import type { IStream } from '../types.js';
/**
 * Accumulate results using a feedback loop that emits one value and feeds back
 * another to be used in the next iteration.
 */
export declare const aggregate: IAggregateCurry;
export type AggregateFunction<I, S, O> = (seed: S, value: I) => {
    seed: S;
    value: O;
};
export interface IAggregateCurry {
    <I, S, O>(f: AggregateFunction<I, S, O>, initial: S, s: IStream<I>): IStream<O>;
    <I, S, O>(f: AggregateFunction<I, S, O>, initial: S): (s: IStream<I>) => IStream<O>;
    <I, S, O>(f: AggregateFunction<I, S, O>): (initial: S) => (s: IStream<I>) => IStream<O>;
}