1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
// This file was procedurally generated from the following sources:
// - src/dstr-binding/ary-ptrn-rest-id-elision.case
// - src/dstr-binding/default/gen-func-decl.template
/*---
description: Rest element following elision elements (generator function declaration)
esid: sec-generator-function-definitions-runtime-semantics-instantiatefunctionobject
features: [generators, destructuring-binding]
flags: [generated]
info: |
GeneratorDeclaration : function * ( FormalParameters ) { GeneratorBody }
[...]
2. Let F be GeneratorFunctionCreate(Normal, FormalParameters,
GeneratorBody, scope, strict).
[...]
9.2.1 [[Call]] ( thisArgument, argumentsList)
[...]
7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
[...]
9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
[...]
9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
[...]
23. Let iteratorRecord be Record {[[iterator]]:
CreateListIterator(argumentsList), [[done]]: false}.
24. If hasDuplicates is true, then
[...]
25. Else,
b. Let formalStatus be IteratorBindingInitialization for formals with
iteratorRecord and env as arguments.
[...]
13.3.3.6 Runtime Semantics: IteratorBindingInitialization
ArrayBindingPattern : [ Elisionopt BindingRestElement ]
1. If Elision is present, then
a. Let status be the result of performing
IteratorDestructuringAssignmentEvaluation of Elision with
iteratorRecord as the argument.
b. ReturnIfAbrupt(status).
2. Return the result of performing IteratorBindingInitialization for
BindingRestElement with iteratorRecord and environment as arguments.
---*/
var values = [1, 2, 3, 4, 5];
var callCount = 0;
function* f([ , , ...x]) {
assert(Array.isArray(x));
assert.sameValue(x.length, 3);
assert.sameValue(x[0], 3);
assert.sameValue(x[1], 4);
assert.sameValue(x[2], 5);
assert.notSameValue(x, values);
callCount = callCount + 1;
};
f(values).next();
assert.sameValue(callCount, 1, 'generator function invoked exactly once');
reportCompare(0, 0);
|
