array-rest-iter-rtrn-close-err.js (2613B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-rest-iter-rtrn-close-err.case 3 // - src/dstr-assignment/default/for-of.template 4 /*--- 5 description: IteratorClose is called when reference evaluation produces a "return" completion (For..of statement) 6 esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation 7 features: [Symbol.iterator, generators, destructuring-binding] 8 flags: [generated] 9 info: | 10 IterationStatement : 11 for ( LeftHandSideExpression of AssignmentExpression ) Statement 12 13 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », 14 AssignmentExpression, iterate). 15 2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement, 16 keyResult, assignment, labelSet). 17 18 13.7.5.13 Runtime Semantics: ForIn/OfBodyEvaluation 19 20 [...] 21 4. If destructuring is true and if lhsKind is assignment, then 22 a. Assert: lhs is a LeftHandSideExpression. 23 b. Let assignmentPattern be the parse of the source text corresponding to 24 lhs using AssignmentPattern as the goal symbol. 25 [...] 26 27 ArrayAssignmentPattern : [ Elisionopt AssignmentRestElement ] 28 29 [...] 30 5. Let result be the result of performing 31 IteratorDestructuringAssignmentEvaluation of AssignmentRestElement with 32 iteratorRecord as the argument 33 6. If iteratorRecord.[[done]] is false, return IteratorClose(iterator, 34 result). 35 36 AssignmentRestElement[Yield] : ... DestructuringAssignmentTarget 37 38 1. If DestructuringAssignmentTarget is neither an ObjectLiteral nor an 39 ArrayLiteral, then 40 a. Let lref be the result of evaluating DestructuringAssignmentTarget. 41 b. ReturnIfAbrupt(lref). 42 43 7.4.6 IteratorClose( iterator, completion ) 44 45 [...] 46 6. Let innerResult be Call(return, iterator, « »). 47 7. If completion.[[type]] is throw, return Completion(completion). 48 8. If innerResult.[[type]] is throw, return Completion(innerResult). 49 50 ---*/ 51 var returnCount = 0; 52 var unreachable = 0; 53 var iterable = {}; 54 var iterator = { 55 return: function() { 56 returnCount += 1; 57 58 throw new Test262Error(); 59 } 60 }; 61 var iter; 62 iterable[Symbol.iterator] = function() { 63 return iterator; 64 }; 65 66 function* g() { 67 68 var counter = 0; 69 70 for ([...{}[yield]] of [iterable]) { 71 unreachable += 1; 72 counter += 1; 73 } 74 75 assert.sameValue(counter, 1); 76 77 } 78 79 iter = g(); 80 iter.next(); 81 assert.throws(Test262Error, function() { 82 iter.return(); 83 }); 84 85 assert.sameValue(returnCount, 1); 86 assert.sameValue(unreachable, 0, 'Unreachable statement was not executed'); 87 88 reportCompare(0, 0);