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node_modules/core-js/library/modules/_meta.js
| 53 lines
| 1.5 KiB
| application/javascript
| JavascriptLexer
|
| r789 | var META = require('./_uid')('meta'); | |||
| var isObject = require('./_is-object'); | ||||
| var has = require('./_has'); | ||||
| var setDesc = require('./_object-dp').f; | ||||
| var id = 0; | ||||
| var isExtensible = Object.isExtensible || function () { | ||||
| return true; | ||||
| }; | ||||
| var FREEZE = !require('./_fails')(function () { | ||||
| return isExtensible(Object.preventExtensions({})); | ||||
| }); | ||||
| var setMeta = function (it) { | ||||
| setDesc(it, META, { value: { | ||||
| i: 'O' + ++id, // object ID | ||||
| w: {} // weak collections IDs | ||||
| } }); | ||||
| }; | ||||
| var fastKey = function (it, create) { | ||||
| // return primitive with prefix | ||||
| if (!isObject(it)) return typeof it == 'symbol' ? it : (typeof it == 'string' ? 'S' : 'P') + it; | ||||
| if (!has(it, META)) { | ||||
| // can't set metadata to uncaught frozen object | ||||
| if (!isExtensible(it)) return 'F'; | ||||
| // not necessary to add metadata | ||||
| if (!create) return 'E'; | ||||
| // add missing metadata | ||||
| setMeta(it); | ||||
| // return object ID | ||||
| } return it[META].i; | ||||
| }; | ||||
| var getWeak = function (it, create) { | ||||
| if (!has(it, META)) { | ||||
| // can't set metadata to uncaught frozen object | ||||
| if (!isExtensible(it)) return true; | ||||
| // not necessary to add metadata | ||||
| if (!create) return false; | ||||
| // add missing metadata | ||||
| setMeta(it); | ||||
| // return hash weak collections IDs | ||||
| } return it[META].w; | ||||
| }; | ||||
| // add metadata on freeze-family methods calling | ||||
| var onFreeze = function (it) { | ||||
| if (FREEZE && meta.NEED && isExtensible(it) && !has(it, META)) setMeta(it); | ||||
| return it; | ||||
| }; | ||||
| var meta = module.exports = { | ||||
| KEY: META, | ||||
| NEED: false, | ||||
| fastKey: fastKey, | ||||
| getWeak: getWeak, | ||||
| onFreeze: onFreeze | ||||
| }; | ||||