es.symbol.js 13 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var global = require('../internals/global');
  4. var getBuiltIn = require('../internals/get-built-in');
  5. var apply = require('../internals/function-apply');
  6. var call = require('../internals/function-call');
  7. var uncurryThis = require('../internals/function-uncurry-this');
  8. var IS_PURE = require('../internals/is-pure');
  9. var DESCRIPTORS = require('../internals/descriptors');
  10. var NATIVE_SYMBOL = require('../internals/native-symbol');
  11. var fails = require('../internals/fails');
  12. var hasOwn = require('../internals/has-own-property');
  13. var isArray = require('../internals/is-array');
  14. var isCallable = require('../internals/is-callable');
  15. var isObject = require('../internals/is-object');
  16. var isPrototypeOf = require('../internals/object-is-prototype-of');
  17. var isSymbol = require('../internals/is-symbol');
  18. var anObject = require('../internals/an-object');
  19. var toObject = require('../internals/to-object');
  20. var toIndexedObject = require('../internals/to-indexed-object');
  21. var toPropertyKey = require('../internals/to-property-key');
  22. var $toString = require('../internals/to-string');
  23. var createPropertyDescriptor = require('../internals/create-property-descriptor');
  24. var nativeObjectCreate = require('../internals/object-create');
  25. var objectKeys = require('../internals/object-keys');
  26. var getOwnPropertyNamesModule = require('../internals/object-get-own-property-names');
  27. var getOwnPropertyNamesExternal = require('../internals/object-get-own-property-names-external');
  28. var getOwnPropertySymbolsModule = require('../internals/object-get-own-property-symbols');
  29. var getOwnPropertyDescriptorModule = require('../internals/object-get-own-property-descriptor');
  30. var definePropertyModule = require('../internals/object-define-property');
  31. var propertyIsEnumerableModule = require('../internals/object-property-is-enumerable');
  32. var arraySlice = require('../internals/array-slice');
  33. var redefine = require('../internals/redefine');
  34. var shared = require('../internals/shared');
  35. var sharedKey = require('../internals/shared-key');
  36. var hiddenKeys = require('../internals/hidden-keys');
  37. var uid = require('../internals/uid');
  38. var wellKnownSymbol = require('../internals/well-known-symbol');
  39. var wrappedWellKnownSymbolModule = require('../internals/well-known-symbol-wrapped');
  40. var defineWellKnownSymbol = require('../internals/define-well-known-symbol');
  41. var setToStringTag = require('../internals/set-to-string-tag');
  42. var InternalStateModule = require('../internals/internal-state');
  43. var $forEach = require('../internals/array-iteration').forEach;
  44. var HIDDEN = sharedKey('hidden');
  45. var SYMBOL = 'Symbol';
  46. var PROTOTYPE = 'prototype';
  47. var TO_PRIMITIVE = wellKnownSymbol('toPrimitive');
  48. var setInternalState = InternalStateModule.set;
  49. var getInternalState = InternalStateModule.getterFor(SYMBOL);
  50. var ObjectPrototype = Object[PROTOTYPE];
  51. var $Symbol = global.Symbol;
  52. var SymbolPrototype = $Symbol && $Symbol[PROTOTYPE];
  53. var TypeError = global.TypeError;
  54. var QObject = global.QObject;
  55. var $stringify = getBuiltIn('JSON', 'stringify');
  56. var nativeGetOwnPropertyDescriptor = getOwnPropertyDescriptorModule.f;
  57. var nativeDefineProperty = definePropertyModule.f;
  58. var nativeGetOwnPropertyNames = getOwnPropertyNamesExternal.f;
  59. var nativePropertyIsEnumerable = propertyIsEnumerableModule.f;
  60. var push = uncurryThis([].push);
