Memoization/JavaScript/3-cacheSize.js at master · HowProgrammingWorks/Memoization

37 lines (32 loc) · 816 Bytes

'use strict';

const argKey = (x) => x.toString() + ':' + typeof x;

const generateKey = (args) => args.map(argKey).join('|');

const memoize = (fn, length) => {

const cache = new Map();

return (...args) => {

const key = generateKey(args);

console.log(`${fn.name}(${key}) call`);

if (cache.has(key)) return cache.get(key);

console.log(`max(${key}) calculate`);

const res = fn(...args);

if (cache.size >= length) {

const firstKey = cache.keys().next().value;

console.log('Delete key:', firstKey);

cache.delete(firstKey);

}

cache.set(key, res);

return res;

};

// Usage

const max = (a, b) => (a > b ? a : b);

const mMax = memoize(max, 3);

mMax(10, 8);

mMax(1, 15);

mMax(12, 3);

mMax(15, 2);

mMax(1, 15);

mMax(10, 8);

mMax(0, 0);

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