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28 lines
773 B
28 lines
773 B
6 years ago
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'use strict';
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var toStr = Object.prototype.toString;
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var hasSymbols = typeof Symbol === 'function' && typeof Symbol() === 'symbol';
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if (hasSymbols) {
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var symToStr = Symbol.prototype.toString;
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var symStringRegex = /^Symbol\(.*\)$/;
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var isSymbolObject = function isSymbolObject(value) {
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if (typeof value.valueOf() !== 'symbol') { return false; }
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return symStringRegex.test(symToStr.call(value));
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};
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module.exports = function isSymbol(value) {
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if (typeof value === 'symbol') { return true; }
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if (toStr.call(value) !== '[object Symbol]') { return false; }
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try {
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return isSymbolObject(value);
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} catch (e) {
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return false;
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}
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};
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} else {
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module.exports = function isSymbol(value) {
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// this environment does not support Symbols.
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return false;
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};
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}
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