WP-Stateless – Google Cloud Storage / 2.3.0

WP-Stateless – Google Cloud Storage v2.3.0

wp-stateless / static / scripts / async.js

async.js in WP-Stateless – Google Cloud Storage 2.3.0, at static/scripts/async.js

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1	(function (global, factory) {
2	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
3	typeof define === 'function' && define.amd ? define(['exports'], factory) :
4	(factory((global.async = global.async \|\| {})));
5	}(this, (function (exports) { 'use strict';
6
7	function slice(arrayLike, start) {
8	start = start\|0;
9	var newLen = Math.max(arrayLike.length - start, 0);
10	var newArr = Array(newLen);
11	for(var idx = 0; idx < newLen; idx++) {
12	newArr[idx] = arrayLike[start + idx];
13	}
14	return newArr;
15	}
16
17	var initialParams = function (fn) {
18	return function (/...args, callback/) {
19	var args = slice(arguments);
20	var callback = args.pop();
21	fn.call(this, args, callback);
22	};
23	};
24
25	/**
26	* Checks if `value` is the
27	* [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
28	* of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
29	*
30	* @static
31	* @memberOf _
32	* @since 0.1.0
33	* @category Lang
34	* @param {*} value The value to check.
35	* @returns {boolean} Returns `true` if `value` is an object, else `false`.
36	* @example
37	*
38	* _.isObject({});
39	* // => true
40	*
41	* _.isObject([1, 2, 3]);
42	* // => true
43	*
44	* _.isObject(_.noop);
45	* // => true
46	*
47	* _.isObject(null);
48	* // => false
49	*/
50	function isObject(value) {
51	var type = typeof value;
52	return value != null && (type == 'object' \|\| type == 'function');
53	}
54
55	var hasSetImmediate = typeof setImmediate === 'function' && setImmediate;
56	var hasNextTick = typeof process === 'object' && typeof process.nextTick === 'function';
57
58	function fallback(fn) {
59	setTimeout(fn, 0);
60	}
61
62	function wrap(defer) {
63	return function (fn/, ...args/) {
64	var args = slice(arguments, 1);
65	defer(function () {
66	fn.apply(null, args);
67	});
68	};
69	}
70
71	var _defer;
72
73	if (hasSetImmediate) {
74	_defer = setImmediate;
75	} else if (hasNextTick) {
76	_defer = process.nextTick;
77	} else {
78	_defer = fallback;
79	}
80
81	var setImmediate$1 = wrap(_defer);
82
83	/**
84	* Take a sync function and make it async, passing its return value to a
85	* callback. This is useful for plugging sync functions into a waterfall,
86	* series, or other async functions. Any arguments passed to the generated
87	* function will be passed to the wrapped function (except for the final
88	* callback argument). Errors thrown will be passed to the callback.
89	*
90	* If the function passed to `asyncify` returns a Promise, that promises's
91	* resolved/rejected state will be used to call the callback, rather than simply
92	* the synchronous return value.
93	*
94	* This also means you can asyncify ES2017 `async` functions.
95	*
96	* @name asyncify
97	* @static
98	* @memberOf module:Utils
99	* @method
100	* @alias wrapSync
101	* @category Util
102	* @param {Function} func - The synchronous function, or Promise-returning
103	* function to convert to an {@link AsyncFunction}.
104	* @returns {AsyncFunction} An asynchronous wrapper of the `func`. To be
105	* invoked with `(args..., callback)`.
106	* @example
107	*
108	* // passing a regular synchronous function
109	* async.waterfall([
110	* async.apply(fs.readFile, filename, "utf8"),
111	* async.asyncify(JSON.parse),
112	* function (data, next) {
113	* // data is the result of parsing the text.
114	* // If there was a parsing error, it would have been caught.
115	* }
116	* ], callback);
117	*
118	* // passing a function returning a promise
119	* async.waterfall([
120	* async.apply(fs.readFile, filename, "utf8"),
121	* async.asyncify(function (contents) {
122	* return db.model.create(contents);
123	* }),
124	* function (model, next) {
125	* // `model` is the instantiated model object.
126	* // If there was an error, this function would be skipped.
127	* }
128	* ], callback);
129	*
130	* // es2017 example, though `asyncify` is not needed if your JS environment
131	* // supports async functions out of the box
132	* var q = async.queue(async.asyncify(async function(file) {
133	* var intermediateStep = await processFile(file);
134	* return await somePromise(intermediateStep)
135	* }));
136	*
137	* q.push(files);
138	*/
139	function asyncify(func) {
140	return initialParams(function (args, callback) {
141	var result;
142	try {
143	result = func.apply(this, args);
144	} catch (e) {
145	return callback(e);
146	}
147	// if result is Promise object
148	if (isObject(result) && typeof result.then === 'function') {
149	result.then(function(value) {
150	invokeCallback(callback, null, value);
151	}, function(err) {
152	invokeCallback(callback, err.message ? err : new Error(err));
153	});
154	} else {
155	callback(null, result);
156	}
157	});
158	}
159
160	function invokeCallback(callback, error, value) {
161	try {
162	callback(error, value);
163	} catch (e) {
164	setImmediate$1(rethrow, e);
165	}
166	}
167
168	function rethrow(error) {
169	throw error;
170	}
171
172	var supportsSymbol = typeof Symbol === 'function';
173
174	function isAsync(fn) {
175	return supportsSymbol && fn[Symbol.toStringTag] === 'AsyncFunction';
176	}
177
178	function wrapAsync(asyncFn) {
179	return isAsync(asyncFn) ? asyncify(asyncFn) : asyncFn;
180	}
181
182	function applyEach$1(eachfn) {
183	return function(fns/, ...args/) {
184	var args = slice(arguments, 1);
185	var go = initialParams(function(args, callback) {
186	var that = this;
187	return eachfn(fns, function (fn, cb) {
188	wrapAsync(fn).apply(that, args.concat(cb));
189	}, callback);
190	});
191	if (args.length) {
192	return go.apply(this, args);
193	}
194	else {
195	return go;
196	}
197	};
198	}
199
200	/** Detect free variable `global` from Node.js. */
201	var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;
202
203	/** Detect free variable `self`. */
204	var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
205
206	/** Used as a reference to the global object. */
207	var root = freeGlobal \|\| freeSelf \|\| Function('return this')();
208
209	/** Built-in value references. */
210	var Symbol$1 = root.Symbol;
211
212	/** Used for built-in method references. */
213	var objectProto = Object.prototype;
214
215	/** Used to check objects for own properties. */
216	var hasOwnProperty = objectProto.hasOwnProperty;
217
218	/**
219	* Used to resolve the
220	* [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
221	* of values.
222	*/
223	var nativeObjectToString = objectProto.toString;
224
225	/** Built-in value references. */
226	var symToStringTag$1 = Symbol$1 ? Symbol$1.toStringTag : undefined;
227
228	/**
229	* A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
230	*
231	* @private
232	* @param {*} value The value to query.
233	* @returns {string} Returns the raw `toStringTag`.
234	*/
235	function getRawTag(value) {
236	var isOwn = hasOwnProperty.call(value, symToStringTag$1),
237	tag = value[symToStringTag$1];
238
239	try {
240	value[symToStringTag$1] = undefined;
241	var unmasked = true;
242	} catch (e) {}
243
244	var result = nativeObjectToString.call(value);
245	if (unmasked) {
246	if (isOwn) {
247	value[symToStringTag$1] = tag;
248	} else {
249	delete value[symToStringTag$1];
250	}
251	}
252	return result;
253	}
254
255	/** Used for built-in method references. */
256	var objectProto$1 = Object.prototype;
257
258	/**
259	* Used to resolve the
260	* [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
261	* of values.
262	*/
263	var nativeObjectToString$1 = objectProto$1.toString;
264
265	/**
266	* Converts `value` to a string using `Object.prototype.toString`.
267	*
268	* @private
269	* @param {*} value The value to convert.
270	* @returns {string} Returns the converted string.
271	*/
272	function objectToString(value) {
273	return nativeObjectToString$1.call(value);
274	}
275
276	/** `Object#toString` result references. */
277	var nullTag = '[object Null]';
278	var undefinedTag = '[object Undefined]';
279
280	/** Built-in value references. */
281	var symToStringTag = Symbol$1 ? Symbol$1.toStringTag : undefined;
282
283	/**
284	* The base implementation of `getTag` without fallbacks for buggy environments.
285	*
286	* @private
287	* @param {*} value The value to query.
288	* @returns {string} Returns the `toStringTag`.
289	*/
290	function baseGetTag(value) {
291	if (value == null) {
292	return value === undefined ? undefinedTag : nullTag;
293	}
294	value = Object(value);
295	return (symToStringTag && symToStringTag in value)
296	? getRawTag(value)
297	: objectToString(value);
298	}
299
300	/** `Object#toString` result references. */
301	var asyncTag = '[object AsyncFunction]';
302	var funcTag = '[object Function]';
303	var genTag = '[object GeneratorFunction]';
304	var proxyTag = '[object Proxy]';
305
306	/**
307	* Checks if `value` is classified as a `Function` object.
308	*
309	* @static
310	* @memberOf _
311	* @since 0.1.0
312	* @category Lang
313	* @param {*} value The value to check.
314	* @returns {boolean} Returns `true` if `value` is a function, else `false`.
315	* @example
316	*
317	* _.isFunction(_);
318	* // => true
319	*
320	* _.isFunction(/abc/);
321	* // => false
322	*/
323	function isFunction(value) {
324	if (!isObject(value)) {
325	return false;
326	}
327	// The use of `Object#toString` avoids issues with the `typeof` operator
328	// in Safari 9 which returns 'object' for typed arrays and other constructors.
329	var tag = baseGetTag(value);
330	return tag == funcTag \|\| tag == genTag \|\| tag == asyncTag \|\| tag == proxyTag;
331	}
332
333	/** Used as references for various `Number` constants. */
334	var MAX_SAFE_INTEGER = 9007199254740991;
335
336	/**
337	* Checks if `value` is a valid array-like length.
338	*
339	* Note: This method is loosely based on
340	* [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
341	*
342	* @static
343	* @memberOf _
344	* @since 4.0.0
345	* @category Lang
346	* @param {*} value The value to check.
347	* @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
348	* @example
349	*
350	* _.isLength(3);
351	* // => true
352	*
353	* _.isLength(Number.MIN_VALUE);
354	* // => false
355	*
356	* _.isLength(Infinity);
357	* // => false
358	*
359	* _.isLength('3');
360	* // => false
361	*/
362	function isLength(value) {
363	return typeof value == 'number' &&
364	value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
365	}
366
367	/**
368	* Checks if `value` is array-like. A value is considered array-like if it's
369	* not a function and has a `value.length` that's an integer greater than or
370	* equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
371	*
372	* @static
373	* @memberOf _
374	* @since 4.0.0
375	* @category Lang
376	* @param {*} value The value to check.
377	* @returns {boolean} Returns `true` if `value` is array-like, else `false`.
378	* @example
379	*
380	* _.isArrayLike([1, 2, 3]);
381	* // => true
382	*
383	* _.isArrayLike(document.body.children);
384	* // => true
385	*
386	* _.isArrayLike('abc');
387	* // => true
388	*
389	* _.isArrayLike(_.noop);
390	* // => false
391	*/
392	function isArrayLike(value) {
393	return value != null && isLength(value.length) && !isFunction(value);
394	}
395
396	// A temporary value used to identify if the loop should be broken.
397	// See #1064, #1293
398	var breakLoop = {};
399
400	/**
401	* This method returns `undefined`.
402	*
403	* @static
404	* @memberOf _
405	* @since 2.3.0
406	* @category Util
407	* @example
408	*
409	* _.times(2, _.noop);
410	* // => [undefined, undefined]
411	*/
412	function noop() {
413	// No operation performed.
414	}
415
416	function once(fn) {
417	return function () {
418	if (fn === null) return;
419	var callFn = fn;
420	fn = null;
421	callFn.apply(this, arguments);
422	};
423	}
424
425	var iteratorSymbol = typeof Symbol === 'function' && Symbol.iterator;
426
427	var getIterator = function (coll) {
428	return iteratorSymbol && coll[iteratorSymbol] && coll[iteratorSymbol]();
429	};
430
431	/**
432	* The base implementation of `_.times` without support for iteratee shorthands
433	* or max array length checks.
434	*
435	* @private
436	* @param {number} n The number of times to invoke `iteratee`.
437	* @param {Function} iteratee The function invoked per iteration.
438	* @returns {Array} Returns the array of results.
439	*/
440	function baseTimes(n, iteratee) {
441	var index = -1,
442	result = Array(n);
443
444	while (++index < n) {
445	result[index] = iteratee(index);
446	}
447	return result;
448	}
449
450	/**
451	* Checks if `value` is object-like. A value is object-like if it's not `null`
452	* and has a `typeof` result of "object".
453	*
454	* @static
455	* @memberOf _
456	* @since 4.0.0
457	* @category Lang
458	* @param {*} value The value to check.
459	* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
460	* @example
461	*
462	* _.isObjectLike({});
463	* // => true
464	*
465	* _.isObjectLike([1, 2, 3]);
466	* // => true
467	*
468	* _.isObjectLike(_.noop);
469	* // => false
470	*
471	* _.isObjectLike(null);
472	* // => false
473	*/
474	function isObjectLike(value) {
475	return value != null && typeof value == 'object';
476	}
477
478	/** `Object#toString` result references. */
479	var argsTag = '[object Arguments]';
480
481	/**
482	* The base implementation of `_.isArguments`.
483	*
484	* @private
485	* @param {*} value The value to check.
486	* @returns {boolean} Returns `true` if `value` is an `arguments` object,
487	*/
488	function baseIsArguments(value) {
489	return isObjectLike(value) && baseGetTag(value) == argsTag;
490	}
491
492	/** Used for built-in method references. */
493	var objectProto$3 = Object.prototype;
494
495	/** Used to check objects for own properties. */
496	var hasOwnProperty$2 = objectProto$3.hasOwnProperty;
497
498	/** Built-in value references. */
499	var propertyIsEnumerable = objectProto$3.propertyIsEnumerable;
500
501	/**
502	* Checks if `value` is likely an `arguments` object.
503	*
504	* @static
505	* @memberOf _
506	* @since 0.1.0
507	* @category Lang
508	* @param {*} value The value to check.
509	* @returns {boolean} Returns `true` if `value` is an `arguments` object,
510	* else `false`.
511	* @example
512	*
513	* _.isArguments(function() { return arguments; }());
514	* // => true
515	*
516	* _.isArguments([1, 2, 3]);
517	* // => false
518	*/
519	var isArguments = baseIsArguments(function() { return arguments; }()) ? baseIsArguments : function(value) {
520	return isObjectLike(value) && hasOwnProperty$2.call(value, 'callee') &&
521	!propertyIsEnumerable.call(value, 'callee');
522	};
523
524	/**
525	* Checks if `value` is classified as an `Array` object.
526	*
527	* @static
528	* @memberOf _
529	* @since 0.1.0
530	* @category Lang
531	* @param {*} value The value to check.
532	* @returns {boolean} Returns `true` if `value` is an array, else `false`.
533	* @example
534	*
535	* _.isArray([1, 2, 3]);
536	* // => true
537	*
538	* _.isArray(document.body.children);
539	* // => false
540	*
541	* _.isArray('abc');
542	* // => false
543	*
544	* _.isArray(_.noop);
545	* // => false
546	*/
547	var isArray = Array.isArray;
548
549	/**
550	* This method returns `false`.
551	*
552	* @static
553	* @memberOf _
554	* @since 4.13.0
555	* @category Util
556	* @returns {boolean} Returns `false`.
557	* @example
558	*
559	* _.times(2, _.stubFalse);
560	* // => [false, false]
561	*/
562	function stubFalse() {
563	return false;
564	}
565
566	/** Detect free variable `exports`. */
567	var freeExports = typeof exports == 'object' && exports && !exports.nodeType && exports;
568
569	/** Detect free variable `module`. */
570	var freeModule = freeExports && typeof module == 'object' && module && !module.nodeType && module;
571
572	/** Detect the popular CommonJS extension `module.exports`. */
573	var moduleExports = freeModule && freeModule.exports === freeExports;
574
575	/** Built-in value references. */
576	var Buffer = moduleExports ? root.Buffer : undefined;
577
578	/* Built-in method references for those with the same name as other `lodash` methods. */
579	var nativeIsBuffer = Buffer ? Buffer.isBuffer : undefined;
580
581	/**
582	* Checks if `value` is a buffer.
583	*
584	* @static
585	* @memberOf _
586	* @since 4.3.0
587	* @category Lang
588	* @param {*} value The value to check.
589	* @returns {boolean} Returns `true` if `value` is a buffer, else `false`.
590	* @example
591	*
592	* _.isBuffer(new Buffer(2));
593	* // => true
594	*
595	* _.isBuffer(new Uint8Array(2));
596	* // => false
597	*/
598	var isBuffer = nativeIsBuffer \|\| stubFalse;
599
600	/** Used as references for various `Number` constants. */
601	var MAX_SAFE_INTEGER$1 = 9007199254740991;
602
603	/** Used to detect unsigned integer values. */
604	var reIsUint = /^(?:0\|[1-9]\d*)$/;
605
606	/**
607	* Checks if `value` is a valid array-like index.
608	*
609	* @private
610	* @param {*} value The value to check.
611	* @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
612	* @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
613	*/
614	function isIndex(value, length) {
615	length = length == null ? MAX_SAFE_INTEGER$1 : length;
616	return !!length &&
617	(typeof value == 'number' \|\| reIsUint.test(value)) &&
618	(value > -1 && value % 1 == 0 && value < length);
619	}
620
621	/** `Object#toString` result references. */
622	var argsTag$1 = '[object Arguments]';
623	var arrayTag = '[object Array]';
624	var boolTag = '[object Boolean]';
625	var dateTag = '[object Date]';
626	var errorTag = '[object Error]';
627	var funcTag$1 = '[object Function]';
628	var mapTag = '[object Map]';
629	var numberTag = '[object Number]';
630	var objectTag = '[object Object]';
631	var regexpTag = '[object RegExp]';
632	var setTag = '[object Set]';
633	var stringTag = '[object String]';
634	var weakMapTag = '[object WeakMap]';
635
636	var arrayBufferTag = '[object ArrayBuffer]';
637	var dataViewTag = '[object DataView]';
638	var float32Tag = '[object Float32Array]';
639	var float64Tag = '[object Float64Array]';
640	var int8Tag = '[object Int8Array]';
641	var int16Tag = '[object Int16Array]';
642	var int32Tag = '[object Int32Array]';
643	var uint8Tag = '[object Uint8Array]';
644	var uint8ClampedTag = '[object Uint8ClampedArray]';
645	var uint16Tag = '[object Uint16Array]';
646	var uint32Tag = '[object Uint32Array]';
647
648	/** Used to identify `toStringTag` values of typed arrays. */
649	var typedArrayTags = {};
650	typedArrayTags[float32Tag] = typedArrayTags[float64Tag] =
651	typedArrayTags[int8Tag] = typedArrayTags[int16Tag] =
652	typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] =
653	typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] =
654	typedArrayTags[uint32Tag] = true;
655	typedArrayTags[argsTag$1] = typedArrayTags[arrayTag] =
656	typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] =
657	typedArrayTags[dataViewTag] = typedArrayTags[dateTag] =
658	typedArrayTags[errorTag] = typedArrayTags[funcTag$1] =
659	typedArrayTags[mapTag] = typedArrayTags[numberTag] =
660	typedArrayTags[objectTag] = typedArrayTags[regexpTag] =
661	typedArrayTags[setTag] = typedArrayTags[stringTag] =
662	typedArrayTags[weakMapTag] = false;
663
664	/**
665	* The base implementation of `_.isTypedArray` without Node.js optimizations.
666	*
667	* @private
668	* @param {*} value The value to check.
669	* @returns {boolean} Returns `true` if `value` is a typed array, else `false`.
670	*/
671	function baseIsTypedArray(value) {
672	return isObjectLike(value) &&
673	isLength(value.length) && !!typedArrayTags[baseGetTag(value)];
674	}
675
676	/**
677	* The base implementation of `_.unary` without support for storing metadata.
678	*
679	* @private
680	* @param {Function} func The function to cap arguments for.
681	* @returns {Function} Returns the new capped function.
682	*/
683	function baseUnary(func) {
684	return function(value) {
685	return func(value);
686	};
687	}
688
689	/** Detect free variable `exports`. */
690	var freeExports$1 = typeof exports == 'object' && exports && !exports.nodeType && exports;
691
692	/** Detect free variable `module`. */
693	var freeModule$1 = freeExports$1 && typeof module == 'object' && module && !module.nodeType && module;
694
695	/** Detect the popular CommonJS extension `module.exports`. */
696	var moduleExports$1 = freeModule$1 && freeModule$1.exports === freeExports$1;
697
698	/** Detect free variable `process` from Node.js. */
699	var freeProcess = moduleExports$1 && freeGlobal.process;
700
701	/** Used to access faster Node.js helpers. */
702	var nodeUtil = (function() {
703	try {
704	return freeProcess && freeProcess.binding('util');
705	} catch (e) {}
706	}());
707
708	/* Node.js helper references. */
709	var nodeIsTypedArray = nodeUtil && nodeUtil.isTypedArray;
710
711	/**
712	* Checks if `value` is classified as a typed array.
713	*
714	* @static
715	* @memberOf _
716	* @since 3.0.0
717	* @category Lang
718	* @param {*} value The value to check.
719	* @returns {boolean} Returns `true` if `value` is a typed array, else `false`.
720	* @example
721	*
722	* _.isTypedArray(new Uint8Array);
723	* // => true
724	*
725	* _.isTypedArray([]);
726	* // => false
727	*/
728	var isTypedArray = nodeIsTypedArray ? baseUnary(nodeIsTypedArray) : baseIsTypedArray;
729
730	/** Used for built-in method references. */
731	var objectProto$2 = Object.prototype;
732
733	/** Used to check objects for own properties. */
734	var hasOwnProperty$1 = objectProto$2.hasOwnProperty;
735
736	/**
737	* Creates an array of the enumerable property names of the array-like `value`.
738	*
739	* @private
740	* @param {*} value The value to query.
741	* @param {boolean} inherited Specify returning inherited property names.
742	* @returns {Array} Returns the array of property names.
743	*/
744	function arrayLikeKeys(value, inherited) {
745	var isArr = isArray(value),
746	isArg = !isArr && isArguments(value),
747	isBuff = !isArr && !isArg && isBuffer(value),
748	isType = !isArr && !isArg && !isBuff && isTypedArray(value),
749	skipIndexes = isArr \|\| isArg \|\| isBuff \|\| isType,
750	result = skipIndexes ? baseTimes(value.length, String) : [],
751	length = result.length;
752
753	for (var key in value) {
754	if ((inherited \|\| hasOwnProperty$1.call(value, key)) &&
755	!(skipIndexes && (
756	// Safari 9 has enumerable `arguments.length` in strict mode.
757	key == 'length' \|\|
758	// Node.js 0.10 has enumerable non-index properties on buffers.
759	(isBuff && (key == 'offset' \|\| key == 'parent')) \|\|
760	// PhantomJS 2 has enumerable non-index properties on typed arrays.
761	(isType && (key == 'buffer' \|\| key == 'byteLength' \|\| key == 'byteOffset')) \|\|
762	// Skip index properties.
763	isIndex(key, length)
764	))) {
765	result.push(key);
766	}
767	}
768	return result;
769	}
770
771	/** Used for built-in method references. */
772	var objectProto$5 = Object.prototype;
773
774	/**
775	* Checks if `value` is likely a prototype object.
776	*
777	* @private
778	* @param {*} value The value to check.
779	* @returns {boolean} Returns `true` if `value` is a prototype, else `false`.
780	*/
781	function isPrototype(value) {
782	var Ctor = value && value.constructor,
783	proto = (typeof Ctor == 'function' && Ctor.prototype) \|\| objectProto$5;
784
785	return value === proto;
786	}
787
788	/**
789	* Creates a unary function that invokes `func` with its argument transformed.
