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

src/sema/sema.c

@@ -346,6 +346,30 @@ static void analyze_enum_variant(AstNode* node, Scope* scope, ErrorList* errors,
         node->type.kind = TYPE_ERROR; return;
     }
     node->as.enum_variant.variant_index = vi;
+    // ADT: 检查 payload
+    TypeKind expected_pt = TYPE_VOID;
+    if (enum_sym->variant_payload_types)
+        expected_pt = enum_sym->variant_payload_types[vi];
+    if (node->as.enum_variant.payload) {
+        if (expected_pt == TYPE_VOID && enum_sym->variant_payload_types) {
+            error_add(errors, "<sema>", node->loc.line, node->loc.col,
+                      "枚举变体 '%s::%s' 不接受 payload",
+                      node->as.enum_variant.enum_name, node->as.enum_variant.variant_name);
+            node->type.kind = TYPE_ERROR; return;
+        }
+        analyze_expr(node->as.enum_variant.payload, scope, errors, a);
+        TypeKind actual = node->as.enum_variant.payload->type.kind;
+        if (actual != TYPE_ERROR && actual != expected_pt) {
+            error_add(errors, "<sema>", node->loc.line, node->loc.col,
+                      "枚举变体 payload 类型不匹配: 期望 '%s'，得到 '%s'",
+                      type_name(expected_pt), type_name(actual));
+        }
+    } else if (expected_pt != TYPE_VOID) {
+        error_add(errors, "<sema>", node->loc.line, node->loc.col,
+                  "枚举变体 '%s::%s' 需要 payload 类型 '%s'",
+                  node->as.enum_variant.enum_name, node->as.enum_variant.variant_name,
+                  type_name(expected_pt));
+    }
     node->type.kind = TYPE_ENUM;
 }
 
@@ -451,6 +475,8 @@ static void analyze_node(AstNode* node, Scope* scope, ErrorList* errors, Arena*
             AstNode* ed = node->as.program.enums[i];
             scope_insert_enum(scope, a, ed->as.enum_decl.name,
                               ed->as.enum_decl.variants,
+                              ed->as.enum_decl.variant_payload_types,
+                              ed->as.enum_decl.variant_payload_struct_names,
                               ed->as.enum_decl.variant_count);
         }
         // 第一遍：收集所有结构体定义