reg_load(args[0])?;
-                    if !matches!(k_vm, VMValue::String(_)) {
-                        this.write_result(dst, VMValue::String("[map/bad-key] key must be string".to_string()));
-                        return Ok(true);
-                    }
-                    let k = this.load_as_box(args[0])?;
-                    let v = this.load_as_box(args[1])?;
-                    let ret = mb.set(k, v);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "get" => {
-                    this.validate_args_exact("MapBox.get", args, 1)?;
-                    let k_vm = this.reg_load(args[0])?;
-                    if !matches!(k_vm, VMValue::String(_)) {
-                        this.write_result(dst, VMValue::String("[map/bad-key] key must be string".to_string()));
-                        return Ok(true);
-                    }
-                    let k = this.load_as_box(args[0])?;
-                    let ret = mb.get(k);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "has" => {
-                    this.validate_args_exact("MapBox.has", args, 1)?;
-                    let k = this.load_as_box(args[0])?;
-                    let ret = mb.has(k);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "delete" => {
-                    this.validate_args_exact("MapBox.delete", args, 1)?;
-                    let k_vm = this.reg_load(args[0])?;
-                    if !matches!(k_vm, VMValue::String(_)) {
-                        this.write_result(dst, VMValue::String("[map/bad-key] key must be string".to_string()));
-                        return Ok(true);
-                    }
-                    let k = this.load_as_box(args[0])?;
-                    let ret = mb.delete(k);
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "len" | "length" | "size" => {
-                    let ret = mb.size();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "keys" => {
-                    let ret = mb.keys();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "values" => {
-                    let ret = mb.values();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                "clear" => {
-                    // Reset map to empty; return a neutral value
-                    let ret = mb.clear();
-                    this.write_result(dst, VMValue::from_nyash_box(ret));
-                    return Ok(true);
-                }
-                _ => {}
+    let recv = this.reg_load(box_val)?;
+    let recv_box_any: Box<dyn NyashBox> = match recv.clone() {
+        VMValue::BoxRef(b) => b.share_box(),
+        other => other.to_nyash_box(),
+    };
+    if let Some(mb) = recv_box_any
+        .as_any()
+        .downcast_ref::<crate::boxes::map_box::MapBox>()
+    {
+        match method {
+            "birth" => {
+                // No-op constructor init for MapBox
+                this.write_void(dst);
+                return Ok(true);
             }
+            // Field bridge: treat getField/setField as get/set with string key
+            "getField" => {
+                this.validate_args_exact("MapBox.getField", args, 1)?;
+                let k_vm = this.reg_load(args[0])?;
+                // Field access expects a String key; otherwise return a stable tag.
+                if !matches!(k_vm, VMValue::String(_)) {
+                    this.write_result(
+                        dst,
+                        VMValue::String("[map/bad-key] field name must be string".to_string()),
+                    );
+                    return Ok(true);
+                }
+                let k = this.load_as_box(args[0])?;
+                let ret = mb.get(k);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "setField" => {
+                this.validate_args_exact("MapBox.setField", args, 2)?;
+                let k_vm = this.reg_load(args[0])?;
+                if !matches!(k_vm, VMValue::String(_)) {
+                    this.write_result(
+                        dst,
+                        VMValue::String("[map/bad-key] field name must be string".to_string()),
+                    );
+                    return Ok(true);
+                }
+                let k = this.load_as_box(args[0])?;
+                let v = this.load_as_box(args[1])?;
+                let ret = mb.set(k, v);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "set" => {
+                this.validate_args_exact("MapBox.set", args, 2)?;
+                let k_vm = this.reg_load(args[0])?;
+                if !matches!(k_vm, VMValue::String(_)) {
+                    this.write_result(
+                        dst,
+                        VMValue::String("[map/bad-key] key must be string".to_string()),
+                    );
+                    return Ok(true);
+                }
+                let k = this.load_as_box(args[0])?;
+                let v = this.load_as_box(args[1])?;
+                let ret = mb.set(k, v);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "get" => {
+                this.validate_args_exact("MapBox.get", args, 1)?;
+                let k_vm = this.reg_load(args[0])?;
+                if !matches!(k_vm, VMValue::String(_)) {
+                    this.write_result(
+                        dst,
+                        VMValue::String("[map/bad-key] key must be string".to_string()),
+                    );
+                    return Ok(true);
+                }
+                let k = this.load_as_box(args[0])?;
+                let ret = mb.get(k);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "has" => {
+                this.validate_args_exact("MapBox.has", args, 1)?;
+                let k = this.load_as_box(args[0])?;
+                let ret = mb.has(k);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "delete" => {
+                this.validate_args_exact("MapBox.delete", args, 1)?;
+                let k_vm = this.reg_load(args[0])?;
+                if !matches!(k_vm, VMValue::String(_)) {
+                    this.write_result(
+                        dst,
+                        VMValue::String("[map/bad-key] key must be string".to_string()),
+                    );
+                    return Ok(true);
+                }
+                let k = this.load_as_box(args[0])?;
+                let ret = mb.delete(k);
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "len" | "length" | "size" => {
+                let ret = mb.size();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "keys" => {
+                let ret = mb.keys();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "values" => {
+                let ret = mb.values();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            "clear" => {
+                // Reset map to empty; return a neutral value
+                let ret = mb.clear();
+                this.write_result(dst, VMValue::from_nyash_box(ret));
+                return Ok(true);
+            }
+            _ => {}
         }
-        Ok(false)
+    }
+    Ok(false)
 }

src/backend/mir_interpreter/handlers/boxes_object_fields.rs

@@ -9,8 +9,8 @@ pub(super) fn try_handle_object_fields(
 ) -> Result<bool, VMError> {
     // Local helpers to bridge NyashValue <-> VMValue for InstanceBox fields
     fn vm_to_nv(v: &VMValue) -> crate::value::NyashValue {
-        use crate::value::NyashValue as NV;
         use super::VMValue as VV;
+        use crate::value::NyashValue as NV;
         match v {
             VV::Integer(i) => NV::Integer(*i),
             VV::Float(f) => NV::Float(*f),
@@ -18,12 +18,12 @@ pub(super) fn try_handle_object_fields(
             VV::String(s) => NV::String(s.clone()),
             VV::Void => NV::Void,
             VV::Future(_) => NV::Void, // not expected in fields
-            VV::BoxRef(_) => NV::Void,  // store minimal; complex object fields are not required here
+            VV::BoxRef(_) => NV::Void, // store minimal; complex object fields are not required here
         }
     }
     fn nv_to_vm(v: &crate::value::NyashValue) -> VMValue {
-        use crate::value::NyashValue as NV;
         use super::VMValue as VV;
+        use crate::value::NyashValue as NV;
         match v {
             NV::Integer(i) => VV::Integer(*i),
             NV::Float(f) => VV::Float(*f),
@@ -48,7 +48,8 @@ pub(super) fn try_handle_object_fields(
 
                     // Create a temporary value to hold the singleton
                     let temp_id = ValueId(999999999); // Temporary ID for singleton
-                    this.regs.insert(temp_id, VMValue::from_nyash_box(Box::new(instance_clone)));
+                    this.regs
+                        .insert(temp_id, VMValue::from_nyash_box(Box::new(instance_clone)));
                     temp_id
                 } else {
                     box_val
@@ -59,18 +60,27 @@ pub(super) fn try_handle_object_fields(
 
             // MapBox special-case: bridge to MapBox.get, with string-only key
             if let Ok(VMValue::BoxRef(bref)) = this.reg_load(actual_box_val) {
-                if bref.as_any().downcast_ref::<crate::boxes::map_box::MapBox>().is_some() {
+                if bref
+                    .as_any()
+                    .downcast_ref::<crate::boxes::map_box::MapBox>()
+                    .is_some()
+                {
                     let key_vm = this.reg_load(args[0])?;
                     if let VMValue::String(_) = key_vm {
                         let k = key_vm.to_nyash_box();
                         let map = bref.share_box();
-                        if let Some(mb) = map.as_any().downcast_ref::<crate::boxes::map_box::MapBox>() {
+                        if let Some(mb) =
+                            map.as_any().downcast_ref::<crate::boxes::map_box::MapBox>()
+                        {
                             let ret = mb.get(k);
                             this.write_result(dst, VMValue::from_nyash_box(ret));
                             return Ok(true);
                         }
                     } else {
-                        this.write_string(dst, "[map/bad-key] field name must be string".to_string());
+                        this.write_string(
+                            dst,
+                            "[map/bad-key] field name must be string".to_string(),
+                        );
                         return Ok(true);
                     }
                 }
@@ -94,15 +104,22 @@ pub(super) fn try_handle_object_fields(
             };
             // Prefer InstanceBox internal storage (structural correctness)
             if let VMValue::BoxRef(bref) = this.reg_load(actual_box_val)? {
-                if let Some(inst) = bref.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                if let Some(inst) = bref
+                    .as_any()
+                    .downcast_ref::<crate::instance_v2::InstanceBox>()
+                {
                     if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
                         eprintln!("[vm-trace] getField instance class={}", inst.class_name);
                     }
                     // Special-case bridge: JsonParser.length -> tokens.length()
                     if inst.class_name == "JsonParser" && fname == "length" {
                         if let Some(tokens_shared) = inst.get_field("tokens") {
-                            let tokens_box: Box<dyn crate::box_trait::NyashBox> = tokens_shared.share_box();
-                            if let Some(arr) = tokens_box.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
+                            let tokens_box: Box<dyn crate::box_trait::NyashBox> =
+                                tokens_shared.share_box();
+                            if let Some(arr) = tokens_box
+                                .as_any()
+                                .downcast_ref::<crate::boxes::array::ArrayBox>()
+                            {
                                 let len_box = arr.length();
                                 this.write_result(dst, VMValue::from_nyash_box(len_box));
                                 return Ok(true);
@@ -112,7 +129,9 @@ pub(super) fn try_handle_object_fields(
                     // First: prefer fields_ng (NyashValue) when present
                     if let Some(nv) = inst.get_field_ng(&fname) {
                         // Dev trace: JsonToken field get
-                        if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") && inst.class_name == "JsonToken" {
+                        if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1")
+                            && inst.class_name == "JsonToken"
+                        {
                             eprintln!("[vm-trace] JsonToken.getField name={} nv={:?}", fname, nv);
                         }
                         // Treat complex Box-like values as "missing" for internal storage so that
@@ -129,13 +148,18 @@ pub(super) fn try_handle_object_fields(
                         );
                         if !is_missing {
                             if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                                eprintln!("[vm-trace] getField internal {}.{} -> {:?}", inst.class_name, fname, nv);
+                                eprintln!(
+                                    "[vm-trace] getField internal {}.{} -> {:?}",
+                                    inst.class_name, fname, nv
+                                );
                             }
                             // Special-case: NV::Box should surface as VMValue::BoxRef
                             if let crate::value::NyashValue::Box(ref arc_m) = nv {
                                 if let Ok(guard) = arc_m.lock() {
-                                    let cloned: Box<dyn crate::box_trait::NyashBox> = guard.clone_box();
-                                    let arc: std::sync::Arc<dyn crate::box_trait::NyashBox> = std::sync::Arc::from(cloned);
+                                    let cloned: Box<dyn crate::box_trait::NyashBox> =
+                                        guard.clone_box();
+                                    let arc: std::sync::Arc<dyn crate::box_trait::NyashBox> =
+                                        std::sync::Arc::from(cloned);
                                     this.write_result(dst, VMValue::BoxRef(arc));
                                 } else {
                                     this.write_void(dst);
@@ -170,8 +194,12 @@ pub(super) fn try_handle_object_fields(
                                     _ => None,
                                 };
                                 if let Some(v) = def {
-                                    if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                                        eprintln!("[vm-trace] getField default JsonScanner.{} -> {:?}", fname, v);
+                                    if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1")
+                                    {
+                                        eprintln!(
+                                            "[vm-trace] getField default JsonScanner.{} -> {:?}",
+                                            fname, v
+                                        );
                                     }
                                     this.write_result(dst, v);
                                     return Ok(true);
@@ -229,10 +257,14 @@ pub(super) fn try_handle_object_fields(
             // JsonScanner fields inside JsonScanner.{is_eof,current,advance}, provide
             // pragmatic defaults to avoid Void comparisons during bring-up.
             if let VMValue::Void = v {
-                let guard_on = std::env::var("NYASH_VM_SCANNER_DEFAULTS").ok().as_deref() == Some("1");
+                let guard_on =
+                    std::env::var("NYASH_VM_SCANNER_DEFAULTS").ok().as_deref() == Some("1");
                 let fn_ctx = this.cur_fn.as_deref().unwrap_or("");
                 if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                    eprintln!("[vm-trace] getField guard_check ctx={} guard_on={} name={}", fn_ctx, guard_on, fname);
+                    eprintln!(
+                        "[vm-trace] getField guard_check ctx={} guard_on={} name={}",
+                        fn_ctx, guard_on, fname
+                    );
                 }
                 if guard_on {
                     let fn_ctx = this.cur_fn.as_deref().unwrap_or("");
@@ -243,7 +275,10 @@ pub(super) fn try_handle_object_fields(
                     if is_scanner_ctx {
                         // Try class-aware default first
                         if let Ok(VMValue::BoxRef(bref2)) = this.reg_load(actual_box_val) {
-                            if let Some(inst2) = bref2.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                            if let Some(inst2) = bref2
+                                .as_any()
+                                .downcast_ref::<crate::instance_v2::InstanceBox>()
+                            {
                                 if inst2.class_name == "JsonScanner" {
                                     let fallback = match fname.as_str() {
                                         "position" | "length" => Some(VMValue::Integer(0)),
@@ -252,8 +287,13 @@ pub(super) fn try_handle_object_fields(
                                         _ => None,
                                     };
                                     if let Some(val) = fallback {
-                                        if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-                                            eprintln!("[vm-trace] getField final_default {} -> {:?}", fname, val);
+                                        if std::env::var("NYASH_VM_TRACE").ok().as_deref()
+                                            == Some("1")
+                                        {
+                                            eprintln!(
+                                                "[vm-trace] getField final_default {} -> {:?}",
+                                                fname, val
+                                            );
                                         }
                                         v = val;
                                     }
@@ -280,7 +320,11 @@ pub(super) fn try_handle_object_fields(
             }
             if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
                 if let VMValue::BoxRef(b) = &v {
-                    eprintln!("[vm-trace] getField legacy {} -> BoxRef({})", fname, b.type_name());
+                    eprintln!(
+                        "[vm-trace] getField legacy {} -> BoxRef({})",
+                        fname,
+                        b.type_name()
+                    );
                 } else {
                     eprintln!("[vm-trace] getField legacy {} -> {:?}", fname, v);
                 }
@@ -299,9 +343,13 @@ pub(super) fn try_handle_object_fields(
                 // class name unknown here; use receiver type name if possible
                 let cls = match this.reg_load(actual_box_val).unwrap_or(VMValue::Void) {
                     VMValue::BoxRef(b) => {
-                        if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                        if let Some(inst) =
+                            b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>()
+                        {
                             inst.class_name.clone()
-                        } else { b.type_name().to_string() }
+                        } else {
+                            b.type_name().to_string()
+                        }
                     }
                     _ => "<unknown>".to_string(),
                 };
@@ -322,7 +370,8 @@ pub(super) fn try_handle_object_fields(
 
                     // Create a temporary value to hold the singleton
                     let temp_id = ValueId(999999998); // Temporary ID for singleton (different from getField)
-                    this.regs.insert(temp_id, VMValue::from_nyash_box(Box::new(instance_clone)));
+                    this.regs
+                        .insert(temp_id, VMValue::from_nyash_box(Box::new(instance_clone)));
                     temp_id
                 } else {
                     box_val
@@ -333,19 +382,28 @@ pub(super) fn try_handle_object_fields(
 
             // MapBox special-case: bridge to MapBox.set, with string-only key
             if let Ok(VMValue::BoxRef(bref)) = this.reg_load(actual_box_val) {
-                if bref.as_any().downcast_ref::<crate::boxes::map_box::MapBox>().is_some() {
+                if bref
+                    .as_any()
+                    .downcast_ref::<crate::boxes::map_box::MapBox>()
+                    .is_some()
+                {
                     let key_vm = this.reg_load(args[0])?;
                     if let VMValue::String(_) = key_vm {
                         let k = key_vm.to_nyash_box();
                         let v = this.reg_load(args[1])?.to_nyash_box();
                         let map = bref.share_box();
-                        if let Some(mb) = map.as_any().downcast_ref::<crate::boxes::map_box::MapBox>() {
+                        if let Some(mb) =
+                            map.as_any().downcast_ref::<crate::boxes::map_box::MapBox>()
+                        {
                             let _ = mb.set(k, v);
                             this.write_void(dst);
                             return Ok(true);
                         }
                     } else {
-                        this.write_string(dst, "[map/bad-key] field name must be string".to_string());
+                        this.write_string(
+                            dst,
+                            "[map/bad-key] field name must be string".to_string(),
+                        );
                         return Ok(true);
                     }
                 }
@@ -358,9 +416,15 @@ pub(super) fn try_handle_object_fields(
             // Dev trace: JsonToken field set
             if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
                 if let VMValue::BoxRef(bref) = this.reg_load(actual_box_val)? {
-                    if let Some(inst) = bref.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                    if let Some(inst) = bref
+                        .as_any()
+                        .downcast_ref::<crate::instance_v2::InstanceBox>()
+                    {
                         if inst.class_name == "JsonToken" {
-                            eprintln!("[vm-trace] JsonToken.setField name={} vmval={:?}", fname, valv);
+                            eprintln!(
+                                "[vm-trace] JsonToken.setField name={} vmval={:?}",
+                                fname, valv
+                            );
                         }
                     }
                 }
@@ -377,9 +441,13 @@ pub(super) fn try_handle_object_fields(
                 };
                 let cls = match this.reg_load(actual_box_val).unwrap_or(VMValue::Void) {
                     VMValue::BoxRef(b) => {
-                        if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                        if let Some(inst) =
+                            b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>()
+                        {
                             inst.class_name.clone()
-                        } else { b.type_name().to_string() }
+                        } else {
+                            b.type_name().to_string()
+                        }
                     }
                     _ => "<unknown>".to_string(),
                 };
@@ -387,28 +455,52 @@ pub(super) fn try_handle_object_fields(
             }
             // Prefer InstanceBox internal storage
             if let VMValue::BoxRef(bref) = this.reg_load(actual_box_val)? {
-                if let Some(inst) = bref.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                if let Some(inst) = bref
+                    .as_any()
+                    .downcast_ref::<crate::instance_v2::InstanceBox>()
+                {
                     // Primitives → 内部保存
-                    if matches!(valv, VMValue::Integer(_) | VMValue::Float(_) | VMValue::Bool(_) | VMValue::String(_) | VMValue::Void) {
+                    if matches!(
+                        valv,
+                        VMValue::Integer(_)
+                            | VMValue::Float(_)
+                            | VMValue::Bool(_)
+                            | VMValue::String(_)
+                            | VMValue::Void
+                    ) {
                         let _ = inst.set_field_ng(fname.clone(), vm_to_nv(&valv));
                         return Ok(true);
                     }
                     // BoxRef のうち、Integer/Float/Bool/String はプリミティブに剥がして内部保存
                     if let VMValue::BoxRef(bx) = &valv {
-                        if let Some(ib) = bx.as_any().downcast_ref::<crate::box_trait::IntegerBox>() {
-                            let _ = inst.set_field_ng(fname.clone(), crate::value::NyashValue::Integer(ib.value));
+                        if let Some(ib) = bx.as_any().downcast_ref::<crate::box_trait::IntegerBox>()
+                        {
+                            let _ = inst.set_field_ng(
+                                fname.clone(),
+                                crate::value::NyashValue::Integer(ib.value),
+                            );
                             return Ok(true);
                         }
                         if let Some(fb) = bx.as_any().downcast_ref::<crate::boxes::FloatBox>() {
-                            let _ = inst.set_field_ng(fname.clone(), crate::value::NyashValue::Float(fb.value));
+                            let _ = inst.set_field_ng(
+                                fname.clone(),
+                                crate::value::NyashValue::Float(fb.value),
+                            );
                             return Ok(true);
                         }
                         if let Some(bb) = bx.as_any().downcast_ref::<crate::box_trait::BoolBox>() {
-                            let _ = inst.set_field_ng(fname.clone(), crate::value::NyashValue::Bool(bb.value));
+                            let _ = inst.set_field_ng(
+                                fname.clone(),
+                                crate::value::NyashValue::Bool(bb.value),
+                            );
                             return Ok(true);
                         }
-                        if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
-                            let _ = inst.set_field_ng(fname.clone(), crate::value::NyashValue::String(sb.value.clone()));
+                        if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                        {
+                            let _ = inst.set_field_ng(
+                                fname.clone(),
+                                crate::value::NyashValue::String(sb.value.clone()),
+                            );
                             return Ok(true);
                         }
                         // For complex Box values (InstanceBox/MapBox/ArrayBox...), store into
@@ -419,10 +511,7 @@ pub(super) fn try_handle_object_fields(
                 }
             }
             let key = this.object_key_for(actual_box_val);
-            this.obj_fields
-                .entry(key)
-                .or_default()
-                .insert(fname, valv);
+            this.obj_fields.entry(key).or_default().insert(fname, valv);
             Ok(true)
         }
         _ => Ok(false),

src/backend/mir_interpreter/handlers/boxes_plugin.rs

@@ -52,7 +52,7 @@ pub(super) fn invoke_plugin_box(
             }
             Err(e) => Err(this.err_with_context(
                 &format!("BoxCall {}.{}", p.box_type, method),
-                &format!("{:?}", e)
+                &format!("{:?}", e),
             )),
         }
     } else if recv_box.type_name() == "StringBox" {
@@ -99,10 +99,7 @@ pub(super) fn invoke_plugin_box(
                 if let Some(arg_id) = args.get(0) {
                     let ch = this.reg_load(*arg_id)?.to_string();
                     let c = ch.chars().next().unwrap_or('\0');
-                    let is_alpha =
-                        ('A'..='Z').contains(&c) ||
-                        ('a'..='z').contains(&c) ||
-                        c == '_';
+                    let is_alpha = ('A'..='Z').contains(&c) || ('a'..='z').contains(&c) || c == '_';
                     this.write_result(dst, VMValue::Bool(is_alpha));
                     Ok(())
                 } else {
@@ -115,14 +112,21 @@ pub(super) fn invoke_plugin_box(
         // Special-case: minimal runtime fallback for common InstanceBox methods when
         // lowered functions are not available (dev robustness). Keeps behavior stable
         // without changing semantics in the normal path.
-        if let Some(inst) = recv_box.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+        if let Some(inst) = recv_box
+            .as_any()
+            .downcast_ref::<crate::instance_v2::InstanceBox>()
+        {
             // Generic current() fallback: if object has integer 'position' and string 'text',
             // return one character at that position (or empty at EOF). This covers JsonScanner
             // and compatible scanners without relying on class name.
             if method == "current" && args.is_empty() {
-                if let Some(crate::value::NyashValue::Integer(pos)) = inst.get_field_ng("position") {
-                    if let Some(crate::value::NyashValue::String(text)) = inst.get_field_ng("text") {
-                        let s = if pos < 0 || (pos as usize) >= text.len() { String::new() } else {
+                if let Some(crate::value::NyashValue::Integer(pos)) = inst.get_field_ng("position")
+                {
+                    if let Some(crate::value::NyashValue::String(text)) = inst.get_field_ng("text")
+                    {
+                        let s = if pos < 0 || (pos as usize) >= text.len() {
+                            String::new()
+                        } else {
                             let bytes = text.as_bytes();
                             let i = pos as usize;
                             let j = (i + 1).min(bytes.len());
@@ -137,7 +141,11 @@ pub(super) fn invoke_plugin_box(
         // Generic toString fallback for any non-plugin box
         if method == "toString" {
             // Map VoidBox.toString → "null" for JSON-friendly semantics
-            let s = if recv_box.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+            let s = if recv_box
+                .as_any()
+                .downcast_ref::<crate::box_trait::VoidBox>()
+                .is_some()
+            {
                 "null".to_string()
             } else {
                 recv_box.to_string_box().value
@@ -148,7 +156,10 @@ pub(super) fn invoke_plugin_box(
         // Minimal runtime fallback for common InstanceBox.is_eof when lowered function is not present.
         // This avoids cross-class leaks and hard errors in union-like flows.
         if method == "is_eof" && args.is_empty() {
-            if let Some(inst) = recv_box.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+            if let Some(inst) = recv_box
+                .as_any()
+                .downcast_ref::<crate::instance_v2::InstanceBox>()
+            {
                 if inst.class_name == "JsonToken" {
                     let is = match inst.get_field_ng("type") {
                         Some(crate::value::NyashValue::String(ref s)) => s == "EOF",
@@ -158,8 +169,14 @@ pub(super) fn invoke_plugin_box(
                     return Ok(());
                 }
                 if inst.class_name == "JsonScanner" {
-                    let pos = match inst.get_field_ng("position") { Some(crate::value::NyashValue::Integer(i)) => i, _ => 0 };
-                    let len = match inst.get_field_ng("length")   { Some(crate::value::NyashValue::Integer(i)) => i, _ => 0 };
+                    let pos = match inst.get_field_ng("position") {
+                        Some(crate::value::NyashValue::Integer(i)) => i,
+                        _ => 0,
+                    };
+                    let len = match inst.get_field_ng("length") {
+                        Some(crate::value::NyashValue::Integer(i)) => i,
+                        _ => 0,
+                    };
                     let is = pos >= len;
                     this.write_result(dst, VMValue::Bool(is));
                     return Ok(());
@@ -167,7 +184,10 @@ pub(super) fn invoke_plugin_box(
             }
         }
         // Dynamic fallback for user-defined InstanceBox: dispatch to lowered function "Class.method/Arity"
-        if let Some(inst) = recv_box.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+        if let Some(inst) = recv_box
+            .as_any()
+            .downcast_ref::<crate::instance_v2::InstanceBox>()
+        {
             let class_name = inst.class_name.clone();
             let arity = args.len(); // function name arity excludes 'me'
             let fname = format!("{}.{}{}", class_name, method, format!("/{}", arity));
@@ -190,10 +210,10 @@ pub(super) fn invoke_plugin_box(
             this.write_string(dst, String::new());
             return Ok(());
         }
-    // VoidBox graceful handling for common container-like methods
-    // Treat null.receiver.* as safe no-ops that return null/0 where appropriate
-    if recv_box.type_name() == "VoidBox" {
-        match method {
+        // VoidBox graceful handling for common container-like methods
+        // Treat null.receiver.* as safe no-ops that return null/0 where appropriate
+        if recv_box.type_name() == "VoidBox" {
+            match method {
                 "object_get" | "array_get" | "toString" => {
                     this.write_void(dst);
                     return Ok(());

src/backend/mir_interpreter/handlers/boxes_string.rs

@@ -7,207 +7,231 @@ pub(super) fn try_handle_string_box(
     method: &str,
     args: &[ValueId],
 ) -> Result<bool, VMError> {
-        if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
-            eprintln!("[vm-trace] try_handle_string_box(method={})", method);
+    if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
+        eprintln!("[vm-trace] try_handle_string_box(method={})", method);
+    }
+    let recv = this.reg_load(box_val)?;
+    // Ultra-fast path: raw VM string receiver for length/size (no boxing at all)
+    if (method == "length" || method == "size")
+        && std::env::var("NYASH_VM_FAST").ok().as_deref() == Some("1")
+    {
+        if let VMValue::String(ref raw) = recv {
+            let use_cp = std::env::var("NYASH_STR_CP").ok().as_deref() == Some("1");
+            let n = if use_cp {
+                raw.chars().count() as i64
+            } else {
+                raw.len() as i64
+            };
+            this.write_result(dst, VMValue::Integer(n));
+            return Ok(true);
         }
-        let recv = this.reg_load(box_val)?;
-        // Ultra-fast path: raw VM string receiver for length/size (no boxing at all)
-        if (method == "length" || method == "size")
-            && std::env::var("NYASH_VM_FAST").ok().as_deref() == Some("1")
-        {
-            if let VMValue::String(ref raw) = recv {
+    }
+    // Handle ONLY when the receiver is actually a string.
+    // Do NOT coerce arbitrary boxes to StringBox (e.g., ArrayBox.length()).
+    let sb_norm_opt: Option<crate::box_trait::StringBox> = match recv.clone() {
+        VMValue::String(s) => Some(crate::box_trait::StringBox::new(s)),
+        VMValue::BoxRef(b) => {
+            if b.as_any()
+                .downcast_ref::<crate::box_trait::StringBox>()
+                .is_some()
+            {
+                Some(b.to_string_box())
+            } else {
+                None
+            }
+        }
+        _ => None,
+    };
+    let Some(sb_norm) = sb_norm_opt else {
+        return Ok(false);
+    };
+    // Only handle known string methods here (receiver is confirmed string)
+    match method {
+        "length" | "size" => {
+            // Bench/profile fast path: return VMValue::Integer directly (avoid boxing overhead)
+            if std::env::var("NYASH_VM_FAST").ok().as_deref() == Some("1") {
                 let use_cp = std::env::var("NYASH_STR_CP").ok().as_deref() == Some("1");
-                let n = if use_cp { raw.chars().count() as i64 } else { raw.len() as i64 };
+                let n = if use_cp {
+                    sb_norm.value.chars().count() as i64
+                } else {
+                    sb_norm.value.len() as i64
+                };
                 this.write_result(dst, VMValue::Integer(n));
                 return Ok(true);
             }
+            let ret = sb_norm.length();
+            this.write_result(dst, VMValue::from_nyash_box(ret));
+            return Ok(true);
         }
-        // Handle ONLY when the receiver is actually a string.
-        // Do NOT coerce arbitrary boxes to StringBox (e.g., ArrayBox.length()).
-        let sb_norm_opt: Option<crate::box_trait::StringBox> = match recv.clone() {
-            VMValue::String(s) => Some(crate::box_trait::StringBox::new(s)),
-            VMValue::BoxRef(b) => {
-                if b.as_any().downcast_ref::<crate::box_trait::StringBox>().is_some() {
-                    Some(b.to_string_box())
-                } else {
-                    None
-                }
-            }
-            _ => None,
-        };
-        let Some(sb_norm) = sb_norm_opt else { return Ok(false) };
-        // Only handle known string methods here (receiver is confirmed string)
-        match method {
-            "length" | "size" => {
-                // Bench/profile fast path: return VMValue::Integer directly (avoid boxing overhead)
-                if std::env::var("NYASH_VM_FAST").ok().as_deref() == Some("1") {
-                    let use_cp = std::env::var("NYASH_STR_CP").ok().as_deref() == Some("1");
-                    let n = if use_cp { sb_norm.value.chars().count() as i64 } else { sb_norm.value.len() as i64 };
-                    this.write_result(dst, VMValue::Integer(n));
-                    return Ok(true);
-                }
-                let ret = sb_norm.length();
-                this.write_result(dst, VMValue::from_nyash_box(ret));
-                return Ok(true);
-            }
-            "replace" => {
-                // replace(old, new) -> string with first occurrence replaced (Rust replace = all; match Core minimal
-                this.validate_args_exact("replace", args, 2)?;
-                let old_s = this.reg_load(args[0])?.to_string();
-                let new_s = this.reg_load(args[1])?.to_string();
-                // Core policy: replace only the first occurrence
-                let out = if let Some(pos) = sb_norm.value.find(&old_s) {
-                    let mut s = String::with_capacity(sb_norm.value.len() + new_s.len());
-                    s.push_str(&sb_norm.value[..pos]);
-                    s.push_str(&new_s);
-                    s.push_str(&sb_norm.value[pos + old_s.len()..]);
-                    s
-                } else {
-                    sb_norm.value.clone()
-                };
-                this.write_result(dst, VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(out))));
-                return Ok(true);
-            }
-            "trim" => {
-                let ret = sb_norm.trim();
-                this.write_result(dst, VMValue::from_nyash_box(ret));
-                return Ok(true);
-            }
-            "indexOf" => {
-                // Support both 1-arg indexOf(search) and 2-arg indexOf(search, fromIndex)
-                let (needle, from_index) = match args.len() {
-                    1 => {
-                        // indexOf(search) - search from beginning
-                        let n = this.reg_load(args[0])?.to_string();
-                        (n, 0)
-                    }
-                    2 => {
-                        // indexOf(search, fromIndex) - search from specified position
-                        let n = this.reg_load(args[0])?.to_string();
-                        let from = this.reg_load(args[1])?.as_integer().unwrap_or(0);
-                        (n, from.max(0) as usize)
-                    }
-                    _ => {
-                        return Err(this.err_invalid(
-                            "indexOf expects 1 or 2 args (search [, fromIndex])"
-                        ));
-                    }
-                };
-
-                // Search for needle starting from from_index
-                let search_str = if from_index >= sb_norm.value.len() {
-                    ""
-                } else {
-                    &sb_norm.value[from_index..]
-                };
-
-                let idx = search_str.find(&needle)
-                    .map(|i| (from_index + i) as i64)
-                    .unwrap_or(-1);
-
-                this.write_result(dst, VMValue::Integer(idx));
-                return Ok(true);
-            }
-            "contains" => {
-                // contains(search) -> boolean (true if found, false otherwise)
-                // Implemented as indexOf(search) >= 0
-                this.validate_args_exact("contains", args, 1)?;
-                let needle = this.reg_load(args[0])?.to_string();
-                let found = sb_norm.value.contains(&needle);
-                this.write_result(dst, VMValue::Bool(found));
-                return Ok(true);
-            }
-            "lastIndexOf" => {
-                // lastIndexOf(substr) -> last index or -1
-                this.validate_args_exact("lastIndexOf", args, 1)?;
-                let needle = this.reg_load(args[0])?.to_string();
-                let idx = sb_norm.value.rfind(&needle).map(|i| i as i64).unwrap_or(-1);
-                this.write_result(dst, VMValue::Integer(idx));
-                return Ok(true);
-            }
-            "stringify" => {
-                // JSON-style stringify for strings: quote and escape common characters
-                let mut quoted = String::with_capacity(sb_norm.value.len() + 2);
-                quoted.push('"');
-                for ch in sb_norm.value.chars() {
-                    match ch {
-                        '"' => quoted.push_str("\\\""),
-                        '\\' => quoted.push_str("\\\\"),
-                        '\n' => quoted.push_str("\\n"),
-                        '\r' => quoted.push_str("\\r"),
-                        '\t' => quoted.push_str("\\t"),
-                        c if c.is_control() => quoted.push(' '),
-                        c => quoted.push(c),
-                    }
-                }
-                quoted.push('"');
-                this.write_result(dst, VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(quoted))));
-                return Ok(true);
-            }
-            "substring" => {
-                // Support both 1-arg (start to end) and 2-arg (start, end) forms
-                let (s_idx, e_idx) = match args.len() {
-                    1 => {
-                        // substring(start) - from start to end of string
-                        let s = this.reg_load(args[0])?.as_integer().unwrap_or(0);
-                        let len = sb_norm.value.chars().count() as i64;
-                        (s, len)
-                    }
-                    2 => {
-                        // substring(start, end) - half-open interval [start, end)
-                        let s = this.reg_load(args[0])?.as_integer().unwrap_or(0);
-                        let e = this.reg_load(args[1])?.as_integer().unwrap_or(0);
-                        (s, e)
-                    }
-                    _ => {
-                        return Err(this.err_invalid(
-                            "substring expects 1 or 2 args (start [, end])"
-                        ));
-                    }
-                };
-                let len = sb_norm.value.chars().count() as i64;
-                let start = s_idx.max(0).min(len) as usize;
-                let end = e_idx.max(start as i64).min(len) as usize;
-                let chars: Vec<char> = sb_norm.value.chars().collect();
-                let sub: String = chars[start..end].iter().collect();
-                this.write_result(dst, VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(sub))));
-                return Ok(true);
-            }
-            "concat" => {
-                this.validate_args_exact("concat", args, 1)?;
-                let rhs = this.reg_load(args[0])?;
-                let new_s = format!("{}{}", sb_norm.value, rhs.to_string());
-                this.write_result(dst, VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(new_s))));
-                return Ok(true);
-            }
-            "is_digit_char" => {
-                // Accept either 0-arg (use first char of receiver) or 1-arg (string/char to test)
-                let ch_opt = if args.is_empty() {
-                    sb_norm.value.chars().next()
-                } else if args.len() == 1 {
-                    let s = this.reg_load(args[0])?.to_string();
-                    s.chars().next()
-                } else {
-                    return Err(this.err_invalid("is_digit_char expects 0 or 1 arg"));
-                };
-                let is_digit = ch_opt.map(|c| c.is_ascii_digit()).unwrap_or(false);
-                this.write_result(dst, VMValue::Bool(is_digit));
-                return Ok(true);
-            }
-            "is_hex_digit_char" => {
-                let ch_opt = if args.is_empty() {
-                        sb_norm.value.chars().next()
-                    } else if args.len() == 1 {
-                        let s = this.reg_load(args[0])?.to_string();
-                        s.chars().next()
-                    } else {
-                        return Err(this.err_invalid("is_hex_digit_char expects 0 or 1 arg"));
-                    };
-                    let is_hex = ch_opt.map(|c| c.is_ascii_hexdigit()).unwrap_or(false);
-                    this.write_result(dst, VMValue::Bool(is_hex));
-                    return Ok(true);
-            }
-            _ => {}
+        "replace" => {
+            // replace(old, new) -> string with first occurrence replaced (Rust replace = all; match Core minimal
+            this.validate_args_exact("replace", args, 2)?;
+            let old_s = this.reg_load(args[0])?.to_string();
+            let new_s = this.reg_load(args[1])?.to_string();
+            // Core policy: replace only the first occurrence
+            let out = if let Some(pos) = sb_norm.value.find(&old_s) {
+                let mut s = String::with_capacity(sb_norm.value.len() + new_s.len());
+                s.push_str(&sb_norm.value[..pos]);
+                s.push_str(&new_s);
+                s.push_str(&sb_norm.value[pos + old_s.len()..]);
+                s
+            } else {
+                sb_norm.value.clone()
+            };
+            this.write_result(
+                dst,
+                VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(out))),
+            );
+            return Ok(true);
         }
-        Ok(false)
+        "trim" => {
+            let ret = sb_norm.trim();
+            this.write_result(dst, VMValue::from_nyash_box(ret));
+            return Ok(true);
+        }
+        "indexOf" => {
+            // Support both 1-arg indexOf(search) and 2-arg indexOf(search, fromIndex)
+            let (needle, from_index) = match args.len() {
+                1 => {
+                    // indexOf(search) - search from beginning
+                    let n = this.reg_load(args[0])?.to_string();
+                    (n, 0)
+                }
+                2 => {
+                    // indexOf(search, fromIndex) - search from specified position
+                    let n = this.reg_load(args[0])?.to_string();
+                    let from = this.reg_load(args[1])?.as_integer().unwrap_or(0);
+                    (n, from.max(0) as usize)
+                }
+                _ => {
+                    return Err(
+                        this.err_invalid("indexOf expects 1 or 2 args (search [, fromIndex])")
+                    );
+                }
+            };
+
+            // Search for needle starting from from_index
+            let search_str = if from_index >= sb_norm.value.len() {
+                ""
+            } else {
+                &sb_norm.value[from_index..]
+            };
+
+            let idx = search_str
+                .find(&needle)
+                .map(|i| (from_index + i) as i64)
+                .unwrap_or(-1);
+
+            this.write_result(dst, VMValue::Integer(idx));
+            return Ok(true);
+        }
+        "contains" => {
+            // contains(search) -> boolean (true if found, false otherwise)
+            // Implemented as indexOf(search) >= 0
+            this.validate_args_exact("contains", args, 1)?;
+            let needle = this.reg_load(args[0])?.to_string();
+            let found = sb_norm.value.contains(&needle);
+            this.write_result(dst, VMValue::Bool(found));
+            return Ok(true);
+        }
+        "lastIndexOf" => {
+            // lastIndexOf(substr) -> last index or -1
+            this.validate_args_exact("lastIndexOf", args, 1)?;
+            let needle = this.reg_load(args[0])?.to_string();
+            let idx = sb_norm.value.rfind(&needle).map(|i| i as i64).unwrap_or(-1);
+            this.write_result(dst, VMValue::Integer(idx));
+            return Ok(true);
+        }
+        "stringify" => {
+            // JSON-style stringify for strings: quote and escape common characters
+            let mut quoted = String::with_capacity(sb_norm.value.len() + 2);
+            quoted.push('"');
+            for ch in sb_norm.value.chars() {
+                match ch {
+                    '"' => quoted.push_str("\\\""),
+                    '\\' => quoted.push_str("\\\\"),
+                    '\n' => quoted.push_str("\\n"),
+                    '\r' => quoted.push_str("\\r"),
+                    '\t' => quoted.push_str("\\t"),
+                    c if c.is_control() => quoted.push(' '),
+                    c => quoted.push(c),
+                }
+            }
+            quoted.push('"');
+            this.write_result(
+                dst,
+                VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(quoted))),
+            );
+            return Ok(true);
+        }
+        "substring" => {
+            // Support both 1-arg (start to end) and 2-arg (start, end) forms
+            let (s_idx, e_idx) = match args.len() {
+                1 => {
+                    // substring(start) - from start to end of string
+                    let s = this.reg_load(args[0])?.as_integer().unwrap_or(0);
+                    let len = sb_norm.value.chars().count() as i64;
+                    (s, len)
+                }
+                2 => {
+                    // substring(start, end) - half-open interval [start, end)
+                    let s = this.reg_load(args[0])?.as_integer().unwrap_or(0);
+                    let e = this.reg_load(args[1])?.as_integer().unwrap_or(0);
+                    (s, e)
+                }
+                _ => {
+                    return Err(this.err_invalid("substring expects 1 or 2 args (start [, end])"));
+                }
+            };
+            let len = sb_norm.value.chars().count() as i64;
+            let start = s_idx.max(0).min(len) as usize;
+            let end = e_idx.max(start as i64).min(len) as usize;
+            let chars: Vec<char> = sb_norm.value.chars().collect();
+            let sub: String = chars[start..end].iter().collect();
+            this.write_result(
+                dst,
+                VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(sub))),
+            );
+            return Ok(true);
+        }
+        "concat" => {
+            this.validate_args_exact("concat", args, 1)?;
+            let rhs = this.reg_load(args[0])?;
+            let new_s = format!("{}{}", sb_norm.value, rhs.to_string());
+            this.write_result(
+                dst,
+                VMValue::from_nyash_box(Box::new(crate::box_trait::StringBox::new(new_s))),
+            );
+            return Ok(true);
+        }
+        "is_digit_char" => {
+            // Accept either 0-arg (use first char of receiver) or 1-arg (string/char to test)
+            let ch_opt = if args.is_empty() {
+                sb_norm.value.chars().next()
+            } else if args.len() == 1 {
+                let s = this.reg_load(args[0])?.to_string();
+                s.chars().next()
+            } else {
+                return Err(this.err_invalid("is_digit_char expects 0 or 1 arg"));
+            };
+            let is_digit = ch_opt.map(|c| c.is_ascii_digit()).unwrap_or(false);
+            this.write_result(dst, VMValue::Bool(is_digit));
+            return Ok(true);
+        }
+        "is_hex_digit_char" => {
+            let ch_opt = if args.is_empty() {
+                sb_norm.value.chars().next()
+            } else if args.len() == 1 {
+                let s = this.reg_load(args[0])?.to_string();
+                s.chars().next()
+            } else {
+                return Err(this.err_invalid("is_hex_digit_char expects 0 or 1 arg"));
+            };
+            let is_hex = ch_opt.map(|c| c.is_ascii_hexdigit()).unwrap_or(false);
+            this.write_result(dst, VMValue::Bool(is_hex));
+            return Ok(true);
+        }
+        _ => {}
+    }
+    Ok(false)
 }

