/**
 * Transform the values of an iterable with a mapping function.
 *
 * @param object - The iterable object of interest.
 *
 * @param fn - The mapping function to invoke for each value.
 *
 * @returns An iterator which yields the transformed values.
 *
 * #### Example
 * ```typescript
 * import { map } from '@lumino/algorithm';
 *
 * let data = [1, 2, 3];
 *
 * let stream = map(data, value => value * 2);
 *
 * Array.from(stream);  // [2, 4, 6]
 * ```
 */
export declare function map<T, U>(object: Iterable<T>, fn: (value: T, index: number) => U): IterableIterator<U>;