790	*
791	* @private
792	* @param {Function} func The function to wrap.
793	* @param {Function} transform The argument transform.
794	* @returns {Function} Returns the new function.
795	*/
796	function overArg(func, transform) {
797	return function(arg) {
798	return func(transform(arg));
799	};
800	}
801
802	/* Built-in method references for those with the same name as other `lodash` methods. */
803	var nativeKeys = overArg(Object.keys, Object);
804
805	/** Used for built-in method references. */
806	var objectProto$4 = Object.prototype;
807
808	/** Used to check objects for own properties. */
809	var hasOwnProperty$3 = objectProto$4.hasOwnProperty;
810
811	/**
812	* The base implementation of `_.keys` which doesn't treat sparse arrays as dense.
813	*
814	* @private
815	* @param {Object} object The object to query.
816	* @returns {Array} Returns the array of property names.
817	*/
818	function baseKeys(object) {
819	if (!isPrototype(object)) {
820	return nativeKeys(object);
821	}
822	var result = [];
823	for (var key in Object(object)) {
824	if (hasOwnProperty$3.call(object, key) && key != 'constructor') {
825	result.push(key);
826	}
827	}
828	return result;
829	}
830
831	/**
832	* Creates an array of the own enumerable property names of `object`.
833	*
834	* Note: Non-object values are coerced to objects. See the
835	* [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys)
836	* for more details.
837	*
838	* @static
839	* @since 0.1.0
840	* @memberOf _
841	* @category Object
842	* @param {Object} object The object to query.
843	* @returns {Array} Returns the array of property names.
844	* @example
845	*
846	* function Foo() {
847	* this.a = 1;
848	* this.b = 2;
849	* }
850	*
851	* Foo.prototype.c = 3;
852	*
853	* _.keys(new Foo);
854	* // => ['a', 'b'] (iteration order is not guaranteed)
855	*
856	* _.keys('hi');
857	* // => ['0', '1']
858	*/
859	function keys(object) {
860	return isArrayLike(object) ? arrayLikeKeys(object) : baseKeys(object);
861	}
862
863	function createArrayIterator(coll) {
864	var i = -1;
865	var len = coll.length;
866	return function next() {
867	return ++i < len ? {value: coll[i], key: i} : null;
868	}
869	}
870
871	function createES2015Iterator(iterator) {
872	var i = -1;
873	return function next() {
874	var item = iterator.next();
875	if (item.done)
876	return null;
877	i++;
878	return {value: item.value, key: i};
879	}
880	}
881
882	function createObjectIterator(obj) {
883	var okeys = keys(obj);
884	var i = -1;
885	var len = okeys.length;
886	return function next() {
887	var key = okeys[++i];
888	return i < len ? {value: obj[key], key: key} : null;
889	};
890	}
891
892	function iterator(coll) {
893	if (isArrayLike(coll)) {
894	return createArrayIterator(coll);
895	}
896
897	var iterator = getIterator(coll);
898	return iterator ? createES2015Iterator(iterator) : createObjectIterator(coll);
899	}
900
901	function onlyOnce(fn) {
902	return function() {
903	if (fn === null) throw new Error("Callback was already called.");
904	var callFn = fn;
905	fn = null;
906	callFn.apply(this, arguments);
907	};
908	}
909
910	function _eachOfLimit(limit) {
911	return function (obj, iteratee, callback) {
912	callback = once(callback \|\| noop);
913	if (limit <= 0 \|\| !obj) {
914	return callback(null);
915	}
916	var nextElem = iterator(obj);
917	var done = false;
918	var running = 0;
919
920	function iterateeCallback(err, value) {
921	running -= 1;
922	if (err) {
923	done = true;
924	callback(err);
925	}
926	else if (value === breakLoop \|\| (done && running <= 0)) {
927	done = true;
928	return callback(null);
929	}
930	else {
931	replenish();
932	}
933	}
934
935	function replenish () {
936	while (running < limit && !done) {
937	var elem = nextElem();
938	if (elem === null) {
939	done = true;
940	if (running <= 0) {
941	callback(null);
942	}
943	return;
944	}
945	running += 1;
946	iteratee(elem.value, elem.key, onlyOnce(iterateeCallback));
947	}
948	}
949
950	replenish();
951	};
952	}
953
954	/**
955	* The same as [`eachOf`]{@link module:Collections.eachOf} but runs a maximum of `limit` async operations at a
956	* time.
957	*
958	* @name eachOfLimit
959	* @static
960	* @memberOf module:Collections
961	* @method
962	* @see [async.eachOf]{@link module:Collections.eachOf}
963	* @alias forEachOfLimit
964	* @category Collection
965	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
966	* @param {number} limit - The maximum number of async operations at a time.
967	* @param {AsyncFunction} iteratee - An async function to apply to each
968	* item in `coll`. The `key` is the item's key, or index in the case of an
969	* array.
970	* Invoked with (item, key, callback).
971	* @param {Function} [callback] - A callback which is called when all
972	* `iteratee` functions have finished, or an error occurs. Invoked with (err).
973	*/
974	function eachOfLimit(coll, limit, iteratee, callback) {
975	_eachOfLimit(limit)(coll, wrapAsync(iteratee), callback);
976	}
977
978	function doLimit(fn, limit) {
979	return function (iterable, iteratee, callback) {
980	return fn(iterable, limit, iteratee, callback);
981	};
982	}
983
984	// eachOf implementation optimized for array-likes
985	function eachOfArrayLike(coll, iteratee, callback) {
986	callback = once(callback \|\| noop);
987	var index = 0,
988	completed = 0,
989	length = coll.length;
990	if (length === 0) {
991	callback(null);
992	}
993
994	function iteratorCallback(err, value) {
995	if (err) {
996	callback(err);
997	} else if ((++completed === length) \|\| value === breakLoop) {
998	callback(null);
999	}
1000	}
1001
1002	for (; index < length; index++) {
1003	iteratee(coll[index], index, onlyOnce(iteratorCallback));
1004	}
1005	}
1006
1007	// a generic version of eachOf which can handle array, object, and iterator cases.
1008	var eachOfGeneric = doLimit(eachOfLimit, Infinity);
1009
1010	/**
1011	* Like [`each`]{@link module:Collections.each}, except that it passes the key (or index) as the second argument
1012	* to the iteratee.
1013	*
1014	* @name eachOf
1015	* @static
1016	* @memberOf module:Collections
1017	* @method
1018	* @alias forEachOf
1019	* @category Collection
1020	* @see [async.each]{@link module:Collections.each}
1021	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
1022	* @param {AsyncFunction} iteratee - A function to apply to each
1023	* item in `coll`.
1024	* The `key` is the item's key, or index in the case of an array.
1025	* Invoked with (item, key, callback).
1026	* @param {Function} [callback] - A callback which is called when all
1027	* `iteratee` functions have finished, or an error occurs. Invoked with (err).
1028	* @example
1029	*
1030	* var obj = {dev: "/dev.json", test: "/test.json", prod: "/prod.json"};
1031	* var configs = {};
1032	*
1033	* async.forEachOf(obj, function (value, key, callback) {
1034	* fs.readFile(__dirname + value, "utf8", function (err, data) {
1035	* if (err) return callback(err);
1036	* try {
1037	* configs[key] = JSON.parse(data);
1038	* } catch (e) {
1039	* return callback(e);
1040	* }
1041	* callback();
1042	* });
1043	* }, function (err) {
1044	* if (err) console.error(err.message);
1045	* // configs is now a map of JSON data
1046	* doSomethingWith(configs);
1047	* });
1048	*/
1049	var eachOf = function(coll, iteratee, callback) {
1050	var eachOfImplementation = isArrayLike(coll) ? eachOfArrayLike : eachOfGeneric;
1051	eachOfImplementation(coll, wrapAsync(iteratee), callback);
1052	};
1053
1054	function doParallel(fn) {
1055	return function (obj, iteratee, callback) {
1056	return fn(eachOf, obj, wrapAsync(iteratee), callback);
1057	};
1058	}
1059
1060	function _asyncMap(eachfn, arr, iteratee, callback) {
1061	callback = callback \|\| noop;
1062	arr = arr \|\| [];
1063	var results = [];
1064	var counter = 0;
1065	var _iteratee = wrapAsync(iteratee);
1066
1067	eachfn(arr, function (value, _, callback) {
1068	var index = counter++;
1069	_iteratee(value, function (err, v) {
1070	results[index] = v;
1071	callback(err);
1072	});
1073	}, function (err) {
1074	callback(err, results);
1075	});
1076	}
1077
1078	/**
1079	* Produces a new collection of values by mapping each value in `coll` through
1080	* the `iteratee` function. The `iteratee` is called with an item from `coll`
1081	* and a callback for when it has finished processing. Each of these callback
1082	* takes 2 arguments: an `error`, and the transformed item from `coll`. If
1083	* `iteratee` passes an error to its callback, the main `callback` (for the
1084	* `map` function) is immediately called with the error.
1085	*
1086	* Note, that since this function applies the `iteratee` to each item in
1087	* parallel, there is no guarantee that the `iteratee` functions will complete
1088	* in order. However, the results array will be in the same order as the
1089	* original `coll`.
1090	*
1091	* If `map` is passed an Object, the results will be an Array. The results
1092	* will roughly be in the order of the original Objects' keys (but this can
1093	* vary across JavaScript engines).
1094	*
1095	* @name map
1096	* @static
1097	* @memberOf module:Collections
1098	* @method
1099	* @category Collection
1100	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
1101	* @param {AsyncFunction} iteratee - An async function to apply to each item in
1102	* `coll`.
1103	* The iteratee should complete with the transformed item.
1104	* Invoked with (item, callback).
1105	* @param {Function} [callback] - A callback which is called when all `iteratee`
1106	* functions have finished, or an error occurs. Results is an Array of the
1107	* transformed items from the `coll`. Invoked with (err, results).
1108	* @example
1109	*
1110	* async.map(['file1','file2','file3'], fs.stat, function(err, results) {
1111	* // results is now an array of stats for each file
1112	* });
1113	*/
1114	var map = doParallel(_asyncMap);
1115
1116	/**
1117	* Applies the provided arguments to each function in the array, calling
1118	* `callback` after all functions have completed. If you only provide the first
1119	* argument, `fns`, then it will return a function which lets you pass in the
1120	* arguments as if it were a single function call. If more arguments are
1121	* provided, `callback` is required while `args` is still optional.
1122	*
1123	* @name applyEach
1124	* @static
1125	* @memberOf module:ControlFlow
1126	* @method
1127	* @category Control Flow
1128	* @param {Array\|Iterable\|Object} fns - A collection of {@link AsyncFunction}s
1129	* to all call with the same arguments
1130	* @param {...*} [args] - any number of separate arguments to pass to the
1131	* function.
1132	* @param {Function} [callback] - the final argument should be the callback,
1133	* called when all functions have completed processing.
1134	* @returns {Function} - If only the first argument, `fns`, is provided, it will
1135	* return a function which lets you pass in the arguments as if it were a single
1136	* function call. The signature is `(..args, callback)`. If invoked with any
1137	* arguments, `callback` is required.
1138	* @example
1139	*
1140	* async.applyEach([enableSearch, updateSchema], 'bucket', callback);
1141	*
1142	* // partial application example:
1143	* async.each(
1144	* buckets,
1145	* async.applyEach([enableSearch, updateSchema]),
1146	* callback
1147	* );
1148	*/
1149	var applyEach = applyEach$1(map);
1150
1151	function doParallelLimit(fn) {
1152	return function (obj, limit, iteratee, callback) {
1153	return fn(_eachOfLimit(limit), obj, wrapAsync(iteratee), callback);
1154	};
1155	}
1156
1157	/**
1158	* The same as [`map`]{@link module:Collections.map} but runs a maximum of `limit` async operations at a time.
1159	*
1160	* @name mapLimit
1161	* @static
1162	* @memberOf module:Collections
1163	* @method
1164	* @see [async.map]{@link module:Collections.map}
1165	* @category Collection
1166	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
1167	* @param {number} limit - The maximum number of async operations at a time.
1168	* @param {AsyncFunction} iteratee - An async function to apply to each item in
1169	* `coll`.
1170	* The iteratee should complete with the transformed item.
1171	* Invoked with (item, callback).
1172	* @param {Function} [callback] - A callback which is called when all `iteratee`
1173	* functions have finished, or an error occurs. Results is an array of the
1174	* transformed items from the `coll`. Invoked with (err, results).
1175	*/
1176	var mapLimit = doParallelLimit(_asyncMap);
1177
1178	/**
1179	* The same as [`map`]{@link module:Collections.map} but runs only a single async operation at a time.
1180	*
1181	* @name mapSeries
1182	* @static
1183	* @memberOf module:Collections
1184	* @method
1185	* @see [async.map]{@link module:Collections.map}
1186	* @category Collection
1187	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
1188	* @param {AsyncFunction} iteratee - An async function to apply to each item in
1189	* `coll`.
1190	* The iteratee should complete with the transformed item.
1191	* Invoked with (item, callback).
1192	* @param {Function} [callback] - A callback which is called when all `iteratee`
1193	* functions have finished, or an error occurs. Results is an array of the
1194	* transformed items from the `coll`. Invoked with (err, results).
1195	*/
1196	var mapSeries = doLimit(mapLimit, 1);
1197
1198	/**
1199	* The same as [`applyEach`]{@link module:ControlFlow.applyEach} but runs only a single async operation at a time.
1200	*
1201	* @name applyEachSeries
1202	* @static
1203	* @memberOf module:ControlFlow
1204	* @method
1205	* @see [async.applyEach]{@link module:ControlFlow.applyEach}
1206	* @category Control Flow
1207	* @param {Array\|Iterable\|Object} fns - A collection of {@link AsyncFunction}s to all
1208	* call with the same arguments
1209	* @param {...*} [args] - any number of separate arguments to pass to the
1210	* function.
1211	* @param {Function} [callback] - the final argument should be the callback,
1212	* called when all functions have completed processing.
1213	* @returns {Function} - If only the first argument is provided, it will return
1214	* a function which lets you pass in the arguments as if it were a single
1215	* function call.
1216	*/
1217	var applyEachSeries = applyEach$1(mapSeries);
1218
1219	/**
1220	* Creates a continuation function with some arguments already applied.
1221	*
1222	* Useful as a shorthand when combined with other control flow functions. Any
1223	* arguments passed to the returned function are added to the arguments
1224	* originally passed to apply.
1225	*
1226	* @name apply
1227	* @static
1228	* @memberOf module:Utils
1229	* @method
1230	* @category Util
1231	* @param {Function} fn - The function you want to eventually apply all
1232	* arguments to. Invokes with (arguments...).
1233	* @param {...*} arguments... - Any number of arguments to automatically apply
1234	* when the continuation is called.
1235	* @returns {Function} the partially-applied function
1236	* @example
1237	*
1238	* // using apply
1239	* async.parallel([
1240	* async.apply(fs.writeFile, 'testfile1', 'test1'),
1241	* async.apply(fs.writeFile, 'testfile2', 'test2')
1242	* ]);
1243	*
1244	*
1245	* // the same process without using apply
1246	* async.parallel([
1247	* function(callback) {
1248	* fs.writeFile('testfile1', 'test1', callback);
1249	* },
1250	* function(callback) {
1251	* fs.writeFile('testfile2', 'test2', callback);
1252	* }
1253	* ]);
1254	*
1255	* // It's possible to pass any number of additional arguments when calling the
1256	* // continuation:
1257	*
1258	* node> var fn = async.apply(sys.puts, 'one');
1259	* node> fn('two', 'three');
1260	* one
1261	* two
1262	* three
1263	*/
1264	var apply = function(fn/, ...args/) {
1265	var args = slice(arguments, 1);
1266	return function(/callArgs/) {
1267	var callArgs = slice(arguments);
1268	return fn.apply(null, args.concat(callArgs));
1269	};
1270	};
1271
1272	/**
1273	* A specialized version of `_.forEach` for arrays without support for
1274	* iteratee shorthands.
1275	*
1276	* @private
1277	* @param {Array} [array] The array to iterate over.
1278	* @param {Function} iteratee The function invoked per iteration.
1279	* @returns {Array} Returns `array`.
1280	*/
1281	function arrayEach(array, iteratee) {
1282	var index = -1,
1283	length = array == null ? 0 : array.length;
1284
1285	while (++index < length) {
1286	if (iteratee(array[index], index, array) === false) {
1287	break;
1288	}
1289	}
1290	return array;
1291	}
1292
1293	/**
1294	* Creates a base function for methods like `_.forIn` and `_.forOwn`.
1295	*
1296	* @private
1297	* @param {boolean} [fromRight] Specify iterating from right to left.
1298	* @returns {Function} Returns the new base function.
1299	*/
1300	function createBaseFor(fromRight) {
1301	return function(object, iteratee, keysFunc) {
1302	var index = -1,
1303	iterable = Object(object),
1304	props = keysFunc(object),
1305	length = props.length;
1306
1307	while (length--) {
1308	var key = props[fromRight ? length : ++index];
1309	if (iteratee(iterable[key], key, iterable) === false) {
1310	break;
1311	}
1312	}
1313	return object;
1314	};
1315	}
1316
1317	/**
1318	* The base implementation of `baseForOwn` which iterates over `object`
1319	* properties returned by `keysFunc` and invokes `iteratee` for each property.
1320	* Iteratee functions may exit iteration early by explicitly returning `false`.
1321	*
1322	* @private
1323	* @param {Object} object The object to iterate over.
1324	* @param {Function} iteratee The function invoked per iteration.
1325	* @param {Function} keysFunc The function to get the keys of `object`.
1326	* @returns {Object} Returns `object`.
1327	*/
1328	var baseFor = createBaseFor();
1329
1330	/**
1331	* The base implementation of `_.forOwn` without support for iteratee shorthands.
1332	*
1333	* @private
1334	* @param {Object} object The object to iterate over.
1335	* @param {Function} iteratee The function invoked per iteration.
1336	* @returns {Object} Returns `object`.
1337	*/
1338	function baseForOwn(object, iteratee) {
1339	return object && baseFor(object, iteratee, keys);
1340	}
1341
1342	/**
1343	* The base implementation of `_.findIndex` and `_.findLastIndex` without
1344	* support for iteratee shorthands.
1345	*
1346	* @private
1347	* @param {Array} array The array to inspect.
1348	* @param {Function} predicate The function invoked per iteration.
1349	* @param {number} fromIndex The index to search from.
1350	* @param {boolean} [fromRight] Specify iterating from right to left.
1351	* @returns {number} Returns the index of the matched value, else `-1`.
1352	*/
1353	function baseFindIndex(array, predicate, fromIndex, fromRight) {
1354	var length = array.length,
1355	index = fromIndex + (fromRight ? 1 : -1);
1356
1357	while ((fromRight ? index-- : ++index < length)) {
1358	if (predicate(array[index], index, array)) {
1359	return index;
1360	}
1361	}
1362	return -1;
1363	}
1364
1365	/**
1366	* The base implementation of `_.isNaN` without support for number objects.
1367	*
1368	* @private
1369	* @param {*} value The value to check.
1370	* @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
1371	*/
1372	function baseIsNaN(value) {
1373	return value !== value;
1374	}
1375
1376	/**
1377	* A specialized version of `_.indexOf` which performs strict equality
1378	* comparisons of values, i.e. `===`.
1379	*
1380	* @private
1381	* @param {Array} array The array to inspect.
1382	* @param {*} value The value to search for.
1383	* @param {number} fromIndex The index to search from.
1384	* @returns {number} Returns the index of the matched value, else `-1`.
1385	*/
1386	function strictIndexOf(array, value, fromIndex) {
1387	var index = fromIndex - 1,
1388	length = array.length;
1389
1390	while (++index < length) {
1391	if (array[index] === value) {
1392	return index;
1393	}
1394	}
1395	return -1;
1396	}
1397
1398	/**
1399	* The base implementation of `_.indexOf` without `fromIndex` bounds checks.
1400	*
1401	* @private
1402	* @param {Array} array The array to inspect.
1403	* @param {*} value The value to search for.
1404	* @param {number} fromIndex The index to search from.
1405	* @returns {number} Returns the index of the matched value, else `-1`.
1406	*/
1407	function baseIndexOf(array, value, fromIndex) {
1408	return value === value
1409	? strictIndexOf(array, value, fromIndex)
1410	: baseFindIndex(array, baseIsNaN, fromIndex);
1411	}
1412
1413	/**
1414	* Determines the best order for running the {@link AsyncFunction}s in `tasks`, based on
1415	* their requirements. Each function can optionally depend on other functions
1416	* being completed first, and each function is run as soon as its requirements
1417	* are satisfied.
1418	*
1419	* If any of the {@link AsyncFunction}s pass an error to their callback, the `auto` sequence
1420	* will stop. Further tasks will not execute (so any other functions depending
1421	* on it will not run), and the main `callback` is immediately called with the
1422	* error.
1423	*
1424	* {@link AsyncFunction}s also receive an object containing the results of functions which
1425	* have completed so far as the first argument, if they have dependencies. If a
1426	* task function has no dependencies, it will only be passed a callback.
1427	*
1428	* @name auto
1429	* @static
1430	* @memberOf module:ControlFlow
1431	* @method
1432	* @category Control Flow
1433	* @param {Object} tasks - An object. Each of its properties is either a
1434	* function or an array of requirements, with the {@link AsyncFunction} itself the last item
1435	* in the array. The object's key of a property serves as the name of the task
1436	* defined by that property, i.e. can be used when specifying requirements for
1437	* other tasks. The function receives one or two arguments:
1438	* * a `results` object, containing the results of the previously executed
1439	* functions, only passed if the task has any dependencies,
1440	* * a `callback(err, result)` function, which must be called when finished,
1441	* passing an `error` (which can be `null`) and the result of the function's
1442	* execution.
1443	* @param {number} [concurrency=Infinity] - An optional `integer` for
1444	* determining the maximum number of tasks that can be run in parallel. By
1445	* default, as many as possible.
1446	* @param {Function} [callback] - An optional callback which is called when all
1447	* the tasks have been completed. It receives the `err` argument if any `tasks`
1448	* pass an error to their callback. Results are always returned; however, if an
1449	* error occurs, no further `tasks` will be performed, and the results object
1450	* will only contain partial results. Invoked with (err, results).
1451	* @returns undefined
1452	* @example
1453	*
1454	* async.auto({
1455	* // this function will just be passed a callback
1456	* readData: async.apply(fs.readFile, 'data.txt', 'utf-8'),
1457	* showData: ['readData', function(results, cb) {
1458	* // results.readData is the file's contents
1459	* // ...
1460	* }]
1461	* }, callback);
1462	*
1463	* async.auto({
1464	* get_data: function(callback) {
1465	* console.log('in get_data');
1466	* // async code to get some data
1467	* callback(null, 'data', 'converted to array');
1468	* },
1469	* make_folder: function(callback) {
1470	* console.log('in make_folder');
1471	* // async code to create a directory to store a file in
1472	* // this is run at the same time as getting the data
1473	* callback(null, 'folder');
1474	* },
1475	* write_file: ['get_data', 'make_folder', function(results, callback) {
1476	* console.log('in write_file', JSON.stringify(results));
1477	* // once there is some data and the directory exists,
1478	* // write the data to a file in the directory
1479	* callback(null, 'filename');
1480	* }],
1481	* email_link: ['write_file', function(results, callback) {
1482	* console.log('in email_link', JSON.stringify(results));
1483	* // once the file is written let's email a link to it...
1484	* // results.write_file contains the filename returned by write_file.
1485	* callback(null, {'file':results.write_file, 'email':'user@example.com'});
1486	* }]
1487	* }, function(err, results) {
1488	* console.log('err = ', err);
1489	* console.log('results = ', results);
1490	* });
1491	*/
1492	var auto = function (tasks, concurrency, callback) {
1493	if (typeof concurrency === 'function') {
1494	// concurrency is optional, shift the args.
