import { Fn, Transformer } from './type.js';
type PipelineArgs<T> = T extends [
    Fn<infer A extends readonly unknown[], any>,
    ...any[]
] ? A : never;
type PipelineOutput<T> = T extends [...any[], Fn<any, infer O>] ? O : never;
type PipelineRecursive<F extends readonly Transformer<any>[], Acc extends any[]> = F extends readonly [Transformer<infer I, infer O>] ? [...Acc, Transformer<I, O>] : F extends readonly [Transformer<infer A, any>, ...infer Tail] ? Tail extends readonly [Transformer<infer B, any>, ...any[]] ? PipelineRecursive<Tail, [...Acc, Transformer<A, B>]> : never : never;
type Pipeline<F extends readonly [Fn<any, any>, ...Transformer<any>[]]> = F extends readonly [Fn<infer A, infer O>] ? [Fn<A, O>] : F extends readonly [Fn<infer A, any>, ...infer Tail] ? Tail extends readonly [Transformer<infer B, any>, ...any[]] ? PipelineRecursive<Tail, [Fn<A, B>]> : never : never;
/**
 * This utility function allows to properly type a pipeline of transformers.
 *
 * @example
 * ```ts
 * // Will be typed as "(input: string) => Promise<number>"
 * const parse = pipe(
 *   async (input: string) => JSON.parse(input),
 *   async (input: unknown) => {
 *     if (typeof input === 'number') return input
 *     throw new TypeError('Invalid input')
 *   },
 *   (input: number) => input * 2,
 * )
 * ```
 */
export declare function pipe<T extends readonly [Fn<any, any>, ...Transformer<any>[]]>(...pipeline: Pipeline<T> extends T ? T : Pipeline<T>): (...args: PipelineArgs<T>) => Promise<PipelineOutput<T>>;
export declare function pipeTwo<A extends readonly unknown[], O, X = unknown>(first: Fn<A, X>, second: Transformer<X, O>): (...args: A) => Promise<O>;
export {};
//# sourceMappingURL=pipe.d.ts.map