import type { IStream } from '../../stream/index.js';
/**
 * Spreads a stream of arrays into a stream of individual elements
 *
 * stream:       --A-------B----C------>
 * spreadArray:  --*-------*----*------>
 *                 |       |    |
 *                 |       |    +-- emits 5,6 synchronously
 *                 |       +-- emits 4
 *                 +-- emits 1,2,3 synchronously
 *
 * where A = [1,2,3], B = [4], C = [5,6]
 */
export declare function spreadArray<T>(source: IStream<T[]>): IStream<T>;