  61. var AllSymbols = shared('symbols');
  62. var ObjectPrototypeSymbols = shared('op-symbols');
  63. var StringToSymbolRegistry = shared('string-to-symbol-registry');
  64. var SymbolToStringRegistry = shared('symbol-to-string-registry');
  65. var WellKnownSymbolsStore = shared('wks');
  66. // Don't use setters in Qt Script, https://github.com/zloirock/core-js/issues/173
  67. var USE_SETTER = !QObject || !QObject[PROTOTYPE] || !QObject[PROTOTYPE].findChild;
  68. // fallback for old Android, https://code.google.com/p/v8/issues/detail?id=687
  69. var setSymbolDescriptor = DESCRIPTORS && fails(function () {
  70. return nativeObjectCreate(nativeDefineProperty({}, 'a', {
  71. get: function () { return nativeDefineProperty(this, 'a', { value: 7 }).a; }
  72. })).a != 7;
  73. }) ? function (O, P, Attributes) {
  74. var ObjectPrototypeDescriptor = nativeGetOwnPropertyDescriptor(ObjectPrototype, P);
  75. if (ObjectPrototypeDescriptor) delete ObjectPrototype[P];
  76. nativeDefineProperty(O, P, Attributes);
  77. if (ObjectPrototypeDescriptor && O !== ObjectPrototype) {
  78. nativeDefineProperty(ObjectPrototype, P, ObjectPrototypeDescriptor);
  79. }
  80. } : nativeDefineProperty;
  81. var wrap = function (tag, description) {
  82. var symbol = AllSymbols[tag] = nativeObjectCreate(SymbolPrototype);
  83. setInternalState(symbol, {
  84. type: SYMBOL,
  85. tag: tag,
  86. description: description
  87. });
  88. if (!DESCRIPTORS) symbol.description = description;
  89. return symbol;
  90. };
  91. var $defineProperty = function defineProperty(O, P, Attributes) {
  92. if (O === ObjectPrototype) $defineProperty(ObjectPrototypeSymbols, P, Attributes);
  93. anObject(O);
  94. var key = toPropertyKey(P);
  95. anObject(Attributes);
  96. if (hasOwn(AllSymbols, key)) {
  97. if (!Attributes.enumerable) {
  98. if (!hasOwn(O, HIDDEN)) nativeDefineProperty(O, HIDDEN, createPropertyDescriptor(1, {}));
  99. O[HIDDEN][key] = true;
  100. } else {
  101. if (hasOwn(O, HIDDEN) && O[HIDDEN][key]) O[HIDDEN][key] = false;
  102. Attributes = nativeObjectCreate(Attributes, { enumerable: createPropertyDescriptor(0, false) });
  103. } return setSymbolDescriptor(O, key, Attributes);
  104. } return nativeDefineProperty(O, key, Attributes);
  105. };
  106. var $defineProperties = function defineProperties(O, Properties) {
  107. anObject(O);
  108. var properties = toIndexedObject(Properties);
  109. var keys = objectKeys(properties).concat($getOwnPropertySymbols(properties));
  110. $forEach(keys, function (key) {
  111. if (!DESCRIPTORS || call($propertyIsEnumerable, properties, key)) $defineProperty(O, key, properties[key]);
  112. });
  113. return O;
  114. };
  115. var $create = function create(O, Properties) {
  116. return Properties === undefined ? nativeObjectCreate(O) : $defineProperties(nativeObjectCreate(O), Properties);
  117. };
  118. var $propertyIsEnumerable = function propertyIsEnumerable(V) {
  119. var P = toPropertyKey(V);
  120. var enumerable = call(nativePropertyIsEnumerable, this, P);
  121. if (this === ObjectPrototype && hasOwn(AllSymbols, P) && !hasOwn(ObjectPrototypeSymbols, P)) return false;
  122. return enumerable || !hasOwn(this, P) || !hasOwn(AllSymbols, P) || hasOwn(this, HIDDEN) && this[HIDDEN][P]
  123. ? enumerable : true;
  124. };
  125. var $getOwnPropertyDescriptor = function getOwnPropertyDescriptor(O, P) {
  126. var it = toIndexedObject(O);
  127. var key = toPropertyKey(P);
  128. if (it === ObjectPrototype && hasOwn(AllSymbols, key) && !hasOwn(ObjectPrototypeSymbols, key)) return;
  129. var descriptor = nativeGetOwnPropertyDescriptor(it, key);
  130. if (descriptor && hasOwn(AllSymbols, key) && !(hasOwn(it, HIDDEN) && it[HIDDEN][key])) {