1495	callback = concurrency;
1496	concurrency = null;
1497	}
1498	callback = callback \|\| noop;
1499	var keys$$1 = keys(tasks);
1500	var numTasks = keys$$1.length;
1501	if (!numTasks) {
1502	return callback(null);
1503	}
1504	if (!concurrency) {
1505	concurrency = numTasks;
1506	}
1507
1508	var results = {};
1509	var runningTasks = 0;
1510	var hasError = false;
1511
1512	var listeners = Object.create(null);
1513
1514	var readyTasks = [];
1515
1516	// for cycle detection:
1517	var readyToCheck = []; // tasks that have been identified as reachable
1518	// without the possibility of returning to an ancestor task
1519	var uncheckedDependencies = {};
1520
1521	baseForOwn(tasks, function (task, key) {
1522	if (!isArray(task)) {
1523	// no dependencies
1524	enqueueTask(key, [task]);
1525	readyToCheck.push(key);
1526	return;
1527	}
1528
1529	var dependencies = task.slice(0, task.length - 1);
1530	var remainingDependencies = dependencies.length;
1531	if (remainingDependencies === 0) {
1532	enqueueTask(key, task);
1533	readyToCheck.push(key);
1534	return;
1535	}
1536	uncheckedDependencies[key] = remainingDependencies;
1537
1538	arrayEach(dependencies, function (dependencyName) {
1539	if (!tasks[dependencyName]) {
1540	throw new Error('async.auto task `' + key +
1541	'` has a non-existent dependency `' +
1542	dependencyName + '` in ' +
1543	dependencies.join(', '));
1544	}
1545	addListener(dependencyName, function () {
1546	remainingDependencies--;
1547	if (remainingDependencies === 0) {
1548	enqueueTask(key, task);
1549	}
1550	});
1551	});
1552	});
1553
1554	checkForDeadlocks();
1555	processQueue();
1556
1557	function enqueueTask(key, task) {
1558	readyTasks.push(function () {
1559	runTask(key, task);
1560	});
1561	}
1562
1563	function processQueue() {
1564	if (readyTasks.length === 0 && runningTasks === 0) {
1565	return callback(null, results);
1566	}
1567	while(readyTasks.length && runningTasks < concurrency) {
1568	var run = readyTasks.shift();
1569	run();
1570	}
1571
1572	}
1573
1574	function addListener(taskName, fn) {
1575	var taskListeners = listeners[taskName];
1576	if (!taskListeners) {
1577	taskListeners = listeners[taskName] = [];
1578	}
1579
1580	taskListeners.push(fn);
1581	}
1582
1583	function taskComplete(taskName) {
1584	var taskListeners = listeners[taskName] \|\| [];
1585	arrayEach(taskListeners, function (fn) {
1586	fn();
1587	});
1588	processQueue();
1589	}
1590
1591
1592	function runTask(key, task) {
1593	if (hasError) return;
1594
1595	var taskCallback = function(err, result) {
1596	runningTasks--;
1597	if (arguments.length > 2) {
1598	result = slice(arguments, 1);
1599	}
1600	if (err) {
1601	var safeResults = {};
1602	baseForOwn(results, function(val, rkey) {
1603	safeResults[rkey] = val;
1604	});
1605	safeResults[key] = result;
1606	hasError = true;
1607	listeners = Object.create(null);
1608
1609	callback(err, safeResults);
1610	} else {
1611	results[key] = result;
1612	callback(err, result);
1613	taskComplete(key);
1614	}
1615	};
1616
1617	runningTasks++;
1618	var taskFn = wrapAsync(task[task.length - 1]);
1619	if (task.length > 1) {
1620	taskFn(results, taskCallback);
1621	} else {
1622	taskFn(taskCallback);
1623	}
1624	}
1625
1626	function checkForDeadlocks() {
1627	// Kahn's algorithm
1628	// https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm
1629	// http://connalle.blogspot.com/2013/10/topological-sortingkahn-algorithm.html
1630	var currentTask;
1631	var counter = 0;
1632	while (readyToCheck.length) {
1633	currentTask = readyToCheck.pop();
1634	counter++;
1635	arrayEach(getDependents(currentTask), function (dependent) {
1636	if (--uncheckedDependencies[dependent] === 0) {
1637	readyToCheck.push(dependent);
1638	}
1639	});
1640	}
1641
1642	if (counter !== numTasks) {
1643	throw new Error(
1644	'async.auto cannot execute tasks due to a recursive dependency'
1645	);
1646	}
1647	}
1648
1649	function getDependents(taskName) {
1650	var result = [];
1651	baseForOwn(tasks, function (task, key) {
1652	if (isArray(task) && baseIndexOf(task, taskName, 0) >= 0) {
1653	result.push(key);
1654	}
1655	});
1656	return result;
1657	}
1658	};
1659
1660	/**
1661	* A specialized version of `_.map` for arrays without support for iteratee
1662	* shorthands.
1663	*
1664	* @private
1665	* @param {Array} [array] The array to iterate over.
1666	* @param {Function} iteratee The function invoked per iteration.
1667	* @returns {Array} Returns the new mapped array.
1668	*/
1669	function arrayMap(array, iteratee) {
1670	var index = -1,
1671	length = array == null ? 0 : array.length,
1672	result = Array(length);
1673
1674	while (++index < length) {
1675	result[index] = iteratee(array[index], index, array);
1676	}
1677	return result;
1678	}
1679
1680	/** `Object#toString` result references. */
1681	var symbolTag = '[object Symbol]';
1682
1683	/**
1684	* Checks if `value` is classified as a `Symbol` primitive or object.
1685	*
1686	* @static
1687	* @memberOf _
1688	* @since 4.0.0
1689	* @category Lang
1690	* @param {*} value The value to check.
1691	* @returns {boolean} Returns `true` if `value` is a symbol, else `false`.
1692	* @example
1693	*
1694	* _.isSymbol(Symbol.iterator);
1695	* // => true
1696	*
1697	* _.isSymbol('abc');
1698	* // => false
1699	*/
1700	function isSymbol(value) {
1701	return typeof value == 'symbol' \|\|
1702	(isObjectLike(value) && baseGetTag(value) == symbolTag);
1703	}
1704
1705	/** Used as references for various `Number` constants. */
1706	var INFINITY = 1 / 0;
1707
1708	/** Used to convert symbols to primitives and strings. */
1709	var symbolProto = Symbol$1 ? Symbol$1.prototype : undefined;
1710	var symbolToString = symbolProto ? symbolProto.toString : undefined;
1711
1712	/**
1713	* The base implementation of `_.toString` which doesn't convert nullish
1714	* values to empty strings.
1715	*
1716	* @private
1717	* @param {*} value The value to process.
1718	* @returns {string} Returns the string.
1719	*/
1720	function baseToString(value) {
1721	// Exit early for strings to avoid a performance hit in some environments.
1722	if (typeof value == 'string') {
1723	return value;
1724	}
1725	if (isArray(value)) {
1726	// Recursively convert values (susceptible to call stack limits).
1727	return arrayMap(value, baseToString) + '';
1728	}
1729	if (isSymbol(value)) {
1730	return symbolToString ? symbolToString.call(value) : '';
1731	}
1732	var result = (value + '');
1733	return (result == '0' && (1 / value) == -INFINITY) ? '-0' : result;
1734	}
1735
1736	/**
1737	* The base implementation of `_.slice` without an iteratee call guard.
1738	*
1739	* @private
1740	* @param {Array} array The array to slice.
1741	* @param {number} [start=0] The start position.
1742	* @param {number} [end=array.length] The end position.
1743	* @returns {Array} Returns the slice of `array`.
1744	*/
1745	function baseSlice(array, start, end) {
1746	var index = -1,
1747	length = array.length;
1748
1749	if (start < 0) {
1750	start = -start > length ? 0 : (length + start);
1751	}
1752	end = end > length ? length : end;
1753	if (end < 0) {
1754	end += length;
1755	}
1756	length = start > end ? 0 : ((end - start) >>> 0);
1757	start >>>= 0;
1758
1759	var result = Array(length);
1760	while (++index < length) {
1761	result[index] = array[index + start];
1762	}
1763	return result;
1764	}
1765
1766	/**
1767	* Casts `array` to a slice if it's needed.
1768	*
1769	* @private
1770	* @param {Array} array The array to inspect.
1771	* @param {number} start The start position.
1772	* @param {number} [end=array.length] The end position.
1773	* @returns {Array} Returns the cast slice.
1774	*/
1775	function castSlice(array, start, end) {
1776	var length = array.length;
1777	end = end === undefined ? length : end;
1778	return (!start && end >= length) ? array : baseSlice(array, start, end);
1779	}
1780
1781	/**
1782	* Used by `_.trim` and `_.trimEnd` to get the index of the last string symbol
1783	* that is not found in the character symbols.
1784	*
1785	* @private
1786	* @param {Array} strSymbols The string symbols to inspect.
1787	* @param {Array} chrSymbols The character symbols to find.
1788	* @returns {number} Returns the index of the last unmatched string symbol.
1789	*/
1790	function charsEndIndex(strSymbols, chrSymbols) {
1791	var index = strSymbols.length;
1792
1793	while (index-- && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
1794	return index;
1795	}
1796
1797	/**
1798	* Used by `_.trim` and `_.trimStart` to get the index of the first string symbol
1799	* that is not found in the character symbols.
1800	*
1801	* @private
1802	* @param {Array} strSymbols The string symbols to inspect.
1803	* @param {Array} chrSymbols The character symbols to find.
1804	* @returns {number} Returns the index of the first unmatched string symbol.
1805	*/
1806	function charsStartIndex(strSymbols, chrSymbols) {
1807	var index = -1,
1808	length = strSymbols.length;
1809
1810	while (++index < length && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
1811	return index;
1812	}
1813
1814	/**
1815	* Converts an ASCII `string` to an array.
1816	*
1817	* @private
1818	* @param {string} string The string to convert.
1819	* @returns {Array} Returns the converted array.
1820	*/
1821	function asciiToArray(string) {
1822	return string.split('');
1823	}
1824
1825	/** Used to compose unicode character classes. */
1826	var rsAstralRange = '\\ud800-\\udfff';
1827	var rsComboMarksRange = '\\u0300-\\u036f\\ufe20-\\ufe23';
1828	var rsComboSymbolsRange = '\\u20d0-\\u20f0';
1829	var rsVarRange = '\\ufe0e\\ufe0f';
1830
1831	/** Used to compose unicode capture groups. */
1832	var rsZWJ = '\\u200d';
1833
1834	/** Used to detect strings with [zero-width joiners or code points from the astral planes](http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/). */
1835	var reHasUnicode = RegExp('[' + rsZWJ + rsAstralRange + rsComboMarksRange + rsComboSymbolsRange + rsVarRange + ']');
1836
1837	/**
1838	* Checks if `string` contains Unicode symbols.
1839	*
1840	* @private
1841	* @param {string} string The string to inspect.
1842	* @returns {boolean} Returns `true` if a symbol is found, else `false`.
1843	*/
1844	function hasUnicode(string) {
1845	return reHasUnicode.test(string);
1846	}
1847
1848	/** Used to compose unicode character classes. */
1849	var rsAstralRange$1 = '\\ud800-\\udfff';
1850	var rsComboMarksRange$1 = '\\u0300-\\u036f\\ufe20-\\ufe23';
1851	var rsComboSymbolsRange$1 = '\\u20d0-\\u20f0';
1852	var rsVarRange$1 = '\\ufe0e\\ufe0f';
1853
1854	/** Used to compose unicode capture groups. */
1855	var rsAstral = '[' + rsAstralRange$1 + ']';
1856	var rsCombo = '[' + rsComboMarksRange$1 + rsComboSymbolsRange$1 + ']';
1857	var rsFitz = '\\ud83c[\\udffb-\\udfff]';
1858	var rsModifier = '(?:' + rsCombo + '\|' + rsFitz + ')';
1859	var rsNonAstral = '[^' + rsAstralRange$1 + ']';
1860	var rsRegional = '(?:\\ud83c[\\udde6-\\uddff]){2}';
1861	var rsSurrPair = '[\\ud800-\\udbff][\\udc00-\\udfff]';
1862	var rsZWJ$1 = '\\u200d';
1863
1864	/** Used to compose unicode regexes. */
1865	var reOptMod = rsModifier + '?';
1866	var rsOptVar = '[' + rsVarRange$1 + ']?';
1867	var rsOptJoin = '(?:' + rsZWJ$1 + '(?:' + [rsNonAstral, rsRegional, rsSurrPair].join('\|') + ')' + rsOptVar + reOptMod + ')*';
1868	var rsSeq = rsOptVar + reOptMod + rsOptJoin;
1869	var rsSymbol = '(?:' + [rsNonAstral + rsCombo + '?', rsCombo, rsRegional, rsSurrPair, rsAstral].join('\|') + ')';
1870
1871	/** Used to match [string symbols](https://mathiasbynens.be/notes/javascript-unicode). */
1872	var reUnicode = RegExp(rsFitz + '(?=' + rsFitz + ')\|' + rsSymbol + rsSeq, 'g');
1873
1874	/**
1875	* Converts a Unicode `string` to an array.
1876	*
1877	* @private
1878	* @param {string} string The string to convert.
1879	* @returns {Array} Returns the converted array.
1880	*/
1881	function unicodeToArray(string) {
1882	return string.match(reUnicode) \|\| [];
1883	}
1884
1885	/**
1886	* Converts `string` to an array.
1887	*
1888	* @private
1889	* @param {string} string The string to convert.
1890	* @returns {Array} Returns the converted array.
1891	*/
1892	function stringToArray(string) {
1893	return hasUnicode(string)
1894	? unicodeToArray(string)
1895	: asciiToArray(string);
1896	}
1897
1898	/**
1899	* Converts `value` to a string. An empty string is returned for `null`
1900	* and `undefined` values. The sign of `-0` is preserved.
1901	*
1902	* @static
1903	* @memberOf _
1904	* @since 4.0.0
1905	* @category Lang
1906	* @param {*} value The value to convert.
1907	* @returns {string} Returns the converted string.
1908	* @example
1909	*
1910	* _.toString(null);
1911	* // => ''
1912	*
1913	* _.toString(-0);
1914	* // => '-0'
1915	*
1916	* _.toString([1, 2, 3]);
1917	* // => '1,2,3'
1918	*/
1919	function toString(value) {
1920	return value == null ? '' : baseToString(value);
1921	}
1922
1923	/** Used to match leading and trailing whitespace. */
1924	var reTrim = /^\s+\|\s+$/g;
1925
1926	/**
1927	* Removes leading and trailing whitespace or specified characters from `string`.
1928	*
1929	* @static
1930	* @memberOf _
1931	* @since 3.0.0
1932	* @category String
1933	* @param {string} [string=''] The string to trim.
1934	* @param {string} [chars=whitespace] The characters to trim.
1935	* @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.
1936	* @returns {string} Returns the trimmed string.
1937	* @example
1938	*
1939	* _.trim(' abc ');
1940	* // => 'abc'
1941	*
1942	* _.trim('-_-abc-_-', '_-');
1943	* // => 'abc'
1944	*
1945	* _.map([' foo ', ' bar '], _.trim);
1946	* // => ['foo', 'bar']
1947	*/
1948	function trim(string, chars, guard) {
1949	string = toString(string);
1950	if (string && (guard \|\| chars === undefined)) {
1951	return string.replace(reTrim, '');
1952	}
1953	if (!string \|\| !(chars = baseToString(chars))) {
1954	return string;
1955	}
1956	var strSymbols = stringToArray(string),
1957	chrSymbols = stringToArray(chars),
1958	start = charsStartIndex(strSymbols, chrSymbols),
1959	end = charsEndIndex(strSymbols, chrSymbols) + 1;
1960
1961	return castSlice(strSymbols, start, end).join('');
1962	}
1963
1964	var FN_ARGS = /^(?:async\s+)?(function)?\s[^\(]\(\s([^\)])\)/m;
1965	var FN_ARG_SPLIT = /,/;
1966	var FN_ARG = /(=.+)?(\s*)$/;
1967	var STRIP_COMMENTS = /((\/\/.$)\|(\/\[\s\S]?\\/))/mg;
1968
1969	function parseParams(func) {
1970	func = func.toString().replace(STRIP_COMMENTS, '');
1971	func = func.match(FN_ARGS)[2].replace(' ', '');
1972	func = func ? func.split(FN_ARG_SPLIT) : [];
1973	func = func.map(function (arg){
1974	return trim(arg.replace(FN_ARG, ''));
1975	});
1976	return func;
1977	}
1978
1979	/**
1980	* A dependency-injected version of the [async.auto]{@link module:ControlFlow.auto} function. Dependent
1981	* tasks are specified as parameters to the function, after the usual callback
1982	* parameter, with the parameter names matching the names of the tasks it
1983	* depends on. This can provide even more readable task graphs which can be
1984	* easier to maintain.
1985	*
1986	* If a final callback is specified, the task results are similarly injected,
1987	* specified as named parameters after the initial error parameter.
1988	*
1989	* The autoInject function is purely syntactic sugar and its semantics are
1990	* otherwise equivalent to [async.auto]{@link module:ControlFlow.auto}.
1991	*
1992	* @name autoInject
1993	* @static
1994	* @memberOf module:ControlFlow
1995	* @method
1996	* @see [async.auto]{@link module:ControlFlow.auto}
1997	* @category Control Flow
1998	* @param {Object} tasks - An object, each of whose properties is an {@link AsyncFunction} of
1999	* the form 'func([dependencies...], callback). The object's key of a property
2000	* serves as the name of the task defined by that property, i.e. can be used
2001	* when specifying requirements for other tasks.
2002	* * The `callback` parameter is a `callback(err, result)` which must be called
2003	* when finished, passing an `error` (which can be `null`) and the result of
2004	* the function's execution. The remaining parameters name other tasks on
2005	* which the task is dependent, and the results from those tasks are the
2006	* arguments of those parameters.
2007	* @param {Function} [callback] - An optional callback which is called when all
2008	* the tasks have been completed. It receives the `err` argument if any `tasks`
2009	* pass an error to their callback, and a `results` object with any completed
2010	* task results, similar to `auto`.
2011	* @example
2012	*
2013	* // The example from `auto` can be rewritten as follows:
2014	* async.autoInject({
2015	* get_data: function(callback) {
2016	* // async code to get some data
2017	* callback(null, 'data', 'converted to array');
2018	* },
2019	* make_folder: function(callback) {
2020	* // async code to create a directory to store a file in
2021	* // this is run at the same time as getting the data
2022	* callback(null, 'folder');
2023	* },
2024	* write_file: function(get_data, make_folder, callback) {
2025	* // once there is some data and the directory exists,
2026	* // write the data to a file in the directory
2027	* callback(null, 'filename');
2028	* },
2029	* email_link: function(write_file, callback) {
2030	* // once the file is written let's email a link to it...
2031	* // write_file contains the filename returned by write_file.
2032	* callback(null, {'file':write_file, 'email':'user@example.com'});
2033	* }
2034	* }, function(err, results) {
2035	* console.log('err = ', err);
2036	* console.log('email_link = ', results.email_link);
2037	* });
2038	*
2039	* // If you are using a JS minifier that mangles parameter names, `autoInject`
2040	* // will not work with plain functions, since the parameter names will be
2041	* // collapsed to a single letter identifier. To work around this, you can
2042	* // explicitly specify the names of the parameters your task function needs
2043	* // in an array, similar to Angular.js dependency injection.
2044	*
2045	* // This still has an advantage over plain `auto`, since the results a task
2046	* // depends on are still spread into arguments.
2047	* async.autoInject({
2048	* //...
2049	* write_file: ['get_data', 'make_folder', function(get_data, make_folder, callback) {
2050	* callback(null, 'filename');
2051	* }],
2052	* email_link: ['write_file', function(write_file, callback) {
2053	* callback(null, {'file':write_file, 'email':'user@example.com'});
2054	* }]
2055	* //...
2056	* }, function(err, results) {
2057	* console.log('err = ', err);
2058	* console.log('email_link = ', results.email_link);
2059	* });
2060	*/
2061	function autoInject(tasks, callback) {
2062	var newTasks = {};
2063
2064	baseForOwn(tasks, function (taskFn, key) {
2065	var params;
2066	var fnIsAsync = isAsync(taskFn);
2067	var hasNoDeps =
2068	(!fnIsAsync && taskFn.length === 1) \|\|
2069	(fnIsAsync && taskFn.length === 0);
2070
2071	if (isArray(taskFn)) {
2072	params = taskFn.slice(0, -1);
2073	taskFn = taskFn[taskFn.length - 1];
2074
2075	newTasks[key] = params.concat(params.length > 0 ? newTask : taskFn);
2076	} else if (hasNoDeps) {
2077	// no dependencies, use the function as-is
2078	newTasks[key] = taskFn;
2079	} else {
2080	params = parseParams(taskFn);
2081	if (taskFn.length === 0 && !fnIsAsync && params.length === 0) {
2082	throw new Error("autoInject task functions require explicit parameters.");
2083	}
2084
2085	// remove callback param
2086	if (!fnIsAsync) params.pop();
2087
2088	newTasks[key] = params.concat(newTask);
2089	}
2090
2091	function newTask(results, taskCb) {
2092	var newArgs = arrayMap(params, function (name) {
2093	return results[name];
2094	});
2095	newArgs.push(taskCb);
2096	wrapAsync(taskFn).apply(null, newArgs);
2097	}
2098	});
2099
2100	auto(newTasks, callback);
2101	}
2102
2103	// Simple doubly linked list (https://en.wikipedia.org/wiki/Doubly_linked_list) implementation
2104	// used for queues. This implementation assumes that the node provided by the user can be modified
2105	// to adjust the next and last properties. We implement only the minimal functionality
2106	// for queue support.
