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// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-elem-id-iter-val-array-prototype.case
// - src/dstr-binding/default/for-of-let.template
/*---
description: Array destructuring uses overriden Array.prototype[Symbol.iterator] (for-of statement)
esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
features: [Symbol.iterator, generators, destructuring-binding]
flags: [generated]
info: |
IterationStatement :
for ( ForDeclaration of AssignmentExpression ) Statement
[...]
3. Return ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult,
lexicalBinding, labelSet).
13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation
[...]
3. Let destructuring be IsDestructuring of lhs.
[...]
5. Repeat
[...]
h. If destructuring is false, then
[...]
i. Else
i. If lhsKind is assignment, then
[...]
ii. Else if lhsKind is varBinding, then
[...]
iii. Else,
1. Assert: lhsKind is lexicalBinding.
2. Assert: lhs is a ForDeclaration.
3. Let status be the result of performing BindingInitialization
for lhs passing nextValue and iterationEnv as arguments.
[...]
Runtime Semantics: IteratorBindingInitialization
SingleNameBinding : BindingIdentifier Initializer_opt
1. Let bindingId be StringValue of BindingIdentifier.
2. Let lhs be ? ResolveBinding(bindingId, environment).
3. If iteratorRecord.[[Done]] is false, then
a. Let next be IteratorStep(iteratorRecord).
b. If next is an abrupt completion, set iteratorRecord.[[Done]] to true.
c. ReturnIfAbrupt(next).
d. If next is false, set iteratorRecord.[[Done]] to true.
e. Else,
i. Let v be IteratorValue(next).
ii. If v is an abrupt completion, set iteratorRecord.[[Done]] to true.
iii. ReturnIfAbrupt(v).
[...]
7. Return InitializeReferencedBinding(lhs, v).
---*/
Array.prototype[Symbol.iterator] = function* () {
if (this.length > 0) {
yield this[0];
}
if (this.length > 1) {
yield this[1];
}
if (this.length > 2) {
yield 42;
}
};
var iterCount = 0;
for (let [x, y, z] of [[1, 2, 3]]) {
assert.sameValue(x, 1);
assert.sameValue(y, 2);
assert.sameValue(z, 42);
iterCount += 1;
}
assert.sameValue(iterCount, 1, 'Iteration occurred as expected');
reportCompare(0, 0);
|
