23 lines
760 B
JavaScript
23 lines
760 B
JavaScript
'use strict';
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var $ = require('../internals/export');
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var aCallable = require('../internals/a-callable');
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var aWeakMap = require('../internals/a-weak-map');
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var WeakMapHelpers = require('../internals/weak-map-helpers');
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var get = WeakMapHelpers.get;
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var has = WeakMapHelpers.has;
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var set = WeakMapHelpers.set;
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// `WeakMap.prototype.getOrInsertComputed` method
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// https://github.com/tc39/proposal-upsert
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$({ target: 'WeakMap', proto: true, real: true, forced: true }, {
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getOrInsertComputed: function getOrInsertComputed(key, callbackfn) {
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aWeakMap(this);
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aCallable(callbackfn);
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if (has(this, key)) return get(this, key);
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set(this, key); // key validation
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var value = callbackfn(key);
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set(this, key, value);
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return value;
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}
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});
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