2107	function DLL() {
2108	this.head = this.tail = null;
2109	this.length = 0;
2110	}
2111
2112	function setInitial(dll, node) {
2113	dll.length = 1;
2114	dll.head = dll.tail = node;
2115	}
2116
2117	DLL.prototype.removeLink = function(node) {
2118	if (node.prev) node.prev.next = node.next;
2119	else this.head = node.next;
2120	if (node.next) node.next.prev = node.prev;
2121	else this.tail = node.prev;
2122
2123	node.prev = node.next = null;
2124	this.length -= 1;
2125	return node;
2126	};
2127
2128	DLL.prototype.empty = function () {
2129	while(this.head) this.shift();
2130	return this;
2131	};
2132
2133	DLL.prototype.insertAfter = function(node, newNode) {
2134	newNode.prev = node;
2135	newNode.next = node.next;
2136	if (node.next) node.next.prev = newNode;
2137	else this.tail = newNode;
2138	node.next = newNode;
2139	this.length += 1;
2140	};
2141
2142	DLL.prototype.insertBefore = function(node, newNode) {
2143	newNode.prev = node.prev;
2144	newNode.next = node;
2145	if (node.prev) node.prev.next = newNode;
2146	else this.head = newNode;
2147	node.prev = newNode;
2148	this.length += 1;
2149	};
2150
2151	DLL.prototype.unshift = function(node) {
2152	if (this.head) this.insertBefore(this.head, node);
2153	else setInitial(this, node);
2154	};
2155
2156	DLL.prototype.push = function(node) {
2157	if (this.tail) this.insertAfter(this.tail, node);
2158	else setInitial(this, node);
2159	};
2160
2161	DLL.prototype.shift = function() {
2162	return this.head && this.removeLink(this.head);
2163	};
2164
2165	DLL.prototype.pop = function() {
2166	return this.tail && this.removeLink(this.tail);
2167	};
2168
2169	DLL.prototype.toArray = function () {
2170	var arr = Array(this.length);
2171	var curr = this.head;
2172	for(var idx = 0; idx < this.length; idx++) {
2173	arr[idx] = curr.data;
2174	curr = curr.next;
2175	}
2176	return arr;
2177	};
2178
2179	DLL.prototype.remove = function (testFn) {
2180	var curr = this.head;
2181	while(!!curr) {
2182	var next = curr.next;
2183	if (testFn(curr)) {
2184	this.removeLink(curr);
2185	}
2186	curr = next;
2187	}
2188	return this;
2189	};
2190
2191	function queue(worker, concurrency, payload) {
2192	if (concurrency == null) {
2193	concurrency = 1;
2194	}
2195	else if(concurrency === 0) {
2196	throw new Error('Concurrency must not be zero');
2197	}
2198
2199	var _worker = wrapAsync(worker);
2200	var numRunning = 0;
2201	var workersList = [];
2202
2203	function _insert(data, insertAtFront, callback) {
2204	if (callback != null && typeof callback !== 'function') {
2205	throw new Error('task callback must be a function');
2206	}
2207	q.started = true;
2208	if (!isArray(data)) {
2209	data = [data];
2210	}
2211	if (data.length === 0 && q.idle()) {
2212	// call drain immediately if there are no tasks
2213	return setImmediate$1(function() {
2214	q.drain();
2215	});
2216	}
2217
2218	for (var i = 0, l = data.length; i < l; i++) {
2219	var item = {
2220	data: data[i],
2221	callback: callback \|\| noop
2222	};
2223
2224	if (insertAtFront) {
2225	q._tasks.unshift(item);
2226	} else {
2227	q._tasks.push(item);
2228	}
2229	}
2230	setImmediate$1(q.process);
2231	}
2232
2233	function _next(tasks) {
2234	return function(err){
2235	numRunning -= 1;
2236
2237	for (var i = 0, l = tasks.length; i < l; i++) {
2238	var task = tasks[i];
2239	var index = baseIndexOf(workersList, task, 0);
2240	if (index >= 0) {
2241	workersList.splice(index);
2242	}
2243
2244	task.callback.apply(task, arguments);
2245
2246	if (err != null) {
2247	q.error(err, task.data);
2248	}
2249	}
2250
2251	if (numRunning <= (q.concurrency - q.buffer) ) {
2252	q.unsaturated();
2253	}
2254
2255	if (q.idle()) {
2256	q.drain();
2257	}
2258	q.process();
2259	};
2260	}
2261
2262	var isProcessing = false;
2263	var q = {
2264	_tasks: new DLL(),
2265	concurrency: concurrency,
2266	payload: payload,
2267	saturated: noop,
2268	unsaturated:noop,
2269	buffer: concurrency / 4,
2270	empty: noop,
2271	drain: noop,
2272	error: noop,
2273	started: false,
2274	paused: false,
2275	push: function (data, callback) {
2276	_insert(data, false, callback);
2277	},
2278	kill: function () {
2279	q.drain = noop;
2280	q._tasks.empty();
2281	},
2282	unshift: function (data, callback) {
2283	_insert(data, true, callback);
2284	},
2285	remove: function (testFn) {
2286	q._tasks.remove(testFn);
2287	},
2288	process: function () {
2289	// Avoid trying to start too many processing operations. This can occur
2290	// when callbacks resolve synchronously (#1267).
2291	if (isProcessing) {
2292	return;
2293	}
2294	isProcessing = true;
2295	while(!q.paused && numRunning < q.concurrency && q._tasks.length){
2296	var tasks = [], data = [];
2297	var l = q._tasks.length;
2298	if (q.payload) l = Math.min(l, q.payload);
2299	for (var i = 0; i < l; i++) {
2300	var node = q._tasks.shift();
2301	tasks.push(node);
2302	data.push(node.data);
2303	}
2304
2305	numRunning += 1;
2306	workersList.push(tasks[0]);
2307
2308	if (q._tasks.length === 0) {
2309	q.empty();
2310	}
2311
2312	if (numRunning === q.concurrency) {
2313	q.saturated();
2314	}
2315
2316	var cb = onlyOnce(_next(tasks));
2317	_worker(data, cb);
2318	}
2319	isProcessing = false;
2320	},
2321	length: function () {
2322	return q._tasks.length;
2323	},
2324	running: function () {
2325	return numRunning;
2326	},
2327	workersList: function () {
2328	return workersList;
2329	},
2330	idle: function() {
2331	return q._tasks.length + numRunning === 0;
2332	},
2333	pause: function () {
2334	q.paused = true;
2335	},
2336	resume: function () {
2337	if (q.paused === false) { return; }
2338	q.paused = false;
2339	setImmediate$1(q.process);
2340	}
2341	};
2342	return q;
2343	}
2344
2345	/**
2346	* A cargo of tasks for the worker function to complete. Cargo inherits all of
2347	* the same methods and event callbacks as [`queue`]{@link module:ControlFlow.queue}.
2348	* @typedef {Object} CargoObject
2349	* @memberOf module:ControlFlow
2350	* @property {Function} length - A function returning the number of items
2351	* waiting to be processed. Invoke like `cargo.length()`.
2352	* @property {number} payload - An `integer` for determining how many tasks
2353	* should be process per round. This property can be changed after a `cargo` is
2354	* created to alter the payload on-the-fly.
2355	* @property {Function} push - Adds `task` to the `queue`. The callback is
2356	* called once the `worker` has finished processing the task. Instead of a
2357	* single task, an array of `tasks` can be submitted. The respective callback is
2358	* used for every task in the list. Invoke like `cargo.push(task, [callback])`.
2359	* @property {Function} saturated - A callback that is called when the
2360	* `queue.length()` hits the concurrency and further tasks will be queued.
2361	* @property {Function} empty - A callback that is called when the last item
2362	* from the `queue` is given to a `worker`.
2363	* @property {Function} drain - A callback that is called when the last item
2364	* from the `queue` has returned from the `worker`.
2365	* @property {Function} idle - a function returning false if there are items
2366	* waiting or being processed, or true if not. Invoke like `cargo.idle()`.
2367	* @property {Function} pause - a function that pauses the processing of tasks
2368	* until `resume()` is called. Invoke like `cargo.pause()`.
2369	* @property {Function} resume - a function that resumes the processing of
2370	* queued tasks when the queue is paused. Invoke like `cargo.resume()`.
2371	* @property {Function} kill - a function that removes the `drain` callback and
2372	* empties remaining tasks from the queue forcing it to go idle. Invoke like `cargo.kill()`.
2373	*/
2374
2375	/**
2376	* Creates a `cargo` object with the specified payload. Tasks added to the
2377	* cargo will be processed altogether (up to the `payload` limit). If the
2378	* `worker` is in progress, the task is queued until it becomes available. Once
2379	* the `worker` has completed some tasks, each callback of those tasks is
2380	* called. Check out [these](https://camo.githubusercontent.com/6bbd36f4cf5b35a0f11a96dcd2e97711ffc2fb37/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130382f62626330636662302d356632392d313165322d393734662d3333393763363464633835382e676966) [animations](https://camo.githubusercontent.com/f4810e00e1c5f5f8addbe3e9f49064fd5d102699/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130312f38346339323036362d356632392d313165322d383134662d3964336430323431336266642e676966)
2381	* for how `cargo` and `queue` work.
2382	*
2383	* While [`queue`]{@link module:ControlFlow.queue} passes only one task to one of a group of workers
2384	* at a time, cargo passes an array of tasks to a single worker, repeating
2385	* when the worker is finished.
2386	*
2387	* @name cargo
2388	* @static
2389	* @memberOf module:ControlFlow
2390	* @method
2391	* @see [async.queue]{@link module:ControlFlow.queue}
2392	* @category Control Flow
2393	* @param {AsyncFunction} worker - An asynchronous function for processing an array
2394	* of queued tasks. Invoked with `(tasks, callback)`.
2395	* @param {number} [payload=Infinity] - An optional `integer` for determining
2396	* how many tasks should be processed per round; if omitted, the default is
2397	* unlimited.
2398	* @returns {module:ControlFlow.CargoObject} A cargo object to manage the tasks. Callbacks can
2399	* attached as certain properties to listen for specific events during the
2400	* lifecycle of the cargo and inner queue.
2401	* @example
2402	*
2403	* // create a cargo object with payload 2
2404	* var cargo = async.cargo(function(tasks, callback) {
2405	* for (var i=0; i<tasks.length; i++) {
2406	* console.log('hello ' + tasks[i].name);
2407	* }
2408	* callback();
2409	* }, 2);
2410	*
2411	* // add some items
2412	* cargo.push({name: 'foo'}, function(err) {
2413	* console.log('finished processing foo');
2414	* });
2415	* cargo.push({name: 'bar'}, function(err) {
2416	* console.log('finished processing bar');
2417	* });
2418	* cargo.push({name: 'baz'}, function(err) {
2419	* console.log('finished processing baz');
2420	* });
2421	*/
2422	function cargo(worker, payload) {
2423	return queue(worker, 1, payload);
2424	}
2425
2426	/**
2427	* The same as [`eachOf`]{@link module:Collections.eachOf} but runs only a single async operation at a time.
2428	*
2429	* @name eachOfSeries
2430	* @static
2431	* @memberOf module:Collections
2432	* @method
2433	* @see [async.eachOf]{@link module:Collections.eachOf}
2434	* @alias forEachOfSeries
2435	* @category Collection
2436	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2437	* @param {AsyncFunction} iteratee - An async function to apply to each item in
2438	* `coll`.
2439	* Invoked with (item, key, callback).
2440	* @param {Function} [callback] - A callback which is called when all `iteratee`
2441	* functions have finished, or an error occurs. Invoked with (err).
2442	*/
2443	var eachOfSeries = doLimit(eachOfLimit, 1);
2444
2445	/**
2446	* Reduces `coll` into a single value using an async `iteratee` to return each
2447	* successive step. `memo` is the initial state of the reduction. This function
2448	* only operates in series.
2449	*
2450	* For performance reasons, it may make sense to split a call to this function
2451	* into a parallel map, and then use the normal `Array.prototype.reduce` on the
2452	* results. This function is for situations where each step in the reduction
2453	* needs to be async; if you can get the data before reducing it, then it's
2454	* probably a good idea to do so.
2455	*
2456	* @name reduce
2457	* @static
2458	* @memberOf module:Collections
2459	* @method
2460	* @alias inject
2461	* @alias foldl
2462	* @category Collection
2463	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2464	* @param {*} memo - The initial state of the reduction.
2465	* @param {AsyncFunction} iteratee - A function applied to each item in the
2466	* array to produce the next step in the reduction.
2467	* The `iteratee` should complete with the next state of the reduction.
2468	* If the iteratee complete with an error, the reduction is stopped and the
2469	* main `callback` is immediately called with the error.
2470	* Invoked with (memo, item, callback).
2471	* @param {Function} [callback] - A callback which is called after all the
2472	* `iteratee` functions have finished. Result is the reduced value. Invoked with
2473	* (err, result).
2474	* @example
2475	*
2476	* async.reduce([1,2,3], 0, function(memo, item, callback) {
2477	* // pointless async:
2478	* process.nextTick(function() {
2479	* callback(null, memo + item)
2480	* });
2481	* }, function(err, result) {
2482	* // result is now equal to the last value of memo, which is 6
2483	* });
2484	*/
2485	function reduce(coll, memo, iteratee, callback) {
2486	callback = once(callback \|\| noop);
2487	var _iteratee = wrapAsync(iteratee);
2488	eachOfSeries(coll, function(x, i, callback) {
2489	_iteratee(memo, x, function(err, v) {
2490	memo = v;
2491	callback(err);
2492	});
2493	}, function(err) {
2494	callback(err, memo);
2495	});
2496	}
2497
2498	/**
2499	* Version of the compose function that is more natural to read. Each function
2500	* consumes the return value of the previous function. It is the equivalent of
2501	* [compose]{@link module:ControlFlow.compose} with the arguments reversed.
2502	*
2503	* Each function is executed with the `this` binding of the composed function.
2504	*
2505	* @name seq
2506	* @static
2507	* @memberOf module:ControlFlow
2508	* @method
2509	* @see [async.compose]{@link module:ControlFlow.compose}
2510	* @category Control Flow
2511	* @param {...AsyncFunction} functions - the asynchronous functions to compose
2512	* @returns {Function} a function that composes the `functions` in order
2513	* @example
2514	*
2515	* // Requires lodash (or underscore), express3 and dresende's orm2.
2516	* // Part of an app, that fetches cats of the logged user.
2517	* // This example uses `seq` function to avoid overnesting and error
2518	* // handling clutter.
2519	* app.get('/cats', function(request, response) {
2520	* var User = request.models.User;
2521	* async.seq(
2522	* _.bind(User.get, User), // 'User.get' has signature (id, callback(err, data))
2523	* function(user, fn) {
2524	* user.getCats(fn); // 'getCats' has signature (callback(err, data))
2525	* }
2526	* )(req.session.user_id, function (err, cats) {
2527	* if (err) {
2528	* console.error(err);
2529	* response.json({ status: 'error', message: err.message });
2530	* } else {
2531	* response.json({ status: 'ok', message: 'Cats found', data: cats });
2532	* }
2533	* });
2534	* });
2535	*/
2536	function seq(/...functions/) {
2537	var _functions = arrayMap(arguments, wrapAsync);
2538	return function(/...args/) {
2539	var args = slice(arguments);
2540	var that = this;
2541
2542	var cb = args[args.length - 1];
2543	if (typeof cb == 'function') {
2544	args.pop();
2545	} else {
2546	cb = noop;
2547	}
2548
2549	reduce(_functions, args, function(newargs, fn, cb) {
2550	fn.apply(that, newargs.concat(function(err/, ...nextargs/) {
2551	var nextargs = slice(arguments, 1);
2552	cb(err, nextargs);
2553	}));
2554	},
2555	function(err, results) {
2556	cb.apply(that, [err].concat(results));
2557	});
2558	};
2559	}
2560
2561	/**
2562	* Creates a function which is a composition of the passed asynchronous
2563	* functions. Each function consumes the return value of the function that
2564	* follows. Composing functions `f()`, `g()`, and `h()` would produce the result
2565	* of `f(g(h()))`, only this version uses callbacks to obtain the return values.
2566	*
2567	* Each function is executed with the `this` binding of the composed function.
2568	*
2569	* @name compose
2570	* @static
2571	* @memberOf module:ControlFlow
2572	* @method
2573	* @category Control Flow
2574	* @param {...AsyncFunction} functions - the asynchronous functions to compose
2575	* @returns {Function} an asynchronous function that is the composed
2576	* asynchronous `functions`
2577	* @example
2578	*
2579	* function add1(n, callback) {
2580	* setTimeout(function () {
2581	* callback(null, n + 1);
2582	* }, 10);
2583	* }
2584	*
2585	* function mul3(n, callback) {
2586	* setTimeout(function () {
2587	* callback(null, n * 3);
2588	* }, 10);
2589	* }
2590	*
2591	* var add1mul3 = async.compose(mul3, add1);
2592	* add1mul3(4, function (err, result) {
2593	* // result now equals 15
2594	* });
2595	*/
2596	var compose = function(/...args/) {
2597	return seq.apply(null, slice(arguments).reverse());
2598	};
2599
2600	function concat$1(eachfn, arr, fn, callback) {
2601	var result = [];
2602	eachfn(arr, function (x, index, cb) {
2603	fn(x, function (err, y) {
2604	result = result.concat(y \|\| []);
2605	cb(err);
2606	});
2607	}, function (err) {
2608	callback(err, result);
2609	});
2610	}
2611
2612	/**
2613	* Applies `iteratee` to each item in `coll`, concatenating the results. Returns
2614	* the concatenated list. The `iteratee`s are called in parallel, and the
2615	* results are concatenated as they return. There is no guarantee that the
2616	* results array will be returned in the original order of `coll` passed to the
2617	* `iteratee` function.
2618	*
2619	* @name concat
2620	* @static
2621	* @memberOf module:Collections
2622	* @method
2623	* @category Collection
2624	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2625	* @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
2626	* which should use an array as its result. Invoked with (item, callback).
2627	* @param {Function} [callback(err)] - A callback which is called after all the
2628	* `iteratee` functions have finished, or an error occurs. Results is an array
2629	* containing the concatenated results of the `iteratee` function. Invoked with
2630	* (err, results).
2631	* @example
2632	*
2633	* async.concat(['dir1','dir2','dir3'], fs.readdir, function(err, files) {
2634	* // files is now a list of filenames that exist in the 3 directories
2635	* });
2636	*/
2637	var concat = doParallel(concat$1);
2638
2639	function doSeries(fn) {
2640	return function (obj, iteratee, callback) {
2641	return fn(eachOfSeries, obj, wrapAsync(iteratee), callback);
2642	};
2643	}
2644
2645	/**
2646	* The same as [`concat`]{@link module:Collections.concat} but runs only a single async operation at a time.
2647	*
2648	* @name concatSeries
2649	* @static
2650	* @memberOf module:Collections
2651	* @method
2652	* @see [async.concat]{@link module:Collections.concat}
2653	* @category Collection
2654	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2655	* @param {AsyncFunction} iteratee - A function to apply to each item in `coll`.
2656	* The iteratee should complete with an array an array of results.
2657	* Invoked with (item, callback).
2658	* @param {Function} [callback(err)] - A callback which is called after all the
2659	* `iteratee` functions have finished, or an error occurs. Results is an array
2660	* containing the concatenated results of the `iteratee` function. Invoked with
2661	* (err, results).
2662	*/
2663	var concatSeries = doSeries(concat$1);
2664
2665	/**
2666	* Returns a function that when called, calls-back with the values provided.
2667	* Useful as the first function in a [`waterfall`]{@link module:ControlFlow.waterfall}, or for plugging values in to
2668	* [`auto`]{@link module:ControlFlow.auto}.
2669	*
2670	* @name constant
2671	* @static
2672	* @memberOf module:Utils
2673	* @method
2674	* @category Util
2675	* @param {...*} arguments... - Any number of arguments to automatically invoke
2676	* callback with.
2677	* @returns {AsyncFunction} Returns a function that when invoked, automatically
2678	* invokes the callback with the previous given arguments.
2679	* @example
2680	*
2681	* async.waterfall([
2682	* async.constant(42),
2683	* function (value, next) {
2684	* // value === 42
2685	* },
2686	* //...
2687	* ], callback);
2688	*
2689	* async.waterfall([
2690	* async.constant(filename, "utf8"),
2691	* fs.readFile,
2692	* function (fileData, next) {
2693	* //...
2694	* }
2695	* //...
2696	* ], callback);
2697	*
2698	* async.auto({
2699	* hostname: async.constant("https://server.net/"),
2700	* port: findFreePort,
2701	* launchServer: ["hostname", "port", function (options, cb) {
2702	* startServer(options, cb);
2703	* }],
2704	* //...
2705	* }, callback);
2706	*/
2707	var constant = function(/...values/) {
2708	var values = slice(arguments);
2709	var args = [null].concat(values);
2710	return function (/...ignoredArgs, callback/) {
2711	var callback = arguments[arguments.length - 1];
2712	return callback.apply(this, args);
2713	};
2714	};
2715
2716	/**
2717	* This method returns the first argument it receives.
2718	*
2719	* @static
2720	* @since 0.1.0
2721	* @memberOf _
2722	* @category Util
2723	* @param {*} value Any value.
2724	* @returns {*} Returns `value`.
2725	* @example
2726	*
2727	* var object = { 'a': 1 };
2728	*
2729	* console.log(_.identity(object) === object);
2730	* // => true
2731	*/
2732	function identity(value) {
2733	return value;
2734	}
2735
2736	function _createTester(check, getResult) {
2737	return function(eachfn, arr, iteratee, cb) {
2738	cb = cb \|\| noop;
2739	var testPassed = false;
2740	var testResult;
2741	eachfn(arr, function(value, _, callback) {
2742	iteratee(value, function(err, result) {
2743	if (err) {
2744	callback(err);
2745	} else if (check(result) && !testResult) {
2746	testPassed = true;
2747	testResult = getResult(true, value);
2748	callback(null, breakLoop);
2749	} else {
2750	callback();
2751	}
2752	});
2753	}, function(err) {
2754	if (err) {
2755	cb(err);
2756	} else {
2757	cb(null, testPassed ? testResult : getResult(false));
2758	}
2759	});
2760	};
2761	}
2762
2763	function _findGetResult(v, x) {
2764	return x;
2765	}
2766
2767	/**
2768	* Returns the first value in `coll` that passes an async truth test. The
2769	* `iteratee` is applied in parallel, meaning the first iteratee to return
2770	* `true` will fire the detect `callback` with that result. That means the
2771	* result might not be the first item in the original `coll` (in terms of order)
2772	* that passes the test.
2773
2774	* If order within the original `coll` is important, then look at
2775	* [`detectSeries`]{@link module:Collections.detectSeries}.
2776	*
2777	* @name detect
2778	* @static
2779	* @memberOf module:Collections
2780	* @method
2781	* @alias find
2782	* @category Collections
2783	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2784	* @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
2785	* The iteratee must complete with a boolean value as its result.
2786	* Invoked with (item, callback).
2787	* @param {Function} [callback] - A callback which is called as soon as any
2788	* iteratee returns `true`, or after all the `iteratee` functions have finished.
2789	* Result will be the first item in the array that passes the truth test
2790	* (iteratee) or the value `undefined` if none passed. Invoked with
2791	* (err, result).
2792	* @example
2793	*
2794	* async.detect(['file1','file2','file3'], function(filePath, callback) {
2795	* fs.access(filePath, function(err) {
2796	* callback(null, !err)
2797	* });
2798	* }, function(err, result) {
2799	* // result now equals the first file in the list that exists
2800	* });
2801	*/
2802	var detect = doParallel(_createTester(identity, _findGetResult));
2803
2804	/**
2805	* The same as [`detect`]{@link module:Collections.detect} but runs a maximum of `limit` async operations at a
2806	* time.
2807	*
2808	* @name detectLimit
2809	* @static
2810	* @memberOf module:Collections
2811	* @method
2812	* @see [async.detect]{@link module:Collections.detect}
2813	* @alias findLimit
2814	* @category Collections
2815	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2816	* @param {number} limit - The maximum number of async operations at a time.
2817	* @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
2818	* The iteratee must complete with a boolean value as its result.
2819	* Invoked with (item, callback).
2820	* @param {Function} [callback] - A callback which is called as soon as any
2821	* iteratee returns `true`, or after all the `iteratee` functions have finished.
2822	* Result will be the first item in the array that passes the truth test
2823	* (iteratee) or the value `undefined` if none passed. Invoked with
2824	* (err, result).
2825	*/
2826	var detectLimit = doParallelLimit(_createTester(identity, _findGetResult));
2827
2828	/**
2829	* The same as [`detect`]{@link module:Collections.detect} but runs only a single async operation at a time.
2830	*
2831	* @name detectSeries
2832	* @static
2833	* @memberOf module:Collections
2834	* @method
2835	* @see [async.detect]{@link module:Collections.detect}
2836	* @alias findSeries
2837	* @category Collections
2838	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
2839	* @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
2840	* The iteratee must complete with a boolean value as its result.
2841	* Invoked with (item, callback).
2842	* @param {Function} [callback] - A callback which is called as soon as any
2843	* iteratee returns `true`, or after all the `iteratee` functions have finished.
2844	* Result will be the first item in the array that passes the truth test
2845	* (iteratee) or the value `undefined` if none passed. Invoked with
2846	* (err, result).
2847	*/
2848	var detectSeries = doLimit(detectLimit, 1);
2849
2850	function consoleFunc(name) {
2851	return function (fn/, ...args/) {
2852	var args = slice(arguments, 1);
2853	args.push(function (err/, ...args/) {
2854	var args = slice(arguments, 1);
2855	if (typeof console === 'object') {
2856	if (err) {
2857	if (console.error) {
2858	console.error(err);
2859	}
2860	} else if (console[name]) {
2861	arrayEach(args, function (x) {
2862	console[name](x);
2863	});
2864	}
2865	}
2866	});
2867	wrapAsync(fn).apply(null, args);
2868	};
2869	}
2870
2871	/**
2872	* Logs the result of an [`async` function]{@link AsyncFunction} to the
2873	* `console` using `console.dir` to display the properties of the resulting object.
