mirror of https://github.com/tc39/test262.git
39 lines
1.3 KiB
JavaScript
39 lines
1.3 KiB
JavaScript
// Copyright (C) 2016 the V8 project authors. All rights reserved.
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// This code is governed by the BSD license found in the LICENSE file.
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/*---
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esid: sec-for-in-and-for-of-statements-runtime-semantics-labelledevaluation
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description: >
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Creation of new lexical environment to serve as a temporal dead zone for
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the statement's AssignmentExpresson
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info: |
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IterationStatement : for ( ForDeclaration of AssignmentExpression ) Statement
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1. Let keyResult be the result of performing ?
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ForIn/OfHeadEvaluation(BoundNames of ForDeclaration,
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AssignmentExpression, iterate).
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[...]
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13.7.5.12 Runtime Semantics: ForIn/OfHeadEvaluation
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[...]
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2. If TDZnames is not an empty List, then
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a. Assert: TDZnames has no duplicate entries.
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b. Let TDZ be NewDeclarativeEnvironment(oldEnv).
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c. Let TDZEnvRec be TDZ's EnvironmentRecord.
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d. For each string name in TDZnames, do
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i. Perform ! TDZEnvRec.CreateMutableBinding(name, false).
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e. Set the running execution context's LexicalEnvironment to TDZ.
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3. Let exprRef be the result of evaluating expr.
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[...]
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features: [let]
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---*/
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let x = 'outside';
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var probeBefore = function() { return x; };
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var probeExpr;
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for (let x of (probeExpr = function() { typeof x; }, [])) ;
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assert.sameValue(probeBefore(), 'outside');
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assert.throws(ReferenceError, probeExpr);
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