import { type Task, type WorkerOptions } from './-private/index.js';
/**
 * Runs a task on many datasets in parallel. The size of datasets can be
 * arbitrarily large (subject to available resources).
 *
 * @param task
 *
 * Some function to call.
 *
 * @param datasets
 *
 * An array of dataset's.
 *
 * @param workerOptions
 *
 * An object to help locate the worker file. The worker file is used when the
 * problem size is large enough.
 *
 * The value of `importMetaUrl` is always `import.meta.url`. For `workerFilePath`,
 * pass the relative path to the worker file.
 *
 * @return
 *
 * An array of the task's return value.
 *
 * @example
 *
 * Analyze files in parallel.
 *
 * ```ts
 * // src/steps/analyze-files.ts
 * import { parallelize } from '@codemod-utils/threads';
 *
 * import type { Options } from '../types/index.js';
 * import { task } from './analyze-files/task.js';
 *
 * export async function analyzeFiles(options: Options): Promise<void> {
 *   const { projectRoot } = options;
 *
 *   const datasets: Parameters<typeof task>[] = [
 *     ['LICENSE.md', projectRoot],
 *     ['README.md', projectRoot],
 *   ];
 *
 *   const results = await parallelize(task, datasets, {
 *     importMetaUrl: import.meta.url,
 *     workerFilePath: './analyze-files/worker.js',
 *   });
 *
 *   // ...
 * }
 * ```
 *
 * ```ts
 * // src/steps/analyze-files/task.ts
 * export function task(filePath: string, projectRoot: string): Result {
 *   // ...
 * }
 * ```
 *
 * ```ts
 * // src/steps/analyze-files/worker.ts
 * import { runWorker } from '@codemod-utils/threads';
 *
 * import { task } from './task.js';
 *
 * runWorker(task);
 * ```
 */
export declare function parallelize<T extends unknown[], U>(task: Task<T, U>, datasets: T[], workerOptions: WorkerOptions): Promise<U[]>;