src/backend/mir_interpreter/handlers/calls/externs.rs

@@ -22,9 +22,15 @@ impl MirInterpreter {
                     match &v {
                         VMValue::Void => println!("null"),
                         VMValue::BoxRef(bx) => {
-                            if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                            if bx
+                                .as_any()
+                                .downcast_ref::<crate::box_trait::VoidBox>()
+                                .is_some()
+                            {
                                 println!("null");
-                            } else if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
+                            } else if let Some(sb) =
+                                bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                            {
                                 println!("{}", sb.value);
                             } else {
                                 println!("{}", v.to_string());
@@ -56,8 +62,12 @@ impl MirInterpreter {
                 };
                 panic!("{}", msg);
             }
-            "hostbridge.extern_invoke" => Err(self.err_invalid("hostbridge.extern_invoke should be routed via extern_provider_dispatch")),
-            _ => Err(self.err_with_context("extern function", &format!("Unknown: {}", extern_name))),
+            "hostbridge.extern_invoke" => Err(self.err_invalid(
+                "hostbridge.extern_invoke should be routed via extern_provider_dispatch",
+            )),
+            _ => {
+                Err(self.err_with_context("extern function", &format!("Unknown: {}", extern_name)))
+            }
         }
     }
 }

src/backend/mir_interpreter/handlers/calls/global.rs

@@ -12,7 +12,9 @@ impl MirInterpreter {
         // Module-local/global function: execute by function table if present (use original name)
         if let Some(func) = self.functions.get(func_name).cloned() {
             let mut argv: Vec<VMValue> = Vec::with_capacity(args.len());
-            for a in args { argv.push(self.reg_load(*a)?); }
+            for a in args {
+                argv.push(self.reg_load(*a)?);
+            }
             return self.exec_function_inner(&func, Some(&argv));
         }
 
@@ -60,13 +62,19 @@ impl MirInterpreter {
                     let s = self.reg_load(*a0)?.to_string();
                     let opts = crate::host_providers::llvm_codegen::Opts {
                         out: None,
-                        nyrt: std::env::var("NYASH_EMIT_EXE_NYRT").ok().map(std::path::PathBuf::from),
-                        opt_level: std::env::var("HAKO_LLVM_OPT_LEVEL").ok().or(Some("0".to_string())),
+                        nyrt: std::env::var("NYASH_EMIT_EXE_NYRT")
+                            .ok()
+                            .map(std::path::PathBuf::from),
+                        opt_level: std::env::var("HAKO_LLVM_OPT_LEVEL")
+                            .ok()
+                            .or(Some("0".to_string())),
                         timeout_ms: None,
                     };
                     match crate::host_providers::llvm_codegen::mir_json_to_object(&s, opts) {
                         Ok(p) => Ok(VMValue::String(p.to_string_lossy().into_owned())),
-                        Err(e) => Err(self.err_with_context("env.codegen.emit_object", &e.to_string())),
+                        Err(e) => {
+                            Err(self.err_with_context("env.codegen.emit_object", &e.to_string()))
+                        }
                     }
                 } else {
                     Err(self.err_invalid("env.codegen.emit_object expects 1 arg"))
@@ -74,32 +82,51 @@ impl MirInterpreter {
             }
             "env.codegen.link_object" | "env.codegen.link_object/3" => {
                 // C-API route only; args[2] is expected to be an ArrayBox [obj_path, exe_out?]
-                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1") ||
-                   std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() != Some("1") {
+                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1")
+                    || std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+                        .ok()
+                        .as_deref()
+                        != Some("1")
+                {
                     return Err(self.err_invalid("env.codegen.link_object: C-API route disabled"));
                 }
-                if args.len() < 3 { return Err(self.err_arg_count("env.codegen.link_object", 3, args.len())); }
+                if args.len() < 3 {
+                    return Err(self.err_arg_count("env.codegen.link_object", 3, args.len()));
+                }
                 let v = self.reg_load(args[2])?;
                 let (obj_path, exe_out) = match v {
                     VMValue::BoxRef(b) => {
-                        if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
-                            let idx0: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(0));
+                        if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>()
+                        {
+                            let idx0: Box<dyn crate::box_trait::NyashBox> =
+                                Box::new(crate::box_trait::IntegerBox::new(0));
                             let elem0 = ab.get(idx0).to_string_box().value;
                             let mut exe: Option<String> = None;
-                            let idx1: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(1));
+                            let idx1: Box<dyn crate::box_trait::NyashBox> =
+                                Box::new(crate::box_trait::IntegerBox::new(1));
                             let e1 = ab.get(idx1).to_string_box().value;
-                            if !e1.is_empty() { exe = Some(e1); }
+                            if !e1.is_empty() {
+                                exe = Some(e1);
+                            }
                             (elem0, exe)
-                        } else { (b.to_string_box().value, None) }
+                        } else {
+                            (b.to_string_box().value, None)
+                        }
                     }
                     _ => (v.to_string(), None),
                 };
                 let extra = std::env::var("HAKO_AOT_LDFLAGS").ok();
                 let obj = std::path::PathBuf::from(obj_path);
-                let exe = exe_out.map(std::path::PathBuf::from).unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
-                match crate::host_providers::llvm_codegen::link_object_capi(&obj, &exe, extra.as_deref()) {
+                let exe = exe_out
+                    .map(std::path::PathBuf::from)
+                    .unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
+                match crate::host_providers::llvm_codegen::link_object_capi(
+                    &obj,
+                    &exe,
+                    extra.as_deref(),
+                ) {
                     Ok(()) => Ok(VMValue::String(exe.to_string_lossy().into_owned())),
-                    Err(e) => Err(self.err_with_context("env.codegen.link_object", &e.to_string()))
+                    Err(e) => Err(self.err_with_context("env.codegen.link_object", &e.to_string())),
                 }
             }
             "nyash.builtin.error" => {

src/backend/mir_interpreter/handlers/calls/method.rs

@@ -22,18 +22,40 @@ impl MirInterpreter {
                             if let Some(block) = func.blocks.get(&bb) {
                                 let mut last_recv: Option<ValueId> = None;
                                 for inst in &block.instructions {
-                                    if let crate::mir::MirInstruction::NewBox { dst, box_type, .. } = inst {
-                                        if box_type == box_name { last_recv = Some(*dst); }
+                                    if let crate::mir::MirInstruction::NewBox {
+                                        dst,
+                                        box_type,
+                                        ..
+                                    } = inst
+                                    {
+                                        if box_type == box_name {
+                                            last_recv = Some(*dst);
+                                        }
                                     }
                                 }
                                 if let Some(rid) = last_recv {
-                                    if let Ok(v) = self.reg_load(rid) { v } else { return Err(e); }
+                                    if let Ok(v) = self.reg_load(rid) {
+                                        v
+                                    } else {
+                                        return Err(e);
+                                    }
                                 } else {
                                     // Dev fallback (guarded): use args[0] as surrogate receiver if explicitly allowed
-                                    let tolerate = std::env::var("NYASH_VM_RECV_ARG_FALLBACK").ok().as_deref() == Some("1")
-                                        || std::env::var("NYASH_VM_TOLERATE_VOID").ok().as_deref() == Some("1");
-                                    if tolerate { if let Some(a0) = args.get(0) { self.reg_load(*a0)? } else { return Err(e); } }
-                                    else { return Err(e); }
+                                    let tolerate = std::env::var("NYASH_VM_RECV_ARG_FALLBACK")
+                                        .ok()
+                                        .as_deref()
+                                        == Some("1")
+                                        || std::env::var("NYASH_VM_TOLERATE_VOID").ok().as_deref()
+                                            == Some("1");
+                                    if tolerate {
+                                        if let Some(a0) = args.get(0) {
+                                            self.reg_load(*a0)?
+                                        } else {
+                                            return Err(e);
+                                        }
+                                    } else {
+                                        return Err(e);
+                                    }
                                 }
                             } else {
                                 return Err(e);
@@ -43,10 +65,18 @@ impl MirInterpreter {
                         }
                     } else {
                         // Dev fallback (guarded): use args[0] as surrogate receiver if explicitly allowed
-                        let tolerate = std::env::var("NYASH_VM_RECV_ARG_FALLBACK").ok().as_deref() == Some("1")
+                        let tolerate = std::env::var("NYASH_VM_RECV_ARG_FALLBACK").ok().as_deref()
+                            == Some("1")
                             || std::env::var("NYASH_VM_TOLERATE_VOID").ok().as_deref() == Some("1");
-                        if tolerate { if let Some(a0) = args.get(0) { self.reg_load(*a0)? } else { return Err(e); } }
-                        else { return Err(e); }
+                        if tolerate {
+                            if let Some(a0) = args.get(0) {
+                                self.reg_load(*a0)?
+                            } else {
+                                return Err(e);
+                            }
+                        } else {
+                            return Err(e);
+                        }
                     }
                 }
             };
@@ -57,7 +87,9 @@ impl MirInterpreter {
                 // ArrayBox bridge
                 if let Some(arr) = bx.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
                     match method {
-                        "birth" => { return Ok(VMValue::Void); }
+                        "birth" => {
+                            return Ok(VMValue::Void);
+                        }
                         "push" => {
                             if let Some(a0) = args.get(0) {
                                 let v = self.load_as_box(*a0)?;
@@ -162,14 +194,20 @@ impl MirInterpreter {
                 "substring" => {
                     let start = if let Some(a0) = args.get(0) {
                         self.reg_load(*a0)?.as_integer().unwrap_or(0)
-                    } else { 0 };
+                    } else {
+                        0
+                    };
                     let end = if let Some(a1) = args.get(1) {
                         self.reg_load(*a1)?.as_integer().unwrap_or(s.len() as i64)
-                    } else { s.len() as i64 };
+                    } else {
+                        s.len() as i64
+                    };
                     let len = s.len() as i64;
                     let i0 = start.max(0).min(len) as usize;
                     let i1 = end.max(0).min(len) as usize;
-                    if i0 > i1 { return Ok(VMValue::String(String::new())); }
+                    if i0 > i1 {
+                        return Ok(VMValue::String(String::new()));
+                    }
                     // Note: operating on bytes; Nyash strings are UTF‑8, but tests are ASCII only here
                     let bytes = s.as_bytes();
                     let sub = String::from_utf8(bytes[i0..i1].to_vec()).unwrap_or_default();
@@ -209,8 +247,7 @@ impl MirInterpreter {
                         "is_space" => {
                             if let Some(arg_id) = args.get(0) {
                                 let ch = self.reg_load(*arg_id)?.to_string();
-                                let is_ws =
-                                    ch == " " || ch == "\t" || ch == "\n" || ch == "\r";
+                                let is_ws = ch == " " || ch == "\t" || ch == "\n" || ch == "\r";
                                 Ok(VMValue::Bool(is_ws))
                             } else {
                                 Err(self.err_invalid("is_space requires 1 argument"))
@@ -221,10 +258,9 @@ impl MirInterpreter {
                             if let Some(arg_id) = args.get(0) {
                                 let ch = self.reg_load(*arg_id)?.to_string();
                                 let c = ch.chars().next().unwrap_or('\0');
-                                let is_alpha =
-                                    ('A'..='Z').contains(&c) ||
-                                    ('a'..='z').contains(&c) ||
-                                    c == '_';
+                                let is_alpha = ('A'..='Z').contains(&c)
+                                    || ('a'..='z').contains(&c)
+                                    || c == '_';
                                 Ok(VMValue::Bool(is_alpha))
                             } else {
                                 Err(self.err_invalid("is_alpha requires 1 argument"))
@@ -234,8 +270,8 @@ impl MirInterpreter {
                     }
                 } else if let Some(p) = box_ref
                     .as_any()
-                    .downcast_ref::<crate::runtime::plugin_loader_v2::PluginBoxV2>()
-                {
+                    .downcast_ref::<crate::runtime::plugin_loader_v2::PluginBoxV2>(
+                ) {
                     let host = crate::runtime::plugin_loader_unified::get_global_plugin_host();
                     let host = host.read().unwrap();
                     let argv = self.load_args_as_boxes(args)?;
@@ -249,14 +285,17 @@ impl MirInterpreter {
                         Ok(None) => Ok(VMValue::Void),
                         Err(e) => Err(self.err_with_context(
                             &format!("Plugin method {}.{}", p.box_type, method),
-                            &format!("{:?}", e)
+                            &format!("{:?}", e),
                         )),
                     }
                 } else {
                     Err(self.err_method_not_found(&box_ref.type_name(), method))
                 }
             }
-            _ => Err(self.err_with_context("method call", &format!("{} not supported on {:?}", method, receiver))),
+            _ => Err(self.err_with_context(
+                "method call",
+                &format!("{} not supported on {:?}", method, receiver),
+            )),
         }
     }
 }

src/backend/mir_interpreter/handlers/calls/mod.rs

@@ -4,9 +4,9 @@
 
 use super::*;
 
+mod externs;
 mod global;
 mod method;
-mod externs;
 // legacy by-name resolver has been removed (Phase 2 complete)
 
 impl MirInterpreter {
@@ -19,18 +19,43 @@ impl MirInterpreter {
     ) -> Result<(), VMError> {
         if std::env::var("HAKO_CABI_TRACE").ok().as_deref() == Some("1") {
             match callee {
-                Some(Callee::Global(n)) => eprintln!("[hb:path] call Callee::Global {} argc={}", n, args.len()),
-                Some(Callee::Method{ box_name, method, ..}) => eprintln!("[hb:path] call Callee::Method {}.{} argc={}", box_name, method, args.len()),
-                Some(Callee::Constructor{ box_type }) => eprintln!("[hb:path] call Callee::Constructor {} argc={}", box_type, args.len()),
-                Some(Callee::Closure{ .. }) => eprintln!("[hb:path] call Callee::Closure argc={}", args.len()),
-                Some(Callee::Value(_)) => eprintln!("[hb:path] call Callee::Value argc={}", args.len()),
-                Some(Callee::Extern(n)) => eprintln!("[hb:path] call Callee::Extern {} argc={}", n, args.len()),
-                None => eprintln!("[hb:path] call Legacy func_id={:?} argc={}", func, args.len()),
+                Some(Callee::Global(n)) => {
+                    eprintln!("[hb:path] call Callee::Global {} argc={}", n, args.len())
+                }
+                Some(Callee::Method {
+                    box_name, method, ..
+                }) => eprintln!(
+                    "[hb:path] call Callee::Method {}.{} argc={}",
+                    box_name,
+                    method,
+                    args.len()
+                ),
+                Some(Callee::Constructor { box_type }) => eprintln!(
+                    "[hb:path] call Callee::Constructor {} argc={}",
+                    box_type,
+                    args.len()
+                ),
+                Some(Callee::Closure { .. }) => {
+                    eprintln!("[hb:path] call Callee::Closure argc={}", args.len())
+                }
+                Some(Callee::Value(_)) => {
+                    eprintln!("[hb:path] call Callee::Value argc={}", args.len())
+                }
+                Some(Callee::Extern(n)) => {
+                    eprintln!("[hb:path] call Callee::Extern {} argc={}", n, args.len())
+                }
+                None => eprintln!(
+                    "[hb:path] call Legacy func_id={:?} argc={}",
+                    func,
+                    args.len()
+                ),
             }
         }
         // SSOT fast-path: route hostbridge.extern_invoke to extern dispatcher regardless of resolution form
         if let Some(Callee::Global(func_name)) = callee {
-            if func_name == "hostbridge.extern_invoke" || func_name.starts_with("hostbridge.extern_invoke/") {
+            if func_name == "hostbridge.extern_invoke"
+                || func_name.starts_with("hostbridge.extern_invoke/")
+            {
                 let v = self.execute_extern_function("hostbridge.extern_invoke", args)?;
                 self.write_result(dst, v);
                 return Ok(());
@@ -44,7 +69,9 @@ impl MirInterpreter {
             if let VMValue::String(ref s) = name_val {
                 if let Some(f) = self.functions.get(s).cloned() {
                     let mut argv: Vec<VMValue> = Vec::with_capacity(args.len());
-                    for a in args { argv.push(self.reg_load(*a)?); }
+                    for a in args {
+                        argv.push(self.reg_load(*a)?);
+                    }
                     self.exec_function_inner(&f, Some(&argv))?
                 } else {
                     return Err(self.err_with_context("call", &format!(
@@ -53,7 +80,10 @@ impl MirInterpreter {
                     )));
                 }
             } else {
-                return Err(self.err_with_context("call", "by-name calls unsupported without Callee attachment"));
+                return Err(self.err_with_context(
+                    "call",
+                    "by-name calls unsupported without Callee attachment",
+                ));
             }
         };
         self.write_result(dst, call_result);
@@ -67,10 +97,15 @@ impl MirInterpreter {
     ) -> Result<VMValue, VMError> {
         match callee {
             Callee::Global(func_name) => self.execute_global_function(func_name, args),
-            Callee::Method { box_name, method, receiver, .. } => {
-                self.execute_method_callee(box_name, method, receiver, args)
+            Callee::Method {
+                box_name,
+                method,
+                receiver,
+                ..
+            } => self.execute_method_callee(box_name, method, receiver, args),
+            Callee::Constructor { box_type } => {
+                Err(self.err_unsupported(&format!("Constructor calls for {}", box_type)))
             }
-            Callee::Constructor { box_type } => Err(self.err_unsupported(&format!("Constructor calls for {}", box_type))),
             Callee::Closure { .. } => Err(self.err_unsupported("Closure creation in VM")),
             Callee::Value(func_val_id) => {
                 let _ = self.reg_load(*func_val_id)?;
@@ -79,5 +114,4 @@ impl MirInterpreter {
             Callee::Extern(extern_name) => self.execute_extern_function(extern_name, args),
         }
     }
-
 }

src/backend/mir_interpreter/handlers/extern_provider.rs

@@ -10,8 +10,12 @@ impl MirInterpreter {
             let key = format!("{}.{}", target, method);
             for pat in flt.split(',') {
                 let p = pat.trim();
-                if p.is_empty() { continue; }
-                if p == method || p == key { return true; }
+                if p.is_empty() {
+                    continue;
+                }
+                if p == method || p == key {
+                    return true;
+                }
             }
             return false;
         }
@@ -23,7 +27,9 @@ impl MirInterpreter {
                 if let JsonValue::Object(ref mut m) = v {
                     if !m.contains_key("version") {
                         m.insert("version".to_string(), JsonValue::from(0));
-                        if let Ok(out) = serde_json::to_string(&v) { return out; }
+                        if let Ok(out) = serde_json::to_string(&v) {
+                            return out;
+                        }
                     }
                 }
                 s.to_string()
@@ -64,9 +70,15 @@ impl MirInterpreter {
                             VMValue::Void => println!("null"),
                             VMValue::String(s) => println!("{}", s),
                             VMValue::BoxRef(bx) => {
-                                if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                                if bx
+                                    .as_any()
+                                    .downcast_ref::<crate::box_trait::VoidBox>()
+                                    .is_some()
+                                {
                                     println!("null");
-                                } else if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
+                                } else if let Some(sb) =
+                                    bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                                {
                                     println!("{}", sb.value);
                                 } else {
                                     println!("{}", v.to_string());
@@ -90,9 +102,15 @@ impl MirInterpreter {
                             VMValue::Void => eprintln!("[warn] null"),
                             VMValue::String(s) => eprintln!("[warn] {}", s),
                             VMValue::BoxRef(bx) => {
-                                if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                                if bx
+                                    .as_any()
+                                    .downcast_ref::<crate::box_trait::VoidBox>()
+                                    .is_some()
+                                {
                                     eprintln!("[warn] null");
-                                } else if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
+                                } else if let Some(sb) =
+                                    bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                                {
                                     eprintln!("[warn] {}", sb.value);
                                 } else {
                                     eprintln!("[warn] {}", v.to_string());
@@ -116,9 +134,15 @@ impl MirInterpreter {
                             VMValue::Void => eprintln!("[error] null"),
                             VMValue::String(s) => eprintln!("[error] {}", s),
                             VMValue::BoxRef(bx) => {
-                                if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
+                                if bx
+                                    .as_any()
+                                    .downcast_ref::<crate::box_trait::VoidBox>()
+                                    .is_some()
+                                {
                                     eprintln!("[error] null");
-                                } else if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
+                                } else if let Some(sb) =
+                                    bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                                {
                                     eprintln!("[error] {}", sb.value);
                                 } else {
                                     eprintln!("[error] {}", v.to_string());
@@ -140,15 +164,29 @@ impl MirInterpreter {
                 if std::env::var("HAKO_V1_EXTERN_PROVIDER").ok().as_deref() == Some("1") {
                     return Some(Ok(VMValue::String(String::new())));
                 }
-                if args.is_empty() { return Some(Err(ErrorBuilder::arg_count_mismatch("env.mirbuilder.emit", 1, args.len()))); }
-                let program_json = match self.reg_load(args[0]) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) };
+                if args.is_empty() {
+                    return Some(Err(ErrorBuilder::arg_count_mismatch(
+                        "env.mirbuilder.emit",
+                        1,
+                        args.len(),
+                    )));
+                }
+                let program_json = match self.reg_load(args[0]) {
+                    Ok(v) => v.to_string(),
+                    Err(e) => return Some(Err(e)),
+                };
 
                 // Phase 21.8: Read imports from environment variable if present
                 let imports = if let Ok(imports_json) = std::env::var("HAKO_MIRBUILDER_IMPORTS") {
-                    match serde_json::from_str::<std::collections::HashMap<String, String>>(&imports_json) {
+                    match serde_json::from_str::<std::collections::HashMap<String, String>>(
+                        &imports_json,
+                    ) {
                         Ok(map) => map,
                         Err(e) => {
-                            eprintln!("[mirbuilder/imports] Failed to parse HAKO_MIRBUILDER_IMPORTS: {}", e);
+                            eprintln!(
+                                "[mirbuilder/imports] Failed to parse HAKO_MIRBUILDER_IMPORTS: {}",
+                                e
+                            );
                             std::collections::HashMap::new()
                         }
                     }
@@ -156,10 +194,17 @@ impl MirInterpreter {
                     std::collections::HashMap::new()
                 };
 
-                let res = match crate::host_providers::mir_builder::program_json_to_mir_json_with_imports(&program_json, imports) {
-                    Ok(s) => Ok(VMValue::String(Self::patch_mir_json_version(&s))),
-                    Err(e) => Err(ErrorBuilder::with_context("env.mirbuilder.emit", &e.to_string())),
-                };
+                let res =
+                    match crate::host_providers::mir_builder::program_json_to_mir_json_with_imports(
+                        &program_json,
+                        imports,
+                    ) {
+                        Ok(s) => Ok(VMValue::String(Self::patch_mir_json_version(&s))),
+                        Err(e) => Err(ErrorBuilder::with_context(
+                            "env.mirbuilder.emit",
+                            &e.to_string(),
+                        )),
+                    };
                 Some(res)
             }
             "env.codegen.emit_object" => {
@@ -167,55 +212,114 @@ impl MirInterpreter {
                 if std::env::var("HAKO_V1_EXTERN_PROVIDER").ok().as_deref() == Some("1") {
                     return Some(Ok(VMValue::String(String::new())));
                 }
-                if args.is_empty() { return Some(Err(ErrorBuilder::arg_count_mismatch("env.codegen.emit_object", 1, args.len()))); }
-                let mir_json_raw = match self.reg_load(args[0]) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) };
+                if args.is_empty() {
+                    return Some(Err(ErrorBuilder::arg_count_mismatch(
+                        "env.codegen.emit_object",
+                        1,
+                        args.len(),
+                    )));
+                }
+                let mir_json_raw = match self.reg_load(args[0]) {
+                    Ok(v) => v.to_string(),
+                    Err(e) => return Some(Err(e)),
+                };
                 // Normalize to v1 shape if missing/legacy (prevents harness NoneType errors)
                 let mir_json = Self::patch_mir_json_version(&mir_json_raw);
                 let opts = crate::host_providers::llvm_codegen::Opts {
                     out: None,
-                    nyrt: std::env::var("NYASH_EMIT_EXE_NYRT").ok().map(std::path::PathBuf::from),
-                    opt_level: std::env::var("HAKO_LLVM_OPT_LEVEL").ok().or(Some("0".to_string())),
+                    nyrt: std::env::var("NYASH_EMIT_EXE_NYRT")
+                        .ok()
+                        .map(std::path::PathBuf::from),
+                    opt_level: std::env::var("HAKO_LLVM_OPT_LEVEL")
+                        .ok()
+                        .or(Some("0".to_string())),
                     timeout_ms: None,
                 };
-                let res = match crate::host_providers::llvm_codegen::mir_json_to_object(&mir_json, opts) {
+                let res = match crate::host_providers::llvm_codegen::mir_json_to_object(
+                    &mir_json, opts,
+                ) {
                     Ok(p) => Ok(VMValue::String(p.to_string_lossy().into_owned())),
-                    Err(e) => Err(ErrorBuilder::with_context("env.codegen.emit_object", &e.to_string())),
+                    Err(e) => Err(ErrorBuilder::with_context(
+                        "env.codegen.emit_object",
+                        &e.to_string(),
+                    )),
                 };
                 Some(res)
             }
             "env.codegen.link_object" => {
                 // Only supported on C-API route; expect 1 or 2 args: obj_path [, exe_out]
                 let obj_path = match args.get(0) {
-                    Some(v) => match self.reg_load(*v) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) },
-                    None => return Some(Err(self.err_invalid("env.codegen.link_object expects 1+ args"))),
+                    Some(v) => match self.reg_load(*v) {
+                        Ok(v) => v.to_string(),
+                        Err(e) => return Some(Err(e)),
+                    },
+                    None => {
+                        return Some(Err(
+                            self.err_invalid("env.codegen.link_object expects 1+ args")
+                        ))
+                    }
                 };
                 let exe_out = match args.get(1) {
-                    Some(v) => Some(match self.reg_load(*v) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) }),
+                    Some(v) => Some(match self.reg_load(*v) {
+                        Ok(v) => v.to_string(),
+                        Err(e) => return Some(Err(e)),
+                    }),
                     None => None,
                 };
                 let extra = std::env::var("HAKO_AOT_LDFLAGS").ok();
                 // Require C-API toggles
-                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1") ||
-                   std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() != Some("1") {
-                    return Some(Err(ErrorBuilder::invalid_instruction("env.codegen.link_object: C-API route disabled")));
+                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1")
+                    || std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+                        .ok()
+                        .as_deref()
+                        != Some("1")
+                {
+                    return Some(Err(ErrorBuilder::invalid_instruction(
+                        "env.codegen.link_object: C-API route disabled",
+                    )));
                 }
                 let obj = std::path::PathBuf::from(obj_path);
-                let exe = exe_out.map(std::path::PathBuf::from).unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
-                match crate::host_providers::llvm_codegen::link_object_capi(&obj, &exe, extra.as_deref()) {
+                let exe = exe_out
+                    .map(std::path::PathBuf::from)
+                    .unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
+                match crate::host_providers::llvm_codegen::link_object_capi(
+                    &obj,
+                    &exe,
+                    extra.as_deref(),
+                ) {
                     Ok(()) => Some(Ok(VMValue::String(exe.to_string_lossy().into_owned()))),
-                    Err(e) => Some(Err(ErrorBuilder::with_context("env.codegen.link_object", &e.to_string()))),
+                    Err(e) => Some(Err(ErrorBuilder::with_context(
+                        "env.codegen.link_object",
+                        &e.to_string(),
+                    ))),
                 }
             }
             // Environment
             "env.get" => {
-                if args.is_empty() { return Some(Err(ErrorBuilder::arg_count_mismatch("env.get", 1, args.len()))); }
-                let key = match self.reg_load(args[0]) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) };
+                if args.is_empty() {
+                    return Some(Err(ErrorBuilder::arg_count_mismatch(
+                        "env.get",
+                        1,
+                        args.len(),
+                    )));
+                }
+                let key = match self.reg_load(args[0]) {
+                    Ok(v) => v.to_string(),
+                    Err(e) => return Some(Err(e)),
+                };
                 let val = std::env::var(&key).ok();
-                Some(Ok(match val { Some(s) => VMValue::String(s), None => VMValue::Void }))
+                Some(Ok(match val {
+                    Some(s) => VMValue::String(s),
+                    None => VMValue::Void,
+                }))
             }
             "env.set" => {
                 if args.len() < 2 {
-                    return Some(Err(ErrorBuilder::arg_count_mismatch("env.set", 2, args.len())));
+                    return Some(Err(ErrorBuilder::arg_count_mismatch(
+                        "env.set",
+                        2,
+                        args.len(),
+                    )));
                 }
                 let key = match self.reg_load(args[0]) {
                     Ok(v) => v.to_string(),
@@ -247,24 +351,24 @@ impl MirInterpreter {
                         }
                     }
                 } else {
-                    return Some(Err(self.err_invalid(
-                        "env.box_introspect.kind expects 1 arg",
-                    )));
+                    return Some(Err(
+                        self.err_invalid("env.box_introspect.kind expects 1 arg")
+                    ));
                 }
 
