Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

engine262/src/runtime-semantics/NewExpression.mts

@@ -0,0 +1,50 @@
+import { surroundingAgent } from '../host-defined/engine.mts';
+import { Evaluate, type ValueEvaluator } from '../evaluator.mts';
+import { Q } from '../completion.mts';
+import type { ParseNode } from '../parser/ParseNode.mts';
+import { ArgumentListEvaluation } from './all.mts';
+import {
+  Assert,
+  Construct,
+  GetValue,
+  IsConstructor,
+} from '#self';
+
+/** https://tc39.es/ecma262/#sec-evaluatenew */
+function* EvaluateNew(constructExpr: ParseNode.LeftHandSideExpression, args: undefined | ParseNode.Arguments) {
+  // 1. Assert: constructExpr is either a NewExpression or a MemberExpression.
+  // 2. Assert: arguments is either empty or an Arguments.
+  Assert(args === undefined || Array.isArray(args));
+  // 3. Let ref be the result of evaluating constructExpr.
+  const ref = Q(yield* Evaluate(constructExpr));
+  // 4. Let constructor be ? GetValue(ref).
+  const constructor = Q(yield* GetValue(ref));
+  let argList;
+  // 5. If arguments is empty, let argList be a new empty List.
+  if (args === undefined) {
+    argList = [];
+  } else { // 6. Else,
+    // a. Let argList be ? ArgumentListEvaluation of arguments.
+    argList = Q(yield* ArgumentListEvaluation(args));
+  }
+  // 7. If IsConstructor(constructor) is false, throw a TypeError exception.
+  if (!IsConstructor(constructor)) {
+    return surroundingAgent.Throw('TypeError', 'NotAConstructor', constructor);
+  }
+  // 8. Return ? Construct(constructor, argList).
+  return Q(yield* Construct(constructor, argList));
+}
+
+/** https://tc39.es/ecma262/#sec-new-operator-runtime-semantics-evaluation */
+//   NewExpression :
+//     `new` NewExpression
+//     `new` MemberExpression Arguments
+export function* Evaluate_NewExpression({ MemberExpression, Arguments }: ParseNode.NewExpression): ValueEvaluator {
+  if (!Arguments) {
+    // 1. Return ? EvaluateNew(NewExpression, empty).
+    return Q(yield* EvaluateNew(MemberExpression, undefined));
+  } else {
+    // 1. Return ? EvaluateNew(MemberExpression, Arguments).
+    return Q(yield* EvaluateNew(MemberExpression, Arguments));
+  }
+}