Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

2026-08-18 21:31:46 +00:00 · 2026-03-27 10:07:29 +05:30
parent 8f26db5a1f 6e92d2345e
commit b42a69d9f8
433 changed files with 90478 additions and 0 deletions
@@ -0,0 +1,212 @@
+import { Value } from '../value.mts';
+import {
+  NormalCompletion,
+  Q, X,
+} from '../completion.mts';
+import { Evaluate, type PlainEvaluator } from '../evaluator.mts';
+import {
+  StringValue,
+  IsAnonymousFunctionDefinition,
+} from '../static-semantics/all.mts';
+import type { ParseNode } from '../parser/ParseNode.mts';
+import { __ts_cast__ } from '../helpers.mts';
+import { NamedEvaluation, BindingInitialization } from './all.mts';
+import {
+  Assert,
+  GetValue,
+  InitializeReferencedBinding,
+  IteratorStep,
+  PutValue,
+  ResolveBinding,
+  ArrayCreate,
+  CreateDataPropertyOrThrow,
+  ToString,
+  F,
+  type IteratorRecord,
+
+  IteratorStepValue,
+  UndefinedValue, type EnvironmentRecord, type FunctionDeclaration,
+} from '#self';
+
+/** https://tc39.es/ecma262/#sec-function-definitions-runtime-semantics-iteratorbindinginitialization */
+// FormalParameters :
+//   [empty]
+//   FormalParameterList `,` FunctionRestParameter
+export function* IteratorBindingInitialization_FormalParameters(FormalParameters: ParseNode.FormalParameters, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  if (FormalParameters.length === 0) {
+    // 1. Return NormalCompletion(empty).
+    return NormalCompletion(undefined);
+  }
+
+  for (const FormalParameter of FormalParameters.slice(0, -1)) {
+    Q(yield* IteratorBindingInitialization_FormalParameter(FormalParameter, iteratorRecord, environment));
+  }
+
+  const last = FormalParameters[FormalParameters.length - 1];
+  if (last.type === 'BindingRestElement') {
+    return yield* IteratorBindingInitialization_FunctionRestParameter(last, iteratorRecord, environment);
+  }
+  return yield* IteratorBindingInitialization_FormalParameter(last, iteratorRecord, environment);
+}
+
+// FormalParameter : BindingElement
+function IteratorBindingInitialization_FormalParameter(BindingElement: ParseNode.FormalParametersElement, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  // TODO
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  return IteratorBindingInitialization_BindingElement(BindingElement as any, iteratorRecord, environment);
+}
+
+// FunctionRestParameter : BindingRestElement
+function IteratorBindingInitialization_FunctionRestParameter(FunctionRestParameter: ParseNode.FunctionRestParameter, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  return IteratorBindingInitialization_BindingRestElement(FunctionRestParameter, iteratorRecord, environment);
+}
+
+// BindingElement :
+//   SingleNameBinding
+//   BindingPattern
+function IteratorBindingInitialization_BindingElement(BindingElement: ParseNode.BindingElement, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  if ('BindingPattern' in BindingElement) {
+    return IteratorBindingInitialization_BindingPattern(BindingElement, iteratorRecord, environment);
+  }
+  return IteratorBindingInitialization_SingleNameBinding(BindingElement, iteratorRecord, environment);
+}
+
+// SingleNameBinding : BindingIdentifier Initializer?
+function* IteratorBindingInitialization_SingleNameBinding({ BindingIdentifier, Initializer }: ParseNode.SingleNameBinding, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue): PlainEvaluator {
+  // 1. Let bindingId be StringValue of BindingIdentifier.
+  const bindingId = StringValue(BindingIdentifier);
+  // 2. Let lhs be ? ResolveBinding(bindingId, environment).
+  const lhs = Q(yield* ResolveBinding(bindingId, environment, BindingIdentifier.strict));
+  let v: Value = Value.undefined;
+  // 3. If iteratorRecord.[[Done]] is false, then
+  if (iteratorRecord.Done === Value.false) {
+    // a. Let next be ? IteratorStepValue(iteratorRecord).
+    const next = Q(yield* IteratorStepValue(iteratorRecord));
+    // d. If next is not DONE,
+    if (next !== 'done') {
+      v = next;
+    }
+  }
+  // 5. If Initializer is present and v is undefined, then
+  if (Initializer && v === Value.undefined) {
+    if (IsAnonymousFunctionDefinition(Initializer)) {
+      v = Q(yield* NamedEvaluation(Initializer as FunctionDeclaration, bindingId));
+    } else {
+      const defaultValue = Q(yield* Evaluate(Initializer));
+      v = Q(yield* GetValue(defaultValue));
+    }
+  }
+  // 6. If environment is undefined, return ? PutValue(lhs, v).
+  if (environment === Value.undefined) {
+    return Q(yield* PutValue(lhs, v));
+  }
+  // 7. Return InitializeReferencedBinding(lhs, v).