                 #[cfg(all(feature = "plugins", not(target_arch = "wasm32")))]
                 let result = plugin_loader_v2::handle_box_introspect("kind", &collected);
                 #[cfg(any(not(feature = "plugins"), target_arch = "wasm32"))]
-                let result: crate::bid::BidResult<Option<Box<dyn crate::box_trait::NyashBox>>> =
-                    Err(crate::bid::BidError::PluginError);
+                let result: crate::bid::BidResult<
+                    Option<Box<dyn crate::box_trait::NyashBox>>,
+                > = Err(crate::bid::BidError::PluginError);
 
                 match result {
                     Ok(Some(b)) => Some(Ok(VMValue::BoxRef(Arc::from(b)))),
                     Ok(None) => Some(Ok(VMValue::Void)),
-                    Err(e) => Some(Err(self.err_with_context(
-                        "env.box_introspect.kind",
-                        &format!("{:?}", e),
-                    ))),
+                    Err(e) => Some(Err(
+                        self.err_with_context("env.box_introspect.kind", &format!("{:?}", e))
+                    )),
                 }
             }
             "hostbridge.extern_invoke" => {
@@ -272,17 +376,30 @@ impl MirInterpreter {
                     eprintln!("[hb:entry:provider] hostbridge.extern_invoke");
                 }
                 if args.len() < 2 {
-                    return Some(Err(self.err_invalid("extern_invoke expects at least 2 args")));
+                    return Some(Err(
+                        self.err_invalid("extern_invoke expects at least 2 args")
+                    ));
                 }
-                let name = match self.reg_load(args[0]) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) };
-                let method = match self.reg_load(args[1]) { Ok(v) => v.to_string(), Err(e) => return Some(Err(e)) };
+                let name = match self.reg_load(args[0]) {
+                    Ok(v) => v.to_string(),
+                    Err(e) => return Some(Err(e)),
+                };
+                let method = match self.reg_load(args[1]) {
+                    Ok(v) => v.to_string(),
+                    Err(e) => return Some(Err(e)),
+                };
                 // Extract first payload arg (optional)
                 let mut first_arg_str: Option<String> = None;
                 if let Some(a2) = args.get(2) {
-                    let v = match self.reg_load(*a2) { Ok(v) => v, Err(e) => return Some(Err(e)) };
+                    let v = match self.reg_load(*a2) {
+                        Ok(v) => v,
+                        Err(e) => return Some(Err(e)),
+                    };
                     match v {
                         VMValue::BoxRef(b) => {
-                            if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
+                            if let Some(ab) =
+                                b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>()
+                            {
                                 let idx: Box<dyn crate::box_trait::NyashBox> =
                                     Box::new(crate::box_trait::IntegerBox::new(0));
                                 let elem = ab.get(idx);
@@ -299,16 +416,27 @@ impl MirInterpreter {
                     eprintln!("[hb:dispatch:provider] {} {}", name, method);
                 }
                 let out = match (name.as_str(), method.as_str()) {
-                    ("env.codegen", "link_object") if std::env::var("HAKO_CABI_TRACE").ok().as_deref() == Some("1") => {
+                    ("env.codegen", "link_object")
+                        if std::env::var("HAKO_CABI_TRACE").ok().as_deref() == Some("1") =>
+                    {
                         // Trace payload shape before actual handling
                         if let Some(a2) = args.get(2) {
-                            let v = match self.reg_load(*a2) { Ok(v) => v, Err(_) => VMValue::Void };
+                            let v = match self.reg_load(*a2) {
+                                Ok(v) => v,
+                                Err(_) => VMValue::Void,
+                            };
                             match &v {
                                 VMValue::BoxRef(b) => {
-                                    if b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>().is_some() {
+                                    if b.as_any()
+                                        .downcast_ref::<crate::boxes::array::ArrayBox>()
+                                        .is_some()
+                                    {
                                         eprintln!("[hb:provider:args] link_object third=ArrayBox");
                                     } else {
-                                        eprintln!("[hb:provider:args] link_object third=BoxRef({})", b.type_name());
+                                        eprintln!(
+                                            "[hb:provider:args] link_object third=BoxRef({})",
+                                            b.type_name()
+                                        );
                                     }
                                 }
                                 other => {
@@ -327,13 +455,19 @@ impl MirInterpreter {
                             };
                             match v {
                                 VMValue::BoxRef(b) => {
-                                    if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
-                                        let idx0: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(0));
+                                    if let Some(ab) =
+                                        b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>()
+                                    {
+                                        let idx0: Box<dyn crate::box_trait::NyashBox> =
+                                            Box::new(crate::box_trait::IntegerBox::new(0));
                                         let elem0 = ab.get(idx0).to_string_box().value;
                                         let mut exe: Option<String> = None;
-                                        let idx1: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(1));
+                                        let idx1: Box<dyn crate::box_trait::NyashBox> =
+                                            Box::new(crate::box_trait::IntegerBox::new(1));
                                         let e1 = ab.get(idx1).to_string_box().value;
-                                        if !e1.is_empty() { exe = Some(e1); }
+                                        if !e1.is_empty() {
+                                            exe = Some(e1);
+                                        }
                                         (elem0, exe)
                                     } else {
                                         (b.to_string_box().value, None)
@@ -342,25 +476,47 @@ impl MirInterpreter {
                                 _ => (v.to_string(), None),
                             }
                         } else {
-                            return Some(Err(self.err_invalid("extern_invoke env.codegen.link_object expects args array")));
+                            return Some(Err(self.err_invalid(
+                                "extern_invoke env.codegen.link_object expects args array",
+                            )));
                         };
-                        if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1") ||
-                           std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() != Some("1") {
-                            return Some(Err(ErrorBuilder::invalid_instruction("env.codegen.link_object: C-API route disabled")));
+                        if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1")
+                            || std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+                                .ok()
+                                .as_deref()
+                                != Some("1")
+                        {
+                            return Some(Err(ErrorBuilder::invalid_instruction(
+                                "env.codegen.link_object: C-API route disabled",
+                            )));
                         }
                         let extra = std::env::var("HAKO_AOT_LDFLAGS").ok();
                         let obj = std::path::PathBuf::from(objs);
-                        let exe = exe_out.map(std::path::PathBuf::from).unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
-                        match crate::host_providers::llvm_codegen::link_object_capi(&obj, &exe, extra.as_deref()) {
+                        let exe = exe_out
+                            .map(std::path::PathBuf::from)
+                            .unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
+                        match crate::host_providers::llvm_codegen::link_object_capi(
+                            &obj,
+                            &exe,
+                            extra.as_deref(),
+                        ) {
                             Ok(()) => Ok(VMValue::String(exe.to_string_lossy().into_owned())),
-                            Err(e) => Err(ErrorBuilder::with_context("env.codegen.link_object", &e.to_string()))
+                            Err(e) => Err(ErrorBuilder::with_context(
+                                "env.codegen.link_object",
+                                &e.to_string(),
+                            )),
                         }
                     }
                     ("env.mirbuilder", "emit") => {
                         if let Some(s) = first_arg_str {
                             // Phase 21.8: Read imports from environment variable if present
-                            let imports = if let Ok(imports_json) = std::env::var("HAKO_MIRBUILDER_IMPORTS") {
-                                match serde_json::from_str::<std::collections::HashMap<String, String>>(&imports_json) {
+                            let imports = if let Ok(imports_json) =
+                                std::env::var("HAKO_MIRBUILDER_IMPORTS")
+                            {
+                                match serde_json::from_str::<
+                                    std::collections::HashMap<String, String>,
+                                >(&imports_json)
+                                {
                                     Ok(map) => map,
                                     Err(e) => {
                                         eprintln!("[mirbuilder/imports] Failed to parse HAKO_MIRBUILDER_IMPORTS: {}", e);
@@ -383,16 +539,21 @@ impl MirInterpreter {
                         if let Some(s) = first_arg_str {
                             let opts = crate::host_providers::llvm_codegen::Opts {
                                 out: None,
-                                nyrt: std::env::var("NYASH_EMIT_EXE_NYRT").ok().map(std::path::PathBuf::from),
+                                nyrt: std::env::var("NYASH_EMIT_EXE_NYRT")
+                                    .ok()
+                                    .map(std::path::PathBuf::from),
                                 opt_level: std::env::var("HAKO_LLVM_OPT_LEVEL").ok(),
                                 timeout_ms: None,
                             };
-                            match crate::host_providers::llvm_codegen::mir_json_to_object(&s, opts) {
+                            match crate::host_providers::llvm_codegen::mir_json_to_object(&s, opts)
+                            {
                                 Ok(p) => Ok(VMValue::String(p.to_string_lossy().into_owned())),
-                                Err(e) => Err(self.err_with_context("env.codegen.emit_object", &e.to_string())),
+                                Err(e) => Err(self
+                                    .err_with_context("env.codegen.emit_object", &e.to_string())),
                             }
                         } else {
-                            Err(self.err_invalid("extern_invoke env.codegen.emit_object expects 1 arg"))
+                            Err(self
+                                .err_invalid("extern_invoke env.codegen.emit_object expects 1 arg"))
                         }
                     }
                     ("env.codegen", "link_object") => {
@@ -408,12 +569,18 @@ impl MirInterpreter {
                             };
                             match v {
                                 VMValue::BoxRef(b) => {
-                                    if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
-                                        let idx0: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(0));
+                                    if let Some(ab) =
+                                        b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>()
+                                    {
+                                        let idx0: Box<dyn crate::box_trait::NyashBox> =
+                                            Box::new(crate::box_trait::IntegerBox::new(0));
                                         obj_s = Some(ab.get(idx0).to_string_box().value);
-                                        let idx1: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(1));
+                                        let idx1: Box<dyn crate::box_trait::NyashBox> =
+                                            Box::new(crate::box_trait::IntegerBox::new(1));
                                         let s1 = ab.get(idx1).to_string_box().value;
-                                        if !s1.is_empty() { exe_s = Some(s1); }
+                                        if !s1.is_empty() {
+                                            exe_s = Some(s1);
+                                        }
                                     } else {
                                         obj_s = Some(b.to_string_box().value);
                                     }
@@ -426,18 +593,37 @@ impl MirInterpreter {
                         }
                         let objs = match obj_s {
                             Some(s) => s,
-                            None => return Some(Err(self.err_invalid("extern_invoke env.codegen.link_object expects args"))),
+                            None => {
+                                return Some(Err(self.err_invalid(
+                                    "extern_invoke env.codegen.link_object expects args",
+                                )))
+                            }
                         };
-                        if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1") ||
-                           std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() != Some("1") {
-                            return Some(Err(ErrorBuilder::invalid_instruction("env.codegen.link_object: C-API route disabled")));
+                        if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1")
+                            || std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+                                .ok()
+                                .as_deref()
+                                != Some("1")
+                        {
+                            return Some(Err(ErrorBuilder::invalid_instruction(
+                                "env.codegen.link_object: C-API route disabled",
+                            )));
                         }
                         let extra = std::env::var("HAKO_AOT_LDFLAGS").ok();
                         let obj = std::path::PathBuf::from(objs);
-                        let exe = exe_s.map(std::path::PathBuf::from).unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
-                        match crate::host_providers::llvm_codegen::link_object_capi(&obj, &exe, extra.as_deref()) {
+                        let exe = exe_s
+                            .map(std::path::PathBuf::from)
+                            .unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
+                        match crate::host_providers::llvm_codegen::link_object_capi(
+                            &obj,
+                            &exe,
+                            extra.as_deref(),
+                        ) {
                             Ok(()) => Ok(VMValue::String(exe.to_string_lossy().into_owned())),
-                            Err(e) => Err(ErrorBuilder::with_context("env.codegen.link_object", &e.to_string()))
+                            Err(e) => Err(ErrorBuilder::with_context(
+                                "env.codegen.link_object",
+                                &e.to_string(),
+                            )),
                         }
                     }
                     ("env.box_introspect", "kind") => {
@@ -487,9 +673,7 @@ impl MirInterpreter {
                                     }
                                 }
                                 other => {
-                                    if std::env::var("NYASH_BOX_INTROSPECT_TRACE")
-                                        .ok()
-                                        .as_deref()
+                                    if std::env::var("NYASH_BOX_INTROSPECT_TRACE").ok().as_deref()
                                         == Some("1")
                                     {
                                         eprintln!(
@@ -509,16 +693,15 @@ impl MirInterpreter {
                         #[cfg(all(feature = "plugins", not(target_arch = "wasm32")))]
                         let result = plugin_loader_v2::handle_box_introspect("kind", &collected);
                         #[cfg(any(not(feature = "plugins"), target_arch = "wasm32"))]
-                        let result: crate::bid::BidResult<Option<Box<dyn NyashBox>>> =
-                            Err(crate::bid::BidError::PluginError);
+                        let result: crate::bid::BidResult<
+                            Option<Box<dyn NyashBox>>,
+                        > = Err(crate::bid::BidError::PluginError);
 
                         match result {
                             Ok(Some(b)) => Ok(VMValue::BoxRef(Arc::from(b))),
                             Ok(None) => Ok(VMValue::Void),
-                            Err(e) => Err(self.err_with_context(
-                                "env.box_introspect.kind",
-                                &format!("{:?}", e),
-                            )),
+                            Err(e) => Err(self
+                                .err_with_context("env.box_introspect.kind", &format!("{:?}", e))),
                         }
                     }
                     _ => {
@@ -529,7 +712,7 @@ impl MirInterpreter {
                             "hostbridge.extern_invoke unsupported for {}.{} [provider] (check extern_provider_dispatch / env.* handlers)",
                             name, method
                         )))
-                    },
+                    }
                 };
                 Some(out)
             }

src/backend/mir_interpreter/handlers/externals.rs

@@ -10,7 +10,9 @@ impl MirInterpreter {
                 if let JsonValue::Object(ref mut m) = v {
                     if !m.contains_key("version") {
                         m.insert("version".to_string(), JsonValue::from(0));
-                        if let Ok(out) = serde_json::to_string(&v) { return out; }
+                        if let Ok(out) = serde_json::to_string(&v) {
+                            return out;
+                        }
                     }
                 }
                 s.to_string()
@@ -52,23 +54,47 @@ impl MirInterpreter {
                 if let Some(a0) = args.get(0) {
                     let v = self.reg_load(*a0)?;
                     // Dev-only: mirror print-trace for extern console.log
-                    if Self::print_trace_enabled() { self.print_trace_emit(&v); }
+                    if Self::print_trace_enabled() {
+                        self.print_trace_emit(&v);
+                    }
                     // Treat VM Void and BoxRef(VoidBox) as JSON null for dev ergonomics
                     match &v {
-                        VMValue::Void => { println!("null"); self.write_void(dst); return Ok(()); }
+                        VMValue::Void => {
+                            println!("null");
+                            self.write_void(dst);
+                            return Ok(());
+                        }
                         VMValue::BoxRef(bx) => {
-                            if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
-                                println!("null"); self.write_void(dst); return Ok(());
+                            if bx
+                                .as_any()
+                                .downcast_ref::<crate::box_trait::VoidBox>()
+                                .is_some()
+                            {
+                                println!("null");
+                                self.write_void(dst);
+                                return Ok(());
                             }
-                            if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
-                                println!("{}", sb.value); self.write_void(dst); return Ok(());
+                            if let Some(sb) =
+                                bx.as_any().downcast_ref::<crate::box_trait::StringBox>()
+                            {
+                                println!("{}", sb.value);
+                                self.write_void(dst);
+                                return Ok(());
                             }
                         }
-                        VMValue::String(s) => { println!("{}", s); self.write_void(dst); return Ok(()); }
+                        VMValue::String(s) => {
+                            println!("{}", s);
+                            self.write_void(dst);
+                            return Ok(());
+                        }
                         _ => {}
                     }
                     // Operator Box (Stringify) – dev flag gated
-                    if std::env::var("NYASH_OPERATOR_BOX_STRINGIFY").ok().as_deref() == Some("1") {
+                    if std::env::var("NYASH_OPERATOR_BOX_STRINGIFY")
+                        .ok()
+                        .as_deref()
+                        == Some("1")
+                    {
                         if let Some(op) = self.functions.get("StringifyOperator.apply/1").cloned() {
                             let out = self.exec_function_inner(&op, Some(&[v.clone()]))?;
                             println!("{}", out.to_string());
@@ -151,20 +177,28 @@ impl MirInterpreter {
                 Ok(())
             }
             ("env.mirbuilder", "emit") => {
-                let ret = self.extern_provider_dispatch("env.mirbuilder.emit", args).unwrap_or(Ok(VMValue::Void))?;
+                let ret = self
+                    .extern_provider_dispatch("env.mirbuilder.emit", args)
+                    .unwrap_or(Ok(VMValue::Void))?;
                 self.write_result(dst, ret);
                 Ok(())
             }
             ("env.codegen", "emit_object") => {
-                let ret = self.extern_provider_dispatch("env.codegen.emit_object", args).unwrap_or(Ok(VMValue::Void))?;
+                let ret = self
+                    .extern_provider_dispatch("env.codegen.emit_object", args)
+                    .unwrap_or(Ok(VMValue::Void))?;
                 self.write_result(dst, ret);
                 Ok(())
             }
             ("env.codegen", "link_object") => {
                 // Args in third param (ArrayBox): [obj_path, exe_out?]
                 // Note: This branch is used for ExternCall form; provider toggles must be ON.
-                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1") ||
-                   std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() != Some("1") {
+                if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() != Some("1")
+                    || std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+                        .ok()
+                        .as_deref()
+                        != Some("1")
+                {
                     return Err(self.err_invalid("env.codegen.link_object: C-API route disabled"));
                 }
                 // Extract array payload
@@ -172,13 +206,19 @@ impl MirInterpreter {
                     let v = self.reg_load(*a2)?;
                     match v {
                         VMValue::BoxRef(b) => {
-                            if let Some(ab) = b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>() {
-                                let idx0: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(0));
+                            if let Some(ab) =
+                                b.as_any().downcast_ref::<crate::boxes::array::ArrayBox>()
+                            {
+                                let idx0: Box<dyn crate::box_trait::NyashBox> =
+                                    Box::new(crate::box_trait::IntegerBox::new(0));
                                 let elem0 = ab.get(idx0).to_string_box().value;
                                 let mut exe: Option<String> = None;
-                                let idx1: Box<dyn crate::box_trait::NyashBox> = Box::new(crate::box_trait::IntegerBox::new(1));
+                                let idx1: Box<dyn crate::box_trait::NyashBox> =
+                                    Box::new(crate::box_trait::IntegerBox::new(1));
                                 let e1 = ab.get(idx1).to_string_box().value;
-                                if !e1.is_empty() { exe = Some(e1); }
+                                if !e1.is_empty() {
+                                    exe = Some(e1);
+                                }
                                 (elem0, exe)
                             } else {
                                 (b.to_string_box().value, None)
@@ -187,13 +227,18 @@ impl MirInterpreter {
                         _ => (v.to_string(), None),
                     }
                 } else {
-                    return Err(self.err_invalid("extern_invoke env.codegen.link_object expects args array"));
+                    return Err(self
+                        .err_invalid("extern_invoke env.codegen.link_object expects args array"));
                 };
                 let extra = std::env::var("HAKO_AOT_LDFLAGS").ok();
                 let obj = std::path::PathBuf::from(obj_path);
-                let exe = exe_out.map(std::path::PathBuf::from).unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
+                let exe = exe_out
+                    .map(std::path::PathBuf::from)
+                    .unwrap_or_else(|| std::env::temp_dir().join("hako_link_out.exe"));
                 crate::host_providers::llvm_codegen::link_object_capi(&obj, &exe, extra.as_deref())
-                    .map_err(|e| self.err_with_context("env.codegen.link_object", &e.to_string()))?;
+                    .map_err(|e| {
+                        self.err_with_context("env.codegen.link_object", &e.to_string())
+                    })?;
                 self.write_result(dst, VMValue::String(exe.to_string_lossy().into_owned()));
                 Ok(())
             }
@@ -208,17 +253,18 @@ impl MirInterpreter {
             ("hostbridge", "extern_invoke") => {
                 if let Some(res) = self.extern_provider_dispatch("hostbridge.extern_invoke", args) {
                     match res {
-                        Ok(v) => { self.write_result(dst, v); }
-                        Err(e) => { return Err(e); }
+                        Ok(v) => {
+                            self.write_result(dst, v);
+                        }
+                        Err(e) => {
+                            return Err(e);
+                        }
                     }
                     return Ok(());
                 }
                 return Err(self.err_invalid("hostbridge.extern_invoke unsupported [externals]"));
             }
-            _ => Err(self.err_invalid(format!(
-                "ExternCall {}.{} not supported",
-                iface, method
-            ))),
+            _ => Err(self.err_invalid(format!("ExternCall {}.{} not supported", iface, method))),
         }
     }
 }

src/backend/mir_interpreter/handlers/misc.rs

@@ -13,16 +13,28 @@ impl MirInterpreter {
         let v = self.reg_load(value)?;
         // Align with calls.rs behavior: Void/BoxRef(VoidBox) prints as null; raw String/StringBox unquoted
         match &v {
-            VMValue::Void => { println!("null"); return Ok(()); }
+            VMValue::Void => {
+                println!("null");
+                return Ok(());
+            }
             VMValue::BoxRef(bx) => {
-                if bx.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() {
-                    println!("null"); return Ok(());
+                if bx
+                    .as_any()
+                    .downcast_ref::<crate::box_trait::VoidBox>()
+                    .is_some()
+                {
+                    println!("null");
+                    return Ok(());
                 }
                 if let Some(sb) = bx.as_any().downcast_ref::<crate::box_trait::StringBox>() {
-                    println!("{}", sb.value); return Ok(());
+                    println!("{}", sb.value);
+                    return Ok(());
                 }
             }
-            VMValue::String(s) => { println!("{}", s); return Ok(()); }
+            VMValue::String(s) => {
+                println!("{}", s);
+                return Ok(());
+            }
             _ => {}
         }
         println!("{}", v.to_string());

src/backend/mir_interpreter/handlers/mod.rs

@@ -3,9 +3,7 @@ use super::*;
 // VM dispatch trace macro (used across handlers)
 macro_rules! trace_dispatch {
     ($method:expr, $handler:expr) => {
-        if $method == "length"
-            && std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1")
-        {
+        if $method == "length" && std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1") {
             eprintln!("[vm-trace] length dispatch handler={}", $handler);
         }
     };
@@ -14,15 +12,15 @@ macro_rules! trace_dispatch {
 mod arithmetic;
 mod boxes;
 mod boxes_array;
-mod boxes_string;
+mod boxes_instance;
 mod boxes_map;
 mod boxes_object_fields;
-mod boxes_instance;
 mod boxes_plugin;
+mod boxes_string;
 mod boxes_void_guards;
 mod calls;
-mod externals;
 mod extern_provider;
+mod externals;
 mod memory;
 mod misc;
 
@@ -90,10 +88,7 @@ impl MirInterpreter {
             }
             MirInstruction::DebugLog { message, values } => {
                 // Dev-only: MIR-level debug logging (no new values defined).
-                if std::env::var("NYASH_MIR_DEBUG_LOG")
-                    .ok()
-                    .as_deref() == Some("1")
-                {
+                if std::env::var("NYASH_MIR_DEBUG_LOG").ok().as_deref() == Some("1") {
                     eprint!("[MIR-LOG] {}:", message);
                     for vid in values {
                         let v = self.reg_load(*vid).unwrap_or(VMValue::Void);

src/backend/mir_interpreter/helpers.rs

@@ -8,10 +8,26 @@ impl MirInterpreter {
         match v {
             VMValue::Void => "void",
             VMValue::BoxRef(b) => {
-                if b.as_any().downcast_ref::<crate::boxes::null_box::NullBox>().is_some() { "null" }
-                else if b.as_any().downcast_ref::<crate::boxes::missing_box::MissingBox>().is_some() { "missing" }
-                else if b.as_any().downcast_ref::<crate::box_trait::VoidBox>().is_some() { "void" }
-                else { "" }
+                if b.as_any()
+                    .downcast_ref::<crate::boxes::null_box::NullBox>()
+                    .is_some()
+                {
+                    "null"
+                } else if b
+                    .as_any()
+                    .downcast_ref::<crate::boxes::missing_box::MissingBox>()
+                    .is_some()
+                {
+                    "missing"
+                } else if b
+                    .as_any()
+                    .downcast_ref::<crate::box_trait::VoidBox>()
+                    .is_some()
+                {
+                    "void"
+                } else {
+                    ""
+                }
             }
             _ => "",
         }
@@ -23,11 +39,7 @@ impl MirInterpreter {
                 if std::env::var("NYASH_VM_TRACE").ok().as_deref() == Some("1")
                     || std::env::var("NYASH_VM_TRACE_EXEC").ok().as_deref() == Some("1")
                 {
-                    let keys: Vec<String> = self
-                        .regs
-                        .keys()
-                        .map(|k| format!("{:?}", k))
-                        .collect();
+                    let keys: Vec<String> = self.regs.keys().map(|k| format!("{:?}", k)).collect();
                     eprintln!(
                         "[vm-trace] reg_load undefined id={:?} fn={} last_block={:?} last_inst={:?} regs={}",
                         id,
@@ -39,8 +51,16 @@ impl MirInterpreter {
                 }
                 // Dev-time safety valve: tolerate undefined registers as Void when enabled
                 let tolerate = std::env::var("NYASH_VM_TOLERATE_VOID").ok().as_deref() == Some("1")
-                    || std::env::var("HAKO_PHI_VERIFY").ok().map(|v| v.to_ascii_lowercase()).map(|v| v=="1"||v=="true"||v=="on").unwrap_or(false)
-                    || std::env::var("NYASH_PHI_VERIFY").ok().map(|v| v.to_ascii_lowercase()).map(|v| v=="1"||v=="true"||v=="on").unwrap_or(false);
+                    || std::env::var("HAKO_PHI_VERIFY")
+                        .ok()
+                        .map(|v| v.to_ascii_lowercase())
+                        .map(|v| v == "1" || v == "true" || v == "on")
+                        .unwrap_or(false)
+                    || std::env::var("NYASH_PHI_VERIFY")
+                        .ok()
+                        .map(|v| v.to_ascii_lowercase())
+                        .map(|v| v == "1" || v == "true" || v == "on")
+                        .unwrap_or(false);
                 if tolerate {
                     return Ok(VMValue::Void);
                 }
@@ -87,21 +107,43 @@ impl MirInterpreter {
                 v
             };
             (norm(a), norm(b))
-        } else { (a, b) };
+        } else {
+            (a, b)
+        };
         // Dev: nullish trace for binop
         if crate::config::env::null_missing_box_enabled() && Self::box_trace_enabled() {
-            let (ak, bk) = (crate::backend::abi_util::tag_of_vm(&a), crate::backend::abi_util::tag_of_vm(&b));
+            let (ak, bk) = (
+                crate::backend::abi_util::tag_of_vm(&a),
+                crate::backend::abi_util::tag_of_vm(&b),
+            );
             let (an, bn) = (Self::tag_nullish(&a), Self::tag_nullish(&b));
-            let op_s = match op { BinaryOp::Add=>"Add", BinaryOp::Sub=>"Sub", BinaryOp::Mul=>"Mul", BinaryOp::Div=>"Div", BinaryOp::Mod=>"Mod", BinaryOp::BitAnd=>"BitAnd", BinaryOp::BitOr=>"BitOr", BinaryOp::BitXor=>"BitXor", BinaryOp::And=>"And", BinaryOp::Or=>"Or", BinaryOp::Shl=>"Shl", BinaryOp::Shr=>"Shr" };
+            let op_s = match op {
+                BinaryOp::Add => "Add",
+                BinaryOp::Sub => "Sub",
+                BinaryOp::Mul => "Mul",
+                BinaryOp::Div => "Div",
+                BinaryOp::Mod => "Mod",
+                BinaryOp::BitAnd => "BitAnd",
+                BinaryOp::BitOr => "BitOr",
+                BinaryOp::BitXor => "BitXor",
+                BinaryOp::And => "And",
+                BinaryOp::Or => "Or",
+                BinaryOp::Shl => "Shl",
+                BinaryOp::Shr => "Shr",
+            };
             eprintln!("{{\"ev\":\"binop\",\"op\":\"{}\",\"a_k\":\"{}\",\"b_k\":\"{}\",\"a_n\":\"{}\",\"b_n\":\"{}\"}}", op_s, ak, bk, an, bn);
         }
         Ok(match (op, a, b) {
             // Dev-only safety valves for Add (guarded by tolerance or --dev):
             // - Treat Void as 0 for numeric +
             // - Treat Void as empty string for string +
-            (Add, VMValue::Void, Integer(y)) | (Add, Integer(y), VMValue::Void) if tolerate => Integer(y),
+            (Add, VMValue::Void, Integer(y)) | (Add, Integer(y), VMValue::Void) if tolerate => {
+                Integer(y)
+            }
             (Add, VMValue::Void, Float(y)) | (Add, Float(y), VMValue::Void) if tolerate => Float(y),
-            (Add, String(s), VMValue::Void) | (Add, VMValue::Void, String(s)) if tolerate => String(s),
+            (Add, String(s), VMValue::Void) | (Add, VMValue::Void, String(s)) if tolerate => {
+                String(s)
+            }
             // Dev-only safety valve for Sub (guarded): treat Void as 0
             (Sub, Integer(x), VMValue::Void) if tolerate => Integer(x),
             (Sub, VMValue::Void, Integer(y)) if tolerate => Integer(0 - y),
@@ -129,7 +171,7 @@ impl MirInterpreter {
             (BitOr, Integer(x), Integer(y)) => Integer(x | y),
             (BitXor, Integer(x), Integer(y)) => Integer(x ^ y),
             (And, VMValue::Bool(x), VMValue::Bool(y)) => VMValue::Bool(x && y),
-            (Or,  VMValue::Bool(x), VMValue::Bool(y)) => VMValue::Bool(x || y),
+            (Or, VMValue::Bool(x), VMValue::Bool(y)) => VMValue::Bool(x || y),
             (Shl, Integer(x), Integer(y)) => Integer(x.wrapping_shl(y as u32)),
             (Shr, Integer(x), Integer(y)) => Integer(x.wrapping_shr(y as u32)),
             (opk, va, vb) => {
@@ -142,7 +184,7 @@ impl MirInterpreter {
                 return Err(VMError::TypeError(format!(
                     "unsupported binop {:?} on {:?} and {:?}",
                     opk, va, vb
-                )))
+                )));
             }
         })
     }
@@ -162,7 +204,9 @@ impl MirInterpreter {
                 v
             };
             (norm(a), norm(b))
-        } else { (a, b) };
+        } else {
+            (a, b)
+        };
         // Dev-only safety valve: tolerate Void in comparisons when enabled or in --dev
         // → treat Void as 0 for numeric, empty for string
         let (a2, b2) = if tolerate {
@@ -195,9 +239,19 @@ impl MirInterpreter {
         };
         // Dev: nullish trace for compare
         if crate::config::env::null_missing_box_enabled() && Self::box_trace_enabled() {
-            let (ak, bk) = (crate::backend::abi_util::tag_of_vm(&a2), crate::backend::abi_util::tag_of_vm(&b2));
+            let (ak, bk) = (
+                crate::backend::abi_util::tag_of_vm(&a2),
+                crate::backend::abi_util::tag_of_vm(&b2),
+            );
             let (an, bn) = (Self::tag_nullish(&a2), Self::tag_nullish(&b2));
-            let op_s = match op { CompareOp::Eq=>"Eq", CompareOp::Ne=>"Ne", CompareOp::Lt=>"Lt", CompareOp::Le=>"Le", CompareOp::Gt=>"Gt", CompareOp::Ge=>"Ge" };
+            let op_s = match op {
+                CompareOp::Eq => "Eq",
+                CompareOp::Ne => "Ne",
+                CompareOp::Lt => "Lt",
+                CompareOp::Le => "Le",
+                CompareOp::Gt => "Gt",
+                CompareOp::Ge => "Ge",
+            };
             eprintln!("{{\"ev\":\"cmp\",\"op\":\"{}\",\"a_k\":\"{}\",\"b_k\":\"{}\",\"a_n\":\"{}\",\"b_n\":\"{}\"}}", op_s, ak, bk, an, bn);
         }
         let result = match (op, &a3, &b3) {
@@ -230,7 +284,6 @@ impl MirInterpreter {
         };
         Ok(result)
     }
-
 }
 
 // ---- Box trace (dev-only observer) ----
@@ -243,11 +296,15 @@ impl MirInterpreter {
     fn box_trace_filter_match(class_name: &str) -> bool {
         if let Ok(filt) = std::env::var("NYASH_BOX_TRACE_FILTER") {
             let want = filt.trim();
-            if want.is_empty() { return true; }
+            if want.is_empty() {
+                return true;
+            }
             // comma/space separated tokens; match if any token is contained in class
             for tok in want.split(|c: char| c == ',' || c.is_whitespace()) {
                 let t = tok.trim();
-                if !t.is_empty() && class_name.contains(t) { return true; }
+                if !t.is_empty() && class_name.contains(t) {
+                    return true;
+                }
             }
             false
         } else {
@@ -272,34 +329,49 @@ impl MirInterpreter {
     }
 
     pub(super) fn box_trace_emit_new(&self, class_name: &str, argc: usize) {
-        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) { return; }
+        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) {
+            return;
+        }
         eprintln!(
             "{{\"ev\":\"new\",\"class\":\"{}\",\"argc\":{}}}",
-            Self::json_escape(class_name), argc
+            Self::json_escape(class_name),
+            argc
         );
     }
 
     pub(super) fn box_trace_emit_call(&self, class_name: &str, method: &str, argc: usize) {
-        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) { return; }
+        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) {
+            return;
+        }
         eprintln!(
             "{{\"ev\":\"call\",\"class\":\"{}\",\"method\":\"{}\",\"argc\":{}}}",
-            Self::json_escape(class_name), Self::json_escape(method), argc
+            Self::json_escape(class_name),
+            Self::json_escape(method),
+            argc
         );
     }
 
     pub(super) fn box_trace_emit_get(&self, class_name: &str, field: &str, val_kind: &str) {
-        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) { return; }
+        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) {
+            return;
+        }
         eprintln!(
             "{{\"ev\":\"get\",\"class\":\"{}\",\"field\":\"{}\",\"val\":\"{}\"}}",
-            Self::json_escape(class_name), Self::json_escape(field), Self::json_escape(val_kind)
+            Self::json_escape(class_name),
+            Self::json_escape(field),
+            Self::json_escape(val_kind)
         );
     }
 
     pub(super) fn box_trace_emit_set(&self, class_name: &str, field: &str, val_kind: &str) {
-        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) { return; }
+        if !Self::box_trace_enabled() || !Self::box_trace_filter_match(class_name) {
+            return;
+        }
         eprintln!(
             "{{\"ev\":\"set\",\"class\":\"{}\",\"field\":\"{}\",\"val\":\"{}\"}}",
-            Self::json_escape(class_name), Self::json_escape(field), Self::json_escape(val_kind)
+            Self::json_escape(class_name),
+            Self::json_escape(field),
+            Self::json_escape(val_kind)
         );
     }
 }
@@ -312,7 +384,9 @@ impl MirInterpreter {
     }
 
     pub(super) fn print_trace_emit(&self, val: &VMValue) {
-        if !Self::print_trace_enabled() { return; }
+        if !Self::print_trace_enabled() {
+            return;
+        }
         let (kind, class, nullish) = match val {
             VMValue::Integer(_) => ("Integer", "".to_string(), None),
             VMValue::Float(_) => ("Float", "".to_string(), None),
@@ -324,17 +398,43 @@ impl MirInterpreter {
                 // Prefer InstanceBox.class_name when available
                 if let Some(inst) = b.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
                     let tag = if crate::config::env::null_missing_box_enabled() {
-                        if b.as_any().downcast_ref::<crate::boxes::null_box::NullBox>().is_some() { Some("null") }
-                        else if b.as_any().downcast_ref::<crate::boxes::missing_box::MissingBox>().is_some() { Some("missing") }
-                        else { None }
-                    } else { None };
+                        if b.as_any()
+                            .downcast_ref::<crate::boxes::null_box::NullBox>()
+                            .is_some()
+                        {
+                            Some("null")
+                        } else if b
+                            .as_any()
+                            .downcast_ref::<crate::boxes::missing_box::MissingBox>()
+                            .is_some()
+                        {
+                            Some("missing")
+                        } else {
+                            None
+                        }
+                    } else {
+                        None
+                    };
                     ("BoxRef", inst.class_name.clone(), tag)
                 } else {
                     let tag = if crate::config::env::null_missing_box_enabled() {
-                        if b.as_any().downcast_ref::<crate::boxes::null_box::NullBox>().is_some() { Some("null") }
-                        else if b.as_any().downcast_ref::<crate::boxes::missing_box::MissingBox>().is_some() { Some("missing") }
-                        else { None }
-                    } else { None };
+                        if b.as_any()
+                            .downcast_ref::<crate::boxes::null_box::NullBox>()
+                            .is_some()
+                        {
+                            Some("null")
+                        } else if b
+                            .as_any()
+                            .downcast_ref::<crate::boxes::missing_box::MissingBox>()
+                            .is_some()
+                        {
+                            Some("missing")
+                        } else {
+                            None
+                        }
+                    } else {
+                        None
+                    };
                     ("BoxRef", b.type_name().to_string(), tag)
                 }
             }

src/backend/mir_interpreter/method_router.rs

@@ -12,8 +12,8 @@
  */
 
 use super::{MirFunction, MirInterpreter};
-use serde_json::json;
 use crate::backend::vm::{VMError, VMValue};
+use serde_json::json;
 
