38 lines
711 B
JavaScript
38 lines
711 B
JavaScript
/*
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MIT License http://www.opensource.org/licenses/mit-license.php
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Author Tobias Koppers @sokra
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*/
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"use strict";
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/**
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* @template T
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* @typedef {() => T} FunctionReturning
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*/
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/**
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* @template T
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* @param {FunctionReturning<T>} fn memorized function
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* @returns {FunctionReturning<T>} new function
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*/
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const memoize = (fn) => {
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let cache = false;
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/** @type {T | undefined} */
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let result;
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return () => {
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if (cache) {
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return /** @type {T} */ (result);
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}
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result = fn();
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cache = true;
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// Allow to clean up memory for fn
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// and all dependent resources
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/** @type {FunctionReturning<T> | undefined} */
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(fn) = undefined;
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return /** @type {T} */ (result);
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};
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};
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module.exports = memoize;
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