20 lines
599 B
JavaScript
20 lines
599 B
JavaScript
"use strict";
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/* tslint:disable no-invalid-this */
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.once = once;
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const instances = new WeakMap();
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/**
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* A class method decorator that limits a method to be called only once. All
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* subsequent calls will return the result of the first call.
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*/
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function once(fn, context) {
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return function (...args) {
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let map = instances.get(this);
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if (!map)
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instances.set(this, (map = new WeakMap()));
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if (!map.has(fn))
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map.set(fn, fn.apply(this, args));
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return map.get(fn);
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};
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}
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