import type { AbortableSignal } from '@naturalcycles/js-lib';
import { ErrorMode } from '@naturalcycles/js-lib/error';
import type { IndexedMapper, Predicate } from '@naturalcycles/js-lib/types';
import { END, SKIP } from '@naturalcycles/js-lib/types';
import type { TransformOptions, TransformTyped } from '../stream.model.js';
import type { TransformMapStats } from './transformMap.js';
export interface TransformMapSyncOptions<IN = any, OUT = IN> extends TransformOptions {
    /**
     * @default true
     */
    objectMode?: boolean;
    /**
     * Predicate to filter outgoing results (after mapper).
     * Allows to not emit all results.
     *
     * Defaults to "pass everything".
     * Simpler way to skip individual entries is to return SKIP symbol.
     */
    predicate?: Predicate<OUT>;
    /**
     * @default THROW_IMMEDIATELY
     */
    errorMode?: ErrorMode;
    /**
     * If defined - will be called on every error happening in the stream.
     * Called BEFORE observable will emit error (unless skipErrors is set to true).
     */
    onError?: (err: Error, input: IN) => any;
    /**
     * A hook that is called when the last item is finished processing.
     * stats object is passed, containing countIn and countOut -
     * number of items that entered the transform and number of items that left it.
     *
     * Callback is called **before** [possible] Aggregated error is thrown,
     * and before [possible] THROW_IMMEDIATELY error.
     *
     * onDone callback will be called before Error is thrown.
     */
    onDone?: (stats: TransformMapStats) => any;
    /**
     * Progress metric
     *
     * @default `stream`
     */
    metric?: string;
    /**
     * Allows to abort (gracefully stop) the stream from inside the Transform.
     */
    signal?: AbortableSignal;
}
/**
 * Sync (not async) version of transformMap.
 * Supposedly faster, for cases when async is not needed.
 */
export declare function transformMapSync<IN = any, OUT = IN>(mapper: IndexedMapper<IN, OUT | typeof SKIP | typeof END>, opt?: TransformMapSyncOptions): TransformTyped<IN, OUT>;