Memoization Decorator - تحسين الأداء

function memoize(fn, keyGenerator = null) {
    const cache = new Map();

    return function(...args) {
        const key = keyGenerator
            ? keyGenerator(...args)
            : JSON.stringify(args);

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

        const result = fn.apply(this, args);
        cache.set(key, result);
        return result;
    };
}

// Advanced: WeakMap for automatic garbage collection
function memoizeWeak(fn) {
    const cache = new WeakMap();

    return function(obj, ...args) {
        if (!cache.has(obj)) {
            cache.set(obj, new Map());
        }

        const objCache = cache.get(obj);
        const key = JSON.stringify(args);

        if (objCache.has(key)) {
            return objCache.get(key);
        }

        const result = fn.apply(this, [obj, ...args]);
        objCache.set(key, result);
        return result;
    };
}

// Example: Fibonacci with memoization
const fibonacci = memoize(function(n) {
    if (n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
});

// Usage
console.log(fibonacci(50)); // Instant result instead of minutes