// Copyright (C) 2016 the V8 project authors. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation description: > Removal of lexical environment to serve as a temporal dead zone for the statement's AssignmentExpresson info: | IterationStatement : for ( ForDeclaration of AssignmentExpression ) Statement 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(BoundNames of ForDeclaration, AssignmentExpression, iterate). [...] 13.7.5.12 Runtime Semantics: ForIn/OfHeadEvaluation [...] 2. If TDZnames is not an empty List, then a. Assert: TDZnames has no duplicate entries. b. Let TDZ be NewDeclarativeEnvironment(oldEnv). c. Let TDZEnvRec be TDZ's EnvironmentRecord. d. For each string name in TDZnames, do i. Perform ! TDZEnvRec.CreateMutableBinding(name, false). e. Set the running execution context's LexicalEnvironment to TDZ. 3. Let exprRef be the result of evaluating expr. 4. Set the running execution context's LexicalEnvironment to oldEnv. [...] features: [let] ---*/ let x = 'outside'; var probeDecl, probeExpr, probeBody; for ( let [x, _ = probeDecl = function() { return x; }] of (probeExpr = function() { typeof x; }, [['inside']]) ) probeBody = function() { return x; }; assert.throws(ReferenceError, probeExpr); assert.sameValue(probeDecl(), 'inside', 'reference from ForDeclaration'); assert.sameValue(probeBody(), 'inside', 'reference from statement body'); reportCompare(0, 0);