2874	* Only works in Node.js or in browsers that support `console.dir` and
2875	* `console.error` (such as FF and Chrome).
2876	* If multiple arguments are returned from the async function,
2877	* `console.dir` is called on each argument in order.
2878	*
2879	* @name dir
2880	* @static
2881	* @memberOf module:Utils
2882	* @method
2883	* @category Util
2884	* @param {AsyncFunction} function - The function you want to eventually apply
2885	* all arguments to.
2886	* @param {...*} arguments... - Any number of arguments to apply to the function.
2887	* @example
2888	*
2889	* // in a module
2890	* var hello = function(name, callback) {
2891	* setTimeout(function() {
2892	* callback(null, {hello: name});
2893	* }, 1000);
2894	* };
2895	*
2896	* // in the node repl
2897	* node> async.dir(hello, 'world');
2898	* {hello: 'world'}
2899	*/
2900	var dir = consoleFunc('dir');
2901
2902	/**
2903	* The post-check version of [`during`]{@link module:ControlFlow.during}. To reflect the difference in
2904	* the order of operations, the arguments `test` and `fn` are switched.
2905	*
2906	* Also a version of [`doWhilst`]{@link module:ControlFlow.doWhilst} with asynchronous `test` function.
2907	* @name doDuring
2908	* @static
2909	* @memberOf module:ControlFlow
2910	* @method
2911	* @see [async.during]{@link module:ControlFlow.during}
2912	* @category Control Flow
2913	* @param {AsyncFunction} fn - An async function which is called each time
2914	* `test` passes. Invoked with (callback).
2915	* @param {AsyncFunction} test - asynchronous truth test to perform before each
2916	* execution of `fn`. Invoked with (...args, callback), where `...args` are the
2917	* non-error args from the previous callback of `fn`.
2918	* @param {Function} [callback] - A callback which is called after the test
2919	* function has failed and repeated execution of `fn` has stopped. `callback`
2920	* will be passed an error if one occurred, otherwise `null`.
2921	*/
2922	function doDuring(fn, test, callback) {
2923	callback = onlyOnce(callback \|\| noop);
2924	var _fn = wrapAsync(fn);
2925	var _test = wrapAsync(test);
2926
2927	function next(err/, ...args/) {
2928	if (err) return callback(err);
2929	var args = slice(arguments, 1);
2930	args.push(check);
2931	_test.apply(this, args);
2932	}
2933
2934	function check(err, truth) {
2935	if (err) return callback(err);
2936	if (!truth) return callback(null);
2937	_fn(next);
2938	}
2939
2940	check(null, true);
2941
2942	}
2943
2944	/**
2945	* The post-check version of [`whilst`]{@link module:ControlFlow.whilst}. To reflect the difference in
2946	* the order of operations, the arguments `test` and `iteratee` are switched.
2947	*
2948	* `doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript.
2949	*
2950	* @name doWhilst
2951	* @static
2952	* @memberOf module:ControlFlow
2953	* @method
2954	* @see [async.whilst]{@link module:ControlFlow.whilst}
2955	* @category Control Flow
2956	* @param {AsyncFunction} iteratee - A function which is called each time `test`
2957	* passes. Invoked with (callback).
2958	* @param {Function} test - synchronous truth test to perform after each
2959	* execution of `iteratee`. Invoked with any non-error callback results of
2960	* `iteratee`.
2961	* @param {Function} [callback] - A callback which is called after the test
2962	* function has failed and repeated execution of `iteratee` has stopped.
2963	* `callback` will be passed an error and any arguments passed to the final
2964	* `iteratee`'s callback. Invoked with (err, [results]);
2965	*/
2966	function doWhilst(iteratee, test, callback) {
2967	callback = onlyOnce(callback \|\| noop);
2968	var _iteratee = wrapAsync(iteratee);
2969	var next = function(err/, ...args/) {
2970	if (err) return callback(err);
2971	var args = slice(arguments, 1);
2972	if (test.apply(this, args)) return _iteratee(next);
2973	callback.apply(null, [null].concat(args));
2974	};
2975	_iteratee(next);
2976	}
2977
2978	/**
2979	* Like ['doWhilst']{@link module:ControlFlow.doWhilst}, except the `test` is inverted. Note the
2980	* argument ordering differs from `until`.
2981	*
2982	* @name doUntil
2983	* @static
2984	* @memberOf module:ControlFlow
2985	* @method
2986	* @see [async.doWhilst]{@link module:ControlFlow.doWhilst}
2987	* @category Control Flow
2988	* @param {AsyncFunction} iteratee - An async function which is called each time
2989	* `test` fails. Invoked with (callback).
2990	* @param {Function} test - synchronous truth test to perform after each
2991	* execution of `iteratee`. Invoked with any non-error callback results of
2992	* `iteratee`.
2993	* @param {Function} [callback] - A callback which is called after the test
2994	* function has passed and repeated execution of `iteratee` has stopped. `callback`
2995	* will be passed an error and any arguments passed to the final `iteratee`'s
2996	* callback. Invoked with (err, [results]);
2997	*/
2998	function doUntil(iteratee, test, callback) {
2999	doWhilst(iteratee, function() {
3000	return !test.apply(this, arguments);
3001	}, callback);
3002	}
3003
3004	/**
3005	* Like [`whilst`]{@link module:ControlFlow.whilst}, except the `test` is an asynchronous function that
3006	* is passed a callback in the form of `function (err, truth)`. If error is
3007	* passed to `test` or `fn`, the main callback is immediately called with the
3008	* value of the error.
3009	*
3010	* @name during
3011	* @static
3012	* @memberOf module:ControlFlow
3013	* @method
3014	* @see [async.whilst]{@link module:ControlFlow.whilst}
3015	* @category Control Flow
3016	* @param {AsyncFunction} test - asynchronous truth test to perform before each
3017	* execution of `fn`. Invoked with (callback).
3018	* @param {AsyncFunction} fn - An async function which is called each time
3019	* `test` passes. Invoked with (callback).
3020	* @param {Function} [callback] - A callback which is called after the test
3021	* function has failed and repeated execution of `fn` has stopped. `callback`
3022	* will be passed an error, if one occurred, otherwise `null`.
3023	* @example
3024	*
3025	* var count = 0;
3026	*
3027	* async.during(
3028	* function (callback) {
3029	* return callback(null, count < 5);
3030	* },
3031	* function (callback) {
3032	* count++;
3033	* setTimeout(callback, 1000);
3034	* },
3035	* function (err) {
3036	* // 5 seconds have passed
3037	* }
3038	* );
3039	*/
3040	function during(test, fn, callback) {
3041	callback = onlyOnce(callback \|\| noop);
3042	var _fn = wrapAsync(fn);
3043	var _test = wrapAsync(test);
3044
3045	function next(err) {
3046	if (err) return callback(err);
3047	_test(check);
3048	}
3049
3050	function check(err, truth) {
3051	if (err) return callback(err);
3052	if (!truth) return callback(null);
3053	_fn(next);
3054	}
3055
3056	_test(check);
3057	}
3058
3059	function _withoutIndex(iteratee) {
3060	return function (value, index, callback) {
3061	return iteratee(value, callback);
3062	};
3063	}
3064
3065	/**
3066	* Applies the function `iteratee` to each item in `coll`, in parallel.
3067	* The `iteratee` is called with an item from the list, and a callback for when
3068	* it has finished. If the `iteratee` passes an error to its `callback`, the
3069	* main `callback` (for the `each` function) is immediately called with the
3070	* error.
3071	*
3072	* Note, that since this function applies `iteratee` to each item in parallel,
3073	* there is no guarantee that the iteratee functions will complete in order.
3074	*
3075	* @name each
3076	* @static
3077	* @memberOf module:Collections
3078	* @method
3079	* @alias forEach
3080	* @category Collection
3081	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3082	* @param {AsyncFunction} iteratee - An async function to apply to
3083	* each item in `coll`. Invoked with (item, callback).
3084	* The array index is not passed to the iteratee.
3085	* If you need the index, use `eachOf`.
3086	* @param {Function} [callback] - A callback which is called when all
3087	* `iteratee` functions have finished, or an error occurs. Invoked with (err).
3088	* @example
3089	*
3090	* // assuming openFiles is an array of file names and saveFile is a function
3091	* // to save the modified contents of that file:
3092	*
3093	* async.each(openFiles, saveFile, function(err){
3094	* // if any of the saves produced an error, err would equal that error
3095	* });
3096	*
3097	* // assuming openFiles is an array of file names
3098	* async.each(openFiles, function(file, callback) {
3099	*
3100	* // Perform operation on file here.
3101	* console.log('Processing file ' + file);
3102	*
3103	* if( file.length > 32 ) {
3104	* console.log('This file name is too long');
3105	* callback('File name too long');
3106	* } else {
3107	* // Do work to process file here
3108	* console.log('File processed');
3109	* callback();
3110	* }
3111	* }, function(err) {
3112	* // if any of the file processing produced an error, err would equal that error
3113	* if( err ) {
3114	* // One of the iterations produced an error.
3115	* // All processing will now stop.
3116	* console.log('A file failed to process');
3117	* } else {
3118	* console.log('All files have been processed successfully');
3119	* }
3120	* });
3121	*/
3122	function eachLimit(coll, iteratee, callback) {
3123	eachOf(coll, _withoutIndex(wrapAsync(iteratee)), callback);
3124	}
3125
3126	/**
3127	* The same as [`each`]{@link module:Collections.each} but runs a maximum of `limit` async operations at a time.
3128	*
3129	* @name eachLimit
3130	* @static
3131	* @memberOf module:Collections
3132	* @method
3133	* @see [async.each]{@link module:Collections.each}
3134	* @alias forEachLimit
3135	* @category Collection
3136	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3137	* @param {number} limit - The maximum number of async operations at a time.
3138	* @param {AsyncFunction} iteratee - An async function to apply to each item in
3139	* `coll`.
3140	* The array index is not passed to the iteratee.
3141	* If you need the index, use `eachOfLimit`.
3142	* Invoked with (item, callback).
3143	* @param {Function} [callback] - A callback which is called when all
3144	* `iteratee` functions have finished, or an error occurs. Invoked with (err).
3145	*/
3146	function eachLimit$1(coll, limit, iteratee, callback) {
3147	_eachOfLimit(limit)(coll, _withoutIndex(wrapAsync(iteratee)), callback);
3148	}
3149
3150	/**
3151	* The same as [`each`]{@link module:Collections.each} but runs only a single async operation at a time.
3152	*
3153	* @name eachSeries
3154	* @static
3155	* @memberOf module:Collections
3156	* @method
3157	* @see [async.each]{@link module:Collections.each}
3158	* @alias forEachSeries
3159	* @category Collection
3160	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3161	* @param {AsyncFunction} iteratee - An async function to apply to each
3162	* item in `coll`.
3163	* The array index is not passed to the iteratee.
3164	* If you need the index, use `eachOfSeries`.
3165	* Invoked with (item, callback).
3166	* @param {Function} [callback] - A callback which is called when all
3167	* `iteratee` functions have finished, or an error occurs. Invoked with (err).
3168	*/
3169	var eachSeries = doLimit(eachLimit$1, 1);
3170
3171	/**
3172	* Wrap an async function and ensure it calls its callback on a later tick of
3173	* the event loop. If the function already calls its callback on a next tick,
3174	* no extra deferral is added. This is useful for preventing stack overflows
3175	* (`RangeError: Maximum call stack size exceeded`) and generally keeping
3176	* [Zalgo](http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony)
3177	* contained. ES2017 `async` functions are returned as-is -- they are immune
3178	* to Zalgo's corrupting influences, as they always resolve on a later tick.
3179	*
3180	* @name ensureAsync
3181	* @static
3182	* @memberOf module:Utils
3183	* @method
3184	* @category Util
3185	* @param {AsyncFunction} fn - an async function, one that expects a node-style
3186	* callback as its last argument.
3187	* @returns {AsyncFunction} Returns a wrapped function with the exact same call
3188	* signature as the function passed in.
3189	* @example
3190	*
3191	* function sometimesAsync(arg, callback) {
3192	* if (cache[arg]) {
3193	* return callback(null, cache[arg]); // this would be synchronous!!
3194	* } else {
3195	* doSomeIO(arg, callback); // this IO would be asynchronous
3196	* }
3197	* }
3198	*
3199	* // this has a risk of stack overflows if many results are cached in a row
3200	* async.mapSeries(args, sometimesAsync, done);
3201	*
3202	* // this will defer sometimesAsync's callback if necessary,
3203	* // preventing stack overflows
3204	* async.mapSeries(args, async.ensureAsync(sometimesAsync), done);
3205	*/
3206	function ensureAsync(fn) {
3207	if (isAsync(fn)) return fn;
3208	return initialParams(function (args, callback) {
3209	var sync = true;
3210	args.push(function () {
3211	var innerArgs = arguments;
3212	if (sync) {
3213	setImmediate$1(function () {
3214	callback.apply(null, innerArgs);
3215	});
3216	} else {
3217	callback.apply(null, innerArgs);
3218	}
3219	});
3220	fn.apply(this, args);
3221	sync = false;
3222	});
3223	}
3224
3225	function notId(v) {
3226	return !v;
3227	}
3228
3229	/**
3230	* Returns `true` if every element in `coll` satisfies an async test. If any
3231	* iteratee call returns `false`, the main `callback` is immediately called.
3232	*
3233	* @name every
3234	* @static
3235	* @memberOf module:Collections
3236	* @method
3237	* @alias all
3238	* @category Collection
3239	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3240	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
3241	* in the collection in parallel.
3242	* The iteratee must complete with a boolean result value.
3243	* Invoked with (item, callback).
3244	* @param {Function} [callback] - A callback which is called after all the
3245	* `iteratee` functions have finished. Result will be either `true` or `false`
3246	* depending on the values of the async tests. Invoked with (err, result).
3247	* @example
3248	*
3249	* async.every(['file1','file2','file3'], function(filePath, callback) {
3250	* fs.access(filePath, function(err) {
3251	* callback(null, !err)
3252	* });
3253	* }, function(err, result) {
3254	* // if result is true then every file exists
3255	* });
3256	*/
3257	var every = doParallel(_createTester(notId, notId));
3258
3259	/**
3260	* The same as [`every`]{@link module:Collections.every} but runs a maximum of `limit` async operations at a time.
3261	*
3262	* @name everyLimit
3263	* @static
3264	* @memberOf module:Collections
3265	* @method
3266	* @see [async.every]{@link module:Collections.every}
3267	* @alias allLimit
3268	* @category Collection
3269	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3270	* @param {number} limit - The maximum number of async operations at a time.
3271	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
3272	* in the collection in parallel.
3273	* The iteratee must complete with a boolean result value.
3274	* Invoked with (item, callback).
3275	* @param {Function} [callback] - A callback which is called after all the
3276	* `iteratee` functions have finished. Result will be either `true` or `false`
3277	* depending on the values of the async tests. Invoked with (err, result).
3278	*/
3279	var everyLimit = doParallelLimit(_createTester(notId, notId));
3280
3281	/**
3282	* The same as [`every`]{@link module:Collections.every} but runs only a single async operation at a time.
3283	*
3284	* @name everySeries
3285	* @static
3286	* @memberOf module:Collections
3287	* @method
3288	* @see [async.every]{@link module:Collections.every}
3289	* @alias allSeries
3290	* @category Collection
3291	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3292	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
3293	* in the collection in series.
3294	* The iteratee must complete with a boolean result value.
3295	* Invoked with (item, callback).
3296	* @param {Function} [callback] - A callback which is called after all the
3297	* `iteratee` functions have finished. Result will be either `true` or `false`
3298	* depending on the values of the async tests. Invoked with (err, result).
3299	*/
3300	var everySeries = doLimit(everyLimit, 1);
3301
3302	/**
3303	* The base implementation of `_.property` without support for deep paths.
3304	*
3305	* @private
3306	* @param {string} key The key of the property to get.
3307	* @returns {Function} Returns the new accessor function.
3308	*/
3309	function baseProperty(key) {
3310	return function(object) {
3311	return object == null ? undefined : object[key];
3312	};
3313	}
3314
3315	function filterArray(eachfn, arr, iteratee, callback) {
3316	var truthValues = new Array(arr.length);
3317	eachfn(arr, function (x, index, callback) {
3318	iteratee(x, function (err, v) {
3319	truthValues[index] = !!v;
3320	callback(err);
3321	});
3322	}, function (err) {
3323	if (err) return callback(err);
3324	var results = [];
3325	for (var i = 0; i < arr.length; i++) {
3326	if (truthValues[i]) results.push(arr[i]);
3327	}
3328	callback(null, results);
3329	});
3330	}
3331
3332	function filterGeneric(eachfn, coll, iteratee, callback) {
3333	var results = [];
3334	eachfn(coll, function (x, index, callback) {
3335	iteratee(x, function (err, v) {
3336	if (err) {
3337	callback(err);
3338	} else {
3339	if (v) {
3340	results.push({index: index, value: x});
3341	}
3342	callback();
3343	}
3344	});
3345	}, function (err) {
3346	if (err) {
3347	callback(err);
3348	} else {
3349	callback(null, arrayMap(results.sort(function (a, b) {
3350	return a.index - b.index;
3351	}), baseProperty('value')));
3352	}
3353	});
3354	}
3355
3356	function _filter(eachfn, coll, iteratee, callback) {
3357	var filter = isArrayLike(coll) ? filterArray : filterGeneric;
3358	filter(eachfn, coll, wrapAsync(iteratee), callback \|\| noop);
3359	}
3360
3361	/**
3362	* Returns a new array of all the values in `coll` which pass an async truth
3363	* test. This operation is performed in parallel, but the results array will be
3364	* in the same order as the original.
3365	*
3366	* @name filter
3367	* @static
3368	* @memberOf module:Collections
3369	* @method
3370	* @alias select
3371	* @category Collection
3372	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3373	* @param {Function} iteratee - A truth test to apply to each item in `coll`.
3374	* The `iteratee` is passed a `callback(err, truthValue)`, which must be called
3375	* with a boolean argument once it has completed. Invoked with (item, callback).
3376	* @param {Function} [callback] - A callback which is called after all the
3377	* `iteratee` functions have finished. Invoked with (err, results).
3378	* @example
3379	*
3380	* async.filter(['file1','file2','file3'], function(filePath, callback) {
3381	* fs.access(filePath, function(err) {
3382	* callback(null, !err)
3383	* });
3384	* }, function(err, results) {
3385	* // results now equals an array of the existing files
3386	* });
3387	*/
3388	var filter = doParallel(_filter);
3389
3390	/**
3391	* The same as [`filter`]{@link module:Collections.filter} but runs a maximum of `limit` async operations at a
3392	* time.
3393	*
3394	* @name filterLimit
3395	* @static
3396	* @memberOf module:Collections
3397	* @method
3398	* @see [async.filter]{@link module:Collections.filter}
3399	* @alias selectLimit
3400	* @category Collection
3401	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3402	* @param {number} limit - The maximum number of async operations at a time.
3403	* @param {Function} iteratee - A truth test to apply to each item in `coll`.
3404	* The `iteratee` is passed a `callback(err, truthValue)`, which must be called
3405	* with a boolean argument once it has completed. Invoked with (item, callback).
3406	* @param {Function} [callback] - A callback which is called after all the
3407	* `iteratee` functions have finished. Invoked with (err, results).
3408	*/
3409	var filterLimit = doParallelLimit(_filter);
3410
3411	/**
3412	* The same as [`filter`]{@link module:Collections.filter} but runs only a single async operation at a time.
3413	*
3414	* @name filterSeries
3415	* @static
3416	* @memberOf module:Collections
3417	* @method
3418	* @see [async.filter]{@link module:Collections.filter}
3419	* @alias selectSeries
3420	* @category Collection
3421	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3422	* @param {Function} iteratee - A truth test to apply to each item in `coll`.
3423	* The `iteratee` is passed a `callback(err, truthValue)`, which must be called
3424	* with a boolean argument once it has completed. Invoked with (item, callback).
3425	* @param {Function} [callback] - A callback which is called after all the
3426	* `iteratee` functions have finished. Invoked with (err, results)
3427	*/
3428	var filterSeries = doLimit(filterLimit, 1);
3429
3430	/**
3431	* Calls the asynchronous function `fn` with a callback parameter that allows it
3432	* to call itself again, in series, indefinitely.
3433
3434	* If an error is passed to the callback then `errback` is called with the
3435	* error, and execution stops, otherwise it will never be called.
3436	*
3437	* @name forever
3438	* @static
3439	* @memberOf module:ControlFlow
3440	* @method
3441	* @category Control Flow
3442	* @param {AsyncFunction} fn - an async function to call repeatedly.
3443	* Invoked with (next).
3444	* @param {Function} [errback] - when `fn` passes an error to it's callback,
3445	* this function will be called, and execution stops. Invoked with (err).
3446	* @example
3447	*
3448	* async.forever(
3449	* function(next) {
3450	* // next is suitable for passing to things that need a callback(err [, whatever]);
3451	* // it will result in this function being called again.
3452	* },
3453	* function(err) {
3454	* // if next is called with a value in its first parameter, it will appear
3455	* // in here as 'err', and execution will stop.
3456	* }
3457	* );
3458	*/
3459	function forever(fn, errback) {
3460	var done = onlyOnce(errback \|\| noop);
3461	var task = wrapAsync(ensureAsync(fn));
3462
3463	function next(err) {
3464	if (err) return done(err);
3465	task(next);
3466	}
3467	next();
3468	}
3469
3470	/**
3471	* The same as [`groupBy`]{@link module:Collections.groupBy} but runs a maximum of `limit` async operations at a time.
3472	*
3473	* @name groupByLimit
3474	* @static
3475	* @memberOf module:Collections
3476	* @method
3477	* @see [async.groupBy]{@link module:Collections.groupBy}
3478	* @category Collection
3479	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3480	* @param {number} limit - The maximum number of async operations at a time.
3481	* @param {AsyncFunction} iteratee - An async function to apply to each item in
3482	* `coll`.
3483	* The iteratee should complete with a `key` to group the value under.
3484	* Invoked with (value, callback).
3485	* @param {Function} [callback] - A callback which is called when all `iteratee`
3486	* functions have finished, or an error occurs. Result is an `Object` whoses
3487	* properties are arrays of values which returned the corresponding key.
3488	*/
3489	var groupByLimit = function(coll, limit, iteratee, callback) {
3490	callback = callback \|\| noop;
3491	var _iteratee = wrapAsync(iteratee);
3492	mapLimit(coll, limit, function(val, callback) {
3493	_iteratee(val, function(err, key) {
3494	if (err) return callback(err);
3495	return callback(null, {key: key, val: val});
3496	});
3497	}, function(err, mapResults) {
3498	var result = {};
3499	// from MDN, handle object having an `hasOwnProperty` prop
3500	var hasOwnProperty = Object.prototype.hasOwnProperty;
3501
3502	for (var i = 0; i < mapResults.length; i++) {
3503	if (mapResults[i]) {
3504	var key = mapResults[i].key;
3505	var val = mapResults[i].val;
3506
3507	if (hasOwnProperty.call(result, key)) {
3508	result[key].push(val);
3509	} else {
3510	result[key] = [val];
3511	}
3512	}
3513	}
3514
3515	return callback(err, result);
3516	});
3517	};
3518
3519	/**
3520	* Returns a new object, where each value corresponds to an array of items, from
3521	* `coll`, that returned the corresponding key. That is, the keys of the object
3522	* correspond to the values passed to the `iteratee` callback.
3523	*
3524	* Note: Since this function applies the `iteratee` to each item in parallel,
3525	* there is no guarantee that the `iteratee` functions will complete in order.
3526	* However, the values for each key in the `result` will be in the same order as
3527	* the original `coll`. For Objects, the values will roughly be in the order of
3528	* the original Objects' keys (but this can vary across JavaScript engines).
3529	*
3530	* @name groupBy
3531	* @static
3532	* @memberOf module:Collections
3533	* @method
3534	* @category Collection
3535	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3536	* @param {AsyncFunction} iteratee - An async function to apply to each item in
3537	* `coll`.