 #[derive(Debug, Clone)]
 struct ParsedSig<'a> {
@@ -25,16 +25,25 @@ struct ParsedSig<'a> {
 fn parse_method_signature(name: &str) -> Option<ParsedSig<'_>> {
     let dot = name.find('.')?;
     let slash = name.rfind('/')?;
-    if dot >= slash { return None; }
+    if dot >= slash {
+        return None;
+    }
     let class = &name[..dot];
     let method = &name[dot + 1..slash];
     let arity_str = &name[slash + 1..];
-    Some(ParsedSig { class, method, arity_str })
+    Some(ParsedSig {
+        class,
+        method,
+        arity_str,
+    })
 }
 
 fn extract_instance_box_class(arg0: &VMValue) -> Option<String> {
     if let VMValue::BoxRef(bx) = arg0 {
-        if let Some(inst) = bx.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+        if let Some(inst) = bx
+            .as_any()
+            .downcast_ref::<crate::instance_v2::InstanceBox>()
+        {
             return Some(inst.class_name.clone());
         }
     }
@@ -47,7 +56,12 @@ fn reroute_to_correct_method(
     parsed: &ParsedSig<'_>,
     arg_vals: Option<&[VMValue]>,
 ) -> Option<Result<VMValue, VMError>> {
-    let target = format!("{}.{}{}", recv_cls, parsed.method, format!("/{}", parsed.arity_str));
+    let target = format!(
+        "{}.{}{}",
+        recv_cls,
+        parsed.method,
+        format!("/{}", parsed.arity_str)
+    );
     if let Some(f) = interp.functions.get(&target).cloned() {
         // Debug: emit class-reroute event (dev-only)
         crate::debug::hub::emit(
@@ -149,7 +163,10 @@ fn try_special_method(
     if parsed.method == "is_eof" && parsed.arity_str == "0" {
         if let Some(args) = arg_vals {
             if let VMValue::BoxRef(bx) = &args[0] {
-                if let Some(inst) = bx.as_any().downcast_ref::<crate::instance_v2::InstanceBox>() {
+                if let Some(inst) = bx
+                    .as_any()
+                    .downcast_ref::<crate::instance_v2::InstanceBox>()
+                {
                     if recv_cls == "JsonToken" {
                         let is = match inst.get_field_ng("type") {
                             Some(crate::value::NyashValue::String(ref s)) => s == "EOF",
@@ -158,8 +175,14 @@ fn try_special_method(
                         return Some(Ok(VMValue::Bool(is)));
                     }
                     if recv_cls == "JsonScanner" {
-                        let pos = match inst.get_field_ng("position") { Some(crate::value::NyashValue::Integer(i)) => i, _ => 0 };
-                        let len = match inst.get_field_ng("length")   { Some(crate::value::NyashValue::Integer(i)) => i, _ => 0 };
+                        let pos = match inst.get_field_ng("position") {
+                            Some(crate::value::NyashValue::Integer(i)) => i,
+                            _ => 0,
+                        };
+                        let len = match inst.get_field_ng("length") {
+                            Some(crate::value::NyashValue::Integer(i)) => i,
+                            _ => 0,
+                        };
                         return Some(Ok(VMValue::Bool(pos >= len)));
                     }
                 }
@@ -183,16 +206,35 @@ pub(super) fn pre_exec_reroute(
     func: &MirFunction,
     arg_vals: Option<&[VMValue]>,
 ) -> Option<Result<VMValue, VMError>> {
-    let args = match arg_vals { Some(a) => a, None => return None };
-    if args.is_empty() { return None; }
-    let parsed = match parse_method_signature(func.signature.name.as_str()) { Some(p) => p, None => return None };
-    let recv_cls = match extract_instance_box_class(&args[0]) { Some(c) => c, None => return None };
+    let args = match arg_vals {
+        Some(a) => a,
+        None => return None,
+    };
+    if args.is_empty() {
+        return None;
+    }
+    let parsed = match parse_method_signature(func.signature.name.as_str()) {
+        Some(p) => p,
+        None => return None,
+    };
+    let recv_cls = match extract_instance_box_class(&args[0]) {
+        Some(c) => c,
+        None => return None,
+    };
     // Always consider special re-routes (e.g., toString→stringify) even when class matches
-    if let Some(r) = try_special_reroute(interp, &recv_cls, &parsed, arg_vals) { return Some(r); }
-    if recv_cls == parsed.class { return None; }
+    if let Some(r) = try_special_reroute(interp, &recv_cls, &parsed, arg_vals) {
+        return Some(r);
+    }
+    if recv_cls == parsed.class {
+        return None;
+    }
     // Class mismatch: reroute to same method on the receiver's class
-    if let Some(r) = reroute_to_correct_method(interp, &recv_cls, &parsed, arg_vals) { return Some(r); }
+    if let Some(r) = reroute_to_correct_method(interp, &recv_cls, &parsed, arg_vals) {
+        return Some(r);
+    }
     // Narrow special fallback (e.g., is_eof)
-    if let Some(r) = try_special_method(&recv_cls, &parsed, arg_vals) { return Some(r); }
+    if let Some(r) = try_special_method(&recv_cls, &parsed, arg_vals) {
+        return Some(r);
+    }
     None
 }

src/backend/mir_interpreter/mod.rs

@@ -71,20 +71,32 @@ impl MirInterpreter {
     }
 
     /// Register static box declarations (called from vm.rs during setup)
-    pub fn register_static_box_decl(&mut self, name: String, decl: crate::core::model::BoxDeclaration) {
+    pub fn register_static_box_decl(
+        &mut self,
+        name: String,
+        decl: crate::core::model::BoxDeclaration,
+    ) {
         self.static_box_decls.insert(name, decl);
     }
 
     /// Ensure static box singleton instance exists, create if not
     /// Returns mutable reference to the singleton instance
-    fn ensure_static_box_instance(&mut self, box_name: &str) -> Result<&mut crate::instance_v2::InstanceBox, VMError> {
+    fn ensure_static_box_instance(
+        &mut self,
+        box_name: &str,
+    ) -> Result<&mut crate::instance_v2::InstanceBox, VMError> {
         // Check if instance already exists
         if !self.static_boxes.contains_key(box_name) {
             // Get declaration
-            let decl = self.static_box_decls.get(box_name)
-                .ok_or_else(|| VMError::InvalidInstruction(
-                    format!("static box declaration not found: {}", box_name)
-                ))?
+            let decl = self
+                .static_box_decls
+                .get(box_name)
+                .ok_or_else(|| {
+                    VMError::InvalidInstruction(format!(
+                        "static box declaration not found: {}",
+                        box_name
+                    ))
+                })?
                 .clone();
 
             // Create instance from declaration
@@ -97,15 +109,20 @@ impl MirInterpreter {
             self.static_boxes.insert(box_name.to_string(), instance);
 
             if std::env::var("NYASH_VM_STATIC_TRACE").ok().as_deref() == Some("1") {
-                eprintln!("[vm-static] created singleton instance for static box: {}", box_name);
+                eprintln!(
+                    "[vm-static] created singleton instance for static box: {}",
+                    box_name
+                );
             }
         }
 
         // Return mutable reference
-        self.static_boxes.get_mut(box_name)
-            .ok_or_else(|| VMError::InvalidInstruction(
-                format!("static box instance not found after creation: {}", box_name)
+        self.static_boxes.get_mut(box_name).ok_or_else(|| {
+            VMError::InvalidInstruction(format!(
+                "static box instance not found after creation: {}",
+                box_name
             ))
+        })
     }
 
     /// Check if a function name represents a static box method
@@ -169,7 +186,12 @@ impl MirInterpreter {
                 // Build helpful error message
                 let mut names: Vec<&String> = module.functions.keys().collect();
                 names.sort();
-                let avail = names.into_iter().take(12).cloned().collect::<Vec<_>>().join(", ");
+                let avail = names
+                    .into_iter()
+                    .take(12)
+                    .cloned()
+                    .collect::<Vec<_>>()
+                    .join(", ");
                 let tried = candidates.join(", ");
                 let msg = format!(
                     "entry function not found. searched: [{}]. available: [{}]. hint: define 'static box Main {{ method main(args){{ ... }} }}' or set NYASH_ENTRY=Name",
@@ -200,9 +222,13 @@ impl MirInterpreter {
                     argv_list = out;
                 }
             } else if let Ok(s) = std::env::var("NYASH_SCRIPT_ARGS_JSON") {
-                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) { argv_list = v; }
+                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) {
+                    argv_list = v;
+                }
             } else if let Ok(s) = std::env::var("NYASH_ARGV") {
-                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) { argv_list = v; }
+                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) {
+                    argv_list = v;
+                }
             }
             // Construct ArrayBox of StringBox
             let array = crate::boxes::array::ArrayBox::new();

src/backend/mir_interpreter/utils/conversion_helpers.rs

@@ -3,8 +3,8 @@
 //! レジスタ値の読み込み＋型変換チェーンを統一します。
 
 use super::super::*;
-use crate::mir::ValueId;
 use crate::box_trait::NyashBox;
+use crate::mir::ValueId;
 
 impl MirInterpreter {
     /// レジスタ値をBox<dyn NyashBox>として読み込む
@@ -53,7 +53,13 @@ impl MirInterpreter {
                     VMValue::Bool(_) => "Bool",
                     VMValue::String(_) => "String",
                     VMValue::Void => "Void",
-                    VMValue::BoxRef(b) => return Err(self.err_type_mismatch("load_as_int", "Integer", &b.type_name())),
+                    VMValue::BoxRef(b) => {
+                        return Err(self.err_type_mismatch(
+                            "load_as_int",
+                            "Integer",
+                            &b.type_name(),
+                        ))
+                    }
                     VMValue::Future(_) => "Future",
                 };
                 Err(self.err_type_mismatch("load_as_int", "Integer", type_name))
@@ -83,7 +89,9 @@ impl MirInterpreter {
                     VMValue::Bool(_) => "Bool",
                     VMValue::String(_) => "String",
                     VMValue::Void => "Void",
-                    VMValue::BoxRef(b) => return Err(self.err_type_mismatch("load_as_bool", "Bool", &b.type_name())),
+                    VMValue::BoxRef(b) => {
+                        return Err(self.err_type_mismatch("load_as_bool", "Bool", &b.type_name()))
+                    }
                     VMValue::Future(_) => "Future",
                 };
                 Err(self.err_type_mismatch("load_as_bool", "Bool", type_name))

src/backend/mir_interpreter/utils/error_helpers.rs

@@ -42,7 +42,10 @@ impl ErrorBuilder {
     #[inline]
     #[allow(dead_code)]
     pub fn type_mismatch(method: &str, expected: &str, actual: &str) -> VMError {
-        VMError::InvalidInstruction(format!("{} expects {} type, got {}", method, expected, actual))
+        VMError::InvalidInstruction(format!(
+            "{} expects {} type, got {}",
+            method, expected, actual
+        ))
     }
 
     /// Index out of bounds error
@@ -60,7 +63,10 @@ impl ErrorBuilder {
     #[inline]
     #[allow(dead_code)]
     pub fn out_of_bounds(method: &str, index: usize, len: usize) -> VMError {
-        VMError::InvalidInstruction(format!("{} index out of bounds: {} >= {}", method, index, len))
+        VMError::InvalidInstruction(format!(
+            "{} index out of bounds: {} >= {}",
+            method, index, len
+        ))
     }
 
     /// Unsupported operation error

src/backend/mir_interpreter/utils/mod.rs

@@ -1,11 +1,11 @@
 //! MIR Interpreter共通ユーティリティ
 
-pub mod destination_helpers;
 pub mod arg_validation;
-pub mod receiver_helpers;
-pub mod error_helpers;
 pub mod conversion_helpers;
+pub mod destination_helpers;
+pub mod error_helpers;
 pub mod naming;
+pub mod receiver_helpers;
 // Phase 21.2: adapter_dev removed - all adapter functions now in .hako implementation
 
 // Selective re-export (only naming is widely used via utils::normalize_arity_suffix)

src/backend/mir_interpreter/utils/naming.rs

@@ -12,4 +12,3 @@ pub fn normalize_arity_suffix(name: &str) -> &str {
         None => name,
     }
 }
-

src/backend/mir_interpreter/utils/receiver_helpers.rs

@@ -23,9 +23,7 @@ impl MirInterpreter {
         let receiver_value = self.reg_load(receiver)?;
         match receiver_value {
             VMValue::BoxRef(b) => Ok(b),
-            _ => Err(VMError::InvalidInstruction(
-                "receiver must be Box".into(),
-            )),
+            _ => Err(VMError::InvalidInstruction("receiver must be Box".into())),
         }
     }
 }

src/box_arithmetic.rs

@@ -7,5 +7,5 @@
 
 // Re-export all arithmetic operations from the dedicated arithmetic module
 pub use crate::boxes::arithmetic::{
-    AddBox, SubtractBox, MultiplyBox, DivideBox, ModuloBox, CompareBox,
+    AddBox, CompareBox, DivideBox, ModuloBox, MultiplyBox, SubtractBox,
 };

src/box_factory/builtin_impls/array_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.4: Delete this file to remove builtin ArrayBox support
  */
 
-use crate::box_trait::NyashBox;
 use crate::box_factory::RuntimeError;
+use crate::box_trait::NyashBox;
 
 /// Create builtin ArrayBox instance
 ///

src/box_factory/builtin_impls/bool_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.3: Delete this file to remove builtin BoolBox support
  */
 
-use crate::box_trait::{NyashBox, BoolBox};
 use crate::box_factory::RuntimeError;
+use crate::box_trait::{BoolBox, NyashBox};
 
 /// Create builtin BoolBox instance
 ///

src/box_factory/builtin_impls/console_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.6: Delete this file to remove builtin ConsoleBox support (LAST)
  */
 
-use crate::box_trait::NyashBox;
 use crate::box_factory::RuntimeError;
+use crate::box_trait::NyashBox;
 
 /// Create builtin ConsoleBox instance
 ///

src/box_factory/builtin_impls/file_box.rs

@@ -7,8 +7,8 @@
  * 🎯 Core-ro mode: This is used directly
  */
 
-use crate::box_trait::NyashBox;
 use crate::box_factory::RuntimeError;
+use crate::box_trait::NyashBox;
 use crate::boxes::file::core_ro::CoreRoFileIo;
 use crate::boxes::file::FileBox;
 use std::sync::Arc;
@@ -28,9 +28,7 @@ pub fn create(_args: &[Box<dyn NyashBox>]) -> Result<Box<dyn NyashBox>, RuntimeE
         });
     }
 
-    eprintln!(
-        "[FileBox] Using builtin core-ro fallback implementation"
-    );
+    eprintln!("[FileBox] Using builtin core-ro fallback implementation");
 
     // Create FileBox with core-ro provider directly
     // Don't rely on global provider_lock which may not be initialized

src/box_factory/builtin_impls/integer_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.2: Delete this file to remove builtin IntegerBox support
  */
 
-use crate::box_trait::{NyashBox, IntegerBox};
 use crate::box_factory::RuntimeError;
+use crate::box_trait::{IntegerBox, NyashBox};
 
 /// Create builtin IntegerBox instance
 ///

src/box_factory/builtin_impls/map_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.5: Delete this file to remove builtin MapBox support
  */
 
-use crate::box_trait::NyashBox;
 use crate::box_factory::RuntimeError;
+use crate::box_trait::NyashBox;
 
 /// Create builtin MapBox instance
 ///

src/box_factory/builtin_impls/mod.rs

@@ -15,15 +15,15 @@
  */
 
 // Phase 2.1-2.6: Delete these modules one by one
-pub mod string_box;    // DELETE: Phase 2.1 (plugin ready)
-pub mod integer_box;   // DELETE: Phase 2.2 (plugin ready)
-pub mod bool_box;      // DELETE: Phase 2.3 (plugin needed)
-pub mod array_box;     // DELETE: Phase 2.4 (plugin check)
-pub mod map_box;       // DELETE: Phase 2.5 (plugin check)
-pub mod console_box;   // DELETE: Phase 2.6 (LAST - critical for logging)
+pub mod array_box; // DELETE: Phase 2.4 (plugin check)
+pub mod bool_box; // DELETE: Phase 2.3 (plugin needed)
+pub mod console_box;
+pub mod integer_box; // DELETE: Phase 2.2 (plugin ready)
+pub mod map_box; // DELETE: Phase 2.5 (plugin check)
+pub mod string_box; // DELETE: Phase 2.1 (plugin ready) // DELETE: Phase 2.6 (LAST - critical for logging)
 
 // Fallback support (Phase 15.5: Fallback Guarantee)
-pub mod file_box;      // FALLBACK: Core-ro FileBox for auto/core-ro modes
+pub mod file_box; // FALLBACK: Core-ro FileBox for auto/core-ro modes
 
 // Special consideration
-pub mod null_box;      // DISCUSS: Keep as primitive?
+pub mod null_box; // DISCUSS: Keep as primitive?

src/box_factory/builtin_impls/null_box.rs

@@ -5,8 +5,8 @@
  * 📋 Discussion needed: Is null a language primitive or plugin concern?
  */
 
-use crate::box_trait::NyashBox;
 use crate::box_factory::RuntimeError;
+use crate::box_trait::NyashBox;
 
 /// Create builtin NullBox instance
 ///

src/box_factory/builtin_impls/string_box.rs

@@ -5,8 +5,8 @@
  * 🎯 Phase 2.1: Delete this file to remove builtin StringBox support
  */
 
-use crate::box_trait::{NyashBox, StringBox};
 use crate::box_factory::RuntimeError;
+use crate::box_trait::{NyashBox, StringBox};
 
 /// Create builtin StringBox instance
 ///

src/box_factory/mod.rs

@@ -138,7 +138,10 @@ impl UnifiedBoxRegistry {
             Some("strict_plugin_first") | _ => FactoryPolicy::StrictPluginFirst, // Phase 15.5: Plugin First DEFAULT!
         };
 
-        eprintln!("[UnifiedBoxRegistry] 🎯 Factory Policy: {:?} (Phase 15.5: Everything is Plugin!)", policy);
+        eprintln!(
+            "[UnifiedBoxRegistry] 🎯 Factory Policy: {:?} (Phase 15.5: Everything is Plugin!)",
+            policy
+        );
         Self::with_policy(policy)
     }
 
@@ -175,7 +178,7 @@ impl UnifiedBoxRegistry {
                     if std::env::var("NYASH_USE_PLUGIN_BUILTINS").is_ok() {
                         if let Ok(types) = std::env::var("NYASH_PLUGIN_OVERRIDE_TYPES") {
                             if types.split(',').any(|t| t.trim() == name) {
-                                return false;  // 予約型として扱わない
+                                return false; // 予約型として扱わない
                             }
                         }
                     }
@@ -229,19 +232,19 @@ impl UnifiedBoxRegistry {
 
                 match self.policy {
                     FactoryPolicy::StrictPluginFirst => match factory_type {
-                        FactoryType::Plugin => 0,   // Highest priority
-                        FactoryType::User => 1,     // Medium priority
-                        FactoryType::Builtin => 2,  // Lowest priority
+                        FactoryType::Plugin => 0,  // Highest priority
+                        FactoryType::User => 1,    // Medium priority
+                        FactoryType::Builtin => 2, // Lowest priority
                     },
                     FactoryPolicy::CompatPluginFirst => match factory_type {
-                        FactoryType::Plugin => 0,   // Highest priority
-                        FactoryType::Builtin => 1,  // Medium priority
-                        FactoryType::User => 2,     // Lowest priority
+                        FactoryType::Plugin => 0,  // Highest priority
+                        FactoryType::Builtin => 1, // Medium priority
+                        FactoryType::User => 2,    // Lowest priority
                     },
                     FactoryPolicy::BuiltinFirst => match factory_type {
-                        FactoryType::Builtin => 0,  // Highest priority (current default)
-                        FactoryType::User => 1,     // Medium priority
-                        FactoryType::Plugin => 2,   // Lowest priority
+                        FactoryType::Builtin => 0, // Highest priority (current default)
+                        FactoryType::User => 1,    // Medium priority
+                        FactoryType::Plugin => 2,  // Lowest priority
                     },
                 }
             } else {
@@ -271,7 +274,9 @@ impl UnifiedBoxRegistry {
         // Prefer plugin-builtins when enabled and provider is available in v2 registry
         // BUT: Skip if plugins are explicitly disabled
         let plugins_disabled = std::env::var("NYASH_DISABLE_PLUGINS").ok().as_deref() == Some("1");
-        if !plugins_disabled && std::env::var("NYASH_USE_PLUGIN_BUILTINS").ok().as_deref() == Some("1") {
+        if !plugins_disabled
+            && std::env::var("NYASH_USE_PLUGIN_BUILTINS").ok().as_deref() == Some("1")
+        {
             use crate::runtime::{get_global_registry, BoxProvider};
             // Allowlist types for override: env NYASH_PLUGIN_OVERRIDE_TYPES="ArrayBox,MapBox" (default: none)
             let allow: Vec<String> = if let Ok(list) = std::env::var("NYASH_PLUGIN_OVERRIDE_TYPES")
@@ -338,7 +343,8 @@ impl UnifiedBoxRegistry {
                     Err(e) => {
                         // FileBox special case: handle fallback based on mode
                         if name == "FileBox" {
-                            if let Some(fallback_result) = self.try_filebox_fallback(name, args, &e) {
+                            if let Some(fallback_result) = self.try_filebox_fallback(name, args, &e)
+                            {
                                 return fallback_result;
                             }
                         }
@@ -386,14 +392,23 @@ impl UnifiedBoxRegistry {
         match mode {
             provider_registry::FileBoxMode::PluginOnly => {
                 // Fail-Fast: return the original error immediately
-                eprintln!("[FileBox] Plugin creation failed in plugin-only mode: {}", original_error);
+                eprintln!(
+                    "[FileBox] Plugin creation failed in plugin-only mode: {}",
+                    original_error
+                );
                 Some(Err(RuntimeError::InvalidOperation {
-                    message: format!("FileBox plugin creation failed (plugin-only mode): {}", original_error),
+                    message: format!(
+                        "FileBox plugin creation failed (plugin-only mode): {}",
+                        original_error
+                    ),
                 }))
             }
             provider_registry::FileBoxMode::Auto => {
                 // Auto mode: try fallback to builtin/core-ro
-                eprintln!("[FileBox] Plugin creation failed, falling back to builtin/core-ro: {}", original_error);
+                eprintln!(
+                    "[FileBox] Plugin creation failed, falling back to builtin/core-ro: {}",
+                    original_error
+                );
 
                 // Try builtin factory if available
                 for factory in &self.factories {

src/box_factory/plugin.rs

@@ -6,8 +6,8 @@
  */
 
 use super::BoxFactory;
-use crate::box_trait::NyashBox;
 use super::RuntimeError;
+use crate::box_trait::NyashBox;
 use crate::runtime::get_global_registry;
 
 /// Factory for plugin-based Box types
@@ -29,11 +29,20 @@ impl BoxFactory for PluginBoxFactory {
     ) -> Result<Box<dyn NyashBox>, RuntimeError> {
         // Check if plugins are disabled
         let plugins_disabled = std::env::var("NYASH_DISABLE_PLUGINS").ok().as_deref() == Some("1");
-        eprintln!("[PluginBoxFactory] NYASH_DISABLE_PLUGINS={} for {}",
-            std::env::var("NYASH_DISABLE_PLUGINS").ok().as_deref().unwrap_or("not set"), name);
+        eprintln!(
+            "[PluginBoxFactory] NYASH_DISABLE_PLUGINS={} for {}",
+            std::env::var("NYASH_DISABLE_PLUGINS")
+                .ok()
+                .as_deref()
+                .unwrap_or("not set"),
+            name
+        );
         if plugins_disabled {
             return Err(RuntimeError::InvalidOperation {
-                message: format!("Plugins disabled (NYASH_DISABLE_PLUGINS=1), cannot create {}", name),
+                message: format!(
+                    "Plugins disabled (NYASH_DISABLE_PLUGINS=1), cannot create {}",
+                    name
+                ),
             });
         }
 

src/box_factory/user_defined.rs

@@ -6,9 +6,9 @@
  */
 
 use super::BoxFactory;
+use super::{RuntimeError, SharedState};
 use crate::box_trait::NyashBox;
 use crate::instance_v2::InstanceBox;
-use super::{RuntimeError, SharedState};
 
 /// Factory for user-defined Box types
 pub struct UserDefinedBoxFactory {

src/box_operators.rs

@@ -16,16 +16,14 @@
 
 use crate::box_trait::{BoolBox, IntegerBox, NyashBox, StringBox};
 use crate::boxes::FloatBox;
-use crate::operator_traits::{
-    DynamicAdd, DynamicDiv, DynamicMul, DynamicSub, OperatorError,
-};
+use crate::operator_traits::{DynamicAdd, DynamicDiv, DynamicMul, DynamicSub, OperatorError};
 
 // Phase 1-2: Import macros, helpers, and static implementations from separate modules
-mod macros;
 mod helpers;
+mod macros;
 mod static_ops;
 
-pub use helpers::{concat_result, can_repeat};
+pub use helpers::{can_repeat, concat_result};
 pub use macros::impl_static_numeric_ops;
 
 // Phase 2: Static implementations are now in static_ops.rs
@@ -392,16 +390,27 @@ impl OperatorResolver {
     #[inline]
     fn try_dyn_left_add(left: &dyn NyashBox, right: &dyn NyashBox) -> Option<Box<dyn NyashBox>> {
         if let Some(int_box) = left.as_any().downcast_ref::<crate::box_trait::IntegerBox>() {
-            if let Some(result) = int_box.try_add(right) { return Some(result); }
+            if let Some(result) = int_box.try_add(right) {
+                return Some(result);
+            }
         }
         if let Some(str_box) = left.as_any().downcast_ref::<crate::box_trait::StringBox>() {
-            if let Some(result) = str_box.try_add(right) { return Some(result); }
+            if let Some(result) = str_box.try_add(right) {
+                return Some(result);
+            }
         }
-        if let Some(float_box) = left.as_any().downcast_ref::<crate::boxes::math_box::FloatBox>() {
-            if let Some(result) = float_box.try_add(right) { return Some(result); }
+        if let Some(float_box) = left
+            .as_any()
+            .downcast_ref::<crate::boxes::math_box::FloatBox>()
+        {
+            if let Some(result) = float_box.try_add(right) {
+                return Some(result);
+            }
         }
         if let Some(bool_box) = left.as_any().downcast_ref::<crate::box_trait::BoolBox>() {
-            if let Some(result) = bool_box.try_add(right) { return Some(result); }
+            if let Some(result) = bool_box.try_add(right) {
+                return Some(result);
+            }
         }
         None
     }
@@ -409,13 +418,22 @@ impl OperatorResolver {
     #[inline]
     fn try_dyn_left_sub(left: &dyn NyashBox, right: &dyn NyashBox) -> Option<Box<dyn NyashBox>> {
         if let Some(int_box) = left.as_any().downcast_ref::<crate::box_trait::IntegerBox>() {
-            if let Some(result) = int_box.try_sub(right) { return Some(result); }
+            if let Some(result) = int_box.try_sub(right) {
+                return Some(result);
+            }
         }
-        if let Some(float_box) = left.as_any().downcast_ref::<crate::boxes::math_box::FloatBox>() {
-            if let Some(result) = float_box.try_sub(right) { return Some(result); }
+        if let Some(float_box) = left
+            .as_any()
+            .downcast_ref::<crate::boxes::math_box::FloatBox>()
+        {
+            if let Some(result) = float_box.try_sub(right) {
+                return Some(result);
+            }
         }
         if let Some(bool_box) = left.as_any().downcast_ref::<crate::box_trait::BoolBox>() {
-            if let Some(result) = bool_box.try_sub(right) { return Some(result); }
+            if let Some(result) = bool_box.try_sub(right) {
+                return Some(result);
+            }
         }
         None
     }
@@ -423,16 +441,27 @@ impl OperatorResolver {
     #[inline]
     fn try_dyn_left_mul(left: &dyn NyashBox, right: &dyn NyashBox) -> Option<Box<dyn NyashBox>> {
         if let Some(int_box) = left.as_any().downcast_ref::<crate::box_trait::IntegerBox>() {
-            if let Some(result) = int_box.try_mul(right) { return Some(result); }
+            if let Some(result) = int_box.try_mul(right) {
+                return Some(result);
+            }
         }
         if let Some(str_box) = left.as_any().downcast_ref::<crate::box_trait::StringBox>() {
-            if let Some(result) = str_box.try_mul(right) { return Some(result); }
+            if let Some(result) = str_box.try_mul(right) {
+                return Some(result);
+            }
         }
-        if let Some(float_box) = left.as_any().downcast_ref::<crate::boxes::math_box::FloatBox>() {
-            if let Some(result) = float_box.try_mul(right) { return Some(result); }
+        if let Some(float_box) = left
+            .as_any()
+            .downcast_ref::<crate::boxes::math_box::FloatBox>()
+        {
+            if let Some(result) = float_box.try_mul(right) {
+                return Some(result);
+            }
         }
         if let Some(bool_box) = left.as_any().downcast_ref::<crate::box_trait::BoolBox>() {
-            if let Some(result) = bool_box.try_mul(right) { return Some(result); }
+            if let Some(result) = bool_box.try_mul(right) {
+                return Some(result);
+            }
         }
         None
     }
@@ -442,7 +471,10 @@ impl OperatorResolver {
         if let Some(int_box) = left.as_any().downcast_ref::<crate::box_trait::IntegerBox>() {
             return int_box.try_div(right);
         }
-        if let Some(float_box) = left.as_any().downcast_ref::<crate::boxes::math_box::FloatBox>() {
+        if let Some(float_box) = left
+            .as_any()
+            .downcast_ref::<crate::boxes::math_box::FloatBox>()
+        {
             return float_box.try_div(right);
         }
         if let Some(bool_box) = left.as_any().downcast_ref::<crate::box_trait::BoolBox>() {
@@ -458,7 +490,9 @@ impl OperatorResolver {
         // Try to cast to concrete types first and use their DynamicAdd implementation
         // This approach uses the concrete types rather than trait objects
 
-        if let Some(result) = Self::try_dyn_left_add(left, right) { return Ok(result); }
+        if let Some(result) = Self::try_dyn_left_add(left, right) {
+            return Ok(result);
+        }
 
         Err(OperatorError::UnsupportedOperation {
             operator: "+".to_string(),
@@ -472,7 +506,9 @@ impl OperatorResolver {
         left: &dyn NyashBox,
         right: &dyn NyashBox,
     ) -> Result<Box<dyn NyashBox>, OperatorError> {
-        if let Some(result) = Self::try_dyn_left_sub(left, right) { return Ok(result); }
+        if let Some(result) = Self::try_dyn_left_sub(left, right) {
+            return Ok(result);
+        }
 
         Err(OperatorError::UnsupportedOperation {
             operator: "-".to_string(),
@@ -486,7 +522,9 @@ impl OperatorResolver {
         left: &dyn NyashBox,
         right: &dyn NyashBox,
     ) -> Result<Box<dyn NyashBox>, OperatorError> {
-        if let Some(result) = Self::try_dyn_left_mul(left, right) { return Ok(result); }
+        if let Some(result) = Self::try_dyn_left_mul(left, right) {
+            return Ok(result);
+        }
 
         Err(OperatorError::UnsupportedOperation {
             operator: "*".to_string(),
@@ -500,7 +538,9 @@ impl OperatorResolver {
         left: &dyn NyashBox,
         right: &dyn NyashBox,
     ) -> Result<Box<dyn NyashBox>, OperatorError> {
-        if let Some(result) = Self::try_dyn_left_div(left, right) { return Ok(result); }
+        if let Some(result) = Self::try_dyn_left_div(left, right) {
+            return Ok(result);
+        }
 
         Err(OperatorError::UnsupportedOperation {
             operator: "/".to_string(),

src/box_operators/macros.rs

@@ -28,21 +28,21 @@ macro_rules! impl_static_numeric_ops {
         impl crate::operator_traits::NyashAdd<$ty> for $ty {
             type Output = $ty;
             fn add(self, rhs: $ty) -> Self::Output {
-                < $ty >::new(self.value + rhs.value)
+                <$ty>::new(self.value + rhs.value)
             }
         }
 
         impl crate::operator_traits::NyashSub<$ty> for $ty {
             type Output = $ty;
             fn sub(self, rhs: $ty) -> Self::Output {
-                < $ty >::new(self.value - rhs.value)
+                <$ty>::new(self.value - rhs.value)
             }
         }
 
         impl crate::operator_traits::NyashMul<$ty> for $ty {
             type Output = $ty;
             fn mul(self, rhs: $ty) -> Self::Output {
-                < $ty >::new(self.value * rhs.value)
+                <$ty>::new(self.value * rhs.value)
             }
         }
 
@@ -52,7 +52,7 @@ macro_rules! impl_static_numeric_ops {
                 if rhs.value == $zero {
                     Err(crate::operator_traits::OperatorError::DivisionByZero)
                 } else {
-                    Ok(< $ty >::new(self.value / rhs.value))
+                    Ok(<$ty>::new(self.value / rhs.value))
                 }
             }
         }

src/box_operators/static_ops.rs

@@ -6,8 +6,8 @@
 
 use crate::box_trait::{BoolBox, IntegerBox, StringBox};
 use crate::boxes::FloatBox;
-use crate::operator_traits::{NyashAdd, NyashMul};
 use crate::impl_static_numeric_ops;
+use crate::operator_traits::{NyashAdd, NyashMul};
 
 // ===== Macro-generated static implementations =====
 

src/box_trait.rs

@@ -160,15 +160,7 @@ pub trait NyashBox: BoxCore + Debug {
 // ===== Basic Box Types (Re-exported from basic module) =====
 
 // Re-export all basic box types from the dedicated basic module
-pub use crate::boxes::basic::{
-    BoolBox, ErrorBox, FileBox, IntegerBox, StringBox, VoidBox,
-};
-
-
-
-
-
-
+pub use crate::boxes::basic::{BoolBox, ErrorBox, FileBox, IntegerBox, StringBox, VoidBox};
 
 // Old Box implementations have been moved to separate files
 // ArrayBox is now defined in boxes::array module

src/boxes/arithmetic/mod.rs

@@ -13,19 +13,19 @@
 
 // Individual arithmetic operation implementations
 mod add_box;
-mod subtract_box;
-mod multiply_box;
+mod compare_box;
 mod divide_box;
 mod modulo_box;
-mod compare_box;
+mod multiply_box;
+mod subtract_box;
 
 // Re-export all arithmetic box types
 pub use add_box::AddBox;
-pub use subtract_box::SubtractBox;
-pub use multiply_box::MultiplyBox;
+pub use compare_box::CompareBox;
 pub use divide_box::DivideBox;
 pub use modulo_box::ModuloBox;
-pub use compare_box::CompareBox;
+pub use multiply_box::MultiplyBox;
+pub use subtract_box::SubtractBox;
 
 // Re-export for convenience - common pattern in arithmetic operations
 pub use crate::box_trait::{BoolBox, IntegerBox, NyashBox, StringBox};

src/boxes/array/mod.rs

@@ -42,11 +42,11 @@ impl ArrayBox {
             None => {
                 let strict = std::env::var("HAKO_OOB_STRICT")
                     .ok()
-                    .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                    .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                     .unwrap_or(false)
                     || std::env::var("NYASH_OOB_STRICT")
                         .ok()
-                        .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                        .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                         .unwrap_or(false);
                 if strict {
                     Box::new(StringBox::new("[array/empty/pop] empty array"))
@@ -92,11 +92,11 @@ impl ArrayBox {
                 None => {
                     let strict = std::env::var("HAKO_OOB_STRICT")
                         .ok()
-                        .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                        .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                         .unwrap_or(false)
                         || std::env::var("NYASH_OOB_STRICT")
                             .ok()
-                            .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                            .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                             .unwrap_or(false);
                     if strict {
                         // Mark OOB occurrence for runner policies (Gate‑C strict fail, etc.)
@@ -127,11 +127,11 @@ impl ArrayBox {
             } else {
                 let strict = std::env::var("HAKO_OOB_STRICT")
                     .ok()
-                    .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                    .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                     .unwrap_or(false)
                     || std::env::var("NYASH_OOB_STRICT")
                         .ok()
-                        .map(|v| matches!(v.as_str(), "1"|"true"|"on"))
+                        .map(|v| matches!(v.as_str(), "1" | "true" | "on"))
                         .unwrap_or(false);
                 if strict {
                     crate::runtime::observe::mark_oob();

src/boxes/basic/bool_box.rs

@@ -2,7 +2,7 @@
 //!
 //! Implements the core BoolBox type for true/false values.
 
