map.js

import doParallel from './internal/doParallel';
import map from './internal/map';

/**
 * Produces a new collection of values by mapping each value in `coll` through
 * the `iteratee` function. The `iteratee` is called with an item from `coll`
 * and a callback for when it has finished processing. Each of these callback
 * takes 2 arguments: an `error`, and the transformed item from `coll`. If
 * `iteratee` passes an error to its callback, the main `callback` (for the
 * `map` function) is immediately called with the error.
 *
 * Note, that since this function applies the `iteratee` to each item in
 * parallel, there is no guarantee that the `iteratee` functions will complete
 * in order. However, the results array will be in the same order as the
 * original `coll`.
 *
 * If `map` is passed an Object, the results will be an Array.  The results
 * will roughly be in the order of the original Objects' keys (but this can
 * vary across JavaScript engines)
 *
 * @name map
 * @static
 * @memberOf module:Collections
 * @method
 * @category Collection
 * @param {Array|Iterable|Object} coll - A collection to iterate over.
 * @param {Function} iteratee - A function to apply to each item in `coll`.
 * The iteratee is passed a `callback(err, transformed)` which must be called
 * once it has completed with an error (which can be `null`) and a
 * transformed item. Invoked with (item, callback).
 * @param {Function} [callback] - A callback which is called when all `iteratee`
 * functions have finished, or an error occurs. Results is an Array of the
 * transformed items from the `coll`. Invoked with (err, results).
 * @example
 *
 * async.map(['file1','file2','file3'], fs.stat, function(err, results) {
 *     // results is now an array of stats for each file
 * });
 */
export default doParallel(map);