38 lines
1.1 KiB
JavaScript
38 lines
1.1 KiB
JavaScript
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'use strict';
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var ToNumber = require('./ToNumber');
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var ToPrimitive = require('./ToPrimitive');
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var Type = require('./Type');
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// https://www.ecma-international.org/ecma-262/6.0/#sec-abstract-equality-comparison
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module.exports = function AbstractEqualityComparison(x, y) {
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var xType = Type(x);
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var yType = Type(y);
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if (xType === yType) {
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return x === y; // ES6+ specified this shortcut anyways.
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}
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if (x == null && y == null) {
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return true;
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}
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if (xType === 'Number' && yType === 'String') {
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return AbstractEqualityComparison(x, ToNumber(y));
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}
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if (xType === 'String' && yType === 'Number') {
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return AbstractEqualityComparison(ToNumber(x), y);
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}
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if (xType === 'Boolean') {
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return AbstractEqualityComparison(ToNumber(x), y);
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}
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if (yType === 'Boolean') {
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return AbstractEqualityComparison(x, ToNumber(y));
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}
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if ((xType === 'String' || xType === 'Number' || xType === 'Symbol') && yType === 'Object') {
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return AbstractEqualityComparison(x, ToPrimitive(y));
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}
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if (xType === 'Object' && (yType === 'String' || yType === 'Number' || yType === 'Symbol')) {
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return AbstractEqualityComparison(ToPrimitive(x), y);
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}
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return false;
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};
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