函数记忆

type HashFunction = (...args: any[]) => any;
// 函数记忆
export function memorize(f: Function, hasher?: HashFunction) {
    const cache: Record<string, any> = {};

    return function (...args: any[]) {
        const key = hasher ? hasher(...args) : JSON.stringify(args);

        if (!cache[key]) {
            cache[key] = f.apply(this, args);
        }

        return cache[key];
    };
}


function add (a, b) {
    return a + b;
}

const memorizedAdd = memorize(add);

console.log(memorizedAdd(1, 2)) // 3
console.log(memorizedAdd(1, 2)) // 不经过计算直接得出3