@newdash/newdash/memoize.js

javascript/typescript utility library

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.memoize = void 0;
const LRUMap_1 = require("./functional/LRUMap");
/**
 * Creates a function that memoizes the result of `func`. If `resolver` is
 * provided, it determines the cache key for storing the result based on the
 * arguments provided to the memoized function. By default, the first argument
 * provided to the memoized function is used as the map cache key. The `func`
 * is invoked with the `this` binding of the memoized function.
 *
 * **Note:** The cache is exposed as the `cache` property on the memoized
 * function. Its creation may be customized by replacing the `memoize.Cache`
 * constructor with one whose instances implement the
 * [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object)
 * method interface of `clear`, `delete`, `get`, `has`, and `set`.
 *
 * @since 5.2.0
 * @category Function
 * @param func The function to have its output memoized.
 * @param resolver The function to resolve the cache key. default will use the **FIRST** argument as key
 * @returns Returns the new memoized function.
 * @example
 *
 *
 * ```js
 * const object = { 'a': 1, 'b': 2 }
 * const other = { 'c': 3, 'd': 4 }
 *
 * const values = memoize(values)
 * values(object)
 * // => [1, 2]
 *
 * values(other)
 * // => [3, 4]
 *
 * object.a = 2
 * values(object)
 * // => [1, 2]
 *
 * // Modify the result cache.
 * values.cache.set(object, ['a', 'b'])
 * values(object)
 * // => ['a', 'b']
 *
 * // Replace `memoize.Cache` constructor implementation.
 * memoize.Cache = WeakMap
 * ```
 */
function memoize(func, resolver) {
    if (typeof func !== "function" || (resolver != null && typeof resolver !== "function")) {
        throw new TypeError("Expected a function");
    }
    const memoized = function (...args) {
        const key = resolver ? resolver.apply(this, args) : args[0];
        const cache = memoized.cache;
        if (cache.has(key)) {
            return cache.get(key);
        }
        const result = func.apply(this, args);
        memoized.cache = cache.set(key, result) || cache;
        return result;
    };
    memoized.cache = new (memoize.Cache || LRUMap_1.LRUMap);
    return memoized;
}
exports.memoize = memoize;
/**
 * Cache constructor of memorize function
 */
memoize.Cache = Map;
exports.default = memoize;