joshuaaron

class ExtendedMap<K, V> extends Map<K, V> {
    update(key: K, updater: (value: V, key: K) => V, reset: V = undefined) {
        if (this.has(key)) {
            this.set(key, updater(this.get(key), key));
        }
        else this.set(key, reset);
    }

    filter(predicate: (value: V, key: K) => boolean) {
        const newMap = new ExtendedMap<K, V>();

joshuaaron

const debounce = <F extends (...args: any[]) => any>(fn: F, delay: number) => {
    let timeout: NodeJS.Timeout;
    const debounced = (...args: any[]) => {
        clearTimeout(timeout);
        timeout = setTimeout(() => fn(...args), delay);
    };

    return debounced as (...args: Parameters<F>) => ReturnType<F>;
};