4b6b75932c
- MainDetectionHelper で main() 検出ロジックを箱化
- Legacy "static method main" と Modern "static box Main { main() }" の両パターン対応
- stage1_run_min.hako を modern 形式に統一
- ドキュメント更新（quickstart 等で static box スタイルに統一）
- パーサ新構文追加なし（仕様統一性保持）
- 後方互換性維持（Stage-B ヘルパーで legacy もサポート）
- テスト結果: 全スモーク PASS
Phase 152-B: Static Method 宣言の整理（Stage-3 仕様統一）
実装パターン: 箱化モジュール化（Phase 133/134 継承）
修正ファイル:
- lang/src/compiler/entry/compiler_stageb.hako: MainDetectionHelper (+103 lines)
- lang/src/compiler/entry/compiler.hako: Legacy Stage-A コメント (+3 lines)
- apps/tests/stage1_run_min.hako: Modern syntax に統一 (-1 line)
- docs/development/selfhosting/quickstart.md: サンプルコード更新
- CURRENT_TASK.md: Phase 152-B 完了記録
MainDetectionHelper 設計:
- findMainBody(): Entry point
- tryLegacyPattern(): "static method main" detection
- tryModernPattern(): "static box Main { main() }" detection
- findPattern(): Pattern search helper
- extractBodyFromPosition(): Brace matching extraction
利点:
✅ 明確な責任分離（各パターン検出が独立モジュール）
✅ テスタビリティ（各メソッド個別テスト可能）
✅ 拡張性（新パターン追加時は新メソッド追加のみ）
✅ 後方互換性（Legacy パターン削除は tryLegacyPattern 削除のみ）
テスト結果:
- stage1_run_min.hako: RC 0
- Selfhost depth-1: RC 0
- 全スモーク: 30/31 PASS (1 timeout は無関係)
148 lines
7.7 KiB
Markdown
148 lines
7.7 KiB
Markdown
# Nyash Grammar (Stage‑2 EBNF)
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Status: Fixed for Phase 15 Stage‑2. Parser implementations (Rust/Python/Nyash selfhost) should conform to this subset.
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program := stmt* EOF
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stmt := 'return' expr
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| 'local' IDENT '=' expr
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| 'if' expr block ('else' block)?
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| 'loop' '('? expr ')' ? block
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| expr ; expression statement
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block := '{' stmt* '}'
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expr := logic
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logic := compare (('&&' | '||') compare)*
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compare := sum (( '==' | '!=' | '<' | '>' | '<=' | '>=' ) sum)?
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sum := term (('+' | '-') term)*
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term := unary (('*' | '/') unary)*
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unary := ('-' | '!' | 'not') unary | factor
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factor := INT
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| STRING
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| IDENT call_tail*
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| '(' expr ')'
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| '(' assignment_expr ')' ; Stage‑3: grouped assignment as expression
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| 'new' IDENT '(' args? ')'
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| '[' args? ']' ; Array literal (Stage‑1 sugar, gated)
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| '{' map_entries? '}' ; Map literal (Stage‑2 sugar, gated)
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| match_expr ; Pattern matching (replaces legacy peek)
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match_expr := 'match' expr '{' match_arm+ default_arm? '}'
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match_arm := pattern guard? '=>' (expr | block) ','?
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default_arm:= '_' '=>' (expr | block) ','?
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pattern := '_'
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| STRING | INT | 'true' | 'false' | 'null'
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| IDENT '(' IDENT? ')' ; Type pattern e.g., StringBox(s)
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| '[' (IDENT (',' '..' IDENT)? )? ']'
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| '{' ( (STRING|IDENT) ':' IDENT (',' '..')? )? '}'
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| pattern '|' pattern ; OR pattern (same arm)
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guard := 'if' expr
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map_entries := (STRING | IDENT) ':' expr (',' (STRING | IDENT) ':' expr)* [',']
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call_tail := '.' IDENT '(' args? ')' ; method
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| '(' args? ')' ; function call
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args := expr (',' expr)*
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; Stage‑3: grouped assignment expression
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; `(x = expr)` だけを式として認める。値と型は右辺 expr と同じ。
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assignment_expr := IDENT '=' expr
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Notes
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- ASI: Newline is the primary statement separator. Do not insert a semicolon between a closed block and a following 'else'.
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- Semicolon (optional): When `NYASH_PARSER_ALLOW_SEMICOLON=1` is set, `;` is accepted as an additional statement separator (equivalent to newline). It is not allowed between `}` and a following `else`.
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- Do‑while: not supported by design. Prefer a single‑entry, pre‑condition loop normalized via sugar (e.g., `repeat N {}` / `until cond {}`) to a `loop` with clear break conditions.
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- Short-circuit: '&&' and '||' must not evaluate the RHS when not needed.
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- Unary minus has higher precedence than '*' and '/'.
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- IDENT names consist of [A-Za-z_][A-Za-z0-9_]*
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- Array literal is enabled when syntax sugar is on (NYASH_SYNTAX_SUGAR_LEVEL=basic|full) or when NYASH_ENABLE_ARRAY_LITERAL=1 is set.
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- Map literal is enabled when syntax sugar is on (NYASH_SYNTAX_SUGAR_LEVEL=basic|full) or when NYASH_ENABLE_MAP_LITERAL=1 is set.
