Step 2完了: peek→match完全統一 + 重大PHI命令バグ発見

## 🎉 Step 2: peek→match完全統一アーキテクチャクリーンアップ完了
- ✅ 15ファイルで PeekExpr → MatchExpr 一括置換完了
- ✅ lowering/peek.rs → match_expr.rs 完全移行
- ✅ AI理解性・コードベース一貫性・保守性大幅向上

## 🔍 Step 3: 複数行パース問題調査完了
- ✅ Task先生による根本原因特定完了
- 原因: オブジェクトリテラルパーサーの改行スキップ不足
- 修正: src/parser/expr/primary.rs の skip_newlines() 追加

## 🚨 重大発見: PHI命令処理バグ
- 問題: gemini_test_case.nyash で期待値2→実際0
- 原因: フェーズM+M.2のPHI統一作業でループ後変数マージに回帰バグ
- 詳細: PHI命令は正常だが、print時に間違ったPHI参照
- 影響: Phase 15セルフホスティング基盤の重大バグ

## 📝 CLAUDE.md更新
- 全進捗状況の詳細記録
- 次のアクション: ChatGPT相談でMIRビルダー修正戦略立案

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

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

CLAUDE.md

@@ -276,18 +276,32 @@ NYASH_DISABLE_PLUGINS=1 ./target/release/nyash program.nyash
 NYASH_LLVM_USE_HARNESS=1 ./target/release/nyash program.nyash
 ```
 
-## 📝 Update (2025-09-23) ✅ Step 1完了！peek→match統一 Step 2開始
+## 📝 Update (2025-09-23) 🚨 重大PHI命令バグ発見！Step 4改行処理も課題
 - ✅ **フェーズM+M.2完全達成！** PHI統一革命でcollect_prints問題根本解決
 - ✅ **Step 1完全達成！** match式オブジェクトリテラル判定修正完了
   - **修正完了**: `src/parser/expr/match_expr.rs` の `is_object_literal()` メソッド追加
   - **副作用修正**: `match_token()` → `current_token()` で副作用除去
   - **動作確認**: 単行match式 + オブジェクトリテラル ✅ 完全動作
-  - **発見**: 複数行パース未対応（後回し決定）
+- ✅ **Step 2完全達成！** peek→match完全統一でアーキテクチャクリーンアップ完了
-- 🚀 **Step 2開始準備！** peek→match完全統一でアーキテクチャクリーンアップ
+  - **統一完了**: 15ファイルで `PeekExpr` → `MatchExpr` 一括置換完了
-  - **対象ファイル**: `json_v0_bridge/ast.rs`, `lowering/peek.rs` → `match_expr.rs`
+  - **ファイル移行**: `lowering/peek.rs` → `match_expr.rs` 完全移行
-  - **統一効果**: AI理解向上・ドキュメント整合性・保守性向上・ソースコード美化
+  - **コンパイル成功**: エラーゼロで正常ビルド完了
-  - **作業順序**: claude.md更新→todo調整→commit→peek構造体→match構造体完全移行
+  - **動作確認**: match式テスト正常動作 ✅
-- 🎯 **アーキテクチャ美化**: ややこしいpeek/match混在状況の完全解消へ
+  - **効果**: AI理解性向上・コードベース一貫性・保守性大幅向上
+- ✅ **Step 3完全達成！** Task先生による複数行パース問題根本原因特定完了
+  - **原因特定**: オブジェクトリテラルパーサーの改行スキップ不足（`src/parser/expr/primary.rs`）
+  - **修正箇所**: L49、L77-79に `skip_newlines()` 追加で解決可能
+  - **工数**: 30分以内の簡単修正
+- 🤔 **Step 4課題発見！** 改行処理アーキテクチャの美しさ問題
+  - **問題**: `skip_newlines()` を各所に散りばめる方法は美しくない
+  - **課題**: 保守性・一貫性・見落としリスク・設計の美しさ
+  - **方針**: Gemini 3相談でアーキテクチャ根本改善検討
+- 🚨 **重大発見！** PHI命令処理バグ（gemini_test_case: 期待値2→実際0）
+  - **問題**: フェーズM+M.2のPHI統一作業でループ後変数マージに回帰バグ
+  - **詳細**: PHI命令は正しく動作（v8→2）だが、print時に間違ったPHI（v4→0）参照
+  - **根本原因**: ループ脱出後の変数PHI接続が初期値を参照している
+  - **影響**: Phase 15セルフホスティング基盤の重大バグ
+  - **次のアクション**: ChatGPT相談でMIRビルダー修正戦略立案
 
 ## 📝 Update (2025-09-22) 🎯 Phase 15 JITアーカイブ完了＆デバッグ大進展！
 - ✅ **JIT/Craneliftアーカイブ完了！** Phase 15集中開発のため全JIT機能を安全にアーカイブ

gemini_test_case.nyash

@@ -0,0 +1,14 @@
+local cond1 = true
+local cond2 = false
+local x = 0
+loop(true) {
+    if(cond1) {
+        if(cond2) {
+            x = 1
+        } else {
+            x = 2
+        }
+        break
+    }
+}
+print(x)

src/ast.rs

@@ -126,8 +126,8 @@ pub enum ExpressionNode {
     MeExpression {
         span: Span,
     },
-    /// peek式: peek <expr> { lit => expr, ... else => expr }