3538	* The iteratee should complete with a `key` to group the value under.
3539	* Invoked with (value, callback).
3540	* @param {Function} [callback] - A callback which is called when all `iteratee`
3541	* functions have finished, or an error occurs. Result is an `Object` whoses
3542	* properties are arrays of values which returned the corresponding key.
3543	* @example
3544	*
3545	* async.groupBy(['userId1', 'userId2', 'userId3'], function(userId, callback) {
3546	* db.findById(userId, function(err, user) {
3547	* if (err) return callback(err);
3548	* return callback(null, user.age);
3549	* });
3550	* }, function(err, result) {
3551	* // result is object containing the userIds grouped by age
3552	* // e.g. { 30: ['userId1', 'userId3'], 42: ['userId2']};
3553	* });
3554	*/
3555	var groupBy = doLimit(groupByLimit, Infinity);
3556
3557	/**
3558	* The same as [`groupBy`]{@link module:Collections.groupBy} but runs only a single async operation at a time.
3559	*
3560	* @name groupBySeries
3561	* @static
3562	* @memberOf module:Collections
3563	* @method
3564	* @see [async.groupBy]{@link module:Collections.groupBy}
3565	* @category Collection
3566	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
3567	* @param {number} limit - The maximum number of async operations at a time.
3568	* @param {AsyncFunction} iteratee - An async function to apply to each item in
3569	* `coll`.
3570	* The iteratee should complete with a `key` to group the value under.
3571	* Invoked with (value, callback).
3572	* @param {Function} [callback] - A callback which is called when all `iteratee`
3573	* functions have finished, or an error occurs. Result is an `Object` whoses
3574	* properties are arrays of values which returned the corresponding key.
3575	*/
3576	var groupBySeries = doLimit(groupByLimit, 1);
3577
3578	/**
3579	* Logs the result of an `async` function to the `console`. Only works in
3580	* Node.js or in browsers that support `console.log` and `console.error` (such
3581	* as FF and Chrome). If multiple arguments are returned from the async
3582	* function, `console.log` is called on each argument in order.
3583	*
3584	* @name log
3585	* @static
3586	* @memberOf module:Utils
3587	* @method
3588	* @category Util
3589	* @param {AsyncFunction} function - The function you want to eventually apply
3590	* all arguments to.
3591	* @param {...*} arguments... - Any number of arguments to apply to the function.
3592	* @example
3593	*
3594	* // in a module
3595	* var hello = function(name, callback) {
3596	* setTimeout(function() {
3597	* callback(null, 'hello ' + name);
3598	* }, 1000);
3599	* };
3600	*
3601	* // in the node repl
3602	* node> async.log(hello, 'world');
3603	* 'hello world'
3604	*/
3605	var log = consoleFunc('log');
3606
3607	/**
3608	* The same as [`mapValues`]{@link module:Collections.mapValues} but runs a maximum of `limit` async operations at a
3609	* time.
3610	*
3611	* @name mapValuesLimit
3612	* @static
3613	* @memberOf module:Collections
3614	* @method
3615	* @see [async.mapValues]{@link module:Collections.mapValues}
3616	* @category Collection
3617	* @param {Object} obj - A collection to iterate over.
3618	* @param {number} limit - The maximum number of async operations at a time.
3619	* @param {AsyncFunction} iteratee - A function to apply to each value and key
3620	* in `coll`.
3621	* The iteratee should complete with the transformed value as its result.
3622	* Invoked with (value, key, callback).
3623	* @param {Function} [callback] - A callback which is called when all `iteratee`
3624	* functions have finished, or an error occurs. `result` is a new object consisting
3625	* of each key from `obj`, with each transformed value on the right-hand side.
3626	* Invoked with (err, result).
3627	*/
3628	function mapValuesLimit(obj, limit, iteratee, callback) {
3629	callback = once(callback \|\| noop);
3630	var newObj = {};
3631	var _iteratee = wrapAsync(iteratee);
3632	eachOfLimit(obj, limit, function(val, key, next) {
3633	_iteratee(val, key, function (err, result) {
3634	if (err) return next(err);
3635	newObj[key] = result;
3636	next();
3637	});
3638	}, function (err) {
3639	callback(err, newObj);
3640	});
3641	}
3642
3643	/**
3644	* A relative of [`map`]{@link module:Collections.map}, designed for use with objects.
3645	*
3646	* Produces a new Object by mapping each value of `obj` through the `iteratee`
3647	* function. The `iteratee` is called each `value` and `key` from `obj` and a
3648	* callback for when it has finished processing. Each of these callbacks takes
3649	* two arguments: an `error`, and the transformed item from `obj`. If `iteratee`
3650	* passes an error to its callback, the main `callback` (for the `mapValues`
3651	* function) is immediately called with the error.
3652	*
3653	* Note, the order of the keys in the result is not guaranteed. The keys will
3654	* be roughly in the order they complete, (but this is very engine-specific)
3655	*
3656	* @name mapValues
3657	* @static
3658	* @memberOf module:Collections
3659	* @method
3660	* @category Collection
3661	* @param {Object} obj - A collection to iterate over.
3662	* @param {AsyncFunction} iteratee - A function to apply to each value and key
3663	* in `coll`.
3664	* The iteratee should complete with the transformed value as its result.
3665	* Invoked with (value, key, callback).
3666	* @param {Function} [callback] - A callback which is called when all `iteratee`
3667	* functions have finished, or an error occurs. `result` is a new object consisting
3668	* of each key from `obj`, with each transformed value on the right-hand side.
3669	* Invoked with (err, result).
3670	* @example
3671	*
3672	* async.mapValues({
3673	* f1: 'file1',
3674	* f2: 'file2',
3675	* f3: 'file3'
3676	* }, function (file, key, callback) {
3677	* fs.stat(file, callback);
3678	* }, function(err, result) {
3679	* // result is now a map of stats for each file, e.g.
3680	* // {
3681	* // f1: [stats for file1],
3682	* // f2: [stats for file2],
3683	* // f3: [stats for file3]
3684	* // }
3685	* });
3686	*/
3687
3688	var mapValues = doLimit(mapValuesLimit, Infinity);
3689
3690	/**
3691	* The same as [`mapValues`]{@link module:Collections.mapValues} but runs only a single async operation at a time.
3692	*
3693	* @name mapValuesSeries
3694	* @static
3695	* @memberOf module:Collections
3696	* @method
3697	* @see [async.mapValues]{@link module:Collections.mapValues}
3698	* @category Collection
3699	* @param {Object} obj - A collection to iterate over.
3700	* @param {AsyncFunction} iteratee - A function to apply to each value and key
3701	* in `coll`.
3702	* The iteratee should complete with the transformed value as its result.
3703	* Invoked with (value, key, callback).
3704	* @param {Function} [callback] - A callback which is called when all `iteratee`
3705	* functions have finished, or an error occurs. `result` is a new object consisting
3706	* of each key from `obj`, with each transformed value on the right-hand side.
3707	* Invoked with (err, result).
3708	*/
3709	var mapValuesSeries = doLimit(mapValuesLimit, 1);
3710
3711	function has(obj, key) {
3712	return key in obj;
3713	}
3714
3715	/**
3716	* Caches the results of an async function. When creating a hash to store
3717	* function results against, the callback is omitted from the hash and an
3718	* optional hash function can be used.
3719	*
3720	* If no hash function is specified, the first argument is used as a hash key,
3721	* which may work reasonably if it is a string or a data type that converts to a
3722	* distinct string. Note that objects and arrays will not behave reasonably.
3723	* Neither will cases where the other arguments are significant. In such cases,
3724	* specify your own hash function.
3725	*
3726	* The cache of results is exposed as the `memo` property of the function
3727	* returned by `memoize`.
3728	*
3729	* @name memoize
3730	* @static
3731	* @memberOf module:Utils
3732	* @method
3733	* @category Util
3734	* @param {AsyncFunction} fn - The async function to proxy and cache results from.
3735	* @param {Function} hasher - An optional function for generating a custom hash
3736	* for storing results. It has all the arguments applied to it apart from the
3737	* callback, and must be synchronous.
3738	* @returns {AsyncFunction} a memoized version of `fn`
3739	* @example
3740	*
3741	* var slow_fn = function(name, callback) {
3742	* // do something
3743	* callback(null, result);
3744	* };
3745	* var fn = async.memoize(slow_fn);
3746	*
3747	* // fn can now be used as if it were slow_fn
3748	* fn('some name', function() {
3749	* // callback
3750	* });
3751	*/
3752	function memoize(fn, hasher) {
3753	var memo = Object.create(null);
3754	var queues = Object.create(null);
3755	hasher = hasher \|\| identity;
3756	var _fn = wrapAsync(fn);
3757	var memoized = initialParams(function memoized(args, callback) {
3758	var key = hasher.apply(null, args);
3759	if (has(memo, key)) {
3760	setImmediate$1(function() {
3761	callback.apply(null, memo[key]);
3762	});
3763	} else if (has(queues, key)) {
3764	queues[key].push(callback);
3765	} else {
3766	queues[key] = [callback];
3767	_fn.apply(null, args.concat(function(/args/) {
3768	var args = slice(arguments);
3769	memo[key] = args;
3770	var q = queues[key];
3771	delete queues[key];
3772	for (var i = 0, l = q.length; i < l; i++) {
3773	q[i].apply(null, args);
3774	}
3775	}));
3776	}
3777	});
3778	memoized.memo = memo;
3779	memoized.unmemoized = fn;
3780	return memoized;
3781	}
3782
3783	/**
3784	* Calls `callback` on a later loop around the event loop. In Node.js this just
3785	* calls `setImmediate`. In the browser it will use `setImmediate` if
3786	* available, otherwise `setTimeout(callback, 0)`, which means other higher
3787	* priority events may precede the execution of `callback`.
3788	*
3789	* This is used internally for browser-compatibility purposes.
3790	*
3791	* @name nextTick
3792	* @static
3793	* @memberOf module:Utils
3794	* @method
3795	* @alias setImmediate
3796	* @category Util
3797	* @param {Function} callback - The function to call on a later loop around
3798	* the event loop. Invoked with (args...).
3799	* @param {...*} args... - any number of additional arguments to pass to the
3800	* callback on the next tick.
3801	* @example
3802	*
3803	* var call_order = [];
3804	* async.nextTick(function() {
3805	* call_order.push('two');
3806	* // call_order now equals ['one','two']
3807	* });
3808	* call_order.push('one');
3809	*
3810	* async.setImmediate(function (a, b, c) {
3811	* // a, b, and c equal 1, 2, and 3
3812	* }, 1, 2, 3);
3813	*/
3814	var _defer$1;
3815
3816	if (hasNextTick) {
3817	_defer$1 = process.nextTick;
3818	} else if (hasSetImmediate) {
3819	_defer$1 = setImmediate;
3820	} else {
3821	_defer$1 = fallback;
3822	}
3823
3824	var nextTick = wrap(_defer$1);
3825
3826	function _parallel(eachfn, tasks, callback) {
3827	callback = callback \|\| noop;
3828	var results = isArrayLike(tasks) ? [] : {};
3829
3830	eachfn(tasks, function (task, key, callback) {
3831	wrapAsync(task)(function (err, result) {
3832	if (arguments.length > 2) {
3833	result = slice(arguments, 1);
3834	}
3835	results[key] = result;
3836	callback(err);
3837	});
3838	}, function (err) {
3839	callback(err, results);
3840	});
3841	}
3842
3843	/**
3844	* Run the `tasks` collection of functions in parallel, without waiting until
3845	* the previous function has completed. If any of the functions pass an error to
3846	* its callback, the main `callback` is immediately called with the value of the
3847	* error. Once the `tasks` have completed, the results are passed to the final
3848	* `callback` as an array.
3849	*
3850	* Note: `parallel` is about kicking-off I/O tasks in parallel, not about
3851	* parallel execution of code. If your tasks do not use any timers or perform
3852	* any I/O, they will actually be executed in series. Any synchronous setup
3853	* sections for each task will happen one after the other. JavaScript remains
3854	* single-threaded.
3855	*
3856	* Hint: Use [`reflect`]{@link module:Utils.reflect} to continue the
3857	* execution of other tasks when a task fails.
3858	*
3859	* It is also possible to use an object instead of an array. Each property will
3860	* be run as a function and the results will be passed to the final `callback`
3861	* as an object instead of an array. This can be a more readable way of handling
3862	* results from {@link async.parallel}.
3863	*
3864	* @name parallel
3865	* @static
3866	* @memberOf module:ControlFlow
3867	* @method
3868	* @category Control Flow
3869	* @param {Array\|Iterable\|Object} tasks - A collection of
3870	* [async functions]{@link AsyncFunction} to run.
3871	* Each async function can complete with any number of optional `result` values.
3872	* @param {Function} [callback] - An optional callback to run once all the
3873	* functions have completed successfully. This function gets a results array
3874	* (or object) containing all the result arguments passed to the task callbacks.
3875	* Invoked with (err, results).
3876	*
3877	* @example
3878	* async.parallel([
3879	* function(callback) {
3880	* setTimeout(function() {
3881	* callback(null, 'one');
3882	* }, 200);
3883	* },
3884	* function(callback) {
3885	* setTimeout(function() {
3886	* callback(null, 'two');
3887	* }, 100);
3888	* }
3889	* ],
3890	* // optional callback
3891	* function(err, results) {
3892	* // the results array will equal ['one','two'] even though
3893	* // the second function had a shorter timeout.
3894	* });
3895	*
3896	* // an example using an object instead of an array
3897	* async.parallel({
3898	* one: function(callback) {
3899	* setTimeout(function() {
3900	* callback(null, 1);
3901	* }, 200);
3902	* },
3903	* two: function(callback) {
3904	* setTimeout(function() {
3905	* callback(null, 2);
3906	* }, 100);
3907	* }
3908	* }, function(err, results) {
3909	* // results is now equals to: {one: 1, two: 2}
3910	* });
3911	*/
3912	function parallelLimit(tasks, callback) {
3913	_parallel(eachOf, tasks, callback);
3914	}
3915
3916	/**
3917	* The same as [`parallel`]{@link module:ControlFlow.parallel} but runs a maximum of `limit` async operations at a
3918	* time.
3919	*
3920	* @name parallelLimit
3921	* @static
3922	* @memberOf module:ControlFlow
3923	* @method
3924	* @see [async.parallel]{@link module:ControlFlow.parallel}
3925	* @category Control Flow
3926	* @param {Array\|Iterable\|Object} tasks - A collection of
3927	* [async functions]{@link AsyncFunction} to run.
3928	* Each async function can complete with any number of optional `result` values.
3929	* @param {number} limit - The maximum number of async operations at a time.
3930	* @param {Function} [callback] - An optional callback to run once all the
3931	* functions have completed successfully. This function gets a results array
3932	* (or object) containing all the result arguments passed to the task callbacks.
3933	* Invoked with (err, results).
3934	*/
3935	function parallelLimit$1(tasks, limit, callback) {
3936	_parallel(_eachOfLimit(limit), tasks, callback);
3937	}
3938
3939	/**
3940	* A queue of tasks for the worker function to complete.
3941	* @typedef {Object} QueueObject
3942	* @memberOf module:ControlFlow
3943	* @property {Function} length - a function returning the number of items
3944	* waiting to be processed. Invoke with `queue.length()`.
3945	* @property {boolean} started - a boolean indicating whether or not any
3946	* items have been pushed and processed by the queue.
3947	* @property {Function} running - a function returning the number of items
3948	* currently being processed. Invoke with `queue.running()`.
3949	* @property {Function} workersList - a function returning the array of items
3950	* currently being processed. Invoke with `queue.workersList()`.
3951	* @property {Function} idle - a function returning false if there are items
3952	* waiting or being processed, or true if not. Invoke with `queue.idle()`.
3953	* @property {number} concurrency - an integer for determining how many `worker`
3954	* functions should be run in parallel. This property can be changed after a
3955	* `queue` is created to alter the concurrency on-the-fly.
3956	* @property {Function} push - add a new task to the `queue`. Calls `callback`
3957	* once the `worker` has finished processing the task. Instead of a single task,
3958	* a `tasks` array can be submitted. The respective callback is used for every
3959	* task in the list. Invoke with `queue.push(task, [callback])`,
3960	* @property {Function} unshift - add a new task to the front of the `queue`.
3961	* Invoke with `queue.unshift(task, [callback])`.
3962	* @property {Function} remove - remove items from the queue that match a test
3963	* function. The test function will be passed an object with a `data` property,
3964	* and a `priority` property, if this is a
3965	* [priorityQueue]{@link module:ControlFlow.priorityQueue} object.
3966	* Invoked with `queue.remove(testFn)`, where `testFn` is of the form
3967	* `function ({data, priority}) {}` and returns a Boolean.
3968	* @property {Function} saturated - a callback that is called when the number of
3969	* running workers hits the `concurrency` limit, and further tasks will be
3970	* queued.
3971	* @property {Function} unsaturated - a callback that is called when the number
3972	* of running workers is less than the `concurrency` & `buffer` limits, and
3973	* further tasks will not be queued.
3974	* @property {number} buffer - A minimum threshold buffer in order to say that
3975	* the `queue` is `unsaturated`.
3976	* @property {Function} empty - a callback that is called when the last item
3977	* from the `queue` is given to a `worker`.
3978	* @property {Function} drain - a callback that is called when the last item
3979	* from the `queue` has returned from the `worker`.
3980	* @property {Function} error - a callback that is called when a task errors.
3981	* Has the signature `function(error, task)`.
3982	* @property {boolean} paused - a boolean for determining whether the queue is
3983	* in a paused state.
3984	* @property {Function} pause - a function that pauses the processing of tasks
3985	* until `resume()` is called. Invoke with `queue.pause()`.
3986	* @property {Function} resume - a function that resumes the processing of
3987	* queued tasks when the queue is paused. Invoke with `queue.resume()`.
3988	* @property {Function} kill - a function that removes the `drain` callback and
3989	* empties remaining tasks from the queue forcing it to go idle. Invoke with `queue.kill()`.
3990	*/
3991
3992	/**
3993	* Creates a `queue` object with the specified `concurrency`. Tasks added to the
3994	* `queue` are processed in parallel (up to the `concurrency` limit). If all
3995	* `worker`s are in progress, the task is queued until one becomes available.
3996	* Once a `worker` completes a `task`, that `task`'s callback is called.
3997	*
3998	* @name queue
3999	* @static
4000	* @memberOf module:ControlFlow
4001	* @method
4002	* @category Control Flow
4003	* @param {AsyncFunction} worker - An async function for processing a queued task.
4004	* If you want to handle errors from an individual task, pass a callback to
4005	* `q.push()`. Invoked with (task, callback).
4006	* @param {number} [concurrency=1] - An `integer` for determining how many
4007	* `worker` functions should be run in parallel. If omitted, the concurrency
4008	* defaults to `1`. If the concurrency is `0`, an error is thrown.
4009	* @returns {module:ControlFlow.QueueObject} A queue object to manage the tasks. Callbacks can
4010	* attached as certain properties to listen for specific events during the
4011	* lifecycle of the queue.
4012	* @example
4013	*
4014	* // create a queue object with concurrency 2
4015	* var q = async.queue(function(task, callback) {
4016	* console.log('hello ' + task.name);
4017	* callback();
4018	* }, 2);
4019	*
4020	* // assign a callback
4021	* q.drain = function() {
4022	* console.log('all items have been processed');
4023	* };
4024	*
4025	* // add some items to the queue
4026	* q.push({name: 'foo'}, function(err) {
4027	* console.log('finished processing foo');
4028	* });
4029	* q.push({name: 'bar'}, function (err) {
4030	* console.log('finished processing bar');
4031	* });
4032	*
4033	* // add some items to the queue (batch-wise)
4034	* q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], function(err) {
4035	* console.log('finished processing item');
4036	* });
4037	*
4038	* // add some items to the front of the queue
4039	* q.unshift({name: 'bar'}, function (err) {
4040	* console.log('finished processing bar');
4041	* });
4042	*/
4043	var queue$1 = function (worker, concurrency) {
4044	var _worker = wrapAsync(worker);
4045	return queue(function (items, cb) {
4046	_worker(items[0], cb);
4047	}, concurrency, 1);
4048	};
4049
4050	/**
4051	* The same as [async.queue]{@link module:ControlFlow.queue} only tasks are assigned a priority and
4052	* completed in ascending priority order.
4053	*
4054	* @name priorityQueue
4055	* @static
4056	* @memberOf module:ControlFlow
4057	* @method
4058	* @see [async.queue]{@link module:ControlFlow.queue}
4059	* @category Control Flow
4060	* @param {AsyncFunction} worker - An async function for processing a queued task.
4061	* If you want to handle errors from an individual task, pass a callback to
4062	* `q.push()`.
4063	* Invoked with (task, callback).
4064	* @param {number} concurrency - An `integer` for determining how many `worker`
4065	* functions should be run in parallel. If omitted, the concurrency defaults to
4066	* `1`. If the concurrency is `0`, an error is thrown.
4067	* @returns {module:ControlFlow.QueueObject} A priorityQueue object to manage the tasks. There are two
4068	* differences between `queue` and `priorityQueue` objects:
4069	* * `push(task, priority, [callback])` - `priority` should be a number. If an
4070	* array of `tasks` is given, all tasks will be assigned the same priority.
4071	* * The `unshift` method was removed.
4072	*/
4073	var priorityQueue = function(worker, concurrency) {
4074	// Start with a normal queue
4075	var q = queue$1(worker, concurrency);
4076
4077	// Override push to accept second parameter representing priority
4078	q.push = function(data, priority, callback) {
4079	if (callback == null) callback = noop;
4080	if (typeof callback !== 'function') {
4081	throw new Error('task callback must be a function');
4082	}
4083	q.started = true;
4084	if (!isArray(data)) {
4085	data = [data];
4086	}
4087	if (data.length === 0) {
4088	// call drain immediately if there are no tasks
4089	return setImmediate$1(function() {
4090	q.drain();
4091	});
4092	}
4093
4094	priority = priority \|\| 0;
4095	var nextNode = q._tasks.head;
4096	while (nextNode && priority >= nextNode.priority) {
4097	nextNode = nextNode.next;
4098	}
4099
4100	for (var i = 0, l = data.length; i < l; i++) {
4101	var item = {
4102	data: data[i],
4103	priority: priority,
4104	callback: callback
4105	};
4106
4107	if (nextNode) {
4108	q._tasks.insertBefore(nextNode, item);
4109	} else {
4110	q._tasks.push(item);
4111	}
4112	}
4113	setImmediate$1(q.process);
4114	};
4115
4116	// Remove unshift function
4117	delete q.unshift;
4118
4119	return q;
4120	};
4121
4122	/**
4123	* Runs the `tasks` array of functions in parallel, without waiting until the
4124	* previous function has completed. Once any of the `tasks` complete or pass an
4125	* error to its callback, the main `callback` is immediately called. It's
4126	* equivalent to `Promise.race()`.
4127	*
4128	* @name race
4129	* @static
4130	* @memberOf module:ControlFlow
4131	* @method
4132	* @category Control Flow
4133	* @param {Array} tasks - An array containing [async functions]{@link AsyncFunction}
4134	* to run. Each function can complete with an optional `result` value.
4135	* @param {Function} callback - A callback to run once any of the functions have
4136	* completed. This function gets an error or result from the first function that
4137	* completed. Invoked with (err, result).
4138	* @returns undefined
4139	* @example
4140	*
4141	* async.race([
4142	* function(callback) {
4143	* setTimeout(function() {
4144	* callback(null, 'one');
4145	* }, 200);
4146	* },
4147	* function(callback) {
4148	* setTimeout(function() {
4149	* callback(null, 'two');
4150	* }, 100);
4151	* }
4152	* ],
4153	* // main callback
4154	* function(err, result) {
4155	* // the result will be equal to 'two' as it finishes earlier
4156	* });
4157	*/
4158	function race(tasks, callback) {
4159	callback = once(callback \|\| noop);
4160	if (!isArray(tasks)) return callback(new TypeError('First argument to race must be an array of functions'));
4161	if (!tasks.length) return callback();
4162	for (var i = 0, l = tasks.length; i < l; i++) {
4163	wrapAsync(tasks[i])(callback);
4164	}
4165	}
4166
4167	/**
4168	* Same as [`reduce`]{@link module:Collections.reduce}, only operates on `array` in reverse order.
