well-known-symbol.js 846 Bytes
var global = require('../internals/global');
var shared = require('../internals/shared');
var has = require('../internals/has');
var uid = require('../internals/uid');
var NATIVE_SYMBOL = require('../internals/native-symbol');
var USE_SYMBOL_AS_UID = require('../internals/use-symbol-as-uid');

var WellKnownSymbolsStore = shared('wks');
var Symbol = global.Symbol;
var createWellKnownSymbol = USE_SYMBOL_AS_UID ? Symbol : Symbol && Symbol.withoutSetter || uid;

module.exports = function (name) {
  if (!has(WellKnownSymbolsStore, name) || !(NATIVE_SYMBOL || typeof WellKnownSymbolsStore[name] == 'string')) {
    if (NATIVE_SYMBOL && has(Symbol, name)) {
      WellKnownSymbolsStore[name] = Symbol[name];
    } else {
      WellKnownSymbolsStore[name] = createWellKnownSymbol('Symbol.' + name);
    }
  } return WellKnownSymbolsStore[name];
};