import type { Awaitable } from "./Awaitable";
type MapFnIndexed<T> = (x: T, i?: number) => Awaitable<any>;
/**
 * log the value and index and return as original stream, handy to debug.
 * Note: stream won't await the log function.
 */
export declare function logs<T>(mapFn?: MapFnIndexed<T>): TransformStream<T, T>;
export {};