4169	*
4170	* @name reduceRight
4171	* @static
4172	* @memberOf module:Collections
4173	* @method
4174	* @see [async.reduce]{@link module:Collections.reduce}
4175	* @alias foldr
4176	* @category Collection
4177	* @param {Array} array - A collection to iterate over.
4178	* @param {*} memo - The initial state of the reduction.
4179	* @param {AsyncFunction} iteratee - A function applied to each item in the
4180	* array to produce the next step in the reduction.
4181	* The `iteratee` should complete with the next state of the reduction.
4182	* If the iteratee complete with an error, the reduction is stopped and the
4183	* main `callback` is immediately called with the error.
4184	* Invoked with (memo, item, callback).
4185	* @param {Function} [callback] - A callback which is called after all the
4186	* `iteratee` functions have finished. Result is the reduced value. Invoked with
4187	* (err, result).
4188	*/
4189	function reduceRight (array, memo, iteratee, callback) {
4190	var reversed = slice(array).reverse();
4191	reduce(reversed, memo, iteratee, callback);
4192	}
4193
4194	/**
4195	* Wraps the async function in another function that always completes with a
4196	* result object, even when it errors.
4197	*
4198	* The result object has either the property `error` or `value`.
4199	*
4200	* @name reflect
4201	* @static
4202	* @memberOf module:Utils
4203	* @method
4204	* @category Util
4205	* @param {AsyncFunction} fn - The async function you want to wrap
4206	* @returns {Function} - A function that always passes null to it's callback as
4207	* the error. The second argument to the callback will be an `object` with
4208	* either an `error` or a `value` property.
4209	* @example
4210	*
4211	* async.parallel([
4212	* async.reflect(function(callback) {
4213	* // do some stuff ...
4214	* callback(null, 'one');
4215	* }),
4216	* async.reflect(function(callback) {
4217	* // do some more stuff but error ...
4218	* callback('bad stuff happened');
4219	* }),
4220	* async.reflect(function(callback) {
4221	* // do some more stuff ...
4222	* callback(null, 'two');
4223	* })
4224	* ],
4225	* // optional callback
4226	* function(err, results) {
4227	* // values
4228	* // results[0].value = 'one'
4229	* // results[1].error = 'bad stuff happened'
4230	* // results[2].value = 'two'
4231	* });
4232	*/
4233	function reflect(fn) {
4234	var _fn = wrapAsync(fn);
4235	return initialParams(function reflectOn(args, reflectCallback) {
4236	args.push(function callback(error, cbArg) {
4237	if (error) {
4238	reflectCallback(null, { error: error });
4239	} else {
4240	var value;
4241	if (arguments.length <= 2) {
4242	value = cbArg;
4243	} else {
4244	value = slice(arguments, 1);
4245	}
4246	reflectCallback(null, { value: value });
4247	}
4248	});
4249
4250	return _fn.apply(this, args);
4251	});
4252	}
4253
4254	function reject$1(eachfn, arr, iteratee, callback) {
4255	_filter(eachfn, arr, function(value, cb) {
4256	iteratee(value, function(err, v) {
4257	cb(err, !v);
4258	});
4259	}, callback);
4260	}
4261
4262	/**
4263	* The opposite of [`filter`]{@link module:Collections.filter}. Removes values that pass an `async` truth test.
4264	*
4265	* @name reject
4266	* @static
4267	* @memberOf module:Collections
4268	* @method
4269	* @see [async.filter]{@link module:Collections.filter}
4270	* @category Collection
4271	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4272	* @param {Function} iteratee - An async truth test to apply to each item in
4273	* `coll`.
4274	* The should complete with a boolean value as its `result`.
4275	* Invoked with (item, callback).
4276	* @param {Function} [callback] - A callback which is called after all the
4277	* `iteratee` functions have finished. Invoked with (err, results).
4278	* @example
4279	*
4280	* async.reject(['file1','file2','file3'], function(filePath, callback) {
4281	* fs.access(filePath, function(err) {
4282	* callback(null, !err)
4283	* });
4284	* }, function(err, results) {
4285	* // results now equals an array of missing files
4286	* createFiles(results);
4287	* });
4288	*/
4289	var reject = doParallel(reject$1);
4290
4291	/**
4292	* A helper function that wraps an array or an object of functions with `reflect`.
4293	*
4294	* @name reflectAll
4295	* @static
4296	* @memberOf module:Utils
4297	* @method
4298	* @see [async.reflect]{@link module:Utils.reflect}
4299	* @category Util
4300	* @param {Array\|Object\|Iterable} tasks - The collection of
4301	* [async functions]{@link AsyncFunction} to wrap in `async.reflect`.
4302	* @returns {Array} Returns an array of async functions, each wrapped in
4303	* `async.reflect`
4304	* @example
4305	*
4306	* let tasks = [
4307	* function(callback) {
4308	* setTimeout(function() {
4309	* callback(null, 'one');
4310	* }, 200);
4311	* },
4312	* function(callback) {
4313	* // do some more stuff but error ...
4314	* callback(new Error('bad stuff happened'));
4315	* },
4316	* function(callback) {
4317	* setTimeout(function() {
4318	* callback(null, 'two');
4319	* }, 100);
4320	* }
4321	* ];
4322	*
4323	* async.parallel(async.reflectAll(tasks),
4324	* // optional callback
4325	* function(err, results) {
4326	* // values
4327	* // results[0].value = 'one'
4328	* // results[1].error = Error('bad stuff happened')
4329	* // results[2].value = 'two'
4330	* });
4331	*
4332	* // an example using an object instead of an array
4333	* let tasks = {
4334	* one: function(callback) {
4335	* setTimeout(function() {
4336	* callback(null, 'one');
4337	* }, 200);
4338	* },
4339	* two: function(callback) {
4340	* callback('two');
4341	* },
4342	* three: function(callback) {
4343	* setTimeout(function() {
4344	* callback(null, 'three');
4345	* }, 100);
4346	* }
4347	* };
4348	*
4349	* async.parallel(async.reflectAll(tasks),
4350	* // optional callback
4351	* function(err, results) {
4352	* // values
4353	* // results.one.value = 'one'
4354	* // results.two.error = 'two'
4355	* // results.three.value = 'three'
4356	* });
4357	*/
4358	function reflectAll(tasks) {
4359	var results;
4360	if (isArray(tasks)) {
4361	results = arrayMap(tasks, reflect);
4362	} else {
4363	results = {};
4364	baseForOwn(tasks, function(task, key) {
4365	results[key] = reflect.call(this, task);
4366	});
4367	}
4368	return results;
4369	}
4370
4371	/**
4372	* The same as [`reject`]{@link module:Collections.reject} but runs a maximum of `limit` async operations at a
4373	* time.
4374	*
4375	* @name rejectLimit
4376	* @static
4377	* @memberOf module:Collections
4378	* @method
4379	* @see [async.reject]{@link module:Collections.reject}
4380	* @category Collection
4381	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4382	* @param {number} limit - The maximum number of async operations at a time.
4383	* @param {Function} iteratee - An async truth test to apply to each item in
4384	* `coll`.
4385	* The should complete with a boolean value as its `result`.
4386	* Invoked with (item, callback).
4387	* @param {Function} [callback] - A callback which is called after all the
4388	* `iteratee` functions have finished. Invoked with (err, results).
4389	*/
4390	var rejectLimit = doParallelLimit(reject$1);
4391
4392	/**
4393	* The same as [`reject`]{@link module:Collections.reject} but runs only a single async operation at a time.
4394	*
4395	* @name rejectSeries
4396	* @static
4397	* @memberOf module:Collections
4398	* @method
4399	* @see [async.reject]{@link module:Collections.reject}
4400	* @category Collection
4401	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4402	* @param {Function} iteratee - An async truth test to apply to each item in
4403	* `coll`.
4404	* The should complete with a boolean value as its `result`.
4405	* Invoked with (item, callback).
4406	* @param {Function} [callback] - A callback which is called after all the
4407	* `iteratee` functions have finished. Invoked with (err, results).
4408	*/
4409	var rejectSeries = doLimit(rejectLimit, 1);
4410
4411	/**
4412	* Creates a function that returns `value`.
4413	*
4414	* @static
4415	* @memberOf _
4416	* @since 2.4.0
4417	* @category Util
4418	* @param {*} value The value to return from the new function.
4419	* @returns {Function} Returns the new constant function.
4420	* @example
4421	*
4422	* var objects = _.times(2, _.constant({ 'a': 1 }));
4423	*
4424	* console.log(objects);
4425	* // => [{ 'a': 1 }, { 'a': 1 }]
4426	*
4427	* console.log(objects[0] === objects[1]);
4428	* // => true
4429	*/
4430	function constant$1(value) {
4431	return function() {
4432	return value;
4433	};
4434	}
4435
4436	/**
4437	* Attempts to get a successful response from `task` no more than `times` times
4438	* before returning an error. If the task is successful, the `callback` will be
4439	* passed the result of the successful task. If all attempts fail, the callback
4440	* will be passed the error and result (if any) of the final attempt.
4441	*
4442	* @name retry
4443	* @static
4444	* @memberOf module:ControlFlow
4445	* @method
4446	* @category Control Flow
4447	* @see [async.retryable]{@link module:ControlFlow.retryable}
4448	* @param {Object\|number} [opts = {times: 5, interval: 0}\| 5] - Can be either an
4449	* object with `times` and `interval` or a number.
4450	* * `times` - The number of attempts to make before giving up. The default
4451	* is `5`.
4452	* * `interval` - The time to wait between retries, in milliseconds. The
4453	* default is `0`. The interval may also be specified as a function of the
4454	* retry count (see example).
4455	* * `errorFilter` - An optional synchronous function that is invoked on
4456	* erroneous result. If it returns `true` the retry attempts will continue;
4457	* if the function returns `false` the retry flow is aborted with the current
4458	* attempt's error and result being returned to the final callback.
4459	* Invoked with (err).
4460	* * If `opts` is a number, the number specifies the number of times to retry,
4461	* with the default interval of `0`.
4462	* @param {AsyncFunction} task - An async function to retry.
4463	* Invoked with (callback).
4464	* @param {Function} [callback] - An optional callback which is called when the
4465	* task has succeeded, or after the final failed attempt. It receives the `err`
4466	* and `result` arguments of the last attempt at completing the `task`. Invoked
4467	* with (err, results).
4468	*
4469	* @example
4470	*
4471	* // The `retry` function can be used as a stand-alone control flow by passing
4472	* // a callback, as shown below:
4473	*
4474	* // try calling apiMethod 3 times
4475	* async.retry(3, apiMethod, function(err, result) {
4476	* // do something with the result
4477	* });
4478	*
4479	* // try calling apiMethod 3 times, waiting 200 ms between each retry
4480	* async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
4481	* // do something with the result
4482	* });
4483	*
4484	* // try calling apiMethod 10 times with exponential backoff
4485	* // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
4486	* async.retry({
4487	* times: 10,
4488	* interval: function(retryCount) {
4489	* return 50 * Math.pow(2, retryCount);
4490	* }
4491	* }, apiMethod, function(err, result) {
4492	* // do something with the result
4493	* });
4494	*
4495	* // try calling apiMethod the default 5 times no delay between each retry
4496	* async.retry(apiMethod, function(err, result) {
4497	* // do something with the result
4498	* });
4499	*
4500	* // try calling apiMethod only when error condition satisfies, all other
4501	* // errors will abort the retry control flow and return to final callback
4502	* async.retry({
4503	* errorFilter: function(err) {
4504	* return err.message === 'Temporary error'; // only retry on a specific error
4505	* }
4506	* }, apiMethod, function(err, result) {
4507	* // do something with the result
4508	* });
4509	*
4510	* // It can also be embedded within other control flow functions to retry
4511	* // individual methods that are not as reliable, like this:
4512	* async.auto({
4513	* users: api.getUsers.bind(api),
4514	* payments: async.retryable(3, api.getPayments.bind(api))
4515	* }, function(err, results) {
4516	* // do something with the results
4517	* });
4518	*
4519	*/
4520	function retry(opts, task, callback) {
4521	var DEFAULT_TIMES = 5;
4522	var DEFAULT_INTERVAL = 0;
4523
4524	var options = {
4525	times: DEFAULT_TIMES,
4526	intervalFunc: constant$1(DEFAULT_INTERVAL)
4527	};
4528
4529	function parseTimes(acc, t) {
4530	if (typeof t === 'object') {
4531	acc.times = +t.times \|\| DEFAULT_TIMES;
4532
4533	acc.intervalFunc = typeof t.interval === 'function' ?
4534	t.interval :
4535	constant$1(+t.interval \|\| DEFAULT_INTERVAL);
4536
4537	acc.errorFilter = t.errorFilter;
4538	} else if (typeof t === 'number' \|\| typeof t === 'string') {
4539	acc.times = +t \|\| DEFAULT_TIMES;
4540	} else {
4541	throw new Error("Invalid arguments for async.retry");
4542	}
4543	}
4544
4545	if (arguments.length < 3 && typeof opts === 'function') {
4546	callback = task \|\| noop;
4547	task = opts;
4548	} else {
4549	parseTimes(options, opts);
4550	callback = callback \|\| noop;
4551	}
4552
4553	if (typeof task !== 'function') {
4554	throw new Error("Invalid arguments for async.retry");
4555	}
4556
4557	var _task = wrapAsync(task);
4558
4559	var attempt = 1;
4560	function retryAttempt() {
4561	_task(function(err) {
4562	if (err && attempt++ < options.times &&
4563	(typeof options.errorFilter != 'function' \|\|
4564	options.errorFilter(err))) {
4565	setTimeout(retryAttempt, options.intervalFunc(attempt));
4566	} else {
4567	callback.apply(null, arguments);
4568	}
4569	});
4570	}
4571
4572	retryAttempt();
4573	}
4574
4575	/**
4576	* A close relative of [`retry`]{@link module:ControlFlow.retry}. This method
4577	* wraps a task and makes it retryable, rather than immediately calling it
4578	* with retries.
4579	*
4580	* @name retryable
4581	* @static
4582	* @memberOf module:ControlFlow
4583	* @method
4584	* @see [async.retry]{@link module:ControlFlow.retry}
4585	* @category Control Flow
4586	* @param {Object\|number} [opts = {times: 5, interval: 0}\| 5] - optional
4587	* options, exactly the same as from `retry`
4588	* @param {AsyncFunction} task - the asynchronous function to wrap.
4589	* This function will be passed any arguments passed to the returned wrapper.
4590	* Invoked with (...args, callback).
4591	* @returns {AsyncFunction} The wrapped function, which when invoked, will
4592	* retry on an error, based on the parameters specified in `opts`.
4593	* This function will accept the same parameters as `task`.
4594	* @example
4595	*
4596	* async.auto({
4597	* dep1: async.retryable(3, getFromFlakyService),
4598	* process: ["dep1", async.retryable(3, function (results, cb) {
4599	* maybeProcessData(results.dep1, cb);
4600	* })]
4601	* }, callback);
4602	*/
4603	var retryable = function (opts, task) {
4604	if (!task) {
4605	task = opts;
4606	opts = null;
4607	}
4608	var _task = wrapAsync(task);
4609	return initialParams(function (args, callback) {
4610	function taskFn(cb) {
4611	_task.apply(null, args.concat(cb));
4612	}
4613
4614	if (opts) retry(opts, taskFn, callback);
4615	else retry(taskFn, callback);
4616
4617	});
4618	};
4619
4620	/**
4621	* Run the functions in the `tasks` collection in series, each one running once
4622	* the previous function has completed. If any functions in the series pass an
4623	* error to its callback, no more functions are run, and `callback` is
4624	* immediately called with the value of the error. Otherwise, `callback`
4625	* receives an array of results when `tasks` have completed.
4626	*
4627	* It is also possible to use an object instead of an array. Each property will
4628	* be run as a function, and the results will be passed to the final `callback`
4629	* as an object instead of an array. This can be a more readable way of handling
4630	* results from {@link async.series}.
4631	*
4632	* Note that while many implementations preserve the order of object
4633	* properties, the [ECMAScript Language Specification](http://www.ecma-international.org/ecma-262/5.1/#sec-8.6)
4634	* explicitly states that
4635	*
4636	* > The mechanics and order of enumerating the properties is not specified.
4637	*
4638	* So if you rely on the order in which your series of functions are executed,
4639	* and want this to work on all platforms, consider using an array.
4640	*
4641	* @name series
4642	* @static
4643	* @memberOf module:ControlFlow
4644	* @method
4645	* @category Control Flow
4646	* @param {Array\|Iterable\|Object} tasks - A collection containing
4647	* [async functions]{@link AsyncFunction} to run in series.
4648	* Each function can complete with any number of optional `result` values.
4649	* @param {Function} [callback] - An optional callback to run once all the
4650	* functions have completed. This function gets a results array (or object)
4651	* containing all the result arguments passed to the `task` callbacks. Invoked
4652	* with (err, result).
4653	* @example
4654	* async.series([
4655	* function(callback) {
4656	* // do some stuff ...
4657	* callback(null, 'one');
4658	* },
4659	* function(callback) {
4660	* // do some more stuff ...
4661	* callback(null, 'two');
4662	* }
4663	* ],
4664	* // optional callback
4665	* function(err, results) {
4666	* // results is now equal to ['one', 'two']
4667	* });
4668	*
4669	* async.series({
4670	* one: function(callback) {
4671	* setTimeout(function() {
4672	* callback(null, 1);
4673	* }, 200);
4674	* },
4675	* two: function(callback){
4676	* setTimeout(function() {
4677	* callback(null, 2);
4678	* }, 100);
4679	* }
4680	* }, function(err, results) {
4681	* // results is now equal to: {one: 1, two: 2}
4682	* });
4683	*/
4684	function series(tasks, callback) {
4685	_parallel(eachOfSeries, tasks, callback);
4686	}
4687
4688	/**
4689	* Returns `true` if at least one element in the `coll` satisfies an async test.
4690	* If any iteratee call returns `true`, the main `callback` is immediately
4691	* called.
4692	*
4693	* @name some
4694	* @static
4695	* @memberOf module:Collections
4696	* @method
4697	* @alias any
4698	* @category Collection
4699	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4700	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
4701	* in the collections in parallel.
4702	* The iteratee should complete with a boolean `result` value.
4703	* Invoked with (item, callback).
4704	* @param {Function} [callback] - A callback which is called as soon as any
4705	* iteratee returns `true`, or after all the iteratee functions have finished.
4706	* Result will be either `true` or `false` depending on the values of the async
4707	* tests. Invoked with (err, result).
4708	* @example
4709	*
4710	* async.some(['file1','file2','file3'], function(filePath, callback) {
4711	* fs.access(filePath, function(err) {
4712	* callback(null, !err)
4713	* });
4714	* }, function(err, result) {
4715	* // if result is true then at least one of the files exists
4716	* });
4717	*/
4718	var some = doParallel(_createTester(Boolean, identity));
4719
4720	/**
4721	* The same as [`some`]{@link module:Collections.some} but runs a maximum of `limit` async operations at a time.
4722	*
4723	* @name someLimit
4724	* @static
4725	* @memberOf module:Collections
4726	* @method
4727	* @see [async.some]{@link module:Collections.some}
4728	* @alias anyLimit
4729	* @category Collection
4730	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4731	* @param {number} limit - The maximum number of async operations at a time.
4732	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
4733	* in the collections in parallel.
4734	* The iteratee should complete with a boolean `result` value.
4735	* Invoked with (item, callback).
4736	* @param {Function} [callback] - A callback which is called as soon as any
4737	* iteratee returns `true`, or after all the iteratee functions have finished.
4738	* Result will be either `true` or `false` depending on the values of the async
4739	* tests. Invoked with (err, result).
4740	*/
4741	var someLimit = doParallelLimit(_createTester(Boolean, identity));
4742
4743	/**
4744	* The same as [`some`]{@link module:Collections.some} but runs only a single async operation at a time.
4745	*
4746	* @name someSeries
4747	* @static
4748	* @memberOf module:Collections
4749	* @method
4750	* @see [async.some]{@link module:Collections.some}
4751	* @alias anySeries
4752	* @category Collection
4753	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4754	* @param {AsyncFunction} iteratee - An async truth test to apply to each item
4755	* in the collections in series.
4756	* The iteratee should complete with a boolean `result` value.
4757	* Invoked with (item, callback).
4758	* @param {Function} [callback] - A callback which is called as soon as any
4759	* iteratee returns `true`, or after all the iteratee functions have finished.
4760	* Result will be either `true` or `false` depending on the values of the async
4761	* tests. Invoked with (err, result).
4762	*/
4763	var someSeries = doLimit(someLimit, 1);
4764
4765	/**
4766	* Sorts a list by the results of running each `coll` value through an async
4767	* `iteratee`.
4768	*
4769	* @name sortBy
4770	* @static
4771	* @memberOf module:Collections
4772	* @method
4773	* @category Collection
4774	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
4775	* @param {AsyncFunction} iteratee - An async function to apply to each item in
4776	* `coll`.
4777	* The iteratee should complete with a value to use as the sort criteria as
4778	* its `result`.
4779	* Invoked with (item, callback).
4780	* @param {Function} callback - A callback which is called after all the
4781	* `iteratee` functions have finished, or an error occurs. Results is the items
4782	* from the original `coll` sorted by the values returned by the `iteratee`
4783	* calls. Invoked with (err, results).
4784	* @example
4785	*
4786	* async.sortBy(['file1','file2','file3'], function(file, callback) {
4787	* fs.stat(file, function(err, stats) {
4788	* callback(err, stats.mtime);
4789	* });
4790	* }, function(err, results) {
4791	* // results is now the original array of files sorted by
4792	* // modified date
4793	* });
4794	*
4795	* // By modifying the callback parameter the
4796	* // sorting order can be influenced:
4797	*
4798	* // ascending order
4799	* async.sortBy([1,9,3,5], function(x, callback) {
4800	* callback(null, x);
4801	* }, function(err,result) {
4802	* // result callback
4803	* });
4804	*
4805	* // descending order
4806	* async.sortBy([1,9,3,5], function(x, callback) {
4807	* callback(null, x-1); //<- x-1 instead of x, turns the order around
4808	* }, function(err,result) {
4809	* // result callback
4810	* });
4811	*/
4812	function sortBy (coll, iteratee, callback) {
4813	var _iteratee = wrapAsync(iteratee);
4814	map(coll, function (x, callback) {
4815	_iteratee(x, function (err, criteria) {
4816	if (err) return callback(err);
4817	callback(null, {value: x, criteria: criteria});
4818	});
4819	}, function (err, results) {
4820	if (err) return callback(err);
4821	callback(null, arrayMap(results.sort(comparator), baseProperty('value')));
4822	});
4823
4824	function comparator(left, right) {
4825	var a = left.criteria, b = right.criteria;
4826	return a < b ? -1 : a > b ? 1 : 0;
4827	}
4828	}
4829
4830	/**
4831	* Sets a time limit on an asynchronous function. If the function does not call
4832	* its callback within the specified milliseconds, it will be called with a
4833	* timeout error. The code property for the error object will be `'ETIMEDOUT'`.
4834	*
4835	* @name timeout
4836	* @static
4837	* @memberOf module:Utils
4838	* @method
4839	* @category Util
4840	* @param {AsyncFunction} asyncFn - The async function to limit in time.
4841	* @param {number} milliseconds - The specified time limit.
4842	* @param {*} [info] - Any variable you want attached (`string`, `object`, etc)
4843	* to timeout Error for more information..
4844	* @returns {AsyncFunction} Returns a wrapped function that can be used with any
4845	* of the control flow functions.