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- Identifier keys (`{name: v}`) are Stage‑3 and require either NYASH_SYNTAX_SUGAR_LEVEL=full or NYASH_ENABLE_MAP_IDENT_KEY=1.
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- Pattern matching: `match` replaces legacy `peek`. MVP supports wildcard `_`, literals, simple type patterns, fixed/variadic array heads `[hd, ..tl]`, simple map key extract `{ "k": v, .. }`, OR patterns, and guards `if`.
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## Box Members (Phase‑15, env gate: NYASH_ENABLE_UNIFIED_MEMBERS; default ON)
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This section adds a minimal grammar for Box members (a unified member model) without changing JSON v0/MIR. Parsing is controlled by env `NYASH_ENABLE_UNIFIED_MEMBERS` (default ON; set `0/false/off` to disable).
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```
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box_decl := 'box' IDENT '{' member* '}'
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member := stored
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| computed
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| once_decl
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| birth_once_decl
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| method_decl
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| block_as_role ; nyash-mode (block-first) equivalent
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stored := IDENT ':' TYPE ( '=' expr )?
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; stored property (read/write). No handlers supported.
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computed := IDENT ':' TYPE ( '=>' expr | block ) handler_tail?
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; computed property (read‑only). Recomputes on each read.
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once_decl := 'once' IDENT ':' TYPE ( '=>' expr | block ) handler_tail?
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; lazy once. First read computes and caches; later reads return cached value.
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birth_once_decl:= 'birth_once' IDENT ':' TYPE ( '=>' expr | block ) handler_tail?
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; eager once. Computed during construction (before user birth), in declaration order.
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method_decl := IDENT '(' params? ')' ( ':' TYPE )? block handler_tail?
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; nyash-mode (block-first) variant — gated with NYASH_ENABLE_UNIFIED_MEMBERS=1
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block_as_role := block 'as' ( 'once' | 'birth_once' )? IDENT ':' TYPE
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handler_tail := ( catch_block )? ( cleanup_block )?
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catch_block := 'catch' ( '(' ( IDENT IDENT | IDENT )? ')' )? block
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cleanup_block := 'cleanup' block
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; Stage‑3 (Phase 1 via normalization gate NYASH_CATCH_NEW=1)
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; Postfix handlers for expressions and calls
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postfix_catch := primary_expr 'catch' ( '(' ( IDENT IDENT | IDENT )? ')' )? block
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postfix_cleanup := primary_expr 'cleanup' block
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```
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Semantics (summary)
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- stored: O(1) slot read; write via assignment. Initializer (if present) evaluates at construction once.
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- computed: read‑only; each read evaluates the block; assignment is an error unless a setter is explicitly defined.
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- once: first read evaluates the block and caches the value; subsequent reads return the cached value. On exception without a `catch`, the property becomes poisoned and rethrows on later reads (no retries).
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- birth_once: evaluated before the user `birth` body, in declaration order; exceptions without a `catch` abort construction; cycles between `birth_once` members are an error.
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- handlers: `catch/cleanup` are permitted for computed/once/birth_once/method blocks (Stage‑3), not for stored.
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Lowering (no JSON v0 change)
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- stored → slot
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- computed → synthesize `__get_name():T { try body; catch; finally }`; reads of `obj.name` become `obj.__get_name()`
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- once → add `__name: Option<T>` and emit `__get_name()` with first‑read initialization; on uncaught exception mark poisoned and rethrow on subsequent reads
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- birth_once → add `__name: T` and insert initialization just before user `birth` in declaration order; handlers apply to each initializer
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- method → existing method forms; optional postfix handlers lower to try/catch/finally
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## Stage‑3 (Gated) Additions
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Enabled when `NYASH_PARSER_STAGE3=1` for the Rust parser (and via `--stage3`/`NYASH_NY_COMPILER_STAGE3=1` for the selfhost parser):
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- try/catch/cleanup
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- `try_stmt := 'try' block ('catch' '(' (IDENT IDENT | IDENT | ε) ')' block) ('cleanup' block)?`
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- MVP policy: single `catch` per `try`。
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- `(Type var)` or `(var)` or `()` are accepted for the catch parameter。
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- Block‑postfix catch/cleanup（Phase 15.5）
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- `block_catch := '{' stmt* '}' ('catch' '(' (IDENT IDENT | IDENT | ε) ')' block)? ('cleanup' block)?`
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- Applies to standalone block statements. Do not attach to `if/else/loop` structural blocks (wrap with a standalone block when needed).
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- Gate: `NYASH_BLOCK_CATCH=1` (or `NYASH_PARSER_STAGE3=1`).
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- throw
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- `throw_stmt := 'throw' expr`
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- Method‑level postfix catch/cleanup（Phase 15.6, gated）
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- `method_decl := 'method' IDENT '(' params? ')' block ('catch' '(' (IDENT IDENT | IDENT | ε) ')' block)? ('cleanup' block)?`
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- Gate: `NYASH_METHOD_CATCH=1`（または `NYASH_PARSER_STAGE3=1` と同梱）
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- Member‑level postfix catch/cleanup（Phase 15.6, gated）
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- Applies to computed/once/birth_once in the unified member model: see “Box Members”.
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- Gate: `NYASH_PARSER_STAGE3=1` (shared). Stored members do not accept handlers.
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These constructs remain experimental; behaviour may degrade to no‑op in some backends until runtime support lands, as tracked in CURRENT_TASK.md.
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