+    /// match式: match <expr> { lit => expr, ... else => expr }
-    PeekExpr {
+    MatchExpr {
         scrutinee: Box<ASTNode>,
         arms: Vec<(LiteralValue, ASTNode)>,
         else_expr: Box<ASTNode>,
@@ -398,8 +398,8 @@ pub enum ASTNode {
         span: Span,
     },
 
-    /// peek式: peek <expr> { lit => expr, ... else => expr }
+    /// match式: match <expr> { lit => expr, ... else => expr }
-    PeekExpr {
+    MatchExpr {
         scrutinee: Box<ASTNode>,
         arms: Vec<(LiteralValue, ASTNode)>,
         else_expr: Box<ASTNode>,

src/ast/utils.rs

@@ -43,7 +43,7 @@ impl ASTNode {
             ASTNode::Throw { .. } => "Throw",
             ASTNode::AwaitExpression { .. } => "AwaitExpression",
             ASTNode::QMarkPropagate { .. } => "QMarkPropagate",
-            ASTNode::PeekExpr { .. } => "PeekExpr",
+            ASTNode::MatchExpr { .. } => "MatchExpr",
             ASTNode::Lambda { .. } => "Lambda",
             ASTNode::ArrayLiteral { .. } => "ArrayLiteral",
             ASTNode::MapLiteral { .. } => "MapLiteral",
@@ -78,7 +78,7 @@ impl ASTNode {
             ASTNode::FromCall { .. } => ASTNodeType::Expression,
             ASTNode::ThisField { .. } => ASTNodeType::Expression,
             ASTNode::MeField { .. } => ASTNodeType::Expression,
-            ASTNode::PeekExpr { .. } => ASTNodeType::Expression,
+            ASTNode::MatchExpr { .. } => ASTNodeType::Expression,
             ASTNode::QMarkPropagate { .. } => ASTNodeType::Expression,
             ASTNode::Lambda { .. } => ASTNodeType::Expression,
             ASTNode::ArrayLiteral { .. } => ASTNodeType::Expression,
@@ -303,7 +303,7 @@ impl ASTNode {
             ASTNode::AwaitExpression { expression, .. } => {
                 format!("Await({:?})", expression)
             }
-            ASTNode::PeekExpr { .. } => "PeekExpr".to_string(),
+            ASTNode::MatchExpr { .. } => "MatchExpr".to_string(),
             ASTNode::QMarkPropagate { .. } => "QMarkPropagate".to_string(),
             ASTNode::Lambda { params, body, .. } => {
                 format!("Lambda({} params, {} statements)", params.len(), body.len())
@@ -356,7 +356,7 @@ impl ASTNode {
             ASTNode::FunctionCall { span, .. } => *span,
             ASTNode::Call { span, .. } => *span,
             ASTNode::AwaitExpression { span, .. } => *span,
-            ASTNode::PeekExpr { span, .. } => *span,
+            ASTNode::MatchExpr { span, .. } => *span,
             ASTNode::QMarkPropagate { span, .. } => *span,
             ASTNode::Lambda { span, .. } => *span,
             ASTNode::ArrayLiteral { span, .. } => *span,

src/llvm_py/pyvm/ops_box.py

@@ -66,8 +66,11 @@ def op_boxcall(owner, fn, inst: Dict[str, Any], regs: Dict[int, Any]) -> None:
                 return
 
     # User-defined box: dispatch to lowered function if available (Box.method/N)
+    # Skip built-in boxes (ArrayBox, MapBox, etc.) to let them fall through to their implementations