4846	* Invoke this function with the same parameters as you would `asyncFunc`.
4847	* @example
4848	*
4849	* function myFunction(foo, callback) {
4850	* doAsyncTask(foo, function(err, data) {
4851	* // handle errors
4852	* if (err) return callback(err);
4853	*
4854	* // do some stuff ...
4855	*
4856	* // return processed data
4857	* return callback(null, data);
4858	* });
4859	* }
4860	*
4861	* var wrapped = async.timeout(myFunction, 1000);
4862	*
4863	* // call `wrapped` as you would `myFunction`
4864	* wrapped({ bar: 'bar' }, function(err, data) {
4865	* // if `myFunction` takes < 1000 ms to execute, `err`
4866	* // and `data` will have their expected values
4867	*
4868	* // else `err` will be an Error with the code 'ETIMEDOUT'
4869	* });
4870	*/
4871	function timeout(asyncFn, milliseconds, info) {
4872	var fn = wrapAsync(asyncFn);
4873
4874	return initialParams(function (args, callback) {
4875	var timedOut = false;
4876	var timer;
4877
4878	function timeoutCallback() {
4879	var name = asyncFn.name \|\| 'anonymous';
4880	var error = new Error('Callback function "' + name + '" timed out.');
4881	error.code = 'ETIMEDOUT';
4882	if (info) {
4883	error.info = info;
4884	}
4885	timedOut = true;
4886	callback(error);
4887	}
4888
4889	args.push(function () {
4890	if (!timedOut) {
4891	callback.apply(null, arguments);
4892	clearTimeout(timer);
4893	}
4894	});
4895
4896	// setup timer and call original function
4897	timer = setTimeout(timeoutCallback, milliseconds);
4898	fn.apply(null, args);
4899	});
4900	}
4901
4902	/* Built-in method references for those with the same name as other `lodash` methods. */
4903	var nativeCeil = Math.ceil;
4904	var nativeMax = Math.max;
4905
4906	/**
4907	* The base implementation of `_.range` and `_.rangeRight` which doesn't
4908	* coerce arguments.
4909	*
4910	* @private
4911	* @param {number} start The start of the range.
4912	* @param {number} end The end of the range.
4913	* @param {number} step The value to increment or decrement by.
4914	* @param {boolean} [fromRight] Specify iterating from right to left.
4915	* @returns {Array} Returns the range of numbers.
4916	*/
4917	function baseRange(start, end, step, fromRight) {
4918	var index = -1,
4919	length = nativeMax(nativeCeil((end - start) / (step \|\| 1)), 0),
4920	result = Array(length);
4921
4922	while (length--) {
4923	result[fromRight ? length : ++index] = start;
4924	start += step;
4925	}
4926	return result;
4927	}
4928
4929	/**
4930	* The same as [times]{@link module:ControlFlow.times} but runs a maximum of `limit` async operations at a
4931	* time.
4932	*
4933	* @name timesLimit
4934	* @static
4935	* @memberOf module:ControlFlow
4936	* @method
4937	* @see [async.times]{@link module:ControlFlow.times}
4938	* @category Control Flow
4939	* @param {number} count - The number of times to run the function.
4940	* @param {number} limit - The maximum number of async operations at a time.
4941	* @param {AsyncFunction} iteratee - The async function to call `n` times.
4942	* Invoked with the iteration index and a callback: (n, next).
4943	* @param {Function} callback - see [async.map]{@link module:Collections.map}.
4944	*/
4945	function timeLimit(count, limit, iteratee, callback) {
4946	var _iteratee = wrapAsync(iteratee);
4947	mapLimit(baseRange(0, count, 1), limit, _iteratee, callback);
4948	}
4949
4950	/**
4951	* Calls the `iteratee` function `n` times, and accumulates results in the same
4952	* manner you would use with [map]{@link module:Collections.map}.
4953	*
4954	* @name times
4955	* @static
4956	* @memberOf module:ControlFlow
4957	* @method
4958	* @see [async.map]{@link module:Collections.map}
4959	* @category Control Flow
4960	* @param {number} n - The number of times to run the function.
4961	* @param {AsyncFunction} iteratee - The async function to call `n` times.
4962	* Invoked with the iteration index and a callback: (n, next).
4963	* @param {Function} callback - see {@link module:Collections.map}.
4964	* @example
4965	*
4966	* // Pretend this is some complicated async factory
4967	* var createUser = function(id, callback) {
4968	* callback(null, {
4969	* id: 'user' + id
4970	* });
4971	* };
4972	*
4973	* // generate 5 users
4974	* async.times(5, function(n, next) {
4975	* createUser(n, function(err, user) {
4976	* next(err, user);
4977	* });
4978	* }, function(err, users) {
4979	* // we should now have 5 users
4980	* });
4981	*/
4982	var times = doLimit(timeLimit, Infinity);
4983
4984	/**
4985	* The same as [times]{@link module:ControlFlow.times} but runs only a single async operation at a time.
4986	*
4987	* @name timesSeries
4988	* @static
4989	* @memberOf module:ControlFlow
4990	* @method
4991	* @see [async.times]{@link module:ControlFlow.times}
4992	* @category Control Flow
4993	* @param {number} n - The number of times to run the function.
4994	* @param {AsyncFunction} iteratee - The async function to call `n` times.
4995	* Invoked with the iteration index and a callback: (n, next).
4996	* @param {Function} callback - see {@link module:Collections.map}.
4997	*/
4998	var timesSeries = doLimit(timeLimit, 1);
4999
5000	/**
5001	* A relative of `reduce`. Takes an Object or Array, and iterates over each
5002	* element in series, each step potentially mutating an `accumulator` value.
5003	* The type of the accumulator defaults to the type of collection passed in.
5004	*
5005	* @name transform
5006	* @static
5007	* @memberOf module:Collections
5008	* @method
5009	* @category Collection
5010	* @param {Array\|Iterable\|Object} coll - A collection to iterate over.
5011	* @param {*} [accumulator] - The initial state of the transform. If omitted,
5012	* it will default to an empty Object or Array, depending on the type of `coll`
5013	* @param {AsyncFunction} iteratee - A function applied to each item in the
5014	* collection that potentially modifies the accumulator.
5015	* Invoked with (accumulator, item, key, callback).
5016	* @param {Function} [callback] - A callback which is called after all the
5017	* `iteratee` functions have finished. Result is the transformed accumulator.
5018	* Invoked with (err, result).
5019	* @example
5020	*
5021	* async.transform([1,2,3], function(acc, item, index, callback) {
5022	* // pointless async:
5023	* process.nextTick(function() {
5024	* acc.push(item * 2)
5025	* callback(null)
5026	* });
5027	* }, function(err, result) {
5028	* // result is now equal to [2, 4, 6]
5029	* });
5030	*
5031	* @example
5032	*
5033	* async.transform({a: 1, b: 2, c: 3}, function (obj, val, key, callback) {
5034	* setImmediate(function () {
5035	* obj[key] = val * 2;
5036	* callback();
5037	* })
5038	* }, function (err, result) {
5039	* // result is equal to {a: 2, b: 4, c: 6}
5040	* })
5041	*/
5042	function transform (coll, accumulator, iteratee, callback) {
5043	if (arguments.length <= 3) {
5044	callback = iteratee;
5045	iteratee = accumulator;
5046	accumulator = isArray(coll) ? [] : {};
5047	}
5048	callback = once(callback \|\| noop);
5049	var _iteratee = wrapAsync(iteratee);
5050
5051	eachOf(coll, function(v, k, cb) {
5052	_iteratee(accumulator, v, k, cb);
5053	}, function(err) {
5054	callback(err, accumulator);
5055	});
5056	}
5057
5058	/**
5059	* It runs each task in series but stops whenever any of the functions were
5060	* successful. If one of the tasks were successful, the `callback` will be
5061	* passed the result of the successful task. If all tasks fail, the callback
5062	* will be passed the error and result (if any) of the final attempt.
5063	*
5064	* @name tryEach
5065	* @static
5066	* @memberOf module:ControlFlow
5067	* @method
5068	* @category Control Flow
5069	* @param {Array\|Iterable\|Object} tasks - A collection containing functions to
5070	* run, each function is passed a `callback(err, result)` it must call on
5071	* completion with an error `err` (which can be `null`) and an optional `result`
5072	* value.
5073	* @param {Function} [callback] - An optional callback which is called when one
5074	* of the tasks has succeeded, or all have failed. It receives the `err` and
5075	* `result` arguments of the last attempt at completing the `task`. Invoked with
5076	* (err, results).
5077	* @example
5078	* async.try([
5079	* function getDataFromFirstWebsite(callback) {
5080	* // Try getting the data from the first website
5081	* callback(err, data);
5082	* },
5083	* function getDataFromSecondWebsite(callback) {
5084	* // First website failed,
5085	* // Try getting the data from the backup website
5086	* callback(err, data);
5087	* }
5088	* ],
5089	* // optional callback
5090	* function(err, results) {
5091	* Now do something with the data.
5092	* });
5093	*
5094	*/
5095	function tryEach(tasks, callback) {
5096	var error = null;
5097	var result;
5098	callback = callback \|\| noop;
5099	eachSeries(tasks, function(task, callback) {
5100	wrapAsync(task)(function (err, res/, ...args/) {
5101	if (arguments.length > 2) {
5102	result = slice(arguments, 1);
5103	} else {
5104	result = res;
5105	}
5106	error = err;
5107	callback(!err);
5108	});
5109	}, function () {
5110	callback(error, result);
5111	});
5112	}
5113
5114	/**
5115	* Undoes a [memoize]{@link module:Utils.memoize}d function, reverting it to the original,
5116	* unmemoized form. Handy for testing.
5117	*
5118	* @name unmemoize
5119	* @static
5120	* @memberOf module:Utils
5121	* @method
5122	* @see [async.memoize]{@link module:Utils.memoize}
5123	* @category Util
5124	* @param {AsyncFunction} fn - the memoized function
5125	* @returns {AsyncFunction} a function that calls the original unmemoized function
5126	*/
5127	function unmemoize(fn) {
5128	return function () {
5129	return (fn.unmemoized \|\| fn).apply(null, arguments);
5130	};
5131	}
5132
5133	/**
5134	* Repeatedly call `iteratee`, while `test` returns `true`. Calls `callback` when
5135	* stopped, or an error occurs.
5136	*
5137	* @name whilst
5138	* @static
5139	* @memberOf module:ControlFlow
5140	* @method
5141	* @category Control Flow
5142	* @param {Function} test - synchronous truth test to perform before each
5143	* execution of `iteratee`. Invoked with ().
5144	* @param {AsyncFunction} iteratee - An async function which is called each time
5145	* `test` passes. Invoked with (callback).
5146	* @param {Function} [callback] - A callback which is called after the test
5147	* function has failed and repeated execution of `iteratee` has stopped. `callback`
5148	* will be passed an error and any arguments passed to the final `iteratee`'s
5149	* callback. Invoked with (err, [results]);
5150	* @returns undefined
5151	* @example
5152	*
5153	* var count = 0;
5154	* async.whilst(
5155	* function() { return count < 5; },
5156	* function(callback) {
5157	* count++;
5158	* setTimeout(function() {
5159	* callback(null, count);
5160	* }, 1000);
5161	* },
5162	* function (err, n) {
5163	* // 5 seconds have passed, n = 5
5164	* }
5165	* );
5166	*/
5167	function whilst(test, iteratee, callback) {
5168	callback = onlyOnce(callback \|\| noop);
5169	var _iteratee = wrapAsync(iteratee);
5170	if (!test()) return callback(null);
5171	var next = function(err/, ...args/) {
5172	if (err) return callback(err);
5173	if (test()) return _iteratee(next);
5174	var args = slice(arguments, 1);
5175	callback.apply(null, [null].concat(args));
5176	};
5177	_iteratee(next);
5178	}
5179
5180	/**
5181	* Repeatedly call `iteratee` until `test` returns `true`. Calls `callback` when
5182	* stopped, or an error occurs. `callback` will be passed an error and any
5183	* arguments passed to the final `iteratee`'s callback.
5184	*
5185	* The inverse of [whilst]{@link module:ControlFlow.whilst}.
5186	*
5187	* @name until
5188	* @static
5189	* @memberOf module:ControlFlow
5190	* @method
5191	* @see [async.whilst]{@link module:ControlFlow.whilst}
5192	* @category Control Flow
5193	* @param {Function} test - synchronous truth test to perform before each
5194	* execution of `iteratee`. Invoked with ().
5195	* @param {AsyncFunction} iteratee - An async function which is called each time
5196	* `test` fails. Invoked with (callback).
5197	* @param {Function} [callback] - A callback which is called after the test
5198	* function has passed and repeated execution of `iteratee` has stopped. `callback`
5199	* will be passed an error and any arguments passed to the final `iteratee`'s
5200	* callback. Invoked with (err, [results]);
5201	*/
5202	function until(test, iteratee, callback) {
5203	whilst(function() {
5204	return !test.apply(this, arguments);
5205	}, iteratee, callback);
5206	}
5207
5208	/**
5209	* Runs the `tasks` array of functions in series, each passing their results to
5210	* the next in the array. However, if any of the `tasks` pass an error to their
5211	* own callback, the next function is not executed, and the main `callback` is
5212	* immediately called with the error.
5213	*
5214	* @name waterfall
5215	* @static
5216	* @memberOf module:ControlFlow
5217	* @method
5218	* @category Control Flow
5219	* @param {Array} tasks - An array of [async functions]{@link AsyncFunction}
5220	* to run.
5221	* Each function should complete with any number of `result` values.
5222	* The `result` values will be passed as arguments, in order, to the next task.
5223	* @param {Function} [callback] - An optional callback to run once all the
5224	* functions have completed. This will be passed the results of the last task's
5225	* callback. Invoked with (err, [results]).
5226	* @returns undefined
5227	* @example
5228	*
5229	* async.waterfall([
5230	* function(callback) {
5231	* callback(null, 'one', 'two');
5232	* },
5233	* function(arg1, arg2, callback) {
5234	* // arg1 now equals 'one' and arg2 now equals 'two'
5235	* callback(null, 'three');
5236	* },
5237	* function(arg1, callback) {
5238	* // arg1 now equals 'three'
5239	* callback(null, 'done');
5240	* }
5241	* ], function (err, result) {
5242	* // result now equals 'done'
5243	* });
5244	*
5245	* // Or, with named functions:
5246	* async.waterfall([
5247	* myFirstFunction,
5248	* mySecondFunction,
5249	* myLastFunction,
5250	* ], function (err, result) {
5251	* // result now equals 'done'
5252	* });
5253	* function myFirstFunction(callback) {
5254	* callback(null, 'one', 'two');
5255	* }
5256	* function mySecondFunction(arg1, arg2, callback) {
5257	* // arg1 now equals 'one' and arg2 now equals 'two'
5258	* callback(null, 'three');
5259	* }
5260	* function myLastFunction(arg1, callback) {
5261	* // arg1 now equals 'three'
5262	* callback(null, 'done');
5263	* }
5264	*/
5265	var waterfall = function(tasks, callback) {
5266	callback = once(callback \|\| noop);
5267	if (!isArray(tasks)) return callback(new Error('First argument to waterfall must be an array of functions'));
5268	if (!tasks.length) return callback();
5269	var taskIndex = 0;
5270
5271	function nextTask(args) {
5272	var task = wrapAsync(tasks[taskIndex++]);
5273	args.push(onlyOnce(next));
5274	task.apply(null, args);
5275	}
5276
5277	function next(err/, ...args/) {
5278	if (err \|\| taskIndex === tasks.length) {
5279	return callback.apply(null, arguments);
5280	}
5281	nextTask(slice(arguments, 1));
5282	}
5283
5284	nextTask([]);
5285	};
5286
5287	/**
5288	* An "async function" in the context of Async is an asynchronous function with
5289	* a variable number of parameters, with the final parameter being a callback.
5290	* (`function (arg1, arg2, ..., callback) {}`)
5291	* The final callback is of the form `callback(err, results...)`, which must be
5292	* called once the function is completed. The callback should be called with a
5293	* Error as its first argument to signal that an error occurred.
5294	* Otherwise, if no error occurred, it should be called with `null` as the first
5295	* argument, and any additional `result` arguments that may apply, to signal
5296	* successful completion.
5297	* The callback must be called exactly once, ideally on a later tick of the
5298	* JavaScript event loop.
5299	*
5300	* This type of function is also referred to as a "Node-style async function",
5301	* or a "continuation passing-style function" (CPS). Most of the methods of this
5302	* library are themselves CPS/Node-style async functions, or functions that
5303	* return CPS/Node-style async functions.
5304	*
5305	* Wherever we accept a Node-style async function, we also directly accept an
5306	* [ES2017 `async` function]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function}.
5307	* In this case, the `async` function will not be passed a final callback
5308	* argument, and any thrown error will be used as the `err` argument of the
5309	* implicit callback, and the return value will be used as the `result` value.
5310	* (i.e. a `rejected` of the returned Promise becomes the `err` callback
5311	* argument, and a `resolved` value becomes the `result`.)
5312	*
5313	* Note, due to JavaScript limitations, we can only detect native `async`
5314	* functions and not transpilied implementations.
5315	* Your environment must have `async`/`await` support for this to work.
5316	* (e.g. Node > v7.6, or a recent version of a modern browser).
5317	* If you are using `async` functions through a transpiler (e.g. Babel), you
5318	* must still wrap the function with [asyncify]{@link module:Utils.asyncify},
5319	* because the `async function` will be compiled to an ordinary function that
5320	* returns a promise.
5321	*
5322	* @typedef {Function} AsyncFunction
5323	* @static
5324	*/
5325
5326	/**
5327	* Async is a utility module which provides straight-forward, powerful functions
5328	* for working with asynchronous JavaScript. Although originally designed for
5329	* use with [Node.js](http://nodejs.org) and installable via
5330	* `npm install --save async`, it can also be used directly in the browser.
5331	* @module async
5332	* @see AsyncFunction
5333	*/
5334
5335
5336	/**
5337	* A collection of `async` functions for manipulating collections, such as
5338	* arrays and objects.
5339	* @module Collections
5340	*/
5341
5342	/**
5343	* A collection of `async` functions for controlling the flow through a script.
5344	* @module ControlFlow
5345	*/
5346
5347	/**
5348	* A collection of `async` utility functions.
5349	* @module Utils
5350	*/
5351
5352	var index = {
5353	applyEach: applyEach,
5354	applyEachSeries: applyEachSeries,
5355	apply: apply,
5356	asyncify: asyncify,
5357	auto: auto,
5358	autoInject: autoInject,
5359	cargo: cargo,
5360	compose: compose,
5361	concat: concat,
5362	concatSeries: concatSeries,
5363	constant: constant,
5364	detect: detect,
5365	detectLimit: detectLimit,
5366	detectSeries: detectSeries,
5367	dir: dir,
5368	doDuring: doDuring,
5369	doUntil: doUntil,
5370	doWhilst: doWhilst,
5371	during: during,
5372	each: eachLimit,
5373	eachLimit: eachLimit$1,
5374	eachOf: eachOf,
5375	eachOfLimit: eachOfLimit,
5376	eachOfSeries: eachOfSeries,
5377	eachSeries: eachSeries,
5378	ensureAsync: ensureAsync,
5379	every: every,
5380	everyLimit: everyLimit,
5381	everySeries: everySeries,
5382	filter: filter,
5383	filterLimit: filterLimit,
5384	filterSeries: filterSeries,
5385	forever: forever,
5386	groupBy: groupBy,
5387	groupByLimit: groupByLimit,
5388	groupBySeries: groupBySeries,
5389	log: log,
5390	map: map,
5391	mapLimit: mapLimit,
5392	mapSeries: mapSeries,
5393	mapValues: mapValues,
5394	mapValuesLimit: mapValuesLimit,
5395	mapValuesSeries: mapValuesSeries,
5396	memoize: memoize,
5397	nextTick: nextTick,
5398	parallel: parallelLimit,
5399	parallelLimit: parallelLimit$1,
5400	priorityQueue: priorityQueue,
5401	queue: queue$1,
5402	race: race,
5403	reduce: reduce,
5404	reduceRight: reduceRight,
5405	reflect: reflect,
5406	reflectAll: reflectAll,
5407	reject: reject,
5408	rejectLimit: rejectLimit,
5409	rejectSeries: rejectSeries,
5410	retry: retry,
5411	retryable: retryable,
5412	seq: seq,
5413	series: series,
5414	setImmediate: setImmediate$1,
5415	some: some,
5416	someLimit: someLimit,
5417	someSeries: someSeries,
5418	sortBy: sortBy,
5419	timeout: timeout,
5420	times: times,
5421	timesLimit: timeLimit,
5422	timesSeries: timesSeries,
5423	transform: transform,
5424	tryEach: tryEach,
5425	unmemoize: unmemoize,
5426	until: until,
5427	waterfall: waterfall,
5428	whilst: whilst,
5429
5430	// aliases
5431	all: every,
5432	any: some,
5433	forEach: eachLimit,
5434	forEachSeries: eachSeries,
5435	forEachLimit: eachLimit$1,
5436	forEachOf: eachOf,
5437	forEachOfSeries: eachOfSeries,
5438	forEachOfLimit: eachOfLimit,
5439	inject: reduce,
5440	foldl: reduce,
5441	foldr: reduceRight,
5442	select: filter,
5443	selectLimit: filterLimit,
5444	selectSeries: filterSeries,
5445	wrapSync: asyncify
5446	};
5447
5448	exports['default'] = index;
5449	exports.applyEach = applyEach;
5450	exports.applyEachSeries = applyEachSeries;
5451	exports.apply = apply;
5452	exports.asyncify = asyncify;
5453	exports.auto = auto;
5454	exports.autoInject = autoInject;
5455	exports.cargo = cargo;
5456	exports.compose = compose;
5457	exports.concat = concat;
5458	exports.concatSeries = concatSeries;
5459	exports.constant = constant;
5460	exports.detect = detect;
5461	exports.detectLimit = detectLimit;
5462	exports.detectSeries = detectSeries;
5463	exports.dir = dir;
5464	exports.doDuring = doDuring;
5465	exports.doUntil = doUntil;
5466	exports.doWhilst = doWhilst;
5467	exports.during = during;
5468	exports.each = eachLimit;
5469	exports.eachLimit = eachLimit$1;
5470	exports.eachOf = eachOf;
5471	exports.eachOfLimit = eachOfLimit;
5472	exports.eachOfSeries = eachOfSeries;
5473	exports.eachSeries = eachSeries;
5474	exports.ensureAsync = ensureAsync;
5475	exports.every = every;
5476	exports.everyLimit = everyLimit;
5477	exports.everySeries = everySeries;
5478	exports.filter = filter;
5479	exports.filterLimit = filterLimit;
5480	exports.filterSeries = filterSeries;
5481	exports.forever = forever;
5482	exports.groupBy = groupBy;
5483	exports.groupByLimit = groupByLimit;
5484	exports.groupBySeries = groupBySeries;
5485	exports.log = log;
5486	exports.map = map;
5487	exports.mapLimit = mapLimit;
5488	exports.mapSeries = mapSeries;
5489	exports.mapValues = mapValues;
5490	exports.mapValuesLimit = mapValuesLimit;
5491	exports.mapValuesSeries = mapValuesSeries;
5492	exports.memoize = memoize;
5493	exports.nextTick = nextTick;
5494	exports.parallel = parallelLimit;
5495	exports.parallelLimit = parallelLimit$1;
5496	exports.priorityQueue = priorityQueue;
5497	exports.queue = queue$1;
5498	exports.race = race;
5499	exports.reduce = reduce;
5500	exports.reduceRight = reduceRight;
5501	exports.reflect = reflect;
5502	exports.reflectAll = reflectAll;
5503	exports.reject = reject;
5504	exports.rejectLimit = rejectLimit;
5505	exports.rejectSeries = rejectSeries;
5506	exports.retry = retry;
5507	exports.retryable = retryable;
5508	exports.seq = seq;
5509	exports.series = series;
