array-elem-target-yield-expr.js (1745B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-assignment/array-elem-target-yield-expr.case 3 // - src/dstr-assignment/default/for-of.template 4 /*--- 5 description: When a `yield` token appears within the DestructuringAssignmentTarget of an AssignmentElement within a generator function body, it behaves as a YieldExpression. (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 ( 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 var value = [33]; 28 var x = {}; 29 var iterationResult, iter; 30 31 iter = (function*() { 32 33 var counter = 0; 34 35 for ([ x[yield] ] of [[33]]) { 36 37 counter += 1; 38 } 39 40 assert.sameValue(counter, 1); 41 42 }()); 43 44 iterationResult = iter.next(); 45 46 assert.sameValue(iterationResult.value, undefined); 47 assert.sameValue(iterationResult.done, false); 48 assert.sameValue(x.prop, undefined); 49 50 iterationResult = iter.next('prop'); 51 52 assert.sameValue(iterationResult.value, undefined); 53 assert.sameValue(iterationResult.done, true); 54 assert.sameValue(x.prop, 33); 55 56 reportCompare(0, 0);