es-next-tools/dist/function/memoize.js

A comprehensive utility library for JavaScript and TypeScript that provides a wide range of functions for common programming tasks, including mathematical operations, date manipulations, array and object handling, string utilities, and more.

/**
 * Creates a memoized version of a function.
 * @param {T} fn - The function to memoize.
 * @returns {(...args: Parameters<T>) => ReturnType<T> | undefined} A memoized version of the input function.
 * @template T
 * @example
 * const expensiveCalculation = (n) => {
 *   console.log('Calculating...');
 *   return n * 2;
 * };
 * const memoizedCalc = memoize(expensiveCalculation);
 *
 * console.log(memoizedCalc(5)); // Logs: Calculating... 10
 * console.log(memoizedCalc(5)); // Logs: 10 (no calculation, result from cache)
 */
export function memoize(fn, limit = 100) {
    const cache = new Map();
    return (...args) => {
        const key = JSON.stringify(args);
        if (!cache.has(key)) {
            if (cache.size >= limit) {
                const firstKey = cache.keys().next().value;
                if (firstKey) {
                    cache.delete(firstKey);
                }
            }
            cache.set(key, fn(...args));
        }
        return cache.get(key);
    };
}