     if isinstance(recv, dict) and isinstance(method, str) and "__box__" in recv:
         box_name = recv.get("__box__")
+        # Skip built-in boxes - let them fall through to built-in implementations below
+        if box_name not in ("ArrayBox", "MapBox", "ConsoleBox", "FileBox", "PathBox", "JsonDocBox", "JsonNodeBox"):
             cand = f"{box_name}.{method}/{len(args)}"
             callee = owner.functions.get(cand)
             if callee is not None:

src/macro/ast_json.rs

@@ -88,8 +88,8 @@ 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::PeekExpr { scrutinee, arms, else_expr, .. } => json!({
+        ASTNode::MatchExpr { scrutinee, arms, else_expr, .. } => json!({
-            "kind":"PeekExpr",
+            "kind":"MatchExpr",
             "scrutinee": ast_to_json(&scrutinee),
             "arms": arms.into_iter().map(|(lit, body)| json!({
                 "literal": {
@@ -147,7 +147,7 @@ pub fn json_to_ast(v: &Value) -> Option<ASTNode> {
         "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() },
-        "PeekExpr" => {
+        "MatchExpr" => {
             let scr = json_to_ast(v.get("scrutinee")?)?;
             let arms_json = v.get("arms")?.as_array()?.iter();
             let mut arms = Vec::new();
@@ -158,7 +158,7 @@ pub fn json_to_ast(v: &Value) -> Option<ASTNode> {
                 arms.push((lit, body));
             }
             let else_expr = json_to_ast(v.get("else")?)?;
-            ASTNode::PeekExpr {
+            ASTNode::MatchExpr {
                 scrutinee: Box::new(scr),
                 arms,
                 else_expr: Box::new(else_expr),

src/mir/builder/exprs.rs

@@ -85,7 +85,7 @@ impl super::MirBuilder {
                 self.build_qmark_propagate_expression(*expression.clone())
             }
 
-            ASTNode::PeekExpr {
+            ASTNode::MatchExpr {
                 scrutinee,
                 arms,
                 else_expr,

src/mir/builder/exprs_lambda.rs

@@ -123,7 +123,7 @@ impl super::MirBuilder {
                 ASTNode::AwaitExpression { expression, .. } => {
                     collect_vars(expression, used, locals);
                 }
-                ASTNode::PeekExpr {
+                ASTNode::MatchExpr {
                     scrutinee,
                     arms,
                     else_expr,

src/mir/builder/stmts.rs

@@ -1,6 +1,7 @@
 use super::{ConstValue, Effect, EffectMask, MirInstruction, ValueId};
 use crate::ast::{ASTNode, CallExpr};
 use crate::mir::TypeOpKind;
+use crate::mir::utils::is_current_block_terminated;
 
 impl super::MirBuilder {
     // Print statement: env.console.log(value) with early TypeOp handling
@@ -141,7 +142,7 @@ impl super::MirBuilder {
             last_value = Some(self.build_expression(statement)?);
             // If the current block was terminated by this statement (e.g., return/throw),
             // do not emit any further instructions for this block.
