From 6598cd3272fc1828d720352dfb90dd1815c5a9fc Mon Sep 17 00:00:00 2001
From: nyash-codex <codex@nyash.local>
Date: Tue, 25 Nov 2025 15:48:00 +0900
Subject: [PATCH] refactor(joinir): F-3 add _with_scope variant for skip_ws
 lowering
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Phase 30 F-3: LoopScopeShape 実データ運用の一歩目

変更内容:
- lower_case_a_skip_ws_with_scope(scope) 追加
  - LoopScopeShape を直接受け取る新 API
  - CaseAContext::from_scope() 経由で ctx 構築
- lower_case_a_skip_ws_core(ctx) 抽出
  - 共通ロジックを分離
  - _for_minimal_skip_ws と _with_scope で共有

設計意図:
- lowerer が scope を明示的に構築できる API を提供
- 将来の boxes 削除時に移行しやすい構造を準備
- 既存 API は後方互換性を維持

テスト結果:
- JoinIR 関連テスト: 全 PASS
- loop_scope_shape テスト: 10/10 PASS

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

Co-Authored-By: Claude <noreply@anthropic.com>
---
 src/mir/join_ir/lowering/generic_case_a.rs | 36 ++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/mir/join_ir/lowering/generic_case_a.rs b/src/mir/join_ir/lowering/generic_case_a.rs
index 74febca6..6bebab0f 100644
--- a/src/mir/join_ir/lowering/generic_case_a.rs
+++ b/src/mir/join_ir/lowering/generic_case_a.rs
@@ -9,6 +9,8 @@
 use std::collections::BTreeMap;
 
 use crate::mir::join_ir::lowering::loop_scope_shape::CaseAContext;
+// Phase 30: LoopScopeShape は将来の _with_scope API 追加時に再インポート
+// use crate::mir::join_ir::lowering::loop_scope_shape::LoopScopeShape;
 use crate::mir::join_ir::lowering::value_id_ranges;
 use crate::mir::join_ir::lowering::value_id_ranges::skip_ws as vid;
 use crate::mir::join_ir::lowering::value_id_ranges::stage1_using_resolver as stage1_vid;
@@ -52,7 +54,37 @@ pub fn lower_case_a_loop_to_joinir_for_minimal_skip_ws(
         |offset| vid::loop_step(offset),
     )?;
 
-    // JoinModule を手書き skip_ws と同じ形で構築（ValueId 範囲も揃える）
+    // コア実装に委譲（Phase 30: _with_scope と共通化）
+    lower_case_a_skip_ws_core(&ctx)
+}
+
+/// Phase 30: LoopScopeShape を直接受け取る skip_ws lowerer
+///
+/// 呼び出し元で LoopScopeShape を明示的に構築し、この関数に渡す。
+/// CaseAContext::from_scope() 経由で ctx を作成。
+///
+/// # Arguments
+///
+/// - `scope`: 事前に構築済みの LoopScopeShape
+///
+/// # Returns
+///
+/// Some(JoinModule) if successful, None if context building fails.
+pub(crate) fn lower_case_a_skip_ws_with_scope(
+    scope: crate::mir::join_ir::lowering::loop_scope_shape::LoopScopeShape,
+) -> Option<JoinModule> {
+    // CaseAContext::from_scope() で ctx を構築
+    let ctx = CaseAContext::from_scope(scope, "skip_ws", |offset| vid::loop_step(offset))?;
+
+    // JoinModule 構築（既存 _for_minimal_skip_ws と同一ロジック）
+    lower_case_a_skip_ws_core(&ctx)
+}
+
+/// skip_ws JoinModule 構築のコア実装
+///
+/// CaseAContext から JoinModule を構築する共通ロジック。
+/// `_for_minimal_skip_ws` と `_with_scope` の両方から呼ばれる。
+fn lower_case_a_skip_ws_core(ctx: &CaseAContext) -> Option<JoinModule> {
     let string_key = ctx.pinned_name_or_first(0)?;
     let len_key = ctx.pinned_name_or_first(1).unwrap_or_else(|| string_key.clone());
     let index_key = ctx.carrier_name_or_first(0)?;
@@ -226,7 +258,7 @@ pub fn lower_case_a_loop_to_joinir_for_minimal_skip_ws(
     join_module.add_function(loop_step_func);
 
     eprintln!(
-        "[joinir/generic_case_a] ✅ constructed JoinIR (functions={}, value_range={}..{})",
+        "[joinir/generic_case_a] ✅ constructed JoinIR via _core (functions={}, value_range={}..{})",
         join_module.functions.len(),
         value_id_ranges::base::SKIP_WS,
         value_id_ranges::base::SKIP_WS + 1999