use-optimized-selector/dist/use-optimized-selector.d.ts

A hook to memoized selector values, useful for bailing out of renders.

/**
 * A memoized or constant function in the form of:
 *
 * `(sourceValue) => derivedValue`
 */
export declare type Selector<Value, Return> = (value: Value) => Return;
/**
 * A memoized or constant function in the form of:
 *
 * `(prevValue, nextValue) => boolean`
 *
 * Return true when objects are considered equivalent.
 */
export declare type Comparer<Return> = (prev: Return, next: Return) => boolean;
/**
 * A hook that caches the value of a selector given an optional comparer.
 *
 * It will return the previous value when present and comparer returns true,
 * bailing out of setState and consequent renders.
 *
 * Useful for optimizing selectors for useContextSelector, useSubscriptions, useMutableSource, etc.
 *
 * @param selector A memoized or constant selector
 * @param comparer A memoized or constant comparer
 */
export declare const useOptimizedSelector: <Value, Return>(selector: Selector<Value, Return>, comparer?: Comparer<Return>) => Selector<Value, Return>;