-            if self.is_current_block_terminated() {
+            if is_current_block_terminated(self)? {
                 break;
             }
         }

src/mir/builder/vars.rs

@@ -118,7 +118,7 @@ pub(super) fn collect_free_vars(
         ASTNode::AwaitExpression { expression, .. } => {
             collect_free_vars(expression, used, locals);
         }
-        ASTNode::PeekExpr {
+        ASTNode::MatchExpr {
             scrutinee,
             arms,
             else_expr,

src/mir/loop_builder.rs

@@ -455,20 +455,8 @@ impl<'a> LoopBuilder<'a> {
                 let mut last = None;
                 for s in statements.into_iter() {
                     last = Some(self.build_statement(s)?);
-                    // Stop early if this block has been terminated (e.g., break/continue)
+                    // フェーズS修正：統一終端検出ユーティリティ使用
-                    let cur_id = self.current_block()?;
+                    if is_current_block_terminated(self.parent_builder)? {
-                    let terminated = {
-                        if let Some(ref fun_ro) = self.parent_builder.current_function {
-                            if let Some(bb) = fun_ro.get_block(cur_id) {
-                                bb.is_terminated()
-                            } else {
-                                false
-                            }
-                        } else {
-                            false
-                        }
-                    };
-                    if terminated {
                         break;
                     }
                 }

src/parser/expr/call.rs

@@ -154,7 +154,7 @@ impl NyashParser {
                 };
 
                 // Wrap with peek: peek expr { null => null, else => access(expr) }
-                expr = ASTNode::PeekExpr {
+                expr = ASTNode::MatchExpr {
                     scrutinee: Box::new(expr.clone()),
                     arms: vec![(
                         crate::ast::LiteralValue::Null,

src/parser/expr/coalesce.rs

@@ -23,7 +23,7 @@ impl NyashParser {
             self.advance();
             let rhs = self.expr_parse_or()?;
             let scr = expr;
-            expr = ASTNode::PeekExpr {
+            expr = ASTNode::MatchExpr {
                 scrutinee: Box::new(scr.clone()),
                 arms: vec![(crate::ast::LiteralValue::Null, rhs)],
                 else_expr: Box::new(scr),

src/parser/expr/match_expr.rs

@@ -193,7 +193,7 @@ impl NyashParser {
         })?;
 
         if !saw_type_arm && !saw_guard {
-            // 既存の Lower を活用するため PeekExpr に落とす（型パターンが無い場合のみ）
+            // 既存の Lower を活用するため MatchExpr に落とす（型パターンが無い場合のみ）
             let mut lit_arms: Vec<(LiteralValue, ASTNode)> = Vec::new();
             for arm in arms_any.into_iter() {
                 match arm {
@@ -206,7 +206,7 @@ impl NyashParser {
                     MatchArm::Type { .. } => unreachable!(),
                 }
             }
-            return Ok(ASTNode::PeekExpr {
+            return Ok(ASTNode::MatchExpr {
                 scrutinee: Box::new(scrutinee),
                 arms: lit_arms,
                 else_expr: Box::new(else_expr),

src/parser/expr/primary.rs

@@ -46,7 +46,9 @@ impl NyashParser {
                 let ident_key_on = std::env::var("NYASH_ENABLE_MAP_IDENT_KEY").ok().as_deref()
                     == Some("1")
                     || sugar_level.as_deref() == Some("full");
+                self.skip_newlines();
                 while !self.match_token(&TokenType::RBRACE) && !self.is_at_end() {
+                    self.skip_newlines();
                     let key = match &self.current_token().token_type {
                         TokenType::STRING(s) => {
                             let v = s.clone();
@@ -76,8 +78,10 @@ impl NyashParser {
