import React, { useEffect, useRef, useState } from 'react'; export const useDebounce = (value: T, delay: number): [T, React.Dispatch>] => { const [debouncedValue, setDebouncedValue] = useState(value); useEffect(() => { const handler = setTimeout(() => { setDebouncedValue(value); }, delay); return () => { clearTimeout(handler); }; }, [value, delay]); return [debouncedValue, setDebouncedValue]; }; const UNINITIALIZED_SENTINEL = {}; export const useStaticValue = (factory: () => T): T => { const valueRef = useRef(UNINITIALIZED_SENTINEL as T); if (valueRef.current === UNINITIALIZED_SENTINEL) valueRef.current = factory(); return valueRef.current; }; export const useInstanceVariable = (value: T) => { const ref = useRef(value); useEffect(() => { ref.current = value; }, [ref, value]); return ref; };