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sortBy.js 6.06 KiB
'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
var _map = require('./map.js');
var _map2 = _interopRequireDefault(_map);
var _wrapAsync = require('./internal/wrapAsync.js');
var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
var _awaitify = require('./internal/awaitify.js');
var _awaitify2 = _interopRequireDefault(_awaitify);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
/**
* Sorts a list by the results of running each `coll` value through an async
* `iteratee`.
*
* @name sortBy
* @static
* @memberOf module:Collections
* @method
* @category Collection
* @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
* @param {AsyncFunction} iteratee - An async function to apply to each item in
* `coll`.
* The iteratee should complete with a value to use as the sort criteria as
* its `result`.
* Invoked with (item, callback).
* @param {Function} callback - A callback which is called after all the
* `iteratee` functions have finished, or an error occurs. Results is the items
* from the original `coll` sorted by the values returned by the `iteratee`
* calls. Invoked with (err, results).
* @returns {Promise} a promise, if no callback passed
* @example
*
* // bigfile.txt is a file that is 251100 bytes in size
* // mediumfile.txt is a file that is 11000 bytes in size
* // smallfile.txt is a file that is 121 bytes in size
*
* // asynchronous function that returns the file size in bytes
* function getFileSizeInBytes(file, callback) {
* fs.stat(file, function(err, stat) {
* if (err) {
* return callback(err);
* }
* callback(null, stat.size);
* });
* }
*
* // Using callbacks
* async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes,
* function(err, results) {
* if (err) {
* console.log(err);
* } else {
* console.log(results);
* // results is now the original array of files sorted by
* // file size (ascending by default), e.g.
* // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
* }
* }
* );
*