refactor(joinir): Phase 223 cleanup - impl consolidation & comment cleanup

Improves code organization and readability after Phase 223-3 implementation.

## Task R-1: impl Block Consolidation

**loop_body_cond_promoter.rs**:
- Merged 2 separate impl blocks into single unified impl
- Added section headers for better organization:
  - Public API (extract_continue_condition, try_promote_for_condition)
  - Private Helpers (contains_continue)
- Improved logical flow and discoverability

## Task R-2: Phase Comment Cleanup

**pattern4_with_continue.rs**:
- Simplified Phase 223-3 comments (removed redundant phase numbers)
- Added concise section header explaining LoopBodyLocal promotion
- Clarified inline comments for better understanding
- Maintained implementation intent while reducing noise

## Impact

- No functional changes
- All tests PASS (5 cond_promoter tests, 8 pattern4 tests)
- Better code organization for future maintenance
- Cleaner git history for Phase 223

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docs/development/current/main/phase223-refactoring-tasks.md

@@ -0,0 +1,205 @@
+# Phase 223 Refactoring Tasks
+
+Phase 223-3 実装完了後のコード品質改善タスク一覧だよ。
+
+---
+
+## Task R-1: impl ブロック統合（優先度: 高）
+
+**問題**:
+`loop_body_cond_promoter.rs` で同じ struct に対して impl が2箇所に分かれている。
+
+**現状**:
+```rust
+impl LoopBodyCondPromoter {
+    pub fn extract_continue_condition(...) { ... }
+    fn contains_continue(...) { ... }
+}
+
+impl LoopBodyCondPromoter {
+    pub fn try_promote_for_condition(...) { ... }
+}
+```
+
+**やること**:
+1. 2つの impl ブロックを1つに統合
+2. メソッドの順序を論理的に整理:
+   - Public API (extract_continue_condition, try_promote_for_condition)
+   - Private helpers (contains_continue)
+
+**影響範囲**: `src/mir/loop_pattern_detection/loop_body_cond_promoter.rs` のみ
+
+**テスト**: `cargo test --release --lib cond_promoter` (5 tests PASS を確認)
+
+**期待**: コード可読性向上、構造の明確化
+
+---
+
+## Task R-2: Phase コメント整理（優先度: 中）
+
+**問題**:
+`pattern4_with_continue.rs` に古い Phase 番号のコメントが残っている。
+
+**現状**:
+```rust
+// Phase 171-C-3: LoopBodyCarrierPromoter integration (削除済みコードへの参照)
+// Phase 223-3: LoopBodyCondPromoter integration (新しいコード)
+```
+
+**やること**:
+1. Phase 171-C-3 の古いコメントを削除
+2. Phase 223-3 のコメントを簡潔に整理
+3. 実装の意図が明確になるようコメントを調整
+
+**候補**:
+```rust
+// Phase 223-3: LoopBodyLocal Condition Promotion
+// Check for LoopBodyLocal in loop/continue conditions and attempt promotion.
+// Safe Trim patterns (Category A-3: skip_whitespace) are promoted to carriers.
+```
+
+**影響範囲**: `src/mir/builder/control_flow/joinir/patterns/pattern4_with_continue.rs`
+
+**テスト**: `cargo test --release --lib pattern4` (8 tests PASS を確認)
+
+---
+
+## Task R-3: エラーメッセージの定数化（優先度: 低）
+
+**問題**:
+Pattern4 のエラーメッセージが複数箇所にハードコードされている。
+
+**現状**:
+```rust
+// pattern4_with_continue.rs
+return Err(format!(
+    "[cf_loop/pattern4] Cannot promote LoopBodyLocal variables {:?}: {}",
+    vars, reason
+));
+
+// loop_body_cond_promoter.rs
+eprintln!(
+    "[cond_promoter] Cannot promote LoopBodyLocal variables {:?}: {}",
+    vars, reason
+);
+```
+
+**やること**:
