feat: impl 关键字改为 extend

src/lexer/lexer.c

@@ -64,7 +64,7 @@ static TokenKind check_keyword(const Token* tok) {
     KW("bool",   TOK_BOOL);   KW("str",    TOK_STR);
     KW("void",   TOK_VOID);
     KW("struct", TOK_STRUCT); KW("type", TOK_TYPE);
-    KW("enum", TOK_ENUM);  KW("impl", TOK_IMPL);  KW("match", TOK_MATCH);
+    KW("enum", TOK_ENUM);  KW("extend", TOK_EXTEND);  KW("match", TOK_MATCH);
     KW("_", TOK_UNDERSCORE);
     KW("true",   TOK_TRUE);   KW("false",  TOK_FALSE);
     #undef KW

src/lexer/token.c

@@ -7,7 +7,7 @@
 static const char* NAMES[] = {
     [TOK_FN] = "fn", [TOK_LET] = "let", [TOK_VAR] = "var", [TOK_IF] = "if",
     [TOK_ELSE] = "else", [TOK_WHILE] = "while", [TOK_FOR] = "for", [TOK_IN] = "in", [TOK_RETURN] = "return",
-    [TOK_STRUCT] = "struct", [TOK_TYPE] = "type", [TOK_ENUM] = "enum", [TOK_IMPL] = "impl",
+    [TOK_STRUCT] = "struct", [TOK_TYPE] = "type", [TOK_ENUM] = "enum", [TOK_EXTEND] = "extend",
     [TOK_MATCH] = "match",
     [TOK_I64] = "i64", [TOK_F64] = "f64", [TOK_BOOL] = "bool", [TOK_STR] = "str", [TOK_VOID] = "void",
     [TOK_INT_LIT] = "整数", [TOK_FLOAT_LIT] = "浮点数", [TOK_STR_LIT] = "字符串",

src/lexer/token.h

@@ -7,7 +7,7 @@
 typedef enum {
     // 关键字
     TOK_FN, TOK_LET, TOK_VAR, TOK_IF, TOK_ELSE, TOK_WHILE, TOK_FOR, TOK_IN, TOK_RETURN,
-    TOK_STRUCT, TOK_TYPE, TOK_ENUM, TOK_IMPL, TOK_MATCH,
+    TOK_STRUCT, TOK_TYPE, TOK_ENUM, TOK_EXTEND, TOK_MATCH,
     // 类型关键字
     TOK_I64, TOK_F64, TOK_BOOL, TOK_STR, TOK_VOID,
     // 字面量

src/parser/parser.c

@@ -777,21 +777,21 @@ AstNode* parse(Arena* a, const Token* tokens, size_t count,
             AstNode* enum_decl = ast_make_enum_decl(p.arena, arena_strdup_impl(p.arena, name->start, name->length), v_arr, vcount, tok_loc(name));
             if (enum_count >= 64) { error->message = "枚举过多 (最多64)"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
             enums[enum_count++] = enum_decl;
-        } else if (peek(&p)->kind == TOK_IMPL) {
+        } else if (peek(&p)->kind == TOK_EXTEND) {
             const Token* i_tok = advance(&p);
-            const Token* st_name = expect(&p, TOK_IDENT, error, "impl 后应为结构体名");
+            const Token* st_name = expect(&p, TOK_IDENT, error, "extend 后应为结构体名");
             if (!st_name) return NULL;
             if (!expect(&p, TOK_LBRACE, error, "缺少 '{'")) return NULL;
             AstNode* methods[64]; int mcount = 0;
             while (peek(&p)->kind != TOK_RBRACE && !error->message) {
                 if (mcount >= 64) { error->message = "方法过多 (最多64)"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
-                if (peek(&p)->kind != TOK_FN) { error->message = "impl 块内只允许 fn"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
+                if (peek(&p)->kind != TOK_FN) { error->message = "extend 块内只允许 fn"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
                 methods[mcount++] = parse_function(&p, error);
             }
             if (!expect(&p, TOK_RBRACE, error, "缺少 '}'")) return NULL;
             AstNode** m_arr = arena_alloc_impl(p.arena, mcount * sizeof(AstNode*));
             memcpy(m_arr, methods, mcount * sizeof(AstNode*));
-            if (impl_count >= 64) { error->message = "impl 块过多 (最多64)"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
+            if (impl_count >= 64) { error->message = "extend 块过多 (最多64)"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
             impls[impl_count++] = ast_make_impl_block(p.arena,
                 arena_strdup_impl(p.arena, st_name->start, st_name->length),
                 m_arr, mcount, tok_loc(i_tok));
@@ -799,7 +799,7 @@ AstNode* parse(Arena* a, const Token* tokens, size_t count,
             if (fn_count >= 256) { error->message = "函数过多 (最多256)"; error->filename = p.filename; error->line = peek(&p)->line; error->col = peek(&p)->col; return NULL; }
             functions[fn_count++] = parse_function(&p, error);
         } else {
-            error->message = "顶层只允许 fn、struct、type、enum 或 impl";
+            error->message = "顶层只允许 fn、struct、type、enum 或 extend";
             error->filename = p.filename;
             error->line = peek(&p)->line;
             error->col = peek(&p)->col;