var-ary-ptrn-elision.js (2117B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-binding/ary-ptrn-elision.case 3 // - src/dstr-binding/default/for-of-var.template 4 /*--- 5 description: Elision advances iterator (for-of statement) 6 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 7 features: [generators, destructuring-binding] 8 flags: [generated] 9 info: | 10 IterationStatement : 11 for ( var ForBinding of AssignmentExpression ) Statement 12 13 [...] 14 3. Return ForIn/OfBodyEvaluation(ForBinding, Statement, keyResult, 15 varBinding, labelSet). 16 17 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 18 19 [...] 20 3. Let destructuring be IsDestructuring of lhs. 21 [...] 22 5. Repeat 23 [...] 24 h. If destructuring is false, then 25 [...] 26 i. Else 27 i. If lhsKind is assignment, then 28 [...] 29 ii. Else if lhsKind is varBinding, then 30 1. Assert: lhs is a ForBinding. 31 2. Let status be the result of performing BindingInitialization 32 for lhs passing nextValue and undefined as the arguments. 33 [...] 34 35 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 36 37 ArrayBindingPattern : [ Elision ] 38 39 1. Return the result of performing 40 IteratorDestructuringAssignmentEvaluation of Elision with iteratorRecord 41 as the argument. 42 43 12.14.5.3 Runtime Semantics: IteratorDestructuringAssignmentEvaluation 44 45 Elision : , 46 47 1. If iteratorRecord.[[done]] is false, then 48 a. Let next be IteratorStep(iteratorRecord.[[iterator]]). 49 b. If next is an abrupt completion, set iteratorRecord.[[done]] to true. 50 c. ReturnIfAbrupt(next). 51 d. If next is false, set iteratorRecord.[[done]] to true. 52 2. Return NormalCompletion(empty). 53 54 ---*/ 55 var first = 0; 56 var second = 0; 57 function* g() { 58 first += 1; 59 yield; 60 second += 1; 61 }; 62 63 var iterCount = 0; 64 65 for (var [,] of [g()]) { 66 assert.sameValue(first, 1); 67 assert.sameValue(second, 0); 68 69 iterCount += 1; 70 } 71 72 assert.sameValue(iterCount, 1, 'Iteration occurred as expected'); 73 74 reportCompare(0, 0);