+1. `error_messages.rs` に Pattern4 用のエラーメッセージ関数を追加
+2. 既存の `format_error_pattern4` パターンに合わせる
+3. ハードコードされたメッセージを関数呼び出しに置き換え
+
+**影響範囲**:
+- `src/mir/loop_pattern_detection/error_messages.rs` (追加)
+- `src/mir/builder/control_flow/joinir/patterns/pattern4_with_continue.rs` (置き換え)
+- `src/mir/loop_pattern_detection/loop_body_cond_promoter.rs` (置き換え)
+
+**テスト**: `cargo test --release --lib error_messages pattern4 cond_promoter`
+
+---
+
+## Task R-4: Pattern4ConditionAnalyzer Box 化（優先度: 低、将来対応）
+
+**問題**:
+Pattern4 の条件分析ロジックが `pattern4_with_continue.rs` に直接書かれている。
+
+**現状**:
+```rust
+// pattern4_with_continue.rs 内にインライン
+let continue_cond = LoopBodyCondPromoter::extract_continue_condition(body_to_analyze);
+let conditions_to_analyze: Vec<&ASTNode> = if let Some(cont_cond) = continue_cond {
+    vec![condition, cont_cond]
+} else {
+    vec![condition]
+};
+let cond_scope = LoopConditionScopeBox::analyze(...);
+```
+
+**候補**:
+```rust
+// 新規 Box: Pattern4ConditionAnalyzer
+pub struct Pattern4ConditionAnalyzer;
+
+impl Pattern4ConditionAnalyzer {
+    /// Analyze all conditions (header + continue) for Pattern4
+    pub fn analyze_all_conditions(
+        loop_param_name: &str,
+        header_cond: &ASTNode,
+        body: &[ASTNode],
+        scope: &LoopScopeShape,
+    ) -> LoopConditionScope {
+        // Extract continue condition
+        // Combine with header condition
+        // Call LoopConditionScopeBox::analyze
+    }
+}
+```
+
+**やること**:
+1. 新規ファイル `src/mir/builder/control_flow/joinir/patterns/pattern4_condition_analyzer.rs` 作成
+2. 条件分析ロジックを切り出し
+3. Pattern4 から呼び出し
+4. ユニットテスト追加
+
+**影響範囲**:
+- 新規: `pattern4_condition_analyzer.rs`
+- 修正: `pattern4_with_continue.rs`
+- 修正: `mod.rs` (モジュール登録)
+
+**テスト**: 新規テスト + 既存 pattern4 テスト
+
+**Note**: 現状で十分動作しているため、Pattern4 の複雑度が増した時に検討。
+
+---
+
+## Task R-5: LoopConditionScopeBox API 改善（優先度: 低、将来対応）
+
+**問題**:
+`analyze()` が `&[&ASTNode]` を受け取るため、呼び出し側で Vec を作る必要がある。
+
+**現状**:
+```rust
+let conditions_to_analyze: Vec<&ASTNode> = ...;
+LoopConditionScopeBox::analyze(&loop_var, &conditions_to_analyze, ...);
+```
+
+**候補**:
+```rust
+// Option 1: Iterator ベース
+LoopConditionScopeBox::analyze_iter(
+    &loop_var,
+    [condition, cont_cond].iter().filter_map(|&c| c),
+    scope,
+);
+
+// Option 2: 複数シグネチャ
+impl LoopConditionScopeBox {
+    pub fn analyze(...) -> LoopConditionScope { ... }
+    pub fn analyze_single(cond: &ASTNode, ...) -> LoopConditionScope { ... }
+    pub fn analyze_pair(cond1: &ASTNode, cond2: Option<&ASTNode>, ...) -> LoopConditionScope { ... }
+}
+```
+
+**影響範囲**: 広範囲（LoopConditionScopeBox を使う全ての箇所）
+
+**Note**: 影響範囲が大きいため、現状維持。必要になったら検討。
+
+---
+
+## 実施方針
+
+1. **Task R-1 (impl 統合)**: 簡単・影響小、すぐ実施可能
+2. **Task R-2 (コメント整理)**: 簡単・影響小、R-1 と一緒に実施可能
+3. **Task R-3 (エラーメッセージ)**: 中程度、既存パターンあり、実施可能
+4. **Task R-4/R-5**: 優先度低、必要になったら検討
+
+## フィードバック項目
+
+- [ ] R-1/R-2 は一緒にやる？
+- [ ] R-3 も含める？
+- [ ] 他に気になる箇所ある？
+- [ ] コメントの書き方（日本語 vs 英語、詳細度）の好み
+
+---
+
+**Note**: 全て既存テスト PASS を前提。退行防止のため各タスク後に `cargo test --release` 実行。

