export default reduce;
/**
 * Pure functional reducer. Can be used for currying stuff.
 *
 * @see {@link ./flatten.js}
 *
 * @template T
 * @template U
 *
 * @param {(previousValue: U, currentValue: T, currentIndex: number, array: Array<T>) => U} callbackfn
 * @param {U} initialValue
 * @return {(x: Array<T>) => U}  Curried function that accepts an array to be reduced.
 */
declare function reduce<T, U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: Array<T>) => U, initialValue: U): (x: Array<T>) => U;