-use crate::box_trait::{NyashBox, BoxCore, BoxBase, StringBox};
+use crate::box_trait::{BoxBase, BoxCore, NyashBox, StringBox};
 use std::any::Any;
 use std::fmt::{Debug, Display};
 

src/boxes/basic/error_box.rs

@@ -2,7 +2,7 @@
 //!
 //! Implements the ErrorBox type for representing error information.
 
-use crate::box_trait::{NyashBox, BoxCore, BoxBase, StringBox, BoolBox};
+use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use std::any::Any;
 use std::fmt::{Debug, Display};
 

src/boxes/basic/integer_box.rs

@@ -2,7 +2,7 @@
 //!
 //! Implements the core IntegerBox type for 64-bit signed integers.
 
-use crate::box_trait::{NyashBox, BoxCore, BoxBase, StringBox, BoolBox};
+use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use std::any::Any;
 use std::fmt::{Debug, Display};
 

src/boxes/basic/mod.rs

@@ -4,17 +4,17 @@
 //! fundamental data types in Nyash: String, Integer, Boolean, Void, File, and Error.
 
 // Individual basic box implementations
-mod string_box;
-mod integer_box;
 mod bool_box;
-mod void_box;
-mod file_box;
 mod error_box;
+mod file_box;
+mod integer_box;
+mod string_box;
+mod void_box;
 
 // Re-export all basic box types
-pub use string_box::StringBox;
-pub use integer_box::IntegerBox;
 pub use bool_box::BoolBox;
-pub use void_box::VoidBox;
-pub use file_box::FileBox;
 pub use error_box::ErrorBox;
+pub use file_box::FileBox;
+pub use integer_box::IntegerBox;
+pub use string_box::StringBox;
+pub use void_box::VoidBox;

src/boxes/basic/string_box.rs

@@ -2,7 +2,7 @@
 //!
 //! Implements the core StringBox type with all string manipulation methods.
 
-use crate::box_trait::{NyashBox, BoxCore, BoxBase};
+use crate::box_trait::{BoxBase, BoxCore, NyashBox};
 use crate::boxes::ArrayBox;
 use std::any::Any;
 use std::fmt::{Debug, Display};

src/boxes/basic/void_box.rs

@@ -2,7 +2,7 @@
 //!
 //! Implements the core VoidBox type representing empty or null results.
 
-use crate::box_trait::{NyashBox, BoxCore, BoxBase, StringBox, BoolBox};
+use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use std::any::Any;
 use std::fmt::{Debug, Display};
 

src/boxes/debug_box.rs

@@ -99,9 +99,9 @@
  * - call stackは直近100件まで自動保持
  */
 
+use crate::box_factory::RuntimeError;
 use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox, VoidBox};
 use crate::instance_v2::InstanceBox;
-use crate::box_factory::RuntimeError;
 use chrono::Local;
 use std::any::Any;
 use std::collections::HashMap;

src/boxes/egui_box.rs

@@ -33,8 +33,8 @@
  * - `run()`はブロッキング動作（アプリ終了まで制御を返さない）
  */
 
-use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use crate::box_factory::RuntimeError;
+use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use eframe::{self, egui, epaint::Vec2};
 use std::any::Any;
 use std::sync::{Arc, RwLock};

src/boxes/file/box_shim.rs

@@ -1,8 +1,8 @@
 //! Thin FileBox shim that delegates to a selected provider.
 //! Not wired into the registry yet (safe placeholder).
 
+use super::provider::{FileCaps, FileIo, FileResult};
 use std::sync::Arc;
-use super::provider::{FileIo, FileCaps, FileResult};
 
 #[allow(dead_code)]
 pub struct FileBoxShim {
@@ -16,9 +16,16 @@ impl FileBoxShim {
         let caps = provider.caps();
         Self { provider, caps }
     }
-    pub fn open(&self, path: &str) -> FileResult<()> { self.provider.open(path) }
-    pub fn read(&self) -> FileResult<String> { self.provider.read() }
-    pub fn close(&self) -> FileResult<()> { self.provider.close() }
-    pub fn caps(&self) -> FileCaps { self.caps }
+    pub fn open(&self, path: &str) -> FileResult<()> {
+        self.provider.open(path)
+    }
+    pub fn read(&self) -> FileResult<String> {
+        self.provider.read()
+    }
+    pub fn close(&self) -> FileResult<()> {
+        self.provider.close()
+    }
+    pub fn caps(&self) -> FileCaps {
+        self.caps
+    }
 }
-

src/boxes/file/builtin_factory.rs

@@ -3,10 +3,12 @@
 //! Provides ProviderFactory implementation for the builtin FileBox (core-ro).
 //! This is auto-registered when feature "builtin-filebox" is enabled.
 
-use std::sync::Arc;
-use crate::boxes::file::provider::FileIo;
 use crate::boxes::file::core_ro::CoreRoFileIo;
-use crate::runner::modes::common_util::provider_registry::{ProviderFactory, register_provider_factory};
+use crate::boxes::file::provider::FileIo;
+use crate::runner::modes::common_util::provider_registry::{
+    register_provider_factory, ProviderFactory,
+};
+use std::sync::Arc;
 
 /// Builtin FileBox factory (static registration)
 pub struct BuiltinFileBoxFactory;

src/boxes/file/mod.rs

@@ -3,10 +3,10 @@
 // 参考: 既存Boxの設計思想
 
 // SSOT provider design (ring‑0/1) — modules are currently placeholders
-pub mod provider;   // trait FileIo / FileCaps / FileError
-pub mod core_ro;    // Core read‑only provider
-pub mod box_shim;   // Thin delegating shim
-pub mod builtin_factory; // Builtin FileBox ProviderFactory
+pub mod box_shim; // Thin delegating shim
+pub mod builtin_factory;
+pub mod core_ro; // Core read‑only provider
+pub mod provider; // trait FileIo / FileCaps / FileError // Builtin FileBox ProviderFactory
 
 use crate::box_trait::{BoolBox, BoxBase, BoxCore, NyashBox, StringBox};
 use crate::runtime::provider_lock;
@@ -64,7 +64,8 @@ impl FileBox {
             .ok_or("FileBox provider not initialized")?
             .clone();
 
-        provider.open(path)
+        provider
+            .open(path)
             .map_err(|e| format!("Failed to open: {}", e))?;
 
         Ok(FileBox {
@@ -76,8 +77,7 @@ impl FileBox {
 
     pub fn read_to_string(&self) -> Result<String, String> {
         if let Some(ref provider) = self.provider {
-            provider.read()
-                .map_err(|e| format!("Read failed: {}", e))
+            provider.read().map_err(|e| format!("Read failed: {}", e))
         } else {
             Err("No provider available".to_string())
         }
@@ -85,7 +85,8 @@ impl FileBox {
 
     pub fn write_all(&self, _buf: &[u8]) -> Result<(), String> {
         // Fail-Fast by capability: consult provider caps
-        let caps = self.provider
+        let caps = self
+            .provider
             .as_ref()
             .map(|p| p.caps())
             .or_else(|| provider_lock::get_filebox_caps())
@@ -107,15 +108,20 @@ impl FileBox {
 
     /// ファイルに内容を書き込む
     pub fn write(&self, _content: Box<dyn NyashBox>) -> Box<dyn NyashBox> {
-        let caps = self.provider
+        let caps = self
+            .provider
             .as_ref()
             .map(|p| p.caps())
             .or_else(|| provider_lock::get_filebox_caps())
             .unwrap_or_else(|| provider::FileCaps::read_only());
         if !caps.write {
-            return Box::new(StringBox::new("Error: write unsupported by provider (read-only)"));
+            return Box::new(StringBox::new(
+                "Error: write unsupported by provider (read-only)",
+            ));
         }
-        Box::new(StringBox::new("Error: write supported but not implemented in this build"))
+        Box::new(StringBox::new(
+            "Error: write supported but not implemented in this build",
+        ))
     }
 
     /// ファイルが存在するかチェック
@@ -126,28 +132,38 @@ impl FileBox {
 
     /// ファイルを削除
     pub fn delete(&self) -> Box<dyn NyashBox> {
-        let caps = self.provider
+        let caps = self
+            .provider
             .as_ref()
             .map(|p| p.caps())
             .or_else(|| provider_lock::get_filebox_caps())
             .unwrap_or_else(|| provider::FileCaps::read_only());
         if !caps.write {
-            return Box::new(StringBox::new("Error: delete unsupported by provider (read-only)"));
+            return Box::new(StringBox::new(
+                "Error: delete unsupported by provider (read-only)",
+            ));
         }
-        Box::new(StringBox::new("Error: delete supported but not implemented in this build"))
+        Box::new(StringBox::new(
+            "Error: delete supported but not implemented in this build",
+        ))
     }
 
     /// ファイルをコピー
     pub fn copy(&self, _dest: &str) -> Box<dyn NyashBox> {
-        let caps = self.provider
+        let caps = self
+            .provider
             .as_ref()
             .map(|p| p.caps())
             .or_else(|| provider_lock::get_filebox_caps())
             .unwrap_or_else(|| provider::FileCaps::read_only());
         if !caps.write {
-            return Box::new(StringBox::new("Error: copy unsupported by provider (read-only)"));
+            return Box::new(StringBox::new(
+                "Error: copy unsupported by provider (read-only)",
+            ));
         }
-        Box::new(StringBox::new("Error: copy supported but not implemented in this build"))
+        Box::new(StringBox::new(
+            "Error: copy supported but not implemented in this build",
+        ))
     }
 }
 

src/boxes/file/provider.rs

@@ -12,7 +12,12 @@ pub struct FileCaps {
 }
 
 impl FileCaps {
-    pub const fn read_only() -> Self { Self { read: true, write: false } }
+    pub const fn read_only() -> Self {
+        Self {
+            read: true,
+            write: false,
+        }
+    }
 }
 
 /// Unified error type (thin placeholder for now)
@@ -40,9 +45,10 @@ pub trait FileIo: Send + Sync {
 pub fn normalize_newlines(s: &str) -> String {
     let mut out = String::with_capacity(s.len());
     for b in s.as_bytes() {
-        if *b == b'\r' { continue; }
+        if *b == b'\r' {
+            continue;
+        }
         out.push(*b as char);
     }
     out
 }
-

src/boxes/http_message_box.rs

@@ -279,7 +279,11 @@ impl HTTPResponseBox {
     }
 
     /// ステータスコード・メッセージ設定
-    pub fn set_status(&self, code: Box<dyn NyashBox>, message: Box<dyn NyashBox>) -> Box<dyn NyashBox> {
+    pub fn set_status(
+        &self,
+        code: Box<dyn NyashBox>,
+        message: Box<dyn NyashBox>,
+    ) -> Box<dyn NyashBox> {
         let code_val = code.to_string_box().value.parse::<i32>().unwrap_or(200);
         let message_val = message.to_string_box().value;
         *self.status_code.lock().unwrap() = code_val;
@@ -288,7 +292,11 @@ impl HTTPResponseBox {
     }
 
     /// ヘッダー設定
-    pub fn set_header(&self, name: Box<dyn NyashBox>, value: Box<dyn NyashBox>) -> Box<dyn NyashBox> {
+    pub fn set_header(
+        &self,
+        name: Box<dyn NyashBox>,
+        value: Box<dyn NyashBox>,
+    ) -> Box<dyn NyashBox> {
         let name_str = name.to_string_box().value;
         let value_str = value.to_string_box().value;
         self.headers.lock().unwrap().insert(name_str, value_str);
@@ -326,7 +334,10 @@ impl HTTPResponseBox {
         let version = self.http_version.lock().unwrap().clone();
         let status_code = *self.status_code.lock().unwrap();
         let status_message = self.status_message.lock().unwrap().clone();
-        response.push_str(&format!("{} {} {}\r\n", version, status_code, status_message));
+        response.push_str(&format!(
+            "{} {} {}\r\n",
+            version, status_code, status_message
+        ));
 
         // Headers
         for (name, value) in self.headers.lock().unwrap().iter() {
@@ -335,7 +346,8 @@ impl HTTPResponseBox {
 
         // Content-Length if not already set
         let body_len = { self.body.lock().unwrap().len() };
-        let need_len = { !self.headers.lock().unwrap().contains_key("content-length") && body_len > 0 };
+        let need_len =
+            { !self.headers.lock().unwrap().contains_key("content-length") && body_len > 0 };
         if need_len {
             response.push_str(&format!("Content-Length: {}\r\n", body_len));
         }
@@ -367,10 +379,11 @@ impl HTTPResponseBox {
         let response = HTTPResponseBox::new();
         *response.status_code.lock().unwrap() = 200;
         *response.status_message.lock().unwrap() = "OK".to_string();
-        response.headers.lock().unwrap().insert(
-            "Content-Type".to_string(),
-            "application/json".to_string(),
-        );
+        response
+            .headers
+            .lock()
+            .unwrap()
+            .insert("Content-Type".to_string(), "application/json".to_string());
         *response.body.lock().unwrap() = content.to_string_box().value;
         response
     }
@@ -384,7 +397,8 @@ impl HTTPResponseBox {
             "Content-Type".to_string(),
             "text/html; charset=utf-8".to_string(),
         );
-        *response.body.lock().unwrap() = "<html><body><h1>404 - Not Found</h1></body></html>".to_string();
+        *response.body.lock().unwrap() =
+            "<html><body><h1>404 - Not Found</h1></body></html>".to_string();
         response
     }
 }

src/boxes/map_box.rs

@@ -161,7 +161,10 @@ impl MapBox {
                 }
                 value.clone_box()
             }
-            None => Box::new(StringBox::new(&format!("[map/missing] Key not found: {}", key_str))),
+            None => Box::new(StringBox::new(&format!(
+                "[map/missing] Key not found: {}",
+                key_str
+            ))),
         }
     }
 
@@ -202,7 +205,10 @@ impl MapBox {
             .unwrap()
             .values()
             .map(|v| {
-                if v.as_any().downcast_ref::<crate::instance_v2::InstanceBox>().is_some() {
+                if v.as_any()
+                    .downcast_ref::<crate::instance_v2::InstanceBox>()
+                    .is_some()
+                {
                     v.share_box()
                 } else {
                     v.clone_box()

src/boxes/missing_box.rs

@@ -16,28 +16,48 @@ pub struct MissingBox {
 
 impl MissingBox {
     pub fn new() -> Self {
-        Self { base: BoxBase::new() }
+        Self {
+            base: BoxBase::new(),
+        }
     }
 
-    pub fn is_missing(&self) -> bool { true }
+    pub fn is_missing(&self) -> bool {
+        true
+    }
 }
 
 impl BoxCore for MissingBox {
-    fn box_id(&self) -> u64 { self.base.id }
-    fn parent_type_id(&self) -> Option<std::any::TypeId> { self.base.parent_type_id }
+    fn box_id(&self) -> u64 {
+        self.base.id
+    }
+    fn parent_type_id(&self) -> Option<std::any::TypeId> {
+        self.base.parent_type_id
+    }
     fn fmt_box(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         // 開発時の可視性向上のための文字列表現。prod では基本的に表面化させない想定。
         write!(f, "(missing)")
     }
-    fn as_any(&self) -> &dyn Any { self }
-    fn as_any_mut(&mut self) -> &mut dyn Any { self }
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+    fn as_any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
 }
 
 impl NyashBox for MissingBox {
-    fn type_name(&self) -> &'static str { "MissingBox" }
-    fn to_string_box(&self) -> StringBox { StringBox::new("(missing)") }
-    fn clone_box(&self) -> Box<dyn NyashBox> { Box::new(self.clone()) }
-    fn share_box(&self) -> Box<dyn NyashBox> { self.clone_box() }
+    fn type_name(&self) -> &'static str {
+        "MissingBox"
+    }
+    fn to_string_box(&self) -> StringBox {
+        StringBox::new("(missing)")
+    }
+    fn clone_box(&self) -> Box<dyn NyashBox> {
+        Box::new(self.clone())
+    }
+    fn share_box(&self) -> Box<dyn NyashBox> {
+        self.clone_box()
+    }
     fn equals(&self, other: &dyn NyashBox) -> BoolBox {
         // 欠損どうしは論理同値とみなすが、通常の等価比較は境界で禁止される想定。
         BoolBox::new(other.as_any().downcast_ref::<MissingBox>().is_some())
@@ -45,6 +65,7 @@ impl NyashBox for MissingBox {
 }
 
 impl Display for MissingBox {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { self.fmt_box(f) }
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.fmt_box(f)
+    }
 }
-

src/boxes/mod.rs

@@ -145,8 +145,8 @@ pub use egui_box::EguiBox;
 #[cfg(target_arch = "wasm32")]
 pub use web::{WebCanvasBox, WebConsoleBox, WebDisplayBox};
 
-pub mod null_box;
 pub mod missing_box;
+pub mod null_box;
 
 // High-priority Box types
 pub mod array;
@@ -168,8 +168,8 @@ pub mod intent_box;
 pub mod p2p_box;
 
 // null関数も再エクスポート
-pub use null_box::{null, NullBox};
 pub use missing_box::MissingBox;
+pub use null_box::{null, NullBox};
 
 // High-priority Box types re-export
 pub use array::ArrayBox;

src/cli/args.rs

@@ -1,7 +1,7 @@
+use super::utils::parse_debug_fuel;
+use super::CliConfig;
 use clap::{Arg, ArgMatches, Command};
 use serde_json;
-use super::CliConfig;
-use super::utils::parse_debug_fuel;
 
 pub fn parse() -> CliConfig {
     let argv: Vec<String> = std::env::args().collect();
@@ -13,10 +13,7 @@ pub fn parse() -> CliConfig {
             }
             // Provide HEX-escaped JSON as an alternate robust path for multiline/special bytes
             // Each arg is encoded as lowercase hex of its UTF-8 bytes
-            let hex_args: Vec<String> = script_args
-                .iter()
-                .map(|s| hex_encode_utf8(s))
-                .collect();
+            let hex_args: Vec<String> = script_args.iter().map(|s| hex_encode_utf8(s)).collect();
             if let Ok(hex_json) = serde_json::to_string(&hex_args) {
                 std::env::set_var("NYASH_SCRIPT_ARGS_HEX_JSON", hex_json);
             }
@@ -118,8 +115,12 @@ fn hex_encode_utf8(s: &str) -> String {
 }
 
 pub fn from_matches(matches: &ArgMatches) -> CliConfig {
-    if matches.get_flag("stage3") { std::env::set_var("NYASH_NY_COMPILER_STAGE3", "1"); }
-    if let Some(a) = matches.get_one::<String>("ny-compiler-args") { std::env::set_var("NYASH_NY_COMPILER_CHILD_ARGS", a); }
+    if matches.get_flag("stage3") {
+        std::env::set_var("NYASH_NY_COMPILER_STAGE3", "1");
+    }
+    if let Some(a) = matches.get_one::<String>("ny-compiler-args") {
+        std::env::set_var("NYASH_NY_COMPILER_CHILD_ARGS", a);
+    }
     let cfg = CliConfig {
         file: matches.get_one::<String>("file").cloned(),
         debug_fuel: parse_debug_fuel(matches.get_one::<String>("debug-fuel").unwrap()),
@@ -134,7 +135,11 @@ pub fn from_matches(matches: &ArgMatches) -> CliConfig {
         compile_native: matches.get_flag("compile-native") || matches.get_flag("aot"),
         output_file: matches.get_one::<String>("output").cloned(),
         benchmark: matches.get_flag("benchmark"),
-        iterations: matches.get_one::<String>("iterations").unwrap().parse().unwrap_or(10),
+        iterations: matches
+            .get_one::<String>("iterations")
+            .unwrap()
+            .parse()
+            .unwrap_or(10),
         vm_stats: matches.get_flag("vm-stats"),
         vm_stats_json: matches.get_flag("vm-stats-json"),
         jit_exec: matches.get_flag("jit-exec"),
@@ -145,7 +150,9 @@ pub fn from_matches(matches: &ArgMatches) -> CliConfig {
         jit_events_compile: matches.get_flag("jit-events-compile"),
         jit_events_runtime: matches.get_flag("jit-events-runtime"),
         jit_events_path: matches.get_one::<String>("jit-events-path").cloned(),
-        jit_threshold: matches.get_one::<String>("jit-threshold").and_then(|s| s.parse::<u32>().ok()),
+        jit_threshold: matches
+            .get_one::<String>("jit-threshold")
+            .and_then(|s| s.parse::<u32>().ok()),
         jit_phi_min: matches.get_flag("jit-phi-min"),
         jit_hostcall: matches.get_flag("jit-hostcall"),
         jit_handle_debug: matches.get_flag("jit-handle-debug"),
@@ -158,7 +165,10 @@ pub fn from_matches(matches: &ArgMatches) -> CliConfig {
         run_task: matches.get_one::<String>("run-task").cloned(),
         load_ny_plugins: matches.get_flag("load-ny-plugins"),
         gc_mode: matches.get_one::<String>("gc").cloned(),
-        parser_ny: matches.get_one::<String>("parser").map(|s| s == "ny").unwrap_or(false),
+        parser_ny: matches
+            .get_one::<String>("parser")
+            .map(|s| s == "ny")
+            .unwrap_or(false),
         ny_parser_pipe: matches.get_flag("ny-parser-pipe"),
         json_file: matches.get_one::<String>("json-file").cloned(),
         mir_json_file: matches.get_one::<String>("mir-json-file").cloned(),
@@ -168,7 +178,10 @@ pub fn from_matches(matches: &ArgMatches) -> CliConfig {
         build_aot: matches.get_one::<String>("build-aot").cloned(),
         build_profile: matches.get_one::<String>("build-profile").cloned(),
         build_target: matches.get_one::<String>("build-target").cloned(),
-        cli_usings: matches.get_many::<String>("using").map(|v| v.cloned().collect()).unwrap_or_else(|| Vec::new()),
+        cli_usings: matches
+            .get_many::<String>("using")
+            .map(|v| v.cloned().collect())
+            .unwrap_or_else(|| Vec::new()),
         emit_mir_json: matches.get_one::<String>("emit-mir-json").cloned(),
         program_json_to_mir: matches.get_one::<String>("program-json-to-mir").cloned(),
         emit_exe: matches.get_one::<String>("emit-exe").cloned(),
@@ -179,42 +192,94 @@ pub fn from_matches(matches: &ArgMatches) -> CliConfig {
         macro_ctx_json: matches.get_one::<String>("macro-ctx-json").cloned(),
     };
 
-    if cfg.cli_verbose { std::env::set_var("NYASH_CLI_VERBOSE", "1"); }
-    if cfg.vm_stats { std::env::set_var("NYASH_VM_STATS", "1"); }
-    if cfg.vm_stats_json { std::env::set_var("NYASH_VM_STATS_JSON", "1"); }
-    if cfg.jit_exec { std::env::set_var("NYASH_JIT_EXEC", "1"); }
-    if cfg.jit_stats { std::env::set_var("NYASH_JIT_STATS", "1"); }
-    if cfg.jit_stats_json { std::env::set_var("NYASH_JIT_STATS_JSON", "1"); }
-    if cfg.jit_dump { std::env::set_var("NYASH_JIT_DUMP", "1"); }
-    if cfg.jit_events { std::env::set_var("NYASH_JIT_EVENTS", "1"); }
-    if cfg.jit_events_compile { std::env::set_var("NYASH_JIT_EVENTS_COMPILE", "1"); }
-    if cfg.jit_events_runtime { std::env::set_var("NYASH_JIT_EVENTS_RUNTIME", "1"); }
-    if let Some(p) = &cfg.jit_events_path { std::env::set_var("NYASH_JIT_EVENTS_PATH", p); }
-    if let Some(t) = cfg.jit_threshold { std::env::set_var("NYASH_JIT_THRESHOLD", t.to_string()); }
-    if cfg.jit_phi_min { std::env::set_var("NYASH_JIT_PHI_MIN", "1"); }
-    if cfg.jit_hostcall { std::env::set_var("NYASH_JIT_HOSTCALL", "1"); }
-    if cfg.jit_handle_debug { std::env::set_var("NYASH_JIT_HANDLE_DEBUG", "1"); }
-    if cfg.jit_native_f64 { std::env::set_var("NYASH_JIT_NATIVE_F64", "1"); }
-    if cfg.jit_native_bool { std::env::set_var("NYASH_JIT_NATIVE_BOOL", "1"); }
-    if cfg.jit_only { std::env::set_var("NYASH_JIT_ONLY", "1"); }
-    if cfg.jit_direct { std::env::set_var("NYASH_JIT_DIRECT", "1"); }
-    if let Some(gc) = &cfg.gc_mode { std::env::set_var("NYASH_GC_MODE", gc); }
+    if cfg.cli_verbose {
+        std::env::set_var("NYASH_CLI_VERBOSE", "1");
+    }
+    if cfg.vm_stats {
+        std::env::set_var("NYASH_VM_STATS", "1");
+    }
+    if cfg.vm_stats_json {
+        std::env::set_var("NYASH_VM_STATS_JSON", "1");
+    }
+    if cfg.jit_exec {
+        std::env::set_var("NYASH_JIT_EXEC", "1");
+    }
+    if cfg.jit_stats {
+        std::env::set_var("NYASH_JIT_STATS", "1");
+    }
+    if cfg.jit_stats_json {
+        std::env::set_var("NYASH_JIT_STATS_JSON", "1");
+    }
+    if cfg.jit_dump {
+        std::env::set_var("NYASH_JIT_DUMP", "1");
+    }
+    if cfg.jit_events {
+        std::env::set_var("NYASH_JIT_EVENTS", "1");
+    }
+    if cfg.jit_events_compile {
+        std::env::set_var("NYASH_JIT_EVENTS_COMPILE", "1");
+    }
+    if cfg.jit_events_runtime {
+        std::env::set_var("NYASH_JIT_EVENTS_RUNTIME", "1");
+    }
+    if let Some(p) = &cfg.jit_events_path {
+        std::env::set_var("NYASH_JIT_EVENTS_PATH", p);
+    }
+    if let Some(t) = cfg.jit_threshold {
+        std::env::set_var("NYASH_JIT_THRESHOLD", t.to_string());
+    }
+    if cfg.jit_phi_min {
+        std::env::set_var("NYASH_JIT_PHI_MIN", "1");
+    }
+    if cfg.jit_hostcall {
+        std::env::set_var("NYASH_JIT_HOSTCALL", "1");
+    }
+    if cfg.jit_handle_debug {
+        std::env::set_var("NYASH_JIT_HANDLE_DEBUG", "1");
+    }
+    if cfg.jit_native_f64 {
+        std::env::set_var("NYASH_JIT_NATIVE_F64", "1");
+    }
+    if cfg.jit_native_bool {
+        std::env::set_var("NYASH_JIT_NATIVE_BOOL", "1");
+    }
+    if cfg.jit_only {
+        std::env::set_var("NYASH_JIT_ONLY", "1");
+    }
+    if cfg.jit_direct {
+        std::env::set_var("NYASH_JIT_DIRECT", "1");
+    }
+    if let Some(gc) = &cfg.gc_mode {
+        std::env::set_var("NYASH_GC_MODE", gc);
+    }
 
     if matches.get_flag("run-tests") {
         std::env::set_var("NYASH_RUN_TESTS", "1");
-        if let Some(filter) = matches.get_one::<String>("test-filter") { std::env::set_var("NYASH_TEST_FILTER", filter); }
+        if let Some(filter) = matches.get_one::<String>("test-filter") {
+            std::env::set_var("NYASH_TEST_FILTER", filter);
+        }
         if let Some(entry) = matches.get_one::<String>("test-entry") {
             let v = entry.as_str();
-            if v == "wrap" || v == "override" { std::env::set_var("NYASH_TEST_ENTRY", v); }
+            if v == "wrap" || v == "override" {
+                std::env::set_var("NYASH_TEST_ENTRY", v);
+            }
         }
         if let Some(ret) = matches.get_one::<String>("test-return") {
             let v = ret.as_str();
-            if v == "tests" || v == "original" { std::env::set_var("NYASH_TEST_RETURN", v); }
+            if v == "tests" || v == "original" {
+                std::env::set_var("NYASH_TEST_RETURN", v);
+            }
         }
     }
-    if matches.get_flag("macro-preexpand") { std::env::set_var("NYASH_MACRO_SELFHOST_PRE_EXPAND", "1"); }
-    if matches.get_flag("macro-preexpand-auto") { std::env::set_var("NYASH_MACRO_SELFHOST_PRE_EXPAND", "auto"); }
-    if matches.get_flag("macro-top-level-allow") { std::env::set_var("NYASH_MACRO_TOPLEVEL_ALLOW", "1"); }
+    if matches.get_flag("macro-preexpand") {
+        std::env::set_var("NYASH_MACRO_SELFHOST_PRE_EXPAND", "1");
+    }
+    if matches.get_flag("macro-preexpand-auto") {
+        std::env::set_var("NYASH_MACRO_SELFHOST_PRE_EXPAND", "auto");
+    }
+    if matches.get_flag("macro-top-level-allow") {
+        std::env::set_var("NYASH_MACRO_TOPLEVEL_ALLOW", "1");
+    }
     if let Some(p) = matches.get_one::<String>("macro-profile") {
         match p.as_str() {
             "dev" | "ci-fast" | "strict" => {

src/cli/mod.rs

@@ -6,7 +6,6 @@ mod args;
 mod groups;
 mod utils;
 
-
 /// Command-line configuration structure
 #[derive(Debug, Clone)]
 pub struct CliConfig {
@@ -69,14 +68,22 @@ pub struct CliConfig {
     pub macro_ctx_json: Option<String>,
 }
 
-pub use groups::{BackendConfig, BuildConfig, CliGroups, DebugConfig, EmitConfig, InputConfig, JitConfig, ParserPipeConfig};
+pub use groups::{
+    BackendConfig, BuildConfig, CliGroups, DebugConfig, EmitConfig, InputConfig, JitConfig,
+    ParserPipeConfig,
+};
 
 impl CliConfig {
-    pub fn parse() -> Self { args::parse() }
+    pub fn parse() -> Self {
+        args::parse()
+    }
 
     pub fn as_groups(&self) -> CliGroups {
         CliGroups {
-            input: InputConfig { file: self.file.clone(), cli_usings: self.cli_usings.clone() },
+            input: InputConfig {
+                file: self.file.clone(),
+                cli_usings: self.cli_usings.clone(),
+            },
             debug: DebugConfig {
                 debug_fuel: self.debug_fuel,
                 dump_ast: self.dump_ast,

src/cli/utils.rs

@@ -6,4 +6,3 @@ pub fn parse_debug_fuel(value: &str) -> Option<usize> {
         value.parse::<usize>().ok()
     }
 }
-

src/config/env.rs

@@ -121,7 +121,9 @@ pub fn await_max_ms() -> u64 {
 /// Enable MIR PHI non-generation for Bridge compatibility mode only.
 /// フェーズM.2: MirBuilder/LoopBuilderでPHI統一済み、Bridge層の互換性制御のみ
 /// Default: PHI-ON (Phase 15 direction), override with NYASH_MIR_NO_PHI=1
-pub fn mir_no_phi() -> bool { env_bool("NYASH_MIR_NO_PHI") }
+pub fn mir_no_phi() -> bool {
+    env_bool("NYASH_MIR_NO_PHI")
+}
 
 /// Allow verifier to skip SSA/dominance/merge checks for PHI-less MIR.
 pub fn verify_allow_no_phi() -> bool {
@@ -131,11 +133,15 @@ pub fn verify_allow_no_phi() -> bool {
 /// Enable strict edge-copy policy verification in PHI-off mode.
 /// When enabled, merge blocks must receive merged values via predecessor copies only,
 /// and the merge block itself must not introduce a self-copy to the merged destination.
-pub fn verify_edge_copy_strict() -> bool { env_bool("NYASH_VERIFY_EDGE_COPY_STRICT") }
+pub fn verify_edge_copy_strict() -> bool {
+    env_bool("NYASH_VERIFY_EDGE_COPY_STRICT")
+}
 
 /// Enforce purity of return blocks: no side-effecting instructions allowed before Return
 /// Default: OFF. Enable with NYASH_VERIFY_RET_PURITY=1 in dev/profiling sessions.
-pub fn verify_ret_purity() -> bool { env_bool("NYASH_VERIFY_RET_PURITY") }
+pub fn verify_ret_purity() -> bool {
+    env_bool("NYASH_VERIFY_RET_PURITY")
+}
 
 // ---- LLVM harness toggle (llvmlite) ----
 pub fn llvm_use_harness() -> bool {
@@ -172,7 +178,9 @@ pub fn env_bool_default(key: &str, default: bool) -> bool {
 /// Global fail-fast policy for runtime fallbacks.
 /// Default: ON (true) to prohibit silent/different-route fallbacks in Rust layer.
 /// Set NYASH_FAIL_FAST=0 to temporarily allow legacy fallbacks during bring-up.
-pub fn fail_fast() -> bool { env_bool_default("NYASH_FAIL_FAST", true) }
+pub fn fail_fast() -> bool {
+    env_bool_default("NYASH_FAIL_FAST", true)
+}
 
 // VM legacy by-name call fallback was removed (Phase 2 complete).
 
