tamda/dist/set/intersection.d.ts

Practical functional programming library for TypeScript

/**
 * Filters items that are both in `arrayA` and `arrayB`.
 * @note From set theory, given sets A and B, denoted A ∩ B,
 * returns the set of intersection members of both A and B.
 * @param arrayA Array to filter.
 * @param arrayB Array to check item existance.
 * @param keyFn Optional function to extract a key for comparison between array items. Default: `identity()`.
 * @example
 * intersection([1, 2, 3], [2, 3, 4]);
 * // [2, 3]
 */
export declare function intersection<T>(arrayA: T[], arrayB: T[], keyFn?: KeyFn<T>): T[];
/**
 * Returns a function that
 * filters items that are both in `arrayA` and `arrayB`.
 * @note From set theory, given sets A and B, denoted A ∩ B,
 * returns the set of intersection members of both A and B.
 * @param arrayB Array to check item existance.
 * @param keyFn Optional function to extract a key for comparison between array items. Default: `identity()`.
 * @example
 * const inBoth = intersection([2, 3, 4]);
 * inBoth([1, 2, 3]);
 * // [2, 3]
 */
export declare function intersection<T>(arrayB: T[], keyFn?: KeyFn<T>): typeof deferred;
/**
 * Filters items that are both in `arrayA` and previously specified `arrayB`.
 * @note From set theory, given sets A and B, denoted A ∩ B,
 * returns the set of intersection members of both A and B.
 * @param arrayA Array to filter.
 */
declare function deferred<T>(arrayA: T[]): T[];
declare type KeyFn<T> = (item: T, index: number) => any;
export {};