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musix-oss/node_modules/core-js/internals/internal-metadata.js

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2020-03-03 20:30:50 +00:00
var hiddenKeys = require('../internals/hidden-keys');
var isObject = require('../internals/is-object');
var has = require('../internals/has');
var defineProperty = require('../internals/object-define-property').f;
var uid = require('../internals/uid');
var FREEZING = require('../internals/freezing');
var METADATA = uid('meta');
var id = 0;
var isExtensible = Object.isExtensible || function () {
return true;
};
var setMetadata = function (it) {
defineProperty(it, METADATA, { value: {
objectID: 'O' + ++id, // object ID
weakData: {} // weak collections IDs
} });
};
var fastKey = function (it, create) {
// return a primitive with prefix
if (!isObject(it)) return typeof it == 'symbol' ? it : (typeof it == 'string' ? 'S' : 'P') + it;
if (!has(it, METADATA)) {
// 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
setMetadata(it);
// return object ID
} return it[METADATA].objectID;
};
var getWeakData = function (it, create) {
if (!has(it, METADATA)) {
// 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
setMetadata(it);
// return the store of weak collections IDs
} return it[METADATA].weakData;
};
// add metadata on freeze-family methods calling
var onFreeze = function (it) {
if (FREEZING && meta.REQUIRED && isExtensible(it) && !has(it, METADATA)) setMetadata(it);
return it;
};
var meta = module.exports = {
REQUIRED: false,
fastKey: fastKey,
getWeakData: getWeakData,
onFreeze: onFreeze
};
hiddenKeys[METADATA] = true;