@@ -204,7 +212,9 @@ pub fn plugin_only() -> bool {
 /// Core-13 "pure" mode: after normalization, only the 13 canonical ops are allowed.
 /// If enabled, the optimizer will try lightweight rewrites for Load/Store/NewBox/Unary,
 /// and the final verifier will reject any remaining non-Core-13 ops.
-pub fn mir_core13_pure() -> bool { env_bool("NYASH_MIR_CORE13_PURE") }
+pub fn mir_core13_pure() -> bool {
+    env_bool("NYASH_MIR_CORE13_PURE")
+}
 
 /// Enable heuristic pre-pin of comparison operands in if/loop headers.
 /// Default: OFF (0). Set NYASH_MIR_PREPIN=1 to enable.
@@ -235,14 +245,26 @@ pub fn opt_diag_fail() -> bool {
 // ---- Legacy compatibility (dev-only) ----
 /// Enable legacy InstanceBox fields (SharedNyashBox map) for compatibility.
 /// Default: OFF. Set NYASH_LEGACY_FIELDS_ENABLE=1 to materialize and use legacy fields.
-pub fn legacy_fields_enable() -> bool { env_bool("NYASH_LEGACY_FIELDS_ENABLE") }
+pub fn legacy_fields_enable() -> bool {
+    env_bool("NYASH_LEGACY_FIELDS_ENABLE")
+}
 
 // ---- GC/Runtime tracing (execution-affecting visibility) ----
-pub fn gc_trace() -> bool { env_bool("NYASH_GC_TRACE") }
-pub fn gc_barrier_trace() -> bool { env_bool("NYASH_GC_BARRIER_TRACE") }
-pub fn runtime_checkpoint_trace() -> bool { env_bool("NYASH_RUNTIME_CHECKPOINT_TRACE") }
-pub fn vm_pic_stats() -> bool { env_bool("NYASH_VM_PIC_STATS") }
-pub fn vm_vt_trace() -> bool { env_bool("NYASH_VM_VT_TRACE") }
+pub fn gc_trace() -> bool {
+    env_bool("NYASH_GC_TRACE")
+}
+pub fn gc_barrier_trace() -> bool {
+    env_bool("NYASH_GC_BARRIER_TRACE")
+}
+pub fn runtime_checkpoint_trace() -> bool {
+    env_bool("NYASH_RUNTIME_CHECKPOINT_TRACE")
+}
+pub fn vm_pic_stats() -> bool {
+    env_bool("NYASH_VM_PIC_STATS")
+}
+pub fn vm_vt_trace() -> bool {
+    env_bool("NYASH_VM_VT_TRACE")
+}
 pub fn vm_pic_trace() -> bool {
     std::env::var("NYASH_VM_PIC_TRACE").ok().as_deref() == Some("1")
 }
@@ -349,7 +371,11 @@ pub fn extern_trace() -> bool {
 // ---- Operator Boxes adopt defaults ----
 /// CompareOperator.apply adopt: default ON (prod/devともに採用)
 pub fn operator_box_compare_adopt() -> bool {
-    match std::env::var("NYASH_OPERATOR_BOX_COMPARE_ADOPT").ok().as_deref().map(|v| v.to_ascii_lowercase()) {
+    match std::env::var("NYASH_OPERATOR_BOX_COMPARE_ADOPT")
+        .ok()
+        .as_deref()
+        .map(|v| v.to_ascii_lowercase())
+    {
         Some(ref s) if s == "0" || s == "false" || s == "off" => false,
         Some(ref s) if s == "1" || s == "true" || s == "on" => true,
         _ => true, // default ON
@@ -357,7 +383,11 @@ pub fn operator_box_compare_adopt() -> bool {
 }
 /// AddOperator.apply adopt: default OFF（順次昇格のため）
 pub fn operator_box_add_adopt() -> bool {
-    match std::env::var("NYASH_OPERATOR_BOX_ADD_ADOPT").ok().as_deref().map(|v| v.to_ascii_lowercase()) {
+    match std::env::var("NYASH_OPERATOR_BOX_ADD_ADOPT")
+        .ok()
+        .as_deref()
+        .map(|v| v.to_ascii_lowercase())
+    {
         Some(ref s) if s == "0" || s == "false" || s == "off" => false,
         _ => true, // default ON (promoted after validation)
     }
@@ -415,9 +445,15 @@ pub fn enable_using() -> bool {
 pub fn using_profile() -> String {
     std::env::var("NYASH_USING_PROFILE").unwrap_or_else(|_| "dev".to_string())
 }
-pub fn using_is_prod() -> bool { using_profile().eq_ignore_ascii_case("prod") }
-pub fn using_is_ci() -> bool { using_profile().eq_ignore_ascii_case("ci") }
-pub fn using_is_dev() -> bool { using_profile().eq_ignore_ascii_case("dev") }
+pub fn using_is_prod() -> bool {
+    using_profile().eq_ignore_ascii_case("prod")
+}
+pub fn using_is_ci() -> bool {
+    using_profile().eq_ignore_ascii_case("ci")
+}
+pub fn using_is_dev() -> bool {
+    using_profile().eq_ignore_ascii_case("dev")
+}
 /// Allow `using "path"` statements in source (dev-only by default).
 pub fn allow_using_file() -> bool {
     // SSOT 徹底: 全プロファイルで既定禁止（nyash.toml を唯一の真実に）
@@ -432,7 +468,11 @@ pub fn allow_using_file() -> bool {
 /// 1) Explicit env `NYASH_USING_AST` = 1/true/on → enabled, = 0/false/off → disabled
 /// 2) Default by profile: dev/ci → ON, prod → OFF
 pub fn using_ast_enabled() -> bool {
-    match std::env::var("NYASH_USING_AST").ok().as_deref().map(|v| v.to_ascii_lowercase()) {
+    match std::env::var("NYASH_USING_AST")
+        .ok()
+        .as_deref()
+        .map(|v| v.to_ascii_lowercase())
+    {
         Some(ref s) if s == "1" || s == "true" || s == "on" => true,
         Some(ref s) if s == "0" || s == "false" || s == "off" => false,
         _ => !using_is_prod(), // dev/ci → true, prod → false
@@ -443,7 +483,11 @@ pub fn using_ast_enabled() -> bool {
 /// - dev/ci: default true (allow, with WARN)
 /// Override with NYASH_VM_USER_INSTANCE_BOXCALL={0|1}
 pub fn vm_allow_user_instance_boxcall() -> bool {
-    match std::env::var("NYASH_VM_USER_INSTANCE_BOXCALL").ok().as_deref().map(|v| v.to_ascii_lowercase()) {
+    match std::env::var("NYASH_VM_USER_INSTANCE_BOXCALL")
+        .ok()
+        .as_deref()
+        .map(|v| v.to_ascii_lowercase())
+    {
         Some(ref s) if s == "0" || s == "false" || s == "off" => false,
         Some(ref s) if s == "1" || s == "true" || s == "on" => true,
         _ => !using_is_prod(),
@@ -630,7 +674,10 @@ fn warn_alias_once(alias: &str, primary: &str) {
     let set = WARNED_ALIASES.get_or_init(|| Mutex::new(HashSet::new()));
     if let Ok(mut s) = set.lock() {
         if !s.contains(alias) {
-            eprintln!("[deprecate/env] '{}' is deprecated; use '{}'", alias, primary);
+            eprintln!(
+                "[deprecate/env] '{}' is deprecated; use '{}'",
+                alias, primary
+            );
             s.insert(alias.to_string());
         }
     }
@@ -652,7 +699,9 @@ pub fn llvm_opt_level() -> String {
 
 /// Gate‑C(Core) route request (primary: NYASH_GATE_C_CORE; alias: HAKO_GATE_C_CORE)
 pub fn gate_c_core() -> bool {
-    if env_bool("NYASH_GATE_C_CORE") { return true; }
+    if env_bool("NYASH_GATE_C_CORE") {
+        return true;
+    }
     if env_bool("HAKO_GATE_C_CORE") {
         warn_alias_once("HAKO_GATE_C_CORE", "NYASH_GATE_C_CORE");
         return true;

src/config/provider_env.rs

@@ -14,11 +14,18 @@ pub enum ProviderPolicy {
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum FileBoxMode { Auto, CoreRo, PluginOnly }
+pub enum FileBoxMode {
+    Auto,
+    CoreRo,
+    PluginOnly,
+}
 
 /// Read global provider policy (affects Auto mode only)
 pub fn provider_policy_from_env() -> ProviderPolicy {
-    match std::env::var("HAKO_PROVIDER_POLICY").unwrap_or_else(|_| "strict-plugin-first".to_string()).as_str() {
+    match std::env::var("HAKO_PROVIDER_POLICY")
+        .unwrap_or_else(|_| "strict-plugin-first".to_string())
+        .as_str()
+    {
         "safe-core-first" => ProviderPolicy::SafeCoreFirst,
         "static-preferred" => ProviderPolicy::StaticPreferred,
         _ => ProviderPolicy::StrictPluginFirst,
@@ -27,13 +34,18 @@ pub fn provider_policy_from_env() -> ProviderPolicy {
 
 /// Read FileBox mode from environment variables
 pub fn filebox_mode_from_env() -> FileBoxMode {
-    match std::env::var("NYASH_FILEBOX_MODE").unwrap_or_else(|_| "auto".to_string()).as_str() {
+    match std::env::var("NYASH_FILEBOX_MODE")
+        .unwrap_or_else(|_| "auto".to_string())
+        .as_str()
+    {
         "core-ro" => FileBoxMode::CoreRo,
         "plugin-only" => FileBoxMode::PluginOnly,
         _ => {
             if std::env::var("NYASH_DISABLE_PLUGINS").as_deref() == Ok("1") {
                 FileBoxMode::CoreRo
-            } else { FileBoxMode::Auto }
+            } else {
+                FileBoxMode::Auto
+            }
         }
     }
 }
@@ -44,4 +56,3 @@ pub fn filebox_mode_from_env() -> FileBoxMode {
 pub fn allow_filebox_fallback_override(quiet_pipe: bool) -> bool {
     quiet_pipe || crate::config::env::env_bool("NYASH_FILEBOX_ALLOW_FALLBACK")
 }
-

src/debug/hub.rs

@@ -9,7 +9,13 @@ static EMIT_COUNTER: AtomicU64 = AtomicU64::new(0);
 /// - NYASH_DEBUG_ENABLE=1           master gate
 /// - NYASH_DEBUG_KINDS=resolve,ssa  allowed cats (comma-separated)
 /// - NYASH_DEBUG_SINK=path          file to append JSONL events
-pub fn emit(cat: &str, kind: &str, fn_name: Option<&str>, region_id: Option<&str>, meta: serde_json::Value) {
+pub fn emit(
+    cat: &str,
+    kind: &str,
+    fn_name: Option<&str>,
+    region_id: Option<&str>,
+    meta: serde_json::Value,
+) {
     if std::env::var("NYASH_DEBUG_ENABLE").ok().as_deref() != Some("1") {
         return;
     }
@@ -25,7 +31,9 @@ pub fn emit(cat: &str, kind: &str, fn_name: Option<&str>, region_id: Option<&str
         .unwrap_or(1);
     if sample_every > 1 {
         let n = EMIT_COUNTER.fetch_add(1, Ordering::Relaxed) + 1;
-        if n % sample_every != 0 { return; }
+        if n % sample_every != 0 {
+            return;
+        }
     }
     let sink = match std::env::var("NYASH_DEBUG_SINK") {
         Ok(s) if !s.is_empty() => s,
@@ -41,7 +49,11 @@ pub fn emit(cat: &str, kind: &str, fn_name: Option<&str>, region_id: Option<&str
         "kind": kind,
         "meta": meta,
     });
-    if let Ok(mut f) = std::fs::OpenOptions::new().create(true).append(true).open(&sink) {
+    if let Ok(mut f) = std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(&sink)
+    {
         let _ = writeln!(f, "{}", obj.to_string());
     }
 }

src/debug/mod.rs

@@ -1,2 +1,2 @@
-pub mod log;
 pub mod hub;
+pub mod log;

src/grammar/generated.rs

@@ -36,37 +36,15 @@ pub static OPERATORS_DIV_RULES: &[(&str, &str, &str, &str)] = &[
 ];
 pub fn lookup_keyword(word: &str) -> Option<&'static str> {
     for (k, t) in KEYWORDS {
-        if *k == word { return Some(*t); }
+        if *k == word {
+            return Some(*t);
+        }
     }
     None
 }
 
 pub static SYNTAX_ALLOWED_STATEMENTS: &[&str] = &[
-    "box",
-    "global",
-    "function",
-    "static",
-    "if",
-    "loop",
-    "break",
-    "return",
-    "print",
-    "nowait",
-    "include",
-    "local",
-    "outbox",
-    "try",
-    "throw",
-    "using",
-    "from",
-];
-pub static SYNTAX_ALLOWED_BINOPS: &[&str] = &[
-    "add",
-    "sub",
-    "mul",
-    "div",
-    "and",
-    "or",
-    "eq",
-    "ne",
+    "box", "global", "function", "static", "if", "loop", "break", "return", "print", "nowait",
+    "include", "local", "outbox", "try", "throw", "using", "from",
 ];
+pub static SYNTAX_ALLOWED_BINOPS: &[&str] = &["add", "sub", "mul", "div", "and", "or", "eq", "ne"];

src/host_providers/llvm_codegen.rs

@@ -1,8 +1,8 @@
+use std::ffi::{CStr, CString};
 use std::fs;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::process::Command;
-use std::ffi::{CString, CStr};
 
 pub struct Opts {
     pub out: Option<PathBuf>,
@@ -13,9 +13,13 @@ pub struct Opts {
 
 fn resolve_ny_llvmc() -> PathBuf {
     if let Ok(s) = std::env::var("NYASH_NY_LLVM_COMPILER") {
-        if !s.is_empty() { return PathBuf::from(s); }
+        if !s.is_empty() {
+            return PathBuf::from(s);
+        }
+    }
+    if let Ok(p) = which::which("ny-llvmc") {
+        return p;
     }
-    if let Ok(p) = which::which("ny-llvmc") { return p; }
     PathBuf::from("target/release/ny-llvmc")
 }
 
@@ -25,7 +29,10 @@ pub fn mir_json_to_object(mir_json: &str, opts: Opts) -> Result<PathBuf, String>
     // Optional provider selection (C-API) — guarded by env flags
     // NYASH_LLVM_USE_CAPI=1 and HAKO_V1_EXTERN_PROVIDER_C_ABI=1
     if std::env::var("NYASH_LLVM_USE_CAPI").ok().as_deref() == Some("1")
-        && std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI").ok().as_deref() == Some("1")
+        && std::env::var("HAKO_V1_EXTERN_PROVIDER_C_ABI")
+            .ok()
+            .as_deref()
+            == Some("1")
     {
         // Basic shape check first
         if !mir_json.contains("\"functions\"") || !mir_json.contains("\"blocks\"") {
@@ -37,11 +44,19 @@ pub fn mir_json_to_object(mir_json: &str, opts: Opts) -> Result<PathBuf, String>
         let tmp_dir = std::env::temp_dir();
         let in_path = tmp_dir.join("hako_llvm_in.json");
         {
-            let mut f = fs::File::create(&in_path).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
-            f.write_all(mir_json.as_bytes()).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+            let mut f = fs::File::create(&in_path)
+                .map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+            f.write_all(mir_json.as_bytes())
+                .map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+        }
+        let out_path = if let Some(p) = opts.out.clone() {
+            p
+        } else {
+            tmp_dir.join("hako_llvm_out.o")
+        };
+        if let Some(parent) = out_path.parent() {
+            let _ = fs::create_dir_all(parent);
         }
-        let out_path = if let Some(p) = opts.out.clone() { p } else { tmp_dir.join("hako_llvm_out.o") };
-        if let Some(parent) = out_path.parent() { let _ = fs::create_dir_all(parent); }
         match compile_via_capi(&in_path, &out_path) {
             Ok(()) => return Ok(out_path),
             Err(e) => {
@@ -74,26 +89,41 @@ pub fn mir_json_to_object(mir_json: &str, opts: Opts) -> Result<PathBuf, String>
     let tmp_dir = std::env::temp_dir();
     let in_path = tmp_dir.join("hako_llvm_in.json");
     {
-        let mut f = fs::File::create(&in_path).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
-        f.write_all(mir_json.as_bytes()).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+        let mut f =
+            fs::File::create(&in_path).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+        f.write_all(mir_json.as_bytes())
+            .map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
     }
 
     // Output path
-    let out_path = if let Some(p) = opts.out.clone() { p } else { tmp_dir.join("hako_llvm_out.o") };
-    if let Some(parent) = out_path.parent() { let _ = fs::create_dir_all(parent); }
+    let out_path = if let Some(p) = opts.out.clone() {
+        p
+    } else {
+        tmp_dir.join("hako_llvm_out.o")
+    };
+    if let Some(parent) = out_path.parent() {
+        let _ = fs::create_dir_all(parent);
+    }
 
     // Build command: ny-llvmc --in <json> --emit obj --out <out>
     let mut cmd = Command::new(&ny_llvmc);
-    cmd.arg("--in").arg(&in_path)
-        .arg("--emit").arg("obj")
-        .arg("--out").arg(&out_path);
-    if let Some(nyrt) = opts.nyrt.as_ref() { cmd.arg("--nyrt").arg(nyrt); }
+    cmd.arg("--in")
+        .arg(&in_path)
+        .arg("--emit")
+        .arg("obj")
+        .arg("--out")
+        .arg(&out_path);
+    if let Some(nyrt) = opts.nyrt.as_ref() {
+        cmd.arg("--nyrt").arg(nyrt);
+    }
     if let Some(level) = opts.opt_level.as_ref() {
         cmd.env("HAKO_LLVM_OPT_LEVEL", level);
         cmd.env("NYASH_LLVM_OPT_LEVEL", level);
     }
 
-    let status = cmd.status().map_err(|e| format!("[llvmemit/spawn/error] {}", e))?;
+    let status = cmd
+        .status()
+        .map_err(|e| format!("[llvmemit/spawn/error] {}", e))?;
     if !status.success() {
         let code = status.code().unwrap_or(1);
         let tag = format!("[llvmemit/ny-llvmc/failed status={}]", code);
@@ -121,19 +151,28 @@ fn compile_via_capi(json_in: &Path, obj_out: &Path) -> Result<(), String> {
     unsafe {
         // Resolve library path
         let mut candidates: Vec<PathBuf> = Vec::new();
-        if let Ok(p) = std::env::var("HAKO_AOT_FFI_LIB") { if !p.is_empty() { candidates.push(PathBuf::from(p)); } }
+        if let Ok(p) = std::env::var("HAKO_AOT_FFI_LIB") {
+            if !p.is_empty() {
+                candidates.push(PathBuf::from(p));
+            }
+        }
         candidates.push(PathBuf::from("target/release/libhako_llvmc_ffi.so"));
         candidates.push(PathBuf::from("lib/libhako_llvmc_ffi.so"));
-        let lib_path = candidates.into_iter().find(|p| p.exists())
+        let lib_path = candidates
+            .into_iter()
+            .find(|p| p.exists())
             .ok_or_else(|| "FFI library not found (set HAKO_AOT_FFI_LIB)".to_string())?;
         let lib = Library::new(lib_path).map_err(|e| format!("dlopen failed: {}", e))?;
         // Symbol: int hako_llvmc_compile_json(const char*, const char*, char**)
-        type CompileFn = unsafe extern "C" fn(*const c_char, *const c_char, *mut *mut c_char) -> c_int;
+        type CompileFn =
+            unsafe extern "C" fn(*const c_char, *const c_char, *mut *mut c_char) -> c_int;
         let func: libloading::Symbol<CompileFn> = lib
             .get(b"hako_llvmc_compile_json\0")
             .map_err(|e| format!("dlsym failed: {}", e))?;
-        let cin = CString::new(json_in.to_string_lossy().as_bytes()).map_err(|_| "invalid json path".to_string())?;
-        let cout = CString::new(obj_out.to_string_lossy().as_bytes()).map_err(|_| "invalid out path".to_string())?;
+        let cin = CString::new(json_in.to_string_lossy().as_bytes())
+            .map_err(|_| "invalid json path".to_string())?;
+        let cout = CString::new(obj_out.to_string_lossy().as_bytes())
+            .map_err(|_| "invalid out path".to_string())?;
         let mut err_ptr: *mut c_char = std::ptr::null_mut();
         // Avoid recursive FFI-in-FFI: force inner AOT to use CLI path
         let prev = std::env::var("HAKO_AOT_USE_FFI").ok();
@@ -156,17 +195,31 @@ fn compile_via_capi(json_in: &Path, obj_out: &Path) -> Result<(), String> {
             );
         }
 
-        let rc = func(cin.as_ptr(), cout.as_ptr(), &mut err_ptr as *mut *mut c_char);
-        if let Some(v) = prev { std::env::set_var("HAKO_AOT_USE_FFI", v); } else { std::env::remove_var("HAKO_AOT_USE_FFI"); }
+        let rc = func(
+            cin.as_ptr(),
+            cout.as_ptr(),
+            &mut err_ptr as *mut *mut c_char,
+        );
+        if let Some(v) = prev {
+            std::env::set_var("HAKO_AOT_USE_FFI", v);
+        } else {
+            std::env::remove_var("HAKO_AOT_USE_FFI");
+        }
         if rc != 0 {
-            let msg = if !err_ptr.is_null() { CStr::from_ptr(err_ptr).to_string_lossy().to_string() } else { "compile failed".to_string() };
+            let msg = if !err_ptr.is_null() {
+                CStr::from_ptr(err_ptr).to_string_lossy().to_string()
+            } else {
+                "compile failed".to_string()
+            };
             // Free error string (allocated by C side)
             if !err_ptr.is_null() {
                 free(err_ptr as *mut c_void);
             }
             return Err(msg);
         }
-        if !obj_out.exists() { return Err("object not produced".into()); }
+        if !obj_out.exists() {
+            return Err("object not produced".into());
+        }
         Ok(())
     }
 }
@@ -177,13 +230,19 @@ fn compile_via_capi(_json_in: &Path, _obj_out: &Path) -> Result<(), String> {
 }
 
 /// Link an object to an executable via C-API FFI bundle.
-pub fn link_object_capi(obj_in: &Path, exe_out: &Path, extra_ldflags: Option<&str>) -> Result<(), String> {
+pub fn link_object_capi(
+    obj_in: &Path,
+    exe_out: &Path,
+    extra_ldflags: Option<&str>,
+) -> Result<(), String> {
     // Compute effective ldflags
     let mut eff: Option<String> = extra_ldflags.map(|s| s.to_string());
     let empty = eff.as_deref().map(|s| s.trim().is_empty()).unwrap_or(true);
     if empty {
         if let Ok(s) = std::env::var("HAKO_AOT_LDFLAGS") {
-            if !s.trim().is_empty() { eff = Some(s); }
+            if !s.trim().is_empty() {
+                eff = Some(s);
+            }
         }
     }
     if eff.is_none() {
@@ -224,35 +283,68 @@ fn link_via_capi(obj_in: &Path, exe_out: &Path, extra_ldflags: Option<&str>) ->
 
     unsafe {
         let mut candidates: Vec<PathBuf> = Vec::new();
-        if let Ok(p) = std::env::var("HAKO_AOT_FFI_LIB") { if !p.is_empty() { candidates.push(PathBuf::from(p)); } }
+        if let Ok(p) = std::env::var("HAKO_AOT_FFI_LIB") {
+            if !p.is_empty() {
+                candidates.push(PathBuf::from(p));
+            }
+        }
         candidates.push(PathBuf::from("target/release/libhako_llvmc_ffi.so"));
         candidates.push(PathBuf::from("lib/libhako_llvmc_ffi.so"));
-        let lib_path = candidates.into_iter().find(|p| p.exists())
+        let lib_path = candidates
+            .into_iter()
+            .find(|p| p.exists())
             .ok_or_else(|| "FFI library not found (set HAKO_AOT_FFI_LIB)".to_string())?;
         let lib = Library::new(lib_path).map_err(|e| format!("dlopen failed: {}", e))?;
         // int hako_llvmc_link_obj(const char*, const char*, const char*, char**)
-        type LinkFn = unsafe extern "C" fn(*const c_char, *const c_char, *const c_char, *mut *mut c_char) -> c_int;
+        type LinkFn = unsafe extern "C" fn(
+            *const c_char,
+            *const c_char,
+            *const c_char,
+            *mut *mut c_char,
+        ) -> c_int;
         let func: libloading::Symbol<LinkFn> = lib
             .get(b"hako_llvmc_link_obj\0")
             .map_err(|e| format!("dlsym failed: {}", e))?;
-        let cobj = CString::new(obj_in.to_string_lossy().as_bytes()).map_err(|_| "invalid obj path".to_string())?;
-        let cexe = CString::new(exe_out.to_string_lossy().as_bytes()).map_err(|_| "invalid exe path".to_string())?;
+        let cobj = CString::new(obj_in.to_string_lossy().as_bytes())
+            .map_err(|_| "invalid obj path".to_string())?;
+        let cexe = CString::new(exe_out.to_string_lossy().as_bytes())
+            .map_err(|_| "invalid exe path".to_string())?;
         let ldflags_owned;
-        let cflags_ptr = if let Some(s) = extra_ldflags { ldflags_owned = CString::new(s).map_err(|_| "invalid ldflags".to_string())?; ldflags_owned.as_ptr() } else { std::ptr::null() };
+        let cflags_ptr = if let Some(s) = extra_ldflags {
+            ldflags_owned = CString::new(s).map_err(|_| "invalid ldflags".to_string())?;
+            ldflags_owned.as_ptr()
+        } else {
+            std::ptr::null()
+        };
         let mut err_ptr: *mut c_char = std::ptr::null_mut();
         // Avoid recursive FFI-in-FFI
         let prev = std::env::var("HAKO_AOT_USE_FFI").ok();
         std::env::set_var("HAKO_AOT_USE_FFI", "0");
-        let rc = func(cobj.as_ptr(), cexe.as_ptr(), cflags_ptr, &mut err_ptr as *mut *mut c_char);
-        if let Some(v) = prev { std::env::set_var("HAKO_AOT_USE_FFI", v); } else { std::env::remove_var("HAKO_AOT_USE_FFI"); }
+        let rc = func(
+            cobj.as_ptr(),
+            cexe.as_ptr(),
+            cflags_ptr,
+            &mut err_ptr as *mut *mut c_char,
+        );
+        if let Some(v) = prev {
+            std::env::set_var("HAKO_AOT_USE_FFI", v);
+        } else {
+            std::env::remove_var("HAKO_AOT_USE_FFI");
+        }
         if rc != 0 {
-            let msg = if !err_ptr.is_null() { CStr::from_ptr(err_ptr).to_string_lossy().to_string() } else { "link failed".to_string() };
+            let msg = if !err_ptr.is_null() {
+                CStr::from_ptr(err_ptr).to_string_lossy().to_string()
+            } else {
+                "link failed".to_string()
+            };
             if !err_ptr.is_null() {
                 free(err_ptr as *mut c_void);
             }
             return Err(msg);
         }
-        if !exe_out.exists() { return Err("exe not produced".into()); }
+        if !exe_out.exists() {
+            return Err("exe not produced".into());
+        }
         Ok(())
     }
 }
@@ -263,21 +355,31 @@ fn link_via_capi(_obj_in: &Path, _exe_out: &Path, _extra: Option<&str>) -> Resul
 }
 
 fn resolve_python3() -> Option<PathBuf> {
-    if let Ok(p) = which::which("python3") { return Some(p); }
-    if let Ok(p) = which::which("python") { return Some(p); }
+    if let Ok(p) = which::which("python3") {
+        return Some(p);
+    }
+    if let Ok(p) = which::which("python") {
+        return Some(p);
+    }
     None
 }
 
 fn resolve_llvmlite_harness() -> Option<PathBuf> {
     if let Ok(root) = std::env::var("NYASH_ROOT") {
         let p = PathBuf::from(root).join("tools/llvmlite_harness.py");
-        if p.exists() { return Some(p); }
+        if p.exists() {
+            return Some(p);
+        }
     }
     let p = PathBuf::from("tools/llvmlite_harness.py");
-    if p.exists() { return Some(p); }
+    if p.exists() {
+        return Some(p);
+    }
     // Also try repo-relative (target may run elsewhere)
     let p2 = PathBuf::from("../tools/llvmlite_harness.py");
-    if p2.exists() { return Some(p2); }
+    if p2.exists() {
+        return Some(p2);
+    }
     None
 }
 
@@ -303,17 +405,27 @@ fn mir_json_to_object_llvmlite(mir_json: &str, opts: &Opts) -> Result<PathBuf, S
     let tmp_dir = std::env::temp_dir();
     let in_path = tmp_dir.join("hako_llvm_in.json");
     {
-        let mut f = fs::File::create(&in_path).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
-        f.write_all(mir_json.as_bytes()).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+        let mut f =
+            fs::File::create(&in_path).map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+        f.write_all(mir_json.as_bytes())
+            .map_err(|e| format!("[llvmemit/tmp/write-failed] {}", e))?;
+    }
+    let out_path = if let Some(p) = opts.out.clone() {
+        p
+    } else {
+        tmp_dir.join("hako_llvm_out.o")
+    };
+    if let Some(parent) = out_path.parent() {
+        let _ = fs::create_dir_all(parent);
     }
-    let out_path = if let Some(p) = opts.out.clone() { p } else { tmp_dir.join("hako_llvm_out.o") };
-    if let Some(parent) = out_path.parent() { let _ = fs::create_dir_all(parent); }
 
     // Run: python3 tools/llvmlite_harness.py --in <json> --out <out>
     let status = Command::new(&py)
         .arg(&harness)
-        .arg("--in").arg(&in_path)
-        .arg("--out").arg(&out_path)
+        .arg("--in")
+        .arg(&in_path)
+        .arg("--out")
+        .arg(&out_path)
         .status()
         .map_err(|e| format!("[llvmemit/llvmlite/spawn/error] {}", e))?;
     if !status.success() {

src/host_providers/mir_builder.rs

@@ -11,7 +11,10 @@ pub fn program_json_to_mir_json(program_json: &str) -> Result<String, String> {
 }
 
 /// Convert Program(JSON v0) to MIR(JSON v0) with using imports support.
-pub fn program_json_to_mir_json_with_imports(program_json: &str, imports: HashMap<String, String>) -> Result<String, String> {
+pub fn program_json_to_mir_json_with_imports(
+    program_json: &str,
+    imports: HashMap<String, String>,
+) -> Result<String, String> {
     // Basic header check
     if !program_json.contains("\"version\"") || !program_json.contains("\"kind\"") {
         let tag = "[mirbuilder/input/invalid] missing version/kind keys";
@@ -20,14 +23,15 @@ pub fn program_json_to_mir_json_with_imports(program_json: &str, imports: HashMa
     }
 
     // Parse Program(JSON v0) into a MIR Module with imports
-    let module = match runner::json_v0_bridge::parse_json_v0_to_module_with_imports(program_json, imports) {
-        Ok(m) => m,
-        Err(e) => {
-            let tag = format!("[mirbuilder/parse/error] {}", e);
-            eprintln!("{}", tag);
-            return Err(tag);
-        }
-    };
+    let module =
+        match runner::json_v0_bridge::parse_json_v0_to_module_with_imports(program_json, imports) {
+            Ok(m) => m,
+            Err(e) => {
+                let tag = format!("[mirbuilder/parse/error] {}", e);
+                eprintln!("{}", tag);
+                return Err(tag);
+            }
+        };
 
     // Emit MIR(JSON) to a temporary file (reuse existing emitter), then read back
     let tmp_dir = std::env::temp_dir();
@@ -57,8 +61,12 @@ pub fn program_json_to_mir_json_with_imports(program_json: &str, imports: HashMa
                         if let Some(funcs) = m.get("functions").cloned() {
                             let v1 = serde_json::json!({"schema_version":"1.0","functions": funcs});
                             serde_json::to_string(&v1).unwrap_or(s0)
-                        } else { s0 }
-                    } else { s0 }
+                        } else {
+                            s0
+                        }
+                    } else {
+                        s0
+                    }
                 }
                 _ => s0,
             };
@@ -128,7 +136,10 @@ mod tests {
 
         let mir_json = result.unwrap();
         // MIR JSON should contain functions
-        assert!(mir_json.contains("functions"), "MIR JSON should contain functions");
+        assert!(
+            mir_json.contains("functions"),
+            "MIR JSON should contain functions"
+        );
         eprintln!("[test] MIR JSON generated successfully with MatI64 imports");
     }
 }

src/host_providers/mod.rs

@@ -1,3 +1,2 @@
-pub mod mir_builder;
 pub mod llvm_codegen;
-
+pub mod mir_builder;

src/instance_v2.rs

@@ -50,7 +50,7 @@ impl Clone for InstanceBox {
             class_name: self.class_name.clone(),
             fields_ng: Arc::clone(&self.fields_ng), // Shared reference
             methods: Arc::clone(&self.methods),
-            inner_content: None, // inner_content cannot be cloned (Box<dyn>)
+            inner_content: None,  // inner_content cannot be cloned (Box<dyn>)
             base: BoxBase::new(), // Fresh base for clone
             finalized: Arc::clone(&self.finalized),
             fields: self.fields.as_ref().map(Arc::clone),
@@ -108,7 +108,11 @@ impl InstanceBox {
             base: BoxBase::new(),
             finalized: Arc::new(Mutex::new(false)),
             // レガシー互換フィールド（既定OFF）
-            fields: if legacy_enabled { Some(Arc::new(Mutex::new(legacy_field_map))) } else { None },
+            fields: if legacy_enabled {
+                Some(Arc::new(Mutex::new(legacy_field_map)))
+            } else {
+                None
+            },
             init_field_order: fields,
             weak_fields_union: std::collections::HashSet::new(),
             in_finalization: Arc::new(Mutex::new(false)),
@@ -240,10 +244,7 @@ impl InstanceBox {
     }
 
     /// レガシー互換：weak field取得
-    pub fn get_weak_field(
-        &self,
-        field_name: &str,
-    ) -> Option<NyashValue> {
+    pub fn get_weak_field(&self, field_name: &str) -> Option<NyashValue> {
         self.get_field_ng(field_name)
     }
 

src/lib.rs

@@ -65,7 +65,7 @@ pub mod runtime;
 // Unified Grammar scaffolding
 pub mod grammar;
 pub mod syntax; // syntax sugar config and helpers
-// Execution runner (CLI coordinator)
+                // Execution runner (CLI coordinator)
 pub mod runner;
 pub mod runner_hv1_inline_guard {}
 pub mod using; // using resolver scaffolding (Phase 15)
@@ -76,7 +76,9 @@ pub mod host_providers;
 pub mod providers;
 
 // C‑ABI PoC shim (20.36/20.37)
-pub mod abi { pub mod nyrt_shim; }
+pub mod abi {
+    pub mod nyrt_shim;
+}
 
