/**
 * Utilities for working with promises.
 *
 * @public
 * @module lang/promise
 */
/**
 * Creates a composite promise which resolves normally or rejects is a specified
 * amount of time elapses.
 *
 * @public
 * @static
 * @async
 * @param {Promise} promise
 * @param {number} milliseconds
 * @param {string=} description
 * @returns {Promise<*>}
 */
export function timeout(promise: Promise<any>, milliseconds: number, description?: string | undefined): Promise<any>;
/**
 * A mapping function that works asynchronously. Given an array of items, each item through
 * a mapping function, which can return a promise. Then, this function returns a single promise
 * which is the result of each mapped promise.
 *
 * @public
 * @static
 * @async
 * @param {Array} items - The items to map
 * @param {Function} mapper - The mapping function (e.g. given an item, return a promise).
 * @param {number=} concurrency - The maximum number of promises that are allowed to run at once.
 * @returns {Promise<Array>}
 */
export function map(items: any[], mapper: Function, concurrency?: number | undefined): Promise<any[]>;
/**
 * Runs a series of functions sequentially (where each function can be
 * synchronous or asynchronous). The result of each function is passed
 * to the successive function and the result of the final function is
 * returned to the consumer.
 *
 * @static
 * @public
 * @async
 * @param {Function[]} functions - An array of functions, each expecting a single argument.
 * @param {*=} input - The argument to pass the first function.
 * @returns {Promise<*>}
 */
export function pipeline(functions: Function[], input?: any | undefined): Promise<any>;
/**
 * Given an array of functions, where each returns a promise, runs
 * the functions in sequential order, until one of the function
 * returns a successful promise with a non-null result. Any
 * rejected promise is ignored.
 *
 * @public
 * @async
 * @param {Function[]} executors
 * @returns {Promise}
 */
export function first(executors: Function[]): Promise<any>;
/**
 * Creates a new promise, given an executor.
 *
 * This is a wrapper for the {@link Promise} constructor; however, any error
 * is caught and the resulting promise is rejected (instead of letting the
 * error bubble up to the top-level handler).
 *
 * @public
 * @static
 * @async
 * @param {Function} executor - A function which has two callback parameters. The first is used to resolve the promise, the second rejects it.
 * @returns {Promise}
 */
export function build(executor: Function): Promise<any>;