feat: 装饰器 #[attr] 语法 — parser 解析并跳过

Token(74): +TOK_HASH, lexer 识别 '#', parser 在 fn/struct/enum 前解析 #[ident]
语法就位, 后续可扩展存储属性到 AST 节点

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lexer/lexer.c

@@ -158,6 +158,7 @@ Token* lex(Arena* a, const char* source, const char* filename,
         else if (c == '.') { tokens[idx++] = make_token(&l, TOK_DOT, l.pos, 1); advance(&l); }
         else if (c == '[') { tokens[idx++] = make_token(&l, TOK_LBRACKET, l.pos, 1); advance(&l); }
         else if (c == ']') { tokens[idx++] = make_token(&l, TOK_RBRACKET, l.pos, 1); advance(&l); }
+        else if (c == '#') { tokens[idx++] = make_token(&l, TOK_HASH, l.pos, 1); advance(&l); }
         else if (c == '(') { tokens[idx++] = make_token(&l, TOK_LPAREN, l.pos, 1); advance(&l); }
         else if (c == ')') { tokens[idx++] = make_token(&l, TOK_RPAREN, l.pos, 1); advance(&l); }
         else if (c == '{') { tokens[idx++] = make_token(&l, TOK_LBRACE, l.pos, 1); advance(&l); }

src/lexer/token.c

@@ -29,7 +29,7 @@ static const char* NAMES[] = {
     [TOK_LBRACKET] = "[", [TOK_RBRACKET] = "]",
     [TOK_COMMA] = ",", [TOK_COLON] = ":", [TOK_SEMICOLON] = ";",
     [TOK_ASSIGN] = "=",
-    [TOK_DOT] = ".", [TOK_COLON_COLON] = "::",
+    [TOK_DOT] = ".", [TOK_COLON_COLON] = "::", [TOK_HASH] = "#",
     [TOK_EOF] = "EOF", [TOK_ERROR] = "错误",
 };
 

src/lexer/token.h

@@ -26,7 +26,7 @@ typedef enum {
     TOK_LBRACKET, TOK_RBRACKET,
     TOK_COMMA, TOK_COLON, TOK_SEMICOLON, TOK_ASSIGN,
     // 特殊
-    TOK_DOT, TOK_COLON_COLON,
+    TOK_DOT, TOK_COLON_COLON, TOK_HASH,
     TOK_EOF, TOK_ERROR,
 } TokenKind;
 

src/parser/parser.c

@@ -413,6 +413,13 @@ AstNode* parse(Arena* a, const Token* tokens, size_t count,
         if (peek(&p)->kind == TOK_PUB) {
             is_pub = true; advance(&p);
         }
+        // 装饰器 #[attr]
+        while (peek(&p)->kind == TOK_HASH) {
+            advance(&p);  // 跳过 #
+            if (!expect(&p, TOK_LBRACKET, error, "# 后应为 '['")) return NULL;
+            if (!expect(&p, TOK_IDENT, error, "装饰器名")) return NULL;
+            if (!expect(&p, TOK_RBRACKET, error, "缺少 ']'")) return NULL;
+        }
         if (peek(&p)->kind == TOK_TRAIT) {
             const Token* tt = advance(&p);
             const Token* tname = expect(&p, TOK_IDENT, error, "trait 后应为接口名");