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