Gecko [ unitednationsplay.com ]

Name	Size	Permission	Date
test	[ DIR ]	drwxr-xr-x	2021-02-04 21:24
.lint	88 B	-rw-r--r--	2015-07-07 12:13
.npmignore	51 B	-rw-r--r--	2015-06-25 13:26
.travis.yml	204 B	-rw-r--r--	2016-05-17 12:54
CHANGES	1.85 KB	-rw-r--r--	2017-03-15 14:58
LICENSE	1.05 KB	-rw-r--r--	2015-06-25 13:26
README.md	2.08 KB	-rw-r--r--	2016-11-11 20:09
implement.js	210 B	-rw-r--r--	2015-06-25 13:26
index.js	96 B	-rw-r--r--	2015-12-11 16:17
is-implemented.js	474 B	-rw-r--r--	2016-05-17 12:54
is-native-implemented.js	166 B	-rw-r--r--	2016-10-18 13:44
is-symbol.js	254 B	-rw-r--r--	2016-05-17 12:54
package.json	1.81 KB	-rw-r--r--	2021-02-04 21:24
polyfill.js	4.97 KB	-rw-r--r--	2016-11-11 20:09
validate-symbol.js	181 B	-rw-r--r--	2015-12-11 16:19

Rename

// ES2015 Symbol polyfill for environments that do not (or partially) support it

'use strict';

var d              = require('d')
  , validateSymbol = require('./validate-symbol')

, create = Object.create, defineProperties = Object.defineProperties
  , defineProperty = Object.defineProperty, objPrototype = Object.prototype
  , NativeSymbol, SymbolPolyfill, HiddenSymbol, globalSymbols = create(null)
  , isNativeSafe;

if (typeof Symbol === 'function') {
	NativeSymbol = Symbol;
	try {
		String(NativeSymbol());
		isNativeSafe = true;
	} catch (ignore) {}
}

// Internal constructor (not one exposed) for creating Symbol instances.
// This one is used to ensure that `someSymbol instanceof Symbol` always return false
HiddenSymbol = function Symbol(description) {
	if (this instanceof HiddenSymbol) throw new TypeError('Symbol is not a constructor');
	return SymbolPolyfill(description);
};

// Exposed `Symbol` constructor
// (returns instances of HiddenSymbol)
module.exports = SymbolPolyfill = function Symbol(description) {
	var symbol;
	if (this instanceof Symbol) throw new TypeError('Symbol is not a constructor');
	if (isNativeSafe) return NativeSymbol(description);
	symbol = create(HiddenSymbol.prototype);
	description = (description === undefined ? '' : String(description));
	return defineProperties(symbol, {
		__description__: d('', description),
		__name__: d('', generateName(description))
	});
};
defineProperties(SymbolPolyfill, {
	for: d(function (key) {
		if (globalSymbols[key]) return globalSymbols[key];
		return (globalSymbols[key] = SymbolPolyfill(String(key)));
	}),
	keyFor: d(function (s) {
		var key;
		validateSymbol(s);
		for (key in globalSymbols) if (globalSymbols[key] === s) return key;
	}),

// To ensure proper interoperability with other native functions (e.g. Array.from)
	// fallback to eventual native implementation of given symbol
	hasInstance: d('', (NativeSymbol && NativeSymbol.hasInstance) || SymbolPolyfill('hasInstance')),
	isConcatSpreadable: d('', (NativeSymbol && NativeSymbol.isConcatSpreadable) ||
		SymbolPolyfill('isConcatSpreadable')),
	iterator: d('', (NativeSymbol && NativeSymbol.iterator) || SymbolPolyfill('iterator')),
	match: d('', (NativeSymbol && NativeSymbol.match) || SymbolPolyfill('match')),
	replace: d('', (NativeSymbol && NativeSymbol.replace) || SymbolPolyfill('replace')),
	search: d('', (NativeSymbol && NativeSymbol.search) || SymbolPolyfill('search')),
	species: d('', (NativeSymbol && NativeSymbol.species) || SymbolPolyfill('species')),
	split: d('', (NativeSymbol && NativeSymbol.split) || SymbolPolyfill('split')),
	toPrimitive: d('', (NativeSymbol && NativeSymbol.toPrimitive) || SymbolPolyfill('toPrimitive')),
	toStringTag: d('', (NativeSymbol && NativeSymbol.toStringTag) || SymbolPolyfill('toStringTag')),
	unscopables: d('', (NativeSymbol && NativeSymbol.unscopables) || SymbolPolyfill('unscopables'))
});

// Internal tweaks for real symbol producer
defineProperties(HiddenSymbol.prototype, {
	constructor: d(SymbolPolyfill),
	toString: d('', function () { return this.__name__; })
});

// Proper implementation of methods exposed on Symbol.prototype
// They won't be accessible on produced symbol instances as they derive from HiddenSymbol.prototype
defineProperties(SymbolPolyfill.prototype, {
	toString: d(function () { return 'Symbol (' + validateSymbol(this).__description__ + ')'; }),
	valueOf: d(function () { return validateSymbol(this); })
});
defineProperty(SymbolPolyfill.prototype, SymbolPolyfill.toPrimitive, d('', function () {
	var symbol = validateSymbol(this);
	if (typeof symbol === 'symbol') return symbol;
	return symbol.toString();
}));
defineProperty(SymbolPolyfill.prototype, SymbolPolyfill.toStringTag, d('c', 'Symbol'));

// Proper implementaton of toPrimitive and toStringTag for returned symbol instances
defineProperty(HiddenSymbol.prototype, SymbolPolyfill.toStringTag,
	d('c', SymbolPolyfill.prototype[SymbolPolyfill.toStringTag]));

// Note: It's important to define `toPrimitive` as last one, as some implementations
// implement `toPrimitive` natively without implementing `toStringTag` (or other specified symbols)
// And that may invoke error in definition flow:
// See: https://github.com/medikoo/es6-symbol/issues/13#issuecomment-164146149
defineProperty(HiddenSymbol.prototype, SymbolPolyfill.toPrimitive,
	d('c', SymbolPolyfill.prototype[SymbolPolyfill.toPrimitive]));