+  return yield* InitializeReferencedBinding(lhs, X(v));
+}
+
+// BindingRestElement :
+//   `...` BindingIdentifier
+//   `...` BindingPattern
+function* IteratorBindingInitialization_BindingRestElement({ BindingIdentifier, BindingPattern }: ParseNode.BindingRestElement, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  if (BindingIdentifier) {
+    // 1. Let lhs be ? ResolveBinding(StringValue of BindingIdentifier, environment).
+    const lhs = Q(yield* ResolveBinding(StringValue(BindingIdentifier), environment, BindingIdentifier.strict));
+    // 2. Let A be ! ArrayCreate(0).
+    const A = X(ArrayCreate(0));
+    // 3. Let n be 0.
+    let n = 0;
+    // 4. Repeat,
+    while (true) {
+      let next: 'done' | Value = 'done';
+      // a. If iteratorRecord.[[Done]] is false, then
+      if (iteratorRecord.Done === Value.false) {
+        // i. Let next be ? IteratorStepValue(iteratorRecord).
+        next = Q(yield* IteratorStepValue(iteratorRecord));
+      }
+      if (next === 'done') {
+        // i. If environment is undefined, return ? PutValue(lhs, A).
+        if (environment === Value.undefined) {
+          return Q(yield* PutValue(lhs, A));
+        }
+        // ii. Return InitializeReferencedBinding(lhs, A).
+        return yield* InitializeReferencedBinding(lhs, A);
+      }
+      // f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(n)), next).
+      X(CreateDataPropertyOrThrow(A, X(ToString(F(n))), next));
+      // g. Set n to n + 1.
+      n += 1;
+    }
+  } else {
+    // 1. Let A be ! ArrayCreate(0).
+    const A = X(ArrayCreate(0));
+    // 2. Let n be 0.
+    let n = 0;
+    // 3. Repeat,
+    while (true) {
+      let next: 'done' | Value = 'done';
+      // a. If iteratorRecord.[[Done]] is false, then
+      if (iteratorRecord.Done === Value.false) {
+        // i. Let next be ? IteratorStepValue(iteratorRecord).
+        next = Q(yield* IteratorStepValue(iteratorRecord));
+      }
+      // b. If next is done, then
+      if (next === 'done') {
+        // i. Return the result of performing BindingInitialization of BindingPattern with A and environment as the arguments.
+        return yield* BindingInitialization(BindingPattern!, A, environment);
+      }
+      // f. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(n)), next).
+      X(CreateDataPropertyOrThrow(A, X(ToString(F(n))), Q(next)));
+      // g. Set n to n + 1.
+      n += 1;
+    }
+  }
+}
+
+function* IteratorBindingInitialization_BindingPattern({ BindingPattern, Initializer }: ParseNode.BindingElement, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue) {
+  let v: Value = Value.undefined;
+  // 1. If iteratorRecord.[[Done]] is false, then
+  if (iteratorRecord.Done === Value.false) {
+    // a. Let next be ? IteratorStepValue(iteratorRecord).
+    const next = Q(yield* IteratorStepValue(iteratorRecord));
+    if (next !== 'done') {
+      v = next;
+    }
+  }
+  // 3. If Initializer is present and v is undefined, then
+  if (Initializer && v instanceof UndefinedValue) {
+    // a. Let defaultValue be the result of evaluating Initializer.
+    const defaultValue = Q(yield* Evaluate(Initializer));
+    // b. Set v to ? GetValue(defaultValue).
+    v = Q(yield* GetValue(defaultValue));
+  }
+  // 4. Return the result of performing BindingInitialization of BindingPattern with v and environment as the arguments.
+  return yield* BindingInitialization(BindingPattern, X(v), environment);
+}
+
+function* IteratorDestructuringAssignmentEvaluation(node: ParseNode.Elision, iteratorRecord: IteratorRecord): PlainEvaluator {
+  Assert(node.type === 'Elision');
+  // 1. If iteratorRecord.[[Done]] is false, then
+  if (iteratorRecord.Done === Value.false) {
+    // a. Perform ? IteratorStep(iteratorRecord).
+    Q(yield* IteratorStep(iteratorRecord));
+  }
+  // 2. Return NormalCompletion(empty).
+  return NormalCompletion(undefined);
+}
+
+export function* IteratorBindingInitialization_ArrayBindingPattern({ BindingElementList, BindingRestElement }: ParseNode.ArrayBindingPattern, iteratorRecord: IteratorRecord, environment: EnvironmentRecord | UndefinedValue): PlainEvaluator {
+  for (const BindingElement of BindingElementList) {
+    if (BindingElement.type === 'Elision') {
+      Q(yield* IteratorDestructuringAssignmentEvaluation(BindingElement, iteratorRecord));
+    } else {
+      // TODO
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      Q(yield* IteratorBindingInitialization_BindingElement(BindingElement as any, iteratorRecord, environment));
+    }
+  }
+
+  if (BindingRestElement) {
+    return Q(yield* IteratorBindingInitialization_BindingRestElement(BindingRestElement, iteratorRecord, environment));
+  }
+  return NormalCompletion(undefined);
+}