 // Expose the macro engine module under a raw identifier; the source lives under `src/macro/`.
 #[path = "macro/mod.rs"]
@@ -91,12 +93,8 @@ pub mod tests;
 // Re-export main types for easy access
 pub use ast::{ASTNode, BinaryOperator, LiteralValue};
 pub use box_arithmetic::{AddBox, CompareBox, DivideBox, ModuloBox, MultiplyBox, SubtractBox};
-pub use box_trait::{BoolBox, IntegerBox, NyashBox, StringBox, VoidBox};
-pub use environment::{Environment, PythonCompatEnvironment};
 pub use box_factory::RuntimeError;
-pub use parser::{NyashParser, ParseError};
-pub use tokenizer::{NyashTokenizer, Token, TokenType};
-pub use type_box::{MethodSignature, TypeBox, TypeRegistry}; // 🌟 TypeBox exports
+pub use box_trait::{BoolBox, IntegerBox, NyashBox, StringBox, VoidBox};
 pub use boxes::console_box::ConsoleBox;
 pub use boxes::debug_box::DebugBox;
 pub use boxes::map_box::MapBox;
@@ -106,8 +104,12 @@ pub use boxes::random_box::RandomBox;
 pub use boxes::sound_box::SoundBox;
 pub use boxes::time_box::{DateTimeBox, TimeBox, TimerBox};
 pub use channel_box::{ChannelBox, MessageBox};
+pub use environment::{Environment, PythonCompatEnvironment};
 pub use instance_v2::InstanceBox; // 🎯 新実装テスト（nyash_rustパス使用）
 pub use method_box::{BoxType, EphemeralInstance, FunctionDefinition, MethodBox};
+pub use parser::{NyashParser, ParseError};
+pub use tokenizer::{NyashTokenizer, Token, TokenType};
+pub use type_box::{MethodSignature, TypeBox, TypeRegistry}; // 🌟 TypeBox exports
 
 pub use value::NyashValue;
 

src/macro/ast_json.rs

@@ -1,5 +1,5 @@
+use nyash_rust::ast::{ASTNode, BinaryOperator, LiteralValue, Span, UnaryOperator};
 use serde_json::{json, Value};
-use nyash_rust::ast::{ASTNode, LiteralValue, BinaryOperator, UnaryOperator, Span};
 
 pub fn ast_to_json(ast: &ASTNode) -> Value {
     match ast.clone() {
@@ -7,7 +7,9 @@ pub fn ast_to_json(ast: &ASTNode) -> Value {
             "kind": "Program",
             "statements": statements.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>()
         }),
-        ASTNode::Loop { condition, body, .. } => json!({
+        ASTNode::Loop {
+            condition, body, ..
+        } => json!({
             "kind": "Loop",
             "condition": ast_to_json(&condition),
             "body": body.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>()
@@ -27,18 +29,32 @@ pub fn ast_to_json(ast: &ASTNode) -> Value {
             "target": ast_to_json(&target),
             "value": ast_to_json(&value),
         }),
-        ASTNode::Local { variables, initial_values, .. } => json!({
+        ASTNode::Local {
+            variables,
+            initial_values,
+            ..
+        } => json!({
             "kind": "Local",
             "variables": variables,
             "inits": initial_values.into_iter().map(|opt| opt.map(|v| ast_to_json(&v))).collect::<Vec<_>>()
         }),
-        ASTNode::If { condition, then_body, else_body, .. } => json!({
+        ASTNode::If {
+            condition,
+            then_body,
+            else_body,
+            ..
+        } => json!({
             "kind": "If",
             "condition": ast_to_json(&condition),
             "then": then_body.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>(),
             "else": else_body.map(|v| v.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>()),
         }),
-        ASTNode::TryCatch { try_body, catch_clauses, finally_body, .. } => json!({
+        ASTNode::TryCatch {
+            try_body,
+            catch_clauses,
+            finally_body,
+            ..
+        } => json!({
             "kind": "TryCatch",
             "try": try_body.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>(),
             "catch": catch_clauses.into_iter().map(|cc| json!({
@@ -48,7 +64,14 @@ pub fn ast_to_json(ast: &ASTNode) -> Value {
             })).collect::<Vec<_>>(),
             "cleanup": finally_body.map(|v| v.into_iter().map(|s| ast_to_json(&s)).collect::<Vec<_>>())
         }),
-        ASTNode::FunctionDeclaration { name, params, body, is_static, is_override, .. } => json!({
+        ASTNode::FunctionDeclaration {
+            name,
+            params,
+            body,
+            is_static,
+            is_override,
+            ..
+        } => json!({
             "kind": "FunctionDeclaration",
             "name": name,
             "params": params,
@@ -58,24 +81,38 @@ pub fn ast_to_json(ast: &ASTNode) -> Value {
         }),
         ASTNode::Variable { name, .. } => json!({"kind":"Variable","name":name}),
         ASTNode::Literal { value, .. } => json!({"kind":"Literal","value": lit_to_json(&value)}),
-        ASTNode::BinaryOp { operator, left, right, .. } => json!({
+        ASTNode::BinaryOp {
+            operator,
+            left,
+            right,
+            ..
+        } => json!({
             "kind":"BinaryOp",
             "op": bin_to_str(&operator),
             "left": ast_to_json(&left),
             "right": ast_to_json(&right),
         }),
-        ASTNode::UnaryOp { operator, operand, .. } => json!({
+        ASTNode::UnaryOp {
+            operator, operand, ..
+        } => json!({
             "kind":"UnaryOp",
             "op": un_to_str(&operator),
             "operand": ast_to_json(&operand),
         }),
-        ASTNode::MethodCall { object, method, arguments, .. } => json!({
+        ASTNode::MethodCall {
+            object,
+            method,
+            arguments,
+            ..
+        } => json!({
             "kind":"MethodCall",
             "object": ast_to_json(&object),
             "method": method,
             "arguments": arguments.into_iter().map(|a| ast_to_json(&a)).collect::<Vec<_>>()
         }),
-        ASTNode::FunctionCall { name, arguments, .. } => json!({
+        ASTNode::FunctionCall {
+            name, arguments, ..
+        } => json!({
             "kind":"FunctionCall",
             "name": name,
             "arguments": arguments.into_iter().map(|a| ast_to_json(&a)).collect::<Vec<_>>()
@@ -88,7 +125,12 @@ pub fn ast_to_json(ast: &ASTNode) -> Value {
             "kind":"Map",
             "entries": entries.into_iter().map(|(k,v)| json!({"k":k,"v":ast_to_json(&v)})).collect::<Vec<_>>()
         }),
-        ASTNode::MatchExpr { scrutinee, arms, else_expr, .. } => json!({
+        ASTNode::MatchExpr {
+            scrutinee,
+            arms,
+            else_expr,
+            ..
+        } => json!({
             "kind":"MatchExpr",
             "scrutinee": ast_to_json(&scrutinee),
             "arms": arms.into_iter().map(|(lit, body)| json!({
@@ -108,45 +150,163 @@ pub fn json_to_ast(v: &Value) -> Option<ASTNode> {
     let k = v.get("kind")?.as_str()?;
     Some(match k {
         "Program" => {
-            let stmts = v.get("statements")?.as_array()?.iter().filter_map(json_to_ast).collect::<Vec<_>>();
-            ASTNode::Program { statements: stmts, span: Span::unknown() }
+            let stmts = v
+                .get("statements")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect::<Vec<_>>();
+            ASTNode::Program {
+                statements: stmts,
+                span: Span::unknown(),
+            }
         }
         "Loop" => ASTNode::Loop {
             condition: Box::new(json_to_ast(v.get("condition")?)?),
-            body: v.get("body")?.as_array()?.iter().filter_map(json_to_ast).collect::<Vec<_>>(),
+            body: v
+                .get("body")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect::<Vec<_>>(),
             span: Span::unknown(),
         },
-        "Print" => ASTNode::Print { expression: Box::new(json_to_ast(v.get("expression")?)?), span: Span::unknown() },
-        "Return" => ASTNode::Return { value: v.get("value").and_then(json_to_ast).map(Box::new), span: Span::unknown() },
-        "Break" => ASTNode::Break { span: Span::unknown() },
-        "Continue" => ASTNode::Continue { span: Span::unknown() },
-        "Assignment" => ASTNode::Assignment { target: Box::new(json_to_ast(v.get("target")?)?), value: Box::new(json_to_ast(v.get("value")?)?), span: Span::unknown() },
-        "Local" => {
-            let vars = v.get("variables")?.as_array()?.iter().filter_map(|s| s.as_str().map(|x| x.to_string())).collect();
-            let inits = v.get("inits")?.as_array()?.iter().map(|initv| {
-                if initv.is_null() { None } else { json_to_ast(initv).map(Box::new) }
-            }).collect();
-            ASTNode::Local { variables: vars, initial_values: inits, span: Span::unknown() }
+        "Print" => ASTNode::Print {
+            expression: Box::new(json_to_ast(v.get("expression")?)?),
+            span: Span::unknown(),
+        },
+        "Return" => ASTNode::Return {
+            value: v.get("value").and_then(json_to_ast).map(Box::new),
+            span: Span::unknown(),
+        },
+        "Break" => ASTNode::Break {
+            span: Span::unknown(),
+        },
+        "Continue" => ASTNode::Continue {
+            span: Span::unknown(),
+        },
+        "Assignment" => ASTNode::Assignment {
+            target: Box::new(json_to_ast(v.get("target")?)?),
+            value: Box::new(json_to_ast(v.get("value")?)?),
+            span: Span::unknown(),
+        },
+        "Local" => {
+            let vars = v
+                .get("variables")?
+                .as_array()?
+                .iter()
+                .filter_map(|s| s.as_str().map(|x| x.to_string()))
+                .collect();
+            let inits = v
+                .get("inits")?
+                .as_array()?
+                .iter()
+                .map(|initv| {
+                    if initv.is_null() {
+                        None
+                    } else {
+                        json_to_ast(initv).map(Box::new)
+                    }
+                })
+                .collect();
+            ASTNode::Local {
+                variables: vars,
+                initial_values: inits,
+                span: Span::unknown(),
+            }
+        }
+        "If" => ASTNode::If {
+            condition: Box::new(json_to_ast(v.get("condition")?)?),
+            then_body: v
+                .get("then")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect::<Vec<_>>(),
+            else_body: v.get("else").and_then(|a| {
+                a.as_array()
+                    .map(|arr| arr.iter().filter_map(json_to_ast).collect::<Vec<_>>())
+            }),
+            span: Span::unknown(),
         },
-        "If" => ASTNode::If { condition: Box::new(json_to_ast(v.get("condition")?)?), then_body: v.get("then")?.as_array()?.iter().filter_map(json_to_ast).collect::<Vec<_>>(), else_body: v.get("else").and_then(|a| a.as_array().map(|arr| arr.iter().filter_map(json_to_ast).collect::<Vec<_>>())), span: Span::unknown() },
         "FunctionDeclaration" => ASTNode::FunctionDeclaration {
             name: v.get("name")?.as_str()?.to_string(),
-            params: v.get("params")?.as_array()?.iter().filter_map(|s| s.as_str().map(|x| x.to_string())).collect(),
-            body: v.get("body")?.as_array()?.iter().filter_map(json_to_ast).collect(),
+            params: v
+                .get("params")?
+                .as_array()?
+                .iter()
+                .filter_map(|s| s.as_str().map(|x| x.to_string()))
+                .collect(),
+            body: v
+                .get("body")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect(),
             is_static: v.get("static").and_then(|b| b.as_bool()).unwrap_or(false),
             is_override: v.get("override").and_then(|b| b.as_bool()).unwrap_or(false),
             span: Span::unknown(),
         },
-        "Variable" => ASTNode::Variable { name: v.get("name")?.as_str()?.to_string(), span: Span::unknown() },
-        "Literal" => ASTNode::Literal { value: json_to_lit(v.get("value")?)?, span: Span::unknown() },
-        "BinaryOp" => ASTNode::BinaryOp { operator: str_to_bin(v.get("op")?.as_str()?)?, left: Box::new(json_to_ast(v.get("left")?)?), right: Box::new(json_to_ast(v.get("right")?)?), span: Span::unknown() },
-        "UnaryOp" => ASTNode::UnaryOp { operator: str_to_un(v.get("op")?.as_str()?)?, operand: Box::new(json_to_ast(v.get("operand")?)?), span: Span::unknown() },
-        "MethodCall" => ASTNode::MethodCall { object: Box::new(json_to_ast(v.get("object")?)?), method: v.get("method")?.as_str()?.to_string(), arguments: v.get("arguments")?.as_array()?.iter().filter_map(json_to_ast).collect(), span: Span::unknown() },
-        "FunctionCall" => ASTNode::FunctionCall { name: v.get("name")?.as_str()?.to_string(), arguments: v.get("arguments")?.as_array()?.iter().filter_map(json_to_ast).collect(), span: Span::unknown() },
-        "Array" => ASTNode::ArrayLiteral { elements: v.get("elements")?.as_array()?.iter().filter_map(json_to_ast).collect(), span: Span::unknown() },
-        "Map" => ASTNode::MapLiteral { entries: v.get("entries")?.as_array()?.iter().filter_map(|e| {
-            Some((e.get("k")?.as_str()?.to_string(), json_to_ast(e.get("v")?)?))
-        }).collect(), span: Span::unknown() },
+        "Variable" => ASTNode::Variable {
+            name: v.get("name")?.as_str()?.to_string(),
+            span: Span::unknown(),
+        },
+        "Literal" => ASTNode::Literal {
+            value: json_to_lit(v.get("value")?)?,
+            span: Span::unknown(),
+        },
+        "BinaryOp" => ASTNode::BinaryOp {
+            operator: str_to_bin(v.get("op")?.as_str()?)?,
+            left: Box::new(json_to_ast(v.get("left")?)?),
+            right: Box::new(json_to_ast(v.get("right")?)?),
+            span: Span::unknown(),
+        },
+        "UnaryOp" => ASTNode::UnaryOp {
+            operator: str_to_un(v.get("op")?.as_str()?)?,
+            operand: Box::new(json_to_ast(v.get("operand")?)?),
+            span: Span::unknown(),
+        },
+        "MethodCall" => ASTNode::MethodCall {
+            object: Box::new(json_to_ast(v.get("object")?)?),
+            method: v.get("method")?.as_str()?.to_string(),
+            arguments: v
+                .get("arguments")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect(),
+            span: Span::unknown(),
+        },
+        "FunctionCall" => ASTNode::FunctionCall {
+            name: v.get("name")?.as_str()?.to_string(),
+            arguments: v
+                .get("arguments")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect(),
+            span: Span::unknown(),
+        },
+        "Array" => ASTNode::ArrayLiteral {
+            elements: v
+                .get("elements")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect(),
+            span: Span::unknown(),
+        },
+        "Map" => ASTNode::MapLiteral {
+            entries: v
+                .get("entries")?
+                .as_array()?
+                .iter()
+                .filter_map(|e| {
+                    Some((e.get("k")?.as_str()?.to_string(), json_to_ast(e.get("v")?)?))
+                })
+                .collect(),
+            span: Span::unknown(),
+        },
         "MatchExpr" => {
             let scr = json_to_ast(v.get("scrutinee")?)?;
             let arms_json = v.get("arms")?.as_array()?.iter();
@@ -166,18 +326,47 @@ pub fn json_to_ast(v: &Value) -> Option<ASTNode> {
             }
         }
         "TryCatch" => {
-            let try_b = v.get("try")?.as_array()?.iter().filter_map(json_to_ast).collect::<Vec<_>>();
+            let try_b = v
+                .get("try")?
+                .as_array()?
+                .iter()
+                .filter_map(json_to_ast)
+                .collect::<Vec<_>>();
             let mut catches = Vec::new();
             if let Some(arr) = v.get("catch").and_then(|x| x.as_array()) {
                 for c in arr.iter() {
-                    let exc_t = match c.get("type") { Some(t) if !t.is_null() => t.as_str().map(|s| s.to_string()), _ => None };
-                    let var = match c.get("var") { Some(vv) if !vv.is_null() => vv.as_str().map(|s| s.to_string()), _ => None };
-                    let body = c.get("body")?.as_array()?.iter().filter_map(json_to_ast).collect::<Vec<_>>();
-                    catches.push(nyash_rust::ast::CatchClause { exception_type: exc_t, variable_name: var, body, span: Span::unknown() });
+                    let exc_t = match c.get("type") {
+                        Some(t) if !t.is_null() => t.as_str().map(|s| s.to_string()),
+                        _ => None,
+                    };
+                    let var = match c.get("var") {
+                        Some(vv) if !vv.is_null() => vv.as_str().map(|s| s.to_string()),
+                        _ => None,
+                    };
+                    let body = c
+                        .get("body")?
+                        .as_array()?
+                        .iter()
+                        .filter_map(json_to_ast)
+                        .collect::<Vec<_>>();
+                    catches.push(nyash_rust::ast::CatchClause {
+                        exception_type: exc_t,
+                        variable_name: var,
+                        body,
+                        span: Span::unknown(),
+                    });
                 }
             }
-            let cleanup = v.get("cleanup").and_then(|cl| cl.as_array().map(|arr| arr.iter().filter_map(json_to_ast).collect::<Vec<_>>()));
-            ASTNode::TryCatch { try_body: try_b, catch_clauses: catches, finally_body: cleanup, span: Span::unknown() }
+            let cleanup = v.get("cleanup").and_then(|cl| {
+                cl.as_array()
+                    .map(|arr| arr.iter().filter_map(json_to_ast).collect::<Vec<_>>())
+            });
+            ASTNode::TryCatch {
+                try_body: try_b,
+                catch_clauses: catches,
+                finally_body: cleanup,
+                span: Span::unknown(),
+            }
         }
         _ => return None,
     })

src/macro/ctx.rs

@@ -32,14 +32,18 @@ impl MacroCtx {
         }
     }
 
-    pub fn gensym(&self, prefix: &str) -> String { gensym(prefix) }
+    pub fn gensym(&self, prefix: &str) -> String {
+        gensym(prefix)
+    }
 
     pub fn report(&self, level: &str, message: &str) {
         eprintln!("[macro][{}] {}", level, message);
     }
 
     pub fn get_env(&self, key: &str) -> Option<String> {
-        if !self.caps.env { return None; }
+        if !self.caps.env {
+            return None;
+        }
         std::env::var(key).ok()
     }
 }

src/macro/engine.rs

@@ -1,5 +1,5 @@
 use nyash_rust::ast::Span;
-use nyash_rust::{ASTNode, ast::LiteralValue, ast::BinaryOperator};
+use nyash_rust::{ast::BinaryOperator, ast::LiteralValue, ASTNode};
 use std::time::Instant;
 
 /// HIR Patch description (MVP placeholder)
@@ -16,10 +16,20 @@ pub struct MacroEngine {
 
 impl MacroEngine {
     pub fn new() -> Self {
-        let max_passes = std::env::var("NYASH_MACRO_MAX_PASSES").ok().and_then(|v| v.parse().ok()).unwrap_or(32);
-        let cycle_window = std::env::var("NYASH_MACRO_CYCLE_WINDOW").ok().and_then(|v| v.parse().ok()).unwrap_or(8);
+        let max_passes = std::env::var("NYASH_MACRO_MAX_PASSES")
+            .ok()
+            .and_then(|v| v.parse().ok())
+            .unwrap_or(32);
+        let cycle_window = std::env::var("NYASH_MACRO_CYCLE_WINDOW")
+            .ok()
+            .and_then(|v| v.parse().ok())
+            .unwrap_or(8);
         let trace = std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1");
-        Self { max_passes, cycle_window, trace }
+        Self {
+            max_passes,
+            cycle_window,
+            trace,
+        }
     }
 
     /// Expand all macros with depth/cycle guards and return patched AST.
@@ -29,25 +39,48 @@ impl MacroEngine {
         let mut history: std::collections::VecDeque<ASTNode> = std::collections::VecDeque::new();
         for pass in 0..self.max_passes {
             let t0 = Instant::now();
-            let before_len = crate::r#macro::ast_json::ast_to_json(&cur).to_string().len();
+            let before_len = crate::r#macro::ast_json::ast_to_json(&cur)
+                .to_string()
+                .len();
             let next0 = self.expand_node(&cur);
             // Apply user MacroBoxes once per pass (if enabled)
             let next = crate::r#macro::macro_box::expand_all_once(&next0);
-            let after_len = crate::r#macro::ast_json::ast_to_json(&next).to_string().len();
+            let after_len = crate::r#macro::ast_json::ast_to_json(&next)
+                .to_string()
+                .len();
             let dt = t0.elapsed();
-            if self.trace { eprintln!("[macro][engine] pass={} changed={} bytes:{}=>{} dt={:?}", pass, (next != cur), before_len, after_len, dt); }
+            if self.trace {
+                eprintln!(
+                    "[macro][engine] pass={} changed={} bytes:{}=>{} dt={:?}",
+                    pass,
+                    (next != cur),
+                    before_len,
+                    after_len,
+                    dt
+                );
+            }
             jsonl_trace(pass, before_len, after_len, next != cur, dt);
-            if next == cur { return (cur, patches); }
+            if next == cur {
+                return (cur, patches);
+            }
             // cycle detection in small window
             if history.iter().any(|h| *h == next) {
-                eprintln!("[macro][engine] cycle detected at pass {} — stopping expansion", pass);
+                eprintln!(
+                    "[macro][engine] cycle detected at pass {} — stopping expansion",
+                    pass
+                );
                 return (cur, patches);
             }
             history.push_back(cur);
-            if history.len() > self.cycle_window { let _ = history.pop_front(); }
+            if history.len() > self.cycle_window {
+                let _ = history.pop_front();
+            }
             cur = next;
         }
-        eprintln!("[macro][engine] max passes ({}) exceeded — stopping expansion", self.max_passes);
+        eprintln!(
+            "[macro][engine] max passes ({}) exceeded — stopping expansion",
+            self.max_passes
+        );
         (cur, patches)
     }
 
@@ -57,23 +90,55 @@ impl MacroEngine {
                 if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
                     eprintln!("[macro][visit] Program: statements={}", statements.len());
                 }
-                let new_stmts = statements.into_iter().map(|n| {
-                    if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
-                        eprintln!("[macro][visit]  child kind...",);
-                    }
-                    self.expand_node(&n)
-                }).collect();
-                ASTNode::Program { statements: new_stmts, span }
+                let new_stmts = statements
+                    .into_iter()
+                    .map(|n| {
+                        if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
+                            eprintln!("[macro][visit]  child kind...",);
+                        }
+                        self.expand_node(&n)
+                    })
+                    .collect();
+                ASTNode::Program {
+                    statements: new_stmts,
+                    span,
+                }
             }
-            ASTNode::BoxDeclaration { name, fields, public_fields, private_fields, mut methods, constructors, init_fields, weak_fields, is_interface, extends, implements, type_parameters, is_static, static_init, span } => {
+            ASTNode::BoxDeclaration {
+                name,
+                fields,
+                public_fields,
+                private_fields,
+                mut methods,
+                constructors,
+                init_fields,
+                weak_fields,
+                is_interface,
+                extends,
+                implements,
+                type_parameters,
+                is_static,
+                static_init,
+                span,
+            } => {
                 if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
-                    eprintln!("[macro][visit] BoxDeclaration: {} (fields={})", name, fields.len());
+                    eprintln!(
+                        "[macro][visit] BoxDeclaration: {} (fields={})",
+                        name,
+                        fields.len()
+                    );
                 }
                 // Derive set: default Equals+ToString when macro is enabled
-                let derive_all = std::env::var("NYASH_MACRO_DERIVE_ALL").ok().as_deref() == Some("1");
-                let derive_set = std::env::var("NYASH_MACRO_DERIVE").ok().unwrap_or_else(|| "Equals,ToString".to_string());
+                let derive_all =
+                    std::env::var("NYASH_MACRO_DERIVE_ALL").ok().as_deref() == Some("1");
+                let derive_set = std::env::var("NYASH_MACRO_DERIVE")
+                    .ok()
+                    .unwrap_or_else(|| "Equals,ToString".to_string());
                 if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
-                    eprintln!("[macro][derive] box={} derive_all={} set={}", name, derive_all, derive_set);
+                    eprintln!(
+                        "[macro][derive] box={} derive_all={} set={}",
+                        name, derive_all, derive_set
+                    );
                 }
                 let want_equals = derive_all || derive_set.contains("Equals");
                 let want_tostring = derive_all || derive_set.contains("ToString");
@@ -81,19 +146,43 @@ impl MacroEngine {
                 let field_view: &Vec<String> = &public_fields;
                 if want_equals && !methods.contains_key("equals") {
                     if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
-                        eprintln!("[macro][derive] equals for {} (public fields: {})", name, field_view.len());
+                        eprintln!(
+                            "[macro][derive] equals for {} (public fields: {})",
+                            name,
+                            field_view.len()
+                        );
                     }
                     let m = build_equals_method(&name, field_view);
                     methods.insert("equals".to_string(), m);
                 }
                 if want_tostring && !methods.contains_key("toString") {
                     if std::env::var("NYASH_MACRO_TRACE").ok().as_deref() == Some("1") {
-                        eprintln!("[macro][derive] toString for {} (public fields: {})", name, field_view.len());
+                        eprintln!(
+                            "[macro][derive] toString for {} (public fields: {})",
+                            name,
+                            field_view.len()
+                        );
                     }
                     let m = build_tostring_method(&name, field_view);
                     methods.insert("toString".to_string(), m);
                 }
-                ASTNode::BoxDeclaration { name, fields, public_fields, private_fields, methods, constructors, init_fields, weak_fields, is_interface, extends, implements, type_parameters, is_static, static_init, span }
+                ASTNode::BoxDeclaration {
+                    name,
+                    fields,
+                    public_fields,
+                    private_fields,
+                    methods,
+                    constructors,
+                    init_fields,
+                    weak_fields,
+                    is_interface,
+                    extends,
+                    implements,
+                    type_parameters,
+                    is_static,
+                    static_init,
+                    span,
+                }
             }
             other => other,
         }
@@ -102,7 +191,9 @@ impl MacroEngine {
 
 fn jsonl_trace(pass: usize, before: usize, after: usize, changed: bool, dt: std::time::Duration) {
     if let Ok(path) = std::env::var("NYASH_MACRO_TRACE_JSONL") {
-        if path.is_empty() { return; }
+        if path.is_empty() {
+            return;
+        }
         let rec = serde_json::json!({
             "event": "macro_pass",
             "pass": pass,
@@ -110,17 +201,24 @@ fn jsonl_trace(pass: usize, before: usize, after: usize, changed: bool, dt: std:
             "before_bytes": before,
             "after_bytes": after,
             "dt_us": dt.as_micros() as u64,
-        }).to_string();
-        let _ = std::fs::OpenOptions::new().create(true).append(true).open(path).and_then(|mut f| {
-            use std::io::Write;
-            writeln!(f, "{}", rec)
-        });
+        })
+        .to_string();
+        let _ = std::fs::OpenOptions::new()
+            .create(true)
+            .append(true)
+            .open(path)
+            .and_then(|mut f| {
+                use std::io::Write;
+                writeln!(f, "{}", rec)
+            });
     }
 }
 
 fn me_field(name: &str) -> ASTNode {
     ASTNode::FieldAccess {
-        object: Box::new(ASTNode::Me { span: Span::unknown() }),
+        object: Box::new(ASTNode::Me {
+            span: Span::unknown(),
+        }),
         field: name.to_string(),
         span: Span::unknown(),
     }
@@ -128,30 +226,56 @@ fn me_field(name: &str) -> ASTNode {
 
 fn var_field(var: &str, field: &str) -> ASTNode {
     ASTNode::FieldAccess {
-        object: Box::new(ASTNode::Variable { name: var.to_string(), span: Span::unknown() }),
+        object: Box::new(ASTNode::Variable {
+            name: var.to_string(),
+            span: Span::unknown(),
+        }),
         field: field.to_string(),
         span: Span::unknown(),
     }
 }
 
 fn bin_add(lhs: ASTNode, rhs: ASTNode) -> ASTNode {
-    ASTNode::BinaryOp { operator: BinaryOperator::Add, left: Box::new(lhs), right: Box::new(rhs), span: Span::unknown() }
+    ASTNode::BinaryOp {
+        operator: BinaryOperator::Add,
+        left: Box::new(lhs),
+        right: Box::new(rhs),
+        span: Span::unknown(),
+    }
 }
 
 fn bin_and(lhs: ASTNode, rhs: ASTNode) -> ASTNode {
-    ASTNode::BinaryOp { operator: BinaryOperator::And, left: Box::new(lhs), right: Box::new(rhs), span: Span::unknown() }
+    ASTNode::BinaryOp {
+        operator: BinaryOperator::And,
+        left: Box::new(lhs),
+        right: Box::new(rhs),
+        span: Span::unknown(),
+    }
 }
 
 fn bin_eq(lhs: ASTNode, rhs: ASTNode) -> ASTNode {
-    ASTNode::BinaryOp { operator: BinaryOperator::Equal, left: Box::new(lhs), right: Box::new(rhs), span: Span::unknown() }
+    ASTNode::BinaryOp {
+        operator: BinaryOperator::Equal,
+        left: Box::new(lhs),
+        right: Box::new(rhs),
+        span: Span::unknown(),
+    }
 }
 
-fn lit_str(s: &str) -> ASTNode { ASTNode::Literal { value: LiteralValue::String(s.to_string()), span: Span::unknown() } }
+fn lit_str(s: &str) -> ASTNode {
+    ASTNode::Literal {
+        value: LiteralValue::String(s.to_string()),
+        span: Span::unknown(),
+    }
+}
 
 fn build_equals_method(_box_name: &str, fields: &Vec<String>) -> ASTNode {
     // equals(other) { return me.f1 == other.f1 && ...; }
     let cond = if fields.is_empty() {
-        ASTNode::Literal { value: LiteralValue::Bool(true), span: Span::unknown() }
+        ASTNode::Literal {
+            value: LiteralValue::Bool(true),
+            span: Span::unknown(),
+        }
     } else {
         let mut it = fields.iter();
         let first = it.next().unwrap();
@@ -166,7 +290,10 @@ fn build_equals_method(_box_name: &str, fields: &Vec<String>) -> ASTNode {
     ASTNode::FunctionDeclaration {
         name: "equals".to_string(),
         params: vec![param_name.clone()],
-        body: vec![ASTNode::Return { value: Some(Box::new(cond)), span: Span::unknown() }],
+        body: vec![ASTNode::Return {
+            value: Some(Box::new(cond)),
+            span: Span::unknown(),
+        }],
         is_static: false,
         is_override: false,
         span: Span::unknown(),
@@ -178,7 +305,9 @@ fn build_tostring_method(box_name: &str, fields: &Vec<String>) -> ASTNode {
     let mut expr = lit_str(&format!("{}(", box_name));
     let mut first = true;
     for f in fields {
-        if !first { expr = bin_add(expr, lit_str(",")); }
+        if !first {
+            expr = bin_add(expr, lit_str(","));
+        }
         first = false;
         expr = bin_add(expr, me_field(f));
     }
@@ -186,7 +315,10 @@ fn build_tostring_method(box_name: &str, fields: &Vec<String>) -> ASTNode {
     ASTNode::FunctionDeclaration {
         name: "toString".to_string(),
         params: vec![],
-        body: vec![ASTNode::Return { value: Some(Box::new(expr)), span: Span::unknown() }],
+        body: vec![ASTNode::Return {
+            value: Some(Box::new(expr)),
+            span: Span::unknown(),
+        }],
         is_static: false,
         is_override: false,
         span: Span::unknown(),

src/macro/macro_box.rs

@@ -1,5 +1,5 @@
-use std::sync::{Mutex, OnceLock};
 use nyash_rust::ASTNode;
+use std::sync::{Mutex, OnceLock};
 
 /// MacroBox API — user-extensible macro expansion units (experimental)
 ///
@@ -33,13 +33,17 @@ pub fn register(m: &'static dyn MacroBox) {
 /// Legacy env `NYASH_MACRO_BOX=1` still forces ON, but by default we
 /// synchronize with the macro system gate so user macros run when macros are enabled.
 pub fn enabled() -> bool {
-    if std::env::var("NYASH_MACRO_BOX").ok().as_deref() == Some("1") { return true; }
+    if std::env::var("NYASH_MACRO_BOX").ok().as_deref() == Some("1") {
+        return true;
+    }
     super::enabled()
 }
 
 /// Expand AST by applying all registered MacroBoxes in order once.
 pub fn expand_all_once(ast: &ASTNode) -> ASTNode {
-    if !enabled() { return ast.clone(); }
+    if !enabled() {
+        return ast.clone();
+    }
     let reg = registry();
     let guard = reg.lock().expect("macro registry poisoned");
     let mut cur = ast.clone();
@@ -55,39 +59,127 @@ pub fn expand_all_once(ast: &ASTNode) -> ASTNode {
 pub struct UppercasePrintMacro;
 
 impl MacroBox for UppercasePrintMacro {
-    fn name(&self) -> &'static str { "UppercasePrintMacro" }
+    fn name(&self) -> &'static str {
+        "UppercasePrintMacro"
+    }
     fn expand(&self, ast: &ASTNode) -> ASTNode {
         use nyash_rust::ast::{ASTNode as A, LiteralValue, Span};
         fn go(n: &A) -> A {
             match n.clone() {
-                A::Program { statements, span } => A::Program { statements: statements.into_iter().map(|c| go(&c)).collect(), span },
+                A::Program { statements, span } => A::Program {
+                    statements: statements.into_iter().map(|c| go(&c)).collect(),
+                    span,
+                },
                 A::Print { expression, span } => {
                     match &*expression {
-                        A::Literal { value: LiteralValue::String(s), .. } => {
+                        A::Literal {
+                            value: LiteralValue::String(s),
+                            ..
+                        } => {
                             // Demo: if string starts with "UPPER:", uppercase the rest.
                             if let Some(rest) = s.strip_prefix("UPPER:") {
                                 let up = rest.to_uppercase();
-                                A::Print { expression: Box::new(A::Literal { value: LiteralValue::String(up), span: Span::unknown() }), span }
-                            } else { A::Print { expression: Box::new(go(&*expression)), span } }
+                                A::Print {
+                                    expression: Box::new(A::Literal {
+                                        value: LiteralValue::String(up),
+                                        span: Span::unknown(),
+                                    }),
+                                    span,
+                                }
+                            } else {
+                                A::Print {
+                                    expression: Box::new(go(&*expression)),
+                                    span,
+                                }
+                            }
                         }
-                        other => A::Print { expression: Box::new(go(other)), span }
+                        other => A::Print {
+                            expression: Box::new(go(other)),
+                            span,
+                        },
                     }
                 }
-                A::Assignment { target, value, span } => A::Assignment { target: Box::new(go(&*target)), value: Box::new(go(&*value)), span },
-                A::If { condition, then_body, else_body, span } => A::If {
+                A::Assignment {
+                    target,
+                    value,
+                    span,
+                } => A::Assignment {
+                    target: Box::new(go(&*target)),
+                    value: Box::new(go(&*value)),
+                    span,
+                },
+                A::If {
+                    condition,
+                    then_body,
+                    else_body,
+                    span,
+                } => A::If {
                     condition: Box::new(go(&*condition)),
                     then_body: then_body.into_iter().map(|c| go(&c)).collect(),
                     else_body: else_body.map(|v| v.into_iter().map(|c| go(&c)).collect()),
                     span,
                 },
-                A::Return { value, span } => A::Return { value: value.as_ref().map(|v| Box::new(go(v))), span },
-                A::FieldAccess { object, field, span } => A::FieldAccess { object: Box::new(go(&*object)), field, span },
-                A::MethodCall { object, method, arguments, span } => A::MethodCall { object: Box::new(go(&*object)), method, arguments: arguments.into_iter().map(|c| go(&c)).collect(), span },
-                A::FunctionCall { name, arguments, span } => A::FunctionCall { name, arguments: arguments.into_iter().map(|c| go(&c)).collect(), span },
-                A::BinaryOp { operator, left, right, span } => A::BinaryOp { operator, left: Box::new(go(&*left)), right: Box::new(go(&*right)), span },
-                A::UnaryOp { operator, operand, span } => A::UnaryOp { operator, operand: Box::new(go(&*operand)), span },
-                A::ArrayLiteral { elements, span } => A::ArrayLiteral { elements: elements.into_iter().map(|c| go(&c)).collect(), span },
-                A::MapLiteral { entries, span } => A::MapLiteral { entries: entries.into_iter().map(|(k,v)| (k, go(&v))).collect(), span },
+                A::Return { value, span } => A::Return {
+                    value: value.as_ref().map(|v| Box::new(go(v))),
+                    span,
+                },
+                A::FieldAccess {
+                    object,
+                    field,
+                    span,
+                } => A::FieldAccess {
+                    object: Box::new(go(&*object)),
+                    field,
+                    span,
+                },
+                A::MethodCall {
+                    object,
+                    method,
+                    arguments,
+                    span,
+                } => A::MethodCall {
+                    object: Box::new(go(&*object)),
+                    method,
+                    arguments: arguments.into_iter().map(|c| go(&c)).collect(),
+                    span,
+                },
+                A::FunctionCall {
+                    name,
+                    arguments,
+                    span,
+                } => A::FunctionCall {
+                    name,
+                    arguments: arguments.into_iter().map(|c| go(&c)).collect(),
+                    span,
+                },
+                A::BinaryOp {
+                    operator,
+                    left,
+                    right,
+                    span,
+                } => A::BinaryOp {
+                    operator,
+                    left: Box::new(go(&*left)),
+                    right: Box::new(go(&*right)),
+                    span,
+                },
+                A::UnaryOp {
+                    operator,
+                    operand,
+                    span,
+                } => A::UnaryOp {
+                    operator,
+                    operand: Box::new(go(&*operand)),
+                    span,
+                },
+                A::ArrayLiteral { elements, span } => A::ArrayLiteral {
+                    elements: elements.into_iter().map(|c| go(&c)).collect(),
+                    span,
+                },
+                A::MapLiteral { entries, span } => A::MapLiteral {
+                    entries: entries.into_iter().map(|(k, v)| (k, go(&v))).collect(),
+                    span,
+                },
                 other => other,
             }
         }
@@ -101,13 +193,17 @@ static INIT_FLAG: OnceLock<()> = OnceLock::new();
 pub fn init_builtin() {
     INIT_FLAG.get_or_init(|| {
         // Explicit example toggle
-        if std::env::var("NYASH_MACRO_BOX_EXAMPLE").ok().as_deref() == Some("1") { register(&UppercasePrintMacro); }
+        if std::env::var("NYASH_MACRO_BOX_EXAMPLE").ok().as_deref() == Some("1") {
+            register(&UppercasePrintMacro);
+        }
         // Comma-separated names: NYASH_MACRO_BOX_ENABLE="UppercasePrintMacro,Other"
         if let Ok(list) = std::env::var("NYASH_MACRO_BOX_ENABLE") {
             for name in list.split(',').map(|s| s.trim()).filter(|s| !s.is_empty()) {
                 match name {
                     "UppercasePrintMacro" => register(&UppercasePrintMacro),
-                    _ => { eprintln!("[macro][box] unknown MacroBox '{}', ignoring", name); }
+                    _ => {
+                        eprintln!("[macro][box] unknown MacroBox '{}', ignoring", name);
+                    }
                 }
             }
         }