  131. descriptor.enumerable = true;
  132. }
  133. return descriptor;
  134. };
  135. var $getOwnPropertyNames = function getOwnPropertyNames(O) {
  136. var names = nativeGetOwnPropertyNames(toIndexedObject(O));
  137. var result = [];
  138. $forEach(names, function (key) {
  139. if (!hasOwn(AllSymbols, key) && !hasOwn(hiddenKeys, key)) push(result, key);
  140. });
  141. return result;
  142. };
  143. var $getOwnPropertySymbols = function getOwnPropertySymbols(O) {
  144. var IS_OBJECT_PROTOTYPE = O === ObjectPrototype;
  145. var names = nativeGetOwnPropertyNames(IS_OBJECT_PROTOTYPE ? ObjectPrototypeSymbols : toIndexedObject(O));
  146. var result = [];
  147. $forEach(names, function (key) {
  148. if (hasOwn(AllSymbols, key) && (!IS_OBJECT_PROTOTYPE || hasOwn(ObjectPrototype, key))) {
  149. push(result, AllSymbols[key]);
  150. }
  151. });
  152. return result;
  153. };
  154. // `Symbol` constructor
  155. // https://tc39.es/ecma262/#sec-symbol-constructor
  156. if (!NATIVE_SYMBOL) {
  157. $Symbol = function Symbol() {
  158. if (isPrototypeOf(SymbolPrototype, this)) throw TypeError('Symbol is not a constructor');
  159. var description = !arguments.length || arguments[0] === undefined ? undefined : $toString(arguments[0]);
  160. var tag = uid(description);
  161. var setter = function (value) {
  162. if (this === ObjectPrototype) call(setter, ObjectPrototypeSymbols, value);
  163. if (hasOwn(this, HIDDEN) && hasOwn(this[HIDDEN], tag)) this[HIDDEN][tag] = false;
  164. setSymbolDescriptor(this, tag, createPropertyDescriptor(1, value));
  165. };
  166. if (DESCRIPTORS && USE_SETTER) setSymbolDescriptor(ObjectPrototype, tag, { configurable: true, set: setter });
  167. return wrap(tag, description);
  168. };
  169. SymbolPrototype = $Symbol[PROTOTYPE];
  170. redefine(SymbolPrototype, 'toString', function toString() {
  171. return getInternalState(this).tag;
  172. });
  173. redefine($Symbol, 'withoutSetter', function (description) {
  174. return wrap(uid(description), description);
  175. });
  176. propertyIsEnumerableModule.f = $propertyIsEnumerable;
  177. definePropertyModule.f = $defineProperty;
  178. getOwnPropertyDescriptorModule.f = $getOwnPropertyDescriptor;
  179. getOwnPropertyNamesModule.f = getOwnPropertyNamesExternal.f = $getOwnPropertyNames;
  180. getOwnPropertySymbolsModule.f = $getOwnPropertySymbols;
  181. wrappedWellKnownSymbolModule.f = function (name) {
  182. return wrap(wellKnownSymbol(name), name);
  183. };
  184. if (DESCRIPTORS) {
  185. // https://github.com/tc39/proposal-Symbol-description
  186. nativeDefineProperty(SymbolPrototype, 'description', {
  187. configurable: true,
  188. get: function description() {
  189. return getInternalState(this).description;
  190. }
  191. });
  192. if (!IS_PURE) {
  193. redefine(ObjectPrototype, 'propertyIsEnumerable', $propertyIsEnumerable, { unsafe: true });
  194. }
  195. }
  196. }
  197. $({ global: true, wrap: true, forced: !NATIVE_SYMBOL, sham: !NATIVE_SYMBOL }, {
  198. Symbol: $Symbol
  199. });
  200. $forEach(objectKeys(WellKnownSymbolsStore), function (name) {
  201. defineWellKnownSymbol(name);
  202. });
  203. $({ target: SYMBOL, stat: true, forced: !NATIVE_SYMBOL }, {
  204. // `Symbol.for` method
  205. // https://tc39.es/ecma262/#sec-symbol.for
  206. 'for': function (key) {
  207. var string = $toString(key);
  208. if (hasOwn(StringToSymbolRegistry, string)) return StringToSymbolRegistry[string];
  209. var symbol = $Symbol(string);
  210. StringToSymbolRegistry[string] = symbol;
  211. SymbolToStringRegistry[symbol] = string;
  212. return symbol;
  213. },
  214. // `Symbol.keyFor` method
