import ReactExports from 'react'; function shallow(objA, objB) { if (Object.is(objA, objB)) { return true; } if (typeof objA !== "object" || objA === null || typeof objB !== "object" || objB === null) { return false; } if (objA instanceof Map && objB instanceof Map) { if (objA.size !== objB.size) return false; for (const [key, value] of objA) { if (!Object.is(value, objB.get(key))) { return false; } } return true; } if (objA instanceof Set && objB instanceof Set) { if (objA.size !== objB.size) return false; for (const value of objA) { if (!objB.has(value)) { return false; } } return true; } const keysA = Object.keys(objA); if (keysA.length !== Object.keys(objB).length) { return false; } for (const keyA of keysA) { if (!Object.prototype.hasOwnProperty.call(objB, keyA) || !Object.is(objA[keyA], objB[keyA])) { return false; } } return true; } const { useRef } = ReactExports; function useShallow(selector) { const prev = useRef(); return (state) => { const next = selector(state); return shallow(prev.current, next) ? prev.current : prev.current = next; }; } export { useShallow };