/**
 * Foldable is a structure that allows a function to all values inside of a
 * structure. The reduction is accumulative and ordered.
 *
 * @module Foldable
 * @since 2.0.0
 */
import "./_dnt.polyfills.js";
import type { $, Hold, Kind } from "./kind.js";
import type { Initializable } from "./initializable.js";
/**
 * A Foldable structure has the method fold.
 *
 * @since 2.0.0
 */
export interface Foldable<U extends Kind> extends Hold<U> {
    readonly fold: <A, O>(reducer: (accumulator: O, value: A) => O, accumulator: O) => <B = never, C = never, D = unknown, E = unknown>(ua: $<U, [A, B, C], [D], [E]>) => O;
}
/**
 * @experimental
 * @since 2.0.0
 */
export declare function collect<U extends Kind, A>({ fold }: Foldable<U>, { combine, init }: Initializable<A>): <B = never, C = never, D = unknown, E = unknown>(ua: $<U, [A, B, C], [D], [E]>) => A;