  215. // https://tc39.es/ecma262/#sec-symbol.keyfor
  216. keyFor: function keyFor(sym) {
  217. if (!isSymbol(sym)) throw TypeError(sym + ' is not a symbol');
  218. if (hasOwn(SymbolToStringRegistry, sym)) return SymbolToStringRegistry[sym];
  219. },
  220. useSetter: function () { USE_SETTER = true; },
  221. useSimple: function () { USE_SETTER = false; }
  222. });
  223. $({ target: 'Object', stat: true, forced: !NATIVE_SYMBOL, sham: !DESCRIPTORS }, {
  224. // `Object.create` method
  225. // https://tc39.es/ecma262/#sec-object.create
  226. create: $create,
  227. // `Object.defineProperty` method
  228. // https://tc39.es/ecma262/#sec-object.defineproperty
  229. defineProperty: $defineProperty,
  230. // `Object.defineProperties` method
  231. // https://tc39.es/ecma262/#sec-object.defineproperties
  232. defineProperties: $defineProperties,
  233. // `Object.getOwnPropertyDescriptor` method
  234. // https://tc39.es/ecma262/#sec-object.getownpropertydescriptors
  235. getOwnPropertyDescriptor: $getOwnPropertyDescriptor
  236. });
  237. $({ target: 'Object', stat: true, forced: !NATIVE_SYMBOL }, {
  238. // `Object.getOwnPropertyNames` method
  239. // https://tc39.es/ecma262/#sec-object.getownpropertynames
  240. getOwnPropertyNames: $getOwnPropertyNames,
  241. // `Object.getOwnPropertySymbols` method
  242. // https://tc39.es/ecma262/#sec-object.getownpropertysymbols
  243. getOwnPropertySymbols: $getOwnPropertySymbols
  244. });
  245. // Chrome 38 and 39 `Object.getOwnPropertySymbols` fails on primitives
  246. // https://bugs.chromium.org/p/v8/issues/detail?id=3443
  247. $({ target: 'Object', stat: true, forced: fails(function () { getOwnPropertySymbolsModule.f(1); }) }, {
  248. getOwnPropertySymbols: function getOwnPropertySymbols(it) {
  249. return getOwnPropertySymbolsModule.f(toObject(it));
  250. }
  251. });
  252. // `JSON.stringify` method behavior with symbols
  253. // https://tc39.es/ecma262/#sec-json.stringify
  254. if ($stringify) {
  255. var FORCED_JSON_STRINGIFY = !NATIVE_SYMBOL || fails(function () {
  256. var symbol = $Symbol();
  257. // MS Edge converts symbol values to JSON as {}
  258. return $stringify([symbol]) != '[null]'
  259. // WebKit converts symbol values to JSON as null
  260. || $stringify({ a: symbol }) != '{}'
  261. // V8 throws on boxed symbols
  262. || $stringify(Object(symbol)) != '{}';
  263. });
  264. $({ target: 'JSON', stat: true, forced: FORCED_JSON_STRINGIFY }, {
  265. // eslint-disable-next-line no-unused-vars -- required for `.length`
  266. stringify: function stringify(it, replacer, space) {
  267. var args = arraySlice(arguments);
  268. var $replacer = replacer;
  269. if (!isObject(replacer) && it === undefined || isSymbol(it)) return; // IE8 returns string on undefined
  270. if (!isArray(replacer)) replacer = function (key, value) {
  271. if (isCallable($replacer)) value = call($replacer, this, key, value);
  272. if (!isSymbol(value)) return value;
  273. };
  274. args[1] = replacer;
  275. return apply($stringify, null, args);
  276. }
  277. });
  278. }
  279. // `Symbol.prototype[@@toPrimitive]` method
  280. // https://tc39.es/ecma262/#sec-symbol.prototype-@@toprimitive
  281. if (!SymbolPrototype[TO_PRIMITIVE]) {
  282. var valueOf = SymbolPrototype.valueOf;
  283. // eslint-disable-next-line no-unused-vars -- required for .length
  284. redefine(SymbolPrototype, TO_PRIMITIVE, function (hint) {
  285. // TODO: improve hint logic
  286. return call(valueOf, this);
  287. });
  288. }
  289. // `Symbol.prototype[@@toStringTag]` property
  290. // https://tc39.es/ecma262/#sec-symbol.prototype-@@tostringtag
  291. setToStringTag($Symbol, SYMBOL);
  292. hiddenKeys[HIDDEN] = true;