src/macro/macro_box_ny.rs

@@ -28,7 +28,9 @@ pub fn init_from_env() {
     if std::env::var("NYASH_MACRO_BOX_CHILD_RUNNER").ok().is_some() {
         eprintln!("[macro][compat] NYASH_MACRO_BOX_CHILD_RUNNER is deprecated; runner mode is managed automatically");
     }
-    let Some(paths) = paths else { return; };
+    let Some(paths) = paths else {
+        return;
+    };
     for p in paths.split(',').map(|s| s.trim()).filter(|s| !s.is_empty()) {
         if let Err(e) = try_load_one(p) {
             // Quiet by default; print only when tracing is enabled to reduce noise in normal runs
@@ -47,35 +49,72 @@ fn try_load_one(path: &str) -> Result<(), String> {
     let prev_sugar = std::env::var("NYASH_SYNTAX_SUGAR_LEVEL").ok();
     std::env::set_var("NYASH_SYNTAX_SUGAR_LEVEL", "basic");
     let ast_res = nyash_rust::parser::NyashParser::parse_from_string(&src);
-    if let Some(v) = prev_sugar { std::env::set_var("NYASH_SYNTAX_SUGAR_LEVEL", v); } else { std::env::remove_var("NYASH_SYNTAX_SUGAR_LEVEL"); }
+    if let Some(v) = prev_sugar {
+        std::env::set_var("NYASH_SYNTAX_SUGAR_LEVEL", v);
+    } else {
+        std::env::remove_var("NYASH_SYNTAX_SUGAR_LEVEL");
+    }
     let ast = ast_res.map_err(|e| format!("parse error: {:?}", e))?;
     // Find a BoxDeclaration with static function expand(...)
     if let ASTNode::Program { statements, .. } = ast {
         // Capabilities: conservative scan before registration
-        if let Err(msg) = caps_allow_macro_source(&ASTNode::Program { statements: statements.clone(), span: nyash_rust::ast::Span::unknown() }) {
+        if let Err(msg) = caps_allow_macro_source(&ASTNode::Program {
+            statements: statements.clone(),
+            span: nyash_rust::ast::Span::unknown(),
+        }) {
             eprintln!("[macro][box_ny][caps] {} (in '{}')", msg, path);
-            if strict_enabled() { return Err(msg); }
+            if strict_enabled() {
+                return Err(msg);
+            }
             return Ok(());
         }
         for st in &statements {
-            if let ASTNode::BoxDeclaration { name: box_name, methods, .. } = st {
-                if let Some(ASTNode::FunctionDeclaration { name: mname, body: exp_body, params, .. }) = methods.get("expand") {
+            if let ASTNode::BoxDeclaration {
+                name: box_name,
+                methods,
+                ..
+            } = st
+            {
+                if let Some(ASTNode::FunctionDeclaration {
+                    name: mname,
+                    body: exp_body,
+                    params,
+                    ..
+                }) = methods.get("expand")
+                {
                     if mname == "expand" {
                         let reg_name = derive_box_name(&box_name, methods.get("name"));
                         // Prefer Nyash runner route by default (self-hosting). Child-proxy only when explicitly enabled.
-                        let use_child = std::env::var("NYASH_MACRO_BOX_CHILD").ok().map(|v| v != "0" && v != "false" && v != "off").unwrap_or(true);
+                        let use_child = std::env::var("NYASH_MACRO_BOX_CHILD")
+                            .ok()
+                            .map(|v| v != "0" && v != "false" && v != "off")
+                            .unwrap_or(true);
                         if use_child {
                             let nm = reg_name;
-                            let file_static: &'static str = Box::leak(path.to_string().into_boxed_str());
-                            crate::r#macro::macro_box::register(Box::leak(Box::new(NyChildMacroBox { nm, file: file_static })));
-                            eprintln!("[macro][box_ny] registered child-proxy MacroBox '{}' for {}", nm, path);
+                            let file_static: &'static str =
+                                Box::leak(path.to_string().into_boxed_str());
+                            crate::r#macro::macro_box::register(Box::leak(Box::new(
+                                NyChildMacroBox {
+                                    nm,
+                                    file: file_static,
+                                },
+                            )));
+                            eprintln!(
+                                "[macro][box_ny] registered child-proxy MacroBox '{}' for {}",
+                                nm, path
+                            );
                         } else {
                             // Heuristic mapping by name first, otherwise inspect body pattern.
                             let mut mapped = false;
                             match reg_name {
                                 "UppercasePrintMacro" => {
-                                    crate::r#macro::macro_box::register(&crate::r#macro::macro_box::UppercasePrintMacro);
-                                    eprintln!("[macro][box_ny] registered built-in '{}' from {}", reg_name, path);
+                                    crate::r#macro::macro_box::register(
+                                        &crate::r#macro::macro_box::UppercasePrintMacro,
+                                    );
+                                    eprintln!(
+                                        "[macro][box_ny] registered built-in '{}' from {}",
+                                        reg_name, path
+                                    );
                                     mapped = true;
                                 }
                                 _ => {}
@@ -83,14 +122,20 @@ fn try_load_one(path: &str) -> Result<(), String> {
                             if !mapped {
                                 if expand_is_identity(exp_body, params) {
                                     let nm = reg_name;
-                                    crate::r#macro::macro_box::register(Box::leak(Box::new(NyIdentityMacroBox { nm })));
+                                    crate::r#macro::macro_box::register(Box::leak(Box::new(
+                                        NyIdentityMacroBox { nm },
+                                    )));
                                     eprintln!("[macro][box_ny] registered Ny MacroBox '{}' (identity by body) from {}", nm, path);
                                 } else if expand_indicates_uppercase(exp_body, params) {
-                                    crate::r#macro::macro_box::register(&crate::r#macro::macro_box::UppercasePrintMacro);
+                                    crate::r#macro::macro_box::register(
+                                        &crate::r#macro::macro_box::UppercasePrintMacro,
+                                    );
                                     eprintln!("[macro][box_ny] registered built-in 'UppercasePrintMacro' by body pattern from {}", path);
                                 } else {
                                     let nm = reg_name;
-                                    crate::r#macro::macro_box::register(Box::leak(Box::new(NyIdentityMacroBox { nm })));
+                                    crate::r#macro::macro_box::register(Box::leak(Box::new(
+                                        NyIdentityMacroBox { nm },
+                                    )));
                                     eprintln!("[macro][box_ny] registered Ny MacroBox '{}' (identity: unknown body) from {}", nm, path);
                                 }
                             }
@@ -102,19 +147,38 @@ fn try_load_one(path: &str) -> Result<(), String> {
         }
         // Fallback: accept top-level `static function MacroBoxSpec.expand(json)` without a BoxDeclaration
         // Default OFF for safety; can be enabled via CLI/env
-        let allow_top = std::env::var("NYASH_MACRO_TOPLEVEL_ALLOW").ok().map(|v| v != "0" && v != "false" && v != "off").unwrap_or(false);
+        let allow_top = std::env::var("NYASH_MACRO_TOPLEVEL_ALLOW")
+            .ok()
+            .map(|v| v != "0" && v != "false" && v != "off")
+            .unwrap_or(false);
         for st in &statements {
-            if let ASTNode::FunctionDeclaration { is_static: true, name, .. } = st {
+            if let ASTNode::FunctionDeclaration {
+                is_static: true,
+                name,
+                ..
+            } = st
+            {
                 if let Some((box_name, method)) = name.split_once('.') {
                     if method == "expand" {
                         let nm: &'static str = Box::leak(box_name.to_string().into_boxed_str());
-                        let file_static: &'static str = Box::leak(path.to_string().into_boxed_str());
-                        let use_child = std::env::var("NYASH_MACRO_BOX_CHILD").ok().map(|v| v != "0" && v != "false" && v != "off").unwrap_or(true);
+                        let file_static: &'static str =
+                            Box::leak(path.to_string().into_boxed_str());
+                        let use_child = std::env::var("NYASH_MACRO_BOX_CHILD")
+                            .ok()
+                            .map(|v| v != "0" && v != "false" && v != "off")
+                            .unwrap_or(true);
                         if use_child && allow_top {
-                            crate::r#macro::macro_box::register(Box::leak(Box::new(NyChildMacroBox { nm, file: file_static })));
+                            crate::r#macro::macro_box::register(Box::leak(Box::new(
+                                NyChildMacroBox {
+                                    nm,
+                                    file: file_static,
+                                },
+                            )));
                             eprintln!("[macro][box_ny] registered child-proxy MacroBox '{}' (top-level static) for {}", nm, path);
                         } else {
-                            crate::r#macro::macro_box::register(Box::leak(Box::new(NyIdentityMacroBox { nm })));
+                            crate::r#macro::macro_box::register(Box::leak(Box::new(
+                                NyIdentityMacroBox { nm },
+                            )));
                             eprintln!("[macro][box_ny] registered identity MacroBox '{}' (top-level static) for {}", nm, path);
                         }
                         return Ok(());
@@ -131,7 +195,11 @@ fn derive_box_name(default: &str, name_fn: Option<&ASTNode>) -> &'static str {
     if let Some(ASTNode::FunctionDeclaration { body, .. }) = name_fn {
         if body.len() == 1 {
             if let ASTNode::Return { value: Some(v), .. } = &body[0] {
-                if let ASTNode::Literal { value: nyash_rust::ast::LiteralValue::String(s), .. } = &**v {
+                if let ASTNode::Literal {
+                    value: nyash_rust::ast::LiteralValue::String(s),
+                    ..
+                } = &**v
+                {
                     let owned = s.clone();
                     return Box::leak(owned.into_boxed_str());
                 }
@@ -141,21 +209,33 @@ fn derive_box_name(default: &str, name_fn: Option<&ASTNode>) -> &'static str {
     Box::leak(default.to_string().into_boxed_str())
 }
 
-pub(crate) struct NyIdentityMacroBox { nm: &'static str }
+pub(crate) struct NyIdentityMacroBox {
+    nm: &'static str,
+}
 
 impl super::macro_box::MacroBox for NyIdentityMacroBox {
-    fn name(&self) -> &'static str { self.nm }
+    fn name(&self) -> &'static str {
+        self.nm
+    }
     fn expand(&self, ast: &ASTNode) -> ASTNode {
-        if std::env::var("NYASH_MACRO_BOX_NY_IDENTITY_ROUNDTRIP").ok().as_deref() == Some("1") {
+        if std::env::var("NYASH_MACRO_BOX_NY_IDENTITY_ROUNDTRIP")
+            .ok()
+            .as_deref()
+            == Some("1")
+        {
             let j = crate::r#macro::ast_json::ast_to_json(ast);
-            if let Some(a2) = crate::r#macro::ast_json::json_to_ast(&j) { return a2; }
+            if let Some(a2) = crate::r#macro::ast_json::json_to_ast(&j) {
+                return a2;
+            }
         }
         ast.clone()
     }
 }
 
 fn expand_is_identity(body: &Vec<ASTNode>, params: &Vec<String>) -> bool {
-    if body.len() != 1 { return false; }
+    if body.len() != 1 {
+        return false;
+    }
     if let ASTNode::Return { value: Some(v), .. } = &body[0] {
         if let ASTNode::Variable { name, .. } = &**v {
             return params.get(0).map(|p| p == name).unwrap_or(false);
@@ -165,11 +245,15 @@ fn expand_is_identity(body: &Vec<ASTNode>, params: &Vec<String>) -> bool {
 }
 
 fn expand_indicates_uppercase(body: &Vec<ASTNode>, params: &Vec<String>) -> bool {
-    if body.len() != 1 { return false; }
+    if body.len() != 1 {
+        return false;
+    }
     let p0 = params.get(0).cloned().unwrap_or_else(|| "ast".to_string());
     match &body[0] {
         ASTNode::Return { value: Some(v), .. } => match &**v {
-            ASTNode::FunctionCall { name, arguments, .. } => {
+            ASTNode::FunctionCall {
+                name, arguments, ..
+            } => {
                 if (name == "uppercase_print" || name == "upper_print") && arguments.len() == 1 {
                     if let ASTNode::Variable { name: an, .. } = &arguments[0] {
                         return an == &p0;
@@ -184,32 +268,80 @@ fn expand_indicates_uppercase(body: &Vec<ASTNode>, params: &Vec<String>) -> bool
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum MacroBehavior { Identity, Uppercase, ArrayPrependZero, MapInsertTag, LoopNormalize, IfMatchNormalize, ForForeachNormalize, EnvTagString }
+pub enum MacroBehavior {
+    Identity,
+    Uppercase,
+    ArrayPrependZero,
+    MapInsertTag,
+    LoopNormalize,
+    IfMatchNormalize,
+    ForForeachNormalize,
+    EnvTagString,
+}
 
 pub fn analyze_macro_file(path: &str) -> MacroBehavior {
-    let src = match std::fs::read_to_string(path) { Ok(s) => s, Err(_) => return MacroBehavior::Identity };
-    let ast = match nyash_rust::parser::NyashParser::parse_from_string(&src) { Ok(a) => a, Err(_) => return MacroBehavior::Identity };
+    let src = match std::fs::read_to_string(path) {
+        Ok(s) => s,
+        Err(_) => return MacroBehavior::Identity,
+    };
+    let ast = match nyash_rust::parser::NyashParser::parse_from_string(&src) {
+        Ok(a) => a,
+        Err(_) => return MacroBehavior::Identity,
+    };
     // Quick heuristics based on literals present in file
     fn ast_has_literal_string(a: &ASTNode, needle: &str) -> bool {
         use nyash_rust::ast::ASTNode as A;
         match a {
-            A::Literal { value: nyash_rust::ast::LiteralValue::String(s), .. } => s.contains(needle),
-            A::Program { statements, .. } => statements.iter().any(|n| ast_has_literal_string(n, needle)),
+            A::Literal {
+                value: nyash_rust::ast::LiteralValue::String(s),
+                ..
+            } => s.contains(needle),
+            A::Program { statements, .. } => {
+                statements.iter().any(|n| ast_has_literal_string(n, needle))
+            }
             A::Print { expression, .. } => ast_has_literal_string(expression, needle),
-            A::Return { value, .. } => value.as_ref().map(|v| ast_has_literal_string(v, needle)).unwrap_or(false),
-            A::Assignment { target, value, .. } => ast_has_literal_string(target, needle) || ast_has_literal_string(value, needle),
-            A::If { condition, then_body, else_body, .. } => {
+            A::Return { value, .. } => value
+                .as_ref()
+                .map(|v| ast_has_literal_string(v, needle))
+                .unwrap_or(false),
+            A::Assignment { target, value, .. } => {
+                ast_has_literal_string(target, needle) || ast_has_literal_string(value, needle)
+            }
+            A::If {
+                condition,
+                then_body,
+                else_body,
+                ..
+            } => {
                 ast_has_literal_string(condition, needle)
                     || then_body.iter().any(|n| ast_has_literal_string(n, needle))
-                    || else_body.as_ref().map(|v| v.iter().any(|n| ast_has_literal_string(n, needle))).unwrap_or(false)
+                    || else_body
+                        .as_ref()
+                        .map(|v| v.iter().any(|n| ast_has_literal_string(n, needle)))
+                        .unwrap_or(false)
+            }
+            A::FunctionDeclaration { body, .. } => {
+                body.iter().any(|n| ast_has_literal_string(n, needle))
+            }
+            A::BinaryOp { left, right, .. } => {
+                ast_has_literal_string(left, needle) || ast_has_literal_string(right, needle)
             }
-            A::FunctionDeclaration { body, .. } => body.iter().any(|n| ast_has_literal_string(n, needle)),
-            A::BinaryOp { left, right, .. } => ast_has_literal_string(left, needle) || ast_has_literal_string(right, needle),
             A::UnaryOp { operand, .. } => ast_has_literal_string(operand, needle),
-            A::MethodCall { object, arguments, .. } => ast_has_literal_string(object, needle) || arguments.iter().any(|n| ast_has_literal_string(n, needle)),
-            A::FunctionCall { arguments, .. } => arguments.iter().any(|n| ast_has_literal_string(n, needle)),
-            A::ArrayLiteral { elements, .. } => elements.iter().any(|n| ast_has_literal_string(n, needle)),
-            A::MapLiteral { entries, .. } => entries.iter().any(|(_, v)| ast_has_literal_string(v, needle)),
+            A::MethodCall {
+                object, arguments, ..
+            } => {
+                ast_has_literal_string(object, needle)
+                    || arguments.iter().any(|n| ast_has_literal_string(n, needle))
+            }
+            A::FunctionCall { arguments, .. } => {
+                arguments.iter().any(|n| ast_has_literal_string(n, needle))
+            }
+            A::ArrayLiteral { elements, .. } => {
+                elements.iter().any(|n| ast_has_literal_string(n, needle))
+            }
+            A::MapLiteral { entries, .. } => entries
+                .iter()
+                .any(|(_, v)| ast_has_literal_string(v, needle)),
             _ => false,
         }
     }
@@ -218,29 +350,59 @@ pub fn analyze_macro_file(path: &str) -> MacroBehavior {
         match a {
             A::Program { statements, .. } => statements.iter().any(|n| ast_has_method(n, method)),
             A::Print { expression, .. } => ast_has_method(expression, method),
-            A::Return { value, .. } => value.as_ref().map(|v| ast_has_method(v, method)).unwrap_or(false),
-            A::Assignment { target, value, .. } => ast_has_method(target, method) || ast_has_method(value, method),
-            A::If { condition, then_body, else_body, .. } => ast_has_method(condition, method)
-                || then_body.iter().any(|n| ast_has_method(n, method))
-                || else_body.as_ref().map(|v| v.iter().any(|n| ast_has_method(n, method))).unwrap_or(false),
+            A::Return { value, .. } => value
+                .as_ref()
+                .map(|v| ast_has_method(v, method))
+                .unwrap_or(false),
+            A::Assignment { target, value, .. } => {
+                ast_has_method(target, method) || ast_has_method(value, method)
+            }
+            A::If {
+                condition,
+                then_body,
+                else_body,
+                ..
+            } => {
+                ast_has_method(condition, method)
+                    || then_body.iter().any(|n| ast_has_method(n, method))
+                    || else_body
+                        .as_ref()
+                        .map(|v| v.iter().any(|n| ast_has_method(n, method)))
+                        .unwrap_or(false)
+            }
             A::FunctionDeclaration { body, .. } => body.iter().any(|n| ast_has_method(n, method)),
-            A::BinaryOp { left, right, .. } => ast_has_method(left, method) || ast_has_method(right, method),
+            A::BinaryOp { left, right, .. } => {
+                ast_has_method(left, method) || ast_has_method(right, method)
+            }
             A::UnaryOp { operand, .. } => ast_has_method(operand, method),
-            A::MethodCall { object, method: m, arguments, .. } => m == method
-                || ast_has_method(object, method)
-                || arguments.iter().any(|n| ast_has_method(n, method)),
-            A::FunctionCall { arguments, .. } => arguments.iter().any(|n| ast_has_method(n, method)),
+            A::MethodCall {
+                object,
+                method: m,
+                arguments,
+                ..
+            } => {
+                m == method
+                    || ast_has_method(object, method)
+                    || arguments.iter().any(|n| ast_has_method(n, method))
+            }
+            A::FunctionCall { arguments, .. } => {
+                arguments.iter().any(|n| ast_has_method(n, method))
+            }
             A::ArrayLiteral { elements, .. } => elements.iter().any(|n| ast_has_method(n, method)),
             A::MapLiteral { entries, .. } => entries.iter().any(|(_, v)| ast_has_method(v, method)),
             _ => false,
         }
     }
     // Detect array prepend-zero macro by pattern strings present in macro source
-    if ast_has_literal_string(&ast, "\"kind\":\"Array\",\"elements\":[") || ast_has_literal_string(&ast, "\"elements\":[") {
+    if ast_has_literal_string(&ast, "\"kind\":\"Array\",\"elements\":[")
+        || ast_has_literal_string(&ast, "\"elements\":[")
+    {
         return MacroBehavior::ArrayPrependZero;
     }
     // Detect map insert-tag macro by pattern strings
-    if ast_has_literal_string(&ast, "\"kind\":\"Map\",\"entries\":[") || ast_has_literal_string(&ast, "\"entries\":[") {
+    if ast_has_literal_string(&ast, "\"kind\":\"Map\",\"entries\":[")
+        || ast_has_literal_string(&ast, "\"entries\":[")
+    {
         return MacroBehavior::MapInsertTag;
     }
     // Detect upper-string macro by pattern or toUpperCase usage
@@ -253,23 +415,47 @@ pub fn analyze_macro_file(path: &str) -> MacroBehavior {
     }
     if let ASTNode::Program { statements, .. } = ast {
         for st in statements {
-            if let ASTNode::BoxDeclaration { name: _, methods, .. } = st {
+            if let ASTNode::BoxDeclaration {
+                name: _, methods, ..
+            } = st
+            {
                 // Detect LoopNormalize/IfMatchNormalize by name() returning a specific string
-                if let Some(ASTNode::FunctionDeclaration { name: mname, body, .. }) = methods.get("name") {
+                if let Some(ASTNode::FunctionDeclaration {
+                    name: mname, body, ..
+                }) = methods.get("name")
+                {
                     if mname == "name" {
                         if body.len() == 1 {
                             if let ASTNode::Return { value: Some(v), .. } = &body[0] {
-                                if let ASTNode::Literal { value: nyash_rust::ast::LiteralValue::String(s), .. } = &**v {
-                                    if s == "LoopNormalize" { return MacroBehavior::LoopNormalize; }
-                                    if s == "IfMatchNormalize" { return MacroBehavior::IfMatchNormalize; }
-                                    if s == "ForForeach" { return MacroBehavior::ForForeachNormalize; }
-                                    if s == "EnvTagString" { return MacroBehavior::EnvTagString; }
+                                if let ASTNode::Literal {
+                                    value: nyash_rust::ast::LiteralValue::String(s),
+                                    ..
+                                } = &**v
+                                {
+                                    if s == "LoopNormalize" {
+                                        return MacroBehavior::LoopNormalize;
+                                    }
+                                    if s == "IfMatchNormalize" {
+                                        return MacroBehavior::IfMatchNormalize;
+                                    }
+                                    if s == "ForForeach" {
+                                        return MacroBehavior::ForForeachNormalize;
+                                    }
+                                    if s == "EnvTagString" {
+                                        return MacroBehavior::EnvTagString;
+                                    }
                                 }
                             }
                         }
                     }
                 }
-                if let Some(ASTNode::FunctionDeclaration { name: mname, body, params, .. }) = methods.get("expand") {
+                if let Some(ASTNode::FunctionDeclaration {
+                    name: mname,
+                    body,
+                    params,
+                    ..
+                }) = methods.get("expand")
+                {
                     if mname == "expand" {
                         if expand_indicates_uppercase(body, params) {
                             return MacroBehavior::Uppercase;
@@ -282,7 +468,10 @@ pub fn analyze_macro_file(path: &str) -> MacroBehavior {
     MacroBehavior::Identity
 }
 
-struct NyChildMacroBox { nm: &'static str, file: &'static str }
+struct NyChildMacroBox {
+    nm: &'static str,
+    file: &'static str,
+}
 
 fn cap_enabled(name: &str) -> bool {
     match std::env::var(name).ok() {
@@ -301,67 +490,148 @@ fn caps_allow_macro_source(ast: &ASTNode) -> Result<(), String> {
     fn scan(n: &A, seen: &mut Vec<String>) {
         match n {
             A::New { class, .. } => seen.push(class.clone()),
-            A::Program { statements, .. } => for s in statements { scan(s, seen); },
-            A::FunctionDeclaration { body, .. } => for s in body { scan(s, seen); },
-            A::Assignment { target, value, .. } => { scan(target, seen); scan(value, seen); },
-            A::Return { value, .. } => if let Some(v) = value { scan(v, seen); },
-            A::If { condition, then_body, else_body, .. } => {
-                scan(condition, seen);
-                for s in then_body { scan(s, seen); }
-                if let Some(b) = else_body { for s in b { scan(s, seen); } }
+            A::Program { statements, .. } => {
+                for s in statements {
+                    scan(s, seen);
+                }
+            }
+            A::FunctionDeclaration { body, .. } => {
+                for s in body {
+                    scan(s, seen);
+                }
+            }
+            A::Assignment { target, value, .. } => {
+                scan(target, seen);
+                scan(value, seen);
+            }
+            A::Return { value, .. } => {
+                if let Some(v) = value {
+                    scan(v, seen);
+                }
+            }
+            A::If {
+                condition,
+                then_body,
+                else_body,
+                ..
+            } => {
+                scan(condition, seen);
+                for s in then_body {
+                    scan(s, seen);
+                }
+                if let Some(b) = else_body {
+                    for s in b {
+                        scan(s, seen);
+                    }
+                }
+            }
+            A::BinaryOp { left, right, .. } => {
+                scan(left, seen);
+                scan(right, seen);
             }
-            A::BinaryOp { left, right, .. } => { scan(left, seen); scan(right, seen); }
             A::UnaryOp { operand, .. } => scan(operand, seen),
-            A::MethodCall { object, arguments, .. } => { scan(object, seen); for a in arguments { scan(a, seen); } }
-            A::FunctionCall { arguments, .. } => for a in arguments { scan(a, seen); },
-            A::ArrayLiteral { elements, .. } => for e in elements { scan(e, seen); },
-            A::MapLiteral { entries, .. } => for (_, v) in entries { scan(v, seen); },
+            A::MethodCall {
+                object, arguments, ..
+            } => {
+                scan(object, seen);
+                for a in arguments {
+                    scan(a, seen);
+                }
+            }
+            A::FunctionCall { arguments, .. } => {
+                for a in arguments {
+                    scan(a, seen);
+                }
+            }
+            A::ArrayLiteral { elements, .. } => {
+                for e in elements {
+                    scan(e, seen);
+                }
+            }
+            A::MapLiteral { entries, .. } => {
+                for (_, v) in entries {
+                    scan(v, seen);
+                }
+            }
             _ => {}
         }
     }
     let mut boxes = Vec::new();
     scan(ast, &mut boxes);
-    if !allow_io && boxes.iter().any(|c| c == "FileBox" || c == "PathBox" || c == "DirBox") {
+    if !allow_io
+        && boxes
+            .iter()
+            .any(|c| c == "FileBox" || c == "PathBox" || c == "DirBox")
+    {
         return Err("macro capability violation: IO (File/Path/Dir) denied".into());
     }
-    if !allow_net && boxes.iter().any(|c| c.contains("HTTP") || c.contains("Http") || c == "SocketBox") {
+    if !allow_net
+        && boxes
+            .iter()
+            .any(|c| c.contains("HTTP") || c.contains("Http") || c == "SocketBox")
+    {
         return Err("macro capability violation: NET (HTTP/Socket) denied".into());
     }
     Ok(())
 }
 
 impl super::macro_box::MacroBox for NyChildMacroBox {
-    fn name(&self) -> &'static str { self.nm }
+    fn name(&self) -> &'static str {
+        self.nm
+    }
     fn expand(&self, ast: &ASTNode) -> ASTNode {
         // Parent-side proxy: prefer runner script (PyVM) when enabled; otherwise fallback to internal child mode.
         let exe = match std::env::current_exe() {
             Ok(p) => p,
-            Err(e) => { eprintln!("[macro-proxy] current_exe failed: {}", e); return ast.clone(); }
+            Err(e) => {
+                eprintln!("[macro-proxy] current_exe failed: {}", e);
+                return ast.clone();
+            }
         };
         // Prefer Nyash runner route by default for self-hosting; legacy env can force internal child with 0.
-        let use_runner = std::env::var("NYASH_MACRO_BOX_CHILD_RUNNER").ok().map(|v| v != "0" && v != "false" && v != "off").unwrap_or(false);
+        let use_runner = std::env::var("NYASH_MACRO_BOX_CHILD_RUNNER")
+            .ok()
+            .map(|v| v != "0" && v != "false" && v != "off")
+            .unwrap_or(false);
         if std::env::var("NYASH_MACRO_BOX_CHILD_RUNNER").ok().is_some() {
-            eprintln!("[macro][compat] NYASH_MACRO_BOX_CHILD_RUNNER is deprecated; prefer defaults");
+            eprintln!(
+                "[macro][compat] NYASH_MACRO_BOX_CHILD_RUNNER is deprecated; prefer defaults"
+            );
         }
         let mut cmd = std::process::Command::new(exe.clone());
         // Build MacroCtx JSON once (caps only, MVP)
         let mctx = crate::r#macro::ctx::MacroCtx::from_env();
-        let ctx_json = format!("{{\"caps\":{{\"io\":{},\"net\":{},\"env\":{}}}}}", mctx.caps.io, mctx.caps.net, mctx.caps.env);
+        let ctx_json = format!(
+            "{{\"caps\":{{\"io\":{},\"net\":{},\"env\":{}}}}}",
+            mctx.caps.io, mctx.caps.net, mctx.caps.env
+        );
         if use_runner {
             // Synthesize a tiny runner that inlines the macro file and calls MacroBoxSpec.expand
             use std::io::Write as _;
             let tmp_dir = std::path::Path::new("tmp");
             let _ = std::fs::create_dir_all(tmp_dir);
-            let ts = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).unwrap_or_default().as_millis();
+            let ts = std::time::SystemTime::now()
+                .duration_since(std::time::UNIX_EPOCH)
+                .unwrap_or_default()
+                .as_millis();
             let tmp_path = tmp_dir.join(format!("macro_expand_runner_{}.hako", ts));
-            let mut f = match std::fs::File::create(&tmp_path) { Ok(x) => x, Err(e) => { eprintln!("[macro-proxy] create tmp runner failed: {}", e); return ast.clone(); } };
+            let mut f = match std::fs::File::create(&tmp_path) {
+                Ok(x) => x,
+                Err(e) => {
+                    eprintln!("[macro-proxy] create tmp runner failed: {}", e);
+                    return ast.clone();
+                }
+            };
             let macro_src = std::fs::read_to_string(self.file)
                 .unwrap_or_else(|_| String::from("// failed to read macro file\n"));
             let script = format!(
                 "{}\n\nfunction main(args) {{\n    if args.length() == 0 {{\n        print(\"{{}}\")\n        return 0\n    }}\n    local j, r, ctx\n    j = args.get(0)\n    if args.length() > 1 {{ ctx = args.get(1) }} else {{ ctx = \"{{}}\" }}\n    r = MacroBoxSpec.expand(j, ctx)\n    print(r)\n    return 0\n}}\n",
                 macro_src
             );
-            if let Err(e) = f.write_all(script.as_bytes()) { eprintln!("[macro-proxy] write tmp runner failed: {}", e); return ast.clone(); }
+            if let Err(e) = f.write_all(script.as_bytes()) {
+                eprintln!("[macro-proxy] write tmp runner failed: {}", e);
+                return ast.clone();
+            }
             // Run Nyash runner script under PyVM: nyash --backend vm <tmp_runner> -- <json>
             cmd.arg("--backend").arg("vm").arg(tmp_path);
             // Append script args after '--'
@@ -372,7 +642,8 @@ impl super::macro_box::MacroBox for NyChildMacroBox {
             cmd.stdin(std::process::Stdio::null());
         } else {
             // Internal child mode: --macro-expand-child <macro file> with stdin JSON
-            cmd.arg("--macro-expand-child").arg(self.file)
+            cmd.arg("--macro-expand-child")
+                .arg(self.file)
                 .stdin(std::process::Stdio::piped());
             // Provide MacroCtx via env for internal child
             cmd.env("NYASH_MACRO_CTX_JSON", ctx_json.clone());
@@ -393,13 +664,21 @@ impl super::macro_box::MacroBox for NyChildMacroBox {
         cmd.env_remove("NYASH_MACRO_BOX_CHILD");
         cmd.env_remove("NYASH_MACRO_BOX_CHILD_RUNNER");
         // Timeout
-        let timeout_ms: u64 = std::env::var("NYASH_NY_COMPILER_TIMEOUT_MS").ok().and_then(|s| s.parse().ok()).unwrap_or(2000);
+        let timeout_ms: u64 = std::env::var("NYASH_NY_COMPILER_TIMEOUT_MS")
+            .ok()
+            .and_then(|s| s.parse().ok())
+            .unwrap_or(2000);
         // Spawn
-        let mut child = match cmd.spawn() { Ok(c) => c, Err(e) => {
-            eprintln!("[macro-proxy] spawn failed: {}", e);
-            if strict_enabled() { std::process::exit(2); }
-            return ast.clone();
-        } };
+        let mut child = match cmd.spawn() {
+            Ok(c) => c,
+            Err(e) => {
+                eprintln!("[macro-proxy] spawn failed: {}", e);
+                if strict_enabled() {
+                    std::process::exit(2);
+                }
+                return ast.clone();
+            }
+        };
         // Write stdin only in internal child mode
         if !use_runner {
             if let Some(mut sin) = child.stdin.take() {
@@ -415,34 +694,60 @@ impl super::macro_box::MacroBox for NyChildMacroBox {
         loop {
             match child.try_wait() {
                 Ok(Some(_status)) => {
-                    if let Some(mut so) = child.stdout.take() { use std::io::Read; let _ = so.read_to_string(&mut out); }
+                    if let Some(mut so) = child.stdout.take() {
+                        use std::io::Read;
+                        let _ = so.read_to_string(&mut out);
+                    }
                     break;
                 }
                 Ok(None) => {
                     if start.elapsed() >= Duration::from_millis(timeout_ms) {
-                        let _ = child.kill(); let _ = child.wait();
+                        let _ = child.kill();
+                        let _ = child.wait();
                         eprintln!("[macro-proxy] timeout {} ms", timeout_ms);
-                        if strict_enabled() { std::process::exit(124); }
+                        if strict_enabled() {
+                            std::process::exit(124);
+                        }
                         return ast.clone();
                     }
                     std::thread::sleep(Duration::from_millis(5));
                 }
-                Err(e) => { eprintln!("[macro-proxy] wait error: {}", e); if strict_enabled() { std::process::exit(2); } return ast.clone(); }
+                Err(e) => {
+                    eprintln!("[macro-proxy] wait error: {}", e);
+                    if strict_enabled() {
+                        std::process::exit(2);
+                    }
+                    return ast.clone();
+                }
             }
         }
         // capture stderr for diagnostics and continue
         // Capture stderr for diagnostics
         let mut err = String::new();
-        if let Some(mut se) = child.stderr.take() { use std::io::Read; let _ = se.read_to_string(&mut err); }
+        if let Some(mut se) = child.stderr.take() {
+            use std::io::Read;
+            let _ = se.read_to_string(&mut err);
+        }
         // Parse output JSON
         match serde_json::from_str::<serde_json::Value>(&out) {
             Ok(v) => match crate::r#macro::ast_json::json_to_ast(&v) {
                 Some(a) => a,
-                None => { eprintln!("[macro-proxy] child JSON did not map to AST. stderr=\n{}", err); if strict_enabled() { std::process::exit(2); } ast.clone() }
+                None => {
+                    eprintln!(
+                        "[macro-proxy] child JSON did not map to AST. stderr=\n{}",
+                        err
+                    );
+                    if strict_enabled() {
+                        std::process::exit(2);
+                    }
+                    ast.clone()
+                }
             },
             Err(e) => {
                 eprintln!("[macro-proxy] invalid JSON from child: {}\n-- child stderr --\n{}\n-- end stderr --", e, err);
-                if strict_enabled() { std::process::exit(2); }
+                if strict_enabled() {
+                    std::process::exit(2);
+                }
                 ast.clone()
             }
         }