src/mir/builder/control_flow/joinir/patterns/pattern4_with_continue.rs

@@ -209,16 +209,18 @@ impl MirBuilder {
         // Phase 195: Use unified trace
         trace::trace().varmap("pattern4_start", &self.variable_map);
 
-        // Phase 223-3: LoopBodyCondPromoter integration
+        // Phase 223-3: LoopBodyLocal Condition Promotion
-        // Check for LoopBodyLocal in continue condition and attempt promotion
+        //
+        // Check for LoopBodyLocal in loop/continue conditions and attempt promotion.
+        // Safe Trim patterns (Category A-3: skip_whitespace) are promoted to carriers.
         {
             use crate::mir::loop_pattern_detection::loop_condition_scope::LoopConditionScopeBox;
             use crate::mir::loop_pattern_detection::loop_body_cond_promoter::{
                 LoopBodyCondPromoter, ConditionPromotionRequest, ConditionPromotionResult,
             };
 
-            // Phase 223-3: Extract continue condition from body (if present)
+            // Extract continue condition from body (if present)
-            // This handles skip_whitespace pattern: if ch == " " || ... { continue }
+            // Handles skip_whitespace pattern: if ch == " " || ... { continue }
             let continue_cond = LoopBodyCondPromoter::extract_continue_condition(body_to_analyze);
 
             // Analyze both header condition and continue condition for LoopBodyLocal
@@ -235,7 +237,7 @@ impl MirBuilder {
             );
 
             if cond_scope.has_loop_body_local() {
-                // Phase 223-3: Try promotion using LoopBodyCondPromoter
+                // Try promotion using LoopBodyCondPromoter
                 let promotion_req = ConditionPromotionRequest {
                     loop_param_name: &loop_var_name,
                     cond_scope: &cond_scope,
@@ -256,7 +258,7 @@ impl MirBuilder {
                             promoted_var, carrier_name
                         );
 
-                        // Phase 223-3: Merge promoted carrier into existing CarrierInfo
+                        // Merge promoted carrier into existing CarrierInfo
                         carrier_info.merge_from(&promoted_carrier);
 
                         eprintln!(
@@ -265,7 +267,7 @@ impl MirBuilder {
                             carrier_info.carrier_count()
                         );
 
-                        // Phase 223-3: Check if this is a safe Trim pattern
+                        // Check if this is a safe Trim pattern
                         if let Some(helper) = carrier_info.trim_helper() {
                             if helper.is_safe_trim() {
                                 eprintln!(
@@ -275,8 +277,7 @@ impl MirBuilder {
                                     "[pattern4/cond_promoter] Carrier: '{}', original var: '{}', whitespace chars: {:?}",
                                     helper.carrier_name, helper.original_var, helper.whitespace_chars
                                 );
-                                // Phase 223-3: Continue with Pattern4 lowering
+                                // Continue with Pattern4 lowering (fall through)
-                                // (fall through to normal lowering path)
                             } else {
                                 return Err(format!(
                                     "[cf_loop/pattern4] Trim pattern detected but not safe: carrier='{}', whitespace_count={}",
@@ -285,11 +286,10 @@ impl MirBuilder {
                                 ));
                             }
                         }
-                        // Phase 223-3: Continue with normal Pattern4 lowering
+                        // Carrier promoted and merged, proceed with normal lowering
-                        // The carrier has been promoted and merged, lowering can proceed
                     }
                     ConditionPromotionResult::CannotPromote { reason, vars } => {
-                        // Phase 223-3: Fail-Fast on promotion failure
+                        // Fail-Fast on promotion failure
                         return Err(format!(
                             "[cf_loop/pattern4] Cannot promote LoopBodyLocal variables {:?}: {}",
                             vars, reason

src/mir/loop_pattern_detection/loop_body_cond_promoter.rs

@@ -85,6 +85,10 @@ pub enum ConditionPromotionResult {
 pub struct LoopBodyCondPromoter;
 
 impl LoopBodyCondPromoter {
+    // ========================================================================
+    // Public API
+    // ========================================================================
+
     /// Extract continue condition from loop body
     ///
     /// Finds the first if statement with continue in then-branch and returns its condition.
@@ -123,33 +127,6 @@ impl LoopBodyCondPromoter {
         None
     }
 
-    /// Check if statements contain a continue statement
-    fn contains_continue(stmts: &[ASTNode]) -> bool {
-        for stmt in stmts {
-            match stmt {
-                ASTNode::Continue { .. } => return true,
-                ASTNode::If {
-                    then_body,
-                    else_body,
-                    ..
-                } => {
-                    if Self::contains_continue(then_body) {
-                        return true;
-                    }
-                    if let Some(else_stmts) = else_body {
-                        if Self::contains_continue(else_stmts) {
-                            return true;
-                        }
-                    }
-                }
-                _ => {}
-            }
-        }
-        false
-    }
-}
-
-impl LoopBodyCondPromoter {
     /// Try to promote LoopBodyLocal variables in conditions
     ///
     /// ## P0 Requirements (Category A-3)
@@ -223,6 +200,35 @@ impl LoopBodyCondPromoter {
             }
         }
     }
+
+    // ========================================================================
+    // Private Helpers
+    // ========================================================================
+
+    /// Check if statements contain a continue statement
+    fn contains_continue(stmts: &[ASTNode]) -> bool {
+        for stmt in stmts {
+            match stmt {
+                ASTNode::Continue { .. } => return true,
+                ASTNode::If {
+                    then_body,
+                    else_body,
+                    ..
+                } => {
+                    if Self::contains_continue(then_body) {
+                        return true;
+                    }
+                    if let Some(else_stmts) = else_body {
+                        if Self::contains_continue(else_stmts) {
+                            return true;
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+        false
+    }
 }
 
 #[cfg(test)]