33 lines
973 B
TypeScript
33 lines
973 B
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import {global as _global} from './global';
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// When Symbol.iterator doesn't exist, retrieves the key used in es6-shim
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declare const Symbol: any;
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let _symbolIterator: any = null;
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export function getSymbolIterator(): string|symbol {
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if (!_symbolIterator) {
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const Symbol = _global['Symbol'];
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if (Symbol && Symbol.iterator) {
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_symbolIterator = Symbol.iterator;
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} else {
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// es6-shim specific logic
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const keys = Object.getOwnPropertyNames(Map.prototype);
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for (let i = 0; i < keys.length; ++i) {
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const key = keys[i];
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if (key !== 'entries' && key !== 'size' &&
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(Map as any).prototype[key] === Map.prototype['entries']) {
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_symbolIterator = key;
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}
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}
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}
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}
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return _symbolIterator;
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}
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