                     entries.push((key, value_expr));
                     if self.match_token(&TokenType::COMMA) {
                         self.advance();
+                        self.skip_newlines();
                     }
                 }
+                self.skip_newlines();
                 self.consume(TokenType::RBRACE)?;
                 Ok(ASTNode::MapLiteral {
                     entries,

src/parser/sugar.rs

@@ -84,12 +84,12 @@ fn rewrite(ast: ASTNode) -> ASTNode {
             operand: Box::new(rewrite(*operand)),
             span,
         },
-        ASTNode::PeekExpr {
+        ASTNode::MatchExpr {
             scrutinee,
             arms,
             else_expr,
             span,
-        } => ASTNode::PeekExpr {
+        } => ASTNode::MatchExpr {
             scrutinee: Box::new(rewrite(*scrutinee)),
             arms: arms.into_iter().map(|(l, e)| (l, rewrite(e))).collect(),
             else_expr: Box::new(rewrite(*else_expr)),

src/runner/json_v0_bridge/ast.rs

@@ -58,7 +58,7 @@ pub(super) struct CatchV0 {
 }
 
 #[derive(Debug, Deserialize, Serialize, Clone)]
-pub(super) struct PeekArmV0 {
+pub(super) struct MatchArmV0 {
     pub(super) label: String,
     pub(super) expr: ExprV0,
 }
@@ -120,9 +120,9 @@ pub(super) enum ExprV0 {
         #[serde(rename = "else")]
         r#else: Box<ExprV0>,
     },
-    Peek {
+    Match {
         scrutinee: Box<ExprV0>,
-        arms: Vec<PeekArmV0>,
+        arms: Vec<MatchArmV0>,
         #[serde(rename = "else")]
         r#else: Box<ExprV0>,
     },

src/runner/json_v0_bridge/lowering.rs

@@ -14,7 +14,7 @@ pub(super) mod loop_;
 pub(super) mod try_catch;
 pub(super) mod expr;
 pub(super) mod ternary; // placeholder (not wired)
-pub(super) mod peek; // placeholder (not wired)
+pub(super) mod match_expr; // placeholder (not wired)
 pub(super) mod throw_ctx; // thread-local ctx for Result-mode throw routing
 
 #[derive(Clone, Copy)]

src/runner/json_v0_bridge/lowering/expr.rs

@@ -1,7 +1,7 @@
 use super::merge::new_block;
 use super::BridgeEnv;
 use super::ternary;
-use super::peek;
+use super::match_expr;
 use crate::mir::{
     BasicBlockId, BinaryOp, ConstValue, EffectMask, MirFunction, MirInstruction, ValueId,
 };
@@ -395,8 +395,8 @@ pub(super) fn lower_expr_with_scope<S: VarScope>(
         }
         ExprV0::Ternary { cond, then, r#else } =>
             ternary::lower_ternary_expr_with_scope(env, f, cur_bb, cond, then, r#else, vars),
-        ExprV0::Peek { scrutinee, arms, r#else } =>
+        ExprV0::Match { scrutinee, arms, r#else } =>
-            peek::lower_peek_expr_with_scope(env, f, cur_bb, scrutinee, arms, r#else, vars),
+            match_expr::lower_match_expr_with_scope(env, f, cur_bb, scrutinee, arms, r#else, vars),
     }
 }
 

src/runner/json_v0_bridge/lowering/match_expr.rs

@@ -1,17 +1,17 @@
-//! Peek/expr-block lowering for JSON v0 bridge.
+//! Match/expr-block lowering for JSON v0 bridge.
 
 use super::merge::new_block;
 use super::BridgeEnv;
 use crate::mir::{BasicBlockId, CompareOp, ConstValue, MirFunction, MirInstruction, ValueId};
-use super::super::ast::{ExprV0, PeekArmV0};
+use super::super::ast::{ExprV0, MatchArmV0};
 use super::expr::{lower_expr_with_scope, VarScope};
 
-pub(super) fn lower_peek_expr_with_scope<S: VarScope>(
+pub(super) fn lower_match_expr_with_scope<S: VarScope>(
     env: &BridgeEnv,
     f: &mut MirFunction,
     cur_bb: BasicBlockId,
     scrutinee: &ExprV0,
-    arms: &[PeekArmV0],
+    arms: &[MatchArmV0],
     else_expr: &ExprV0,
     vars: &mut S,
 ) -> Result<(ValueId, BasicBlockId), String> {

src/runner/modes/macro_child/transforms/mod.rs

@@ -42,7 +42,7 @@ pub(super) fn transform_postfix_handlers(ast: &nyash_rust::ASTNode) -> nyash_rus
 }
 
 // Core normalization pass used by runners (always-on when macros enabled).
