feat: 枚举关联数据 ADT — enum Option { Some(i64), None }

src/ast/ast.h

@@ -104,9 +104,14 @@ struct AstNode {
         // AST_TYPE_ALIAS
         struct { const char* name; TypeKind aliased_type; const char* aliased_struct_name; } type_alias;
         // AST_ENUM_DECL
-        struct { const char* name; const char** variants; size_t variant_count; } enum_decl;
+        struct { const char* name; const char** variants;
+                 TypeKind* variant_payload_types;           // 每个变体的 payload 类型(TYPE_VOID=无)
+                 const char** variant_payload_struct_names;  // payload 为 struct 时的类型名
+                 size_t variant_count; } enum_decl;
         // AST_ENUM_VARIANT
-        struct { const char* enum_name; const char* variant_name; int variant_index; } enum_variant;
+        struct { const char* enum_name; const char* variant_name;
+                 AstNode* payload;   // payload 表达式 (NULL=无 payload)
+                 int variant_index; } enum_variant;
         // AST_INDEX_EXPR
         struct { struct AstNode* array; struct AstNode* index; } index_expr;
         // AST_ARRAY_ASSIGN_STMT
@@ -150,8 +155,11 @@ AstNode* ast_make_struct_init(void* alloc, const char* type_name, const char** f
 AstNode* ast_make_field_access(void* alloc, AstNode* object, const char* field, SourceLoc loc);
 AstNode* ast_make_type_alias(void* alloc, const char* name, TypeKind aliased,
                               const char* aliased_struct, SourceLoc loc);
-AstNode* ast_make_enum_decl(void* alloc, const char* name, const char** variants, size_t count, SourceLoc loc);
-AstNode* ast_make_enum_variant(void* alloc, const char* enum_name, const char* variant_name, SourceLoc loc);
+AstNode* ast_make_enum_decl(void* alloc, const char* name, const char** variants,
+                             TypeKind* payload_types, const char** payload_struct_names,
+                             size_t count, SourceLoc loc);
+AstNode* ast_make_enum_variant(void* alloc, const char* enum_name, const char* variant_name,
+                                AstNode* payload, SourceLoc loc);
 AstNode* ast_make_index_expr(void* alloc, AstNode* array, AstNode* index, SourceLoc loc);
 AstNode* ast_make_array_assign(void* alloc, const char* name, AstNode* index, AstNode* value, SourceLoc loc);
 AstNode* ast_make_impl_block(void* alloc, const char* struct_name, AstNode** methods, size_t count, SourceLoc loc);