mirror of https://github.com/tc39/test262.git
82 lines
2.0 KiB
JavaScript
82 lines
2.0 KiB
JavaScript
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// Copyright (C) 2019 Leo Balter. 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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description: >
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Short circuit if the CoalesceExpressionHead is not undefined or null (0)
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esid: sec-conditional-operator
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info: |
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ConditionalExpression :
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ShortCircuitExpression
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ShortCircuitExpression ? AssignmentExpression : AssignmentExpression
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ShortCircuitExpression :
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LogicalORExpression
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CoalesceExpression
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CoalesceExpression :
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CoalesceExpressionHead ?? BitwiseORExpression
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CoalesceExpressionHead :
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CoalesceExpression
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BitwiseORExpression
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Runtime Semantics: Evaluation
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CoalesceExpression:CoalesceExpressionHead??BitwiseORExpression
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1. Let lref be the result of evaluating CoalesceExpressionHead.
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2. Let lval be ? GetValue(lref).
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3. If lval is undefined or null,
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a. Let rref be the result of evaluating BitwiseORExpression.
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b. Return ? GetValue(rref).
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4. Otherwise, return lval.
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features: [coalesce-expression]
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---*/
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var x;
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x = undefined;
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x = 0 ?? 1;
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assert.sameValue(x, 0, '0 ?? 1');
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x = undefined;
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x = 0 ?? null;
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assert.sameValue(x, 0, '0 ?? null');
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x = undefined;
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x = 0 ?? undefined;
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assert.sameValue(x, 0, '0 ?? undefined');
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x = undefined;
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x = 0 ?? null ?? undefined;
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assert.sameValue(x, 0, '0 ?? null ?? undefined');
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x = undefined;
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x = 0 ?? undefined ?? null;
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assert.sameValue(x, 0, '0 ?? undefined ?? null');
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x = undefined;
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x = 0 ?? null ?? null;
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assert.sameValue(x, 0, '0 ?? null ?? null');
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x = undefined;
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x = 0 ?? undefined ?? undefined;
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assert.sameValue(x, 0, '0 ?? null ?? null');
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x = undefined;
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x = null ?? 0 ?? null;
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assert.sameValue(x, 0, 'null ?? 0 ?? null');
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x = undefined;
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x = null ?? 0 ?? undefined;
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assert.sameValue(x, 0, 'null ?? 0 ?? undefined');
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x = undefined;
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x = undefined ?? 0 ?? null;
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assert.sameValue(x, 0, 'undefined ?? 0 ?? null');
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x = undefined;
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x = undefined ?? 0 ?? undefined;
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assert.sameValue(x, 0, 'undefined ?? 0 ?? undefined');
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