-// Order matters: for/foreach → match(PeekExpr) → loop tail alignment.
+// Order matters: for/foreach → match(MatchExpr) → loop tail alignment.
 pub fn normalize_core_pass(ast: &nyash_rust::ASTNode) -> nyash_rust::ASTNode {
     let a1 = transform_for_foreach(ast);
     let a2 = transform_peek_match_literal(&a1);

src/runner/modes/macro_child/transforms/peek.rs

@@ -2,7 +2,7 @@ fn map_expr_to_stmt(e: nyash_rust::ASTNode) -> nyash_rust::ASTNode { e }
 
 fn transform_peek_to_if_expr(peek: &nyash_rust::ASTNode) -> Option<nyash_rust::ASTNode> {
     use nyash_rust::ast::{ASTNode as A, BinaryOperator, Span};
-    if let A::PeekExpr { scrutinee, arms, else_expr, .. } = peek {
+    if let A::MatchExpr { scrutinee, arms, else_expr, .. } = peek {
         let mut conds_bodies: Vec<(nyash_rust::ast::LiteralValue, A)> = Vec::new();
         for (lit, body) in arms { conds_bodies.push((lit.clone(), (*body).clone())); }
         let mut current: A = *(*else_expr).clone();
@@ -19,7 +19,7 @@ fn transform_peek_to_if_expr(peek: &nyash_rust::ASTNode) -> Option<nyash_rust::A
 
 fn transform_peek_to_if_stmt_assign(peek: &nyash_rust::ASTNode, target: &nyash_rust::ASTNode) -> Option<nyash_rust::ASTNode> {
     use nyash_rust::ast::{ASTNode as A, BinaryOperator, Span};
-    if let A::PeekExpr { scrutinee, arms, else_expr, .. } = peek {
+    if let A::MatchExpr { scrutinee, arms, else_expr, .. } = peek {
         let mut pairs: Vec<(nyash_rust::ast::LiteralValue, A)> = Vec::new();
         for (lit, body) in arms { pairs.push((lit.clone(), (*body).clone())); }
         let mut current: A = *(*else_expr).clone();
@@ -36,7 +36,7 @@ fn transform_peek_to_if_stmt_assign(peek: &nyash_rust::ASTNode, target: &nyash_r
 
 fn transform_peek_to_if_stmt_return(peek: &nyash_rust::ASTNode) -> Option<nyash_rust::ASTNode> {
     use nyash_rust::ast::{ASTNode as A, BinaryOperator, Span};
-    if let A::PeekExpr { scrutinee, arms, else_expr, .. } = peek {
+    if let A::MatchExpr { scrutinee, arms, else_expr, .. } = peek {
         let mut pairs: Vec<(nyash_rust::ast::LiteralValue, A)> = Vec::new();
         for (lit, body) in arms { pairs.push((lit.clone(), (*body).clone())); }
         let mut current: A = *(*else_expr).clone();
@@ -53,7 +53,7 @@ fn transform_peek_to_if_stmt_return(peek: &nyash_rust::ASTNode) -> Option<nyash_
 
 fn transform_peek_to_if_stmt_print(peek: &nyash_rust::ASTNode) -> Option<nyash_rust::ASTNode> {
     use nyash_rust::ast::{ASTNode as A, BinaryOperator, Span};
-    if let A::PeekExpr { scrutinee, arms, else_expr, .. } = peek {
+    if let A::MatchExpr { scrutinee, arms, else_expr, .. } = peek {
         let mut pairs: Vec<(nyash_rust::ast::LiteralValue, A)> = Vec::new();
         for (lit, body) in arms { pairs.push((lit.clone(), (*body).clone())); }
         let mut current: A = *(*else_expr).clone();

src/tests/mir_peek_lower.rs

@@ -4,7 +4,7 @@ use crate::ast::{ASTNode, LiteralValue, Span};
 #[test]
 fn mir_lowering_of_peek_expr() {
     // Build AST: peek 2 { 1 => 10, 2 => 20, else => 30 }
-    let ast = ASTNode::PeekExpr {
+    let ast = ASTNode::MatchExpr {
         scrutinee: Box::new(ASTNode::Literal { value: LiteralValue::Integer(2), span: Span::unknown() }),
         arms: vec![
             (LiteralValue::Integer(1), ASTNode::Literal { value: LiteralValue::Integer(10), span: Span::unknown() }),

src/tests/parser_peek_block.rs

@@ -11,10 +11,10 @@ fn parse_match_with_block_arm() {
         }
     "#;
     let ast = NyashParser::parse_from_string(src).expect("parse ok");
-    // Quick structural check: ensure AST contains PeekExpr and Program nodes inside arms
+    // Quick structural check: ensure AST contains MatchExpr and Program nodes inside arms
     fn find_peek(ast: &crate::ast::ASTNode) -> bool {
         match ast {
-            crate::ast::ASTNode::PeekExpr { arms, else_expr, .. } => {
+            crate::ast::ASTNode::MatchExpr { arms, else_expr, .. } => {
                 // Expect at least one Program arm
                 let has_block = arms.iter().any(|(_, e)| matches!(e, crate::ast::ASTNode::Program { .. }));
                 let else_is_block = matches!(**else_expr, crate::ast::ASTNode::Program { .. });

src/tests/sugar_coalesce_test.rs

@@ -21,7 +21,7 @@ fn coalesce_peek_rewrite() {
     }
 
     match assign.1.as_ref() {
-        ASTNode::PeekExpr {
+        ASTNode::MatchExpr {
             scrutinee,
             arms,
             else_expr,
@@ -42,6 +42,6 @@ fn coalesce_peek_rewrite() {
                 _ => panic!("else not a"),
             }
         }
-        other => panic!("expected PeekExpr, got {:?}", other),
+        other => panic!("expected MatchExpr, got {:?}", other),
     }
 }

src/tests/sugar_safe_access_test.rs

@@ -16,7 +16,7 @@ fn safe_access_field_and_method() {
     // a = user?.profile
     match &program[0] {
         ASTNode::Assignment { value, .. } => match value.as_ref() {
-            ASTNode::PeekExpr {
+            ASTNode::MatchExpr {
                 scrutinee,
                 else_expr,
                 ..
@@ -36,7 +36,7 @@ fn safe_access_field_and_method() {
                     other => panic!("else not field access, got {:?}", other),
                 }
             }
-            other => panic!("expected PeekExpr, got {:?}", other),
+            other => panic!("expected MatchExpr, got {:?}", other),
         },
         other => panic!("expected assignment, got {:?}", other),
     }
@@ -44,7 +44,7 @@ fn safe_access_field_and_method() {
     // b = user?.m(1)
     match &program[1] {
         ASTNode::Assignment { value, .. } => match value.as_ref() {
-            ASTNode::PeekExpr {
+            ASTNode::MatchExpr {
                 scrutinee,
                 else_expr,
                 ..
@@ -70,7 +70,7 @@ fn safe_access_field_and_method() {
                     other => panic!("else not method call, got {:?}", other),
                 }
             }
-            other => panic!("expected PeekExpr, got {:?}", other),
+            other => panic!("expected MatchExpr, got {:?}", other),
         },
         other => panic!("expected assignment, got {:?}", other),
     }

test.nyash

@@ -0,0 +1,14 @@
+local cond1 = true
+local cond2 = false
+local x = 0
+loop(true) {
+    if(cond1) {
+        if(cond2) {
+            x = 1
+        } else {
+            x = 2
+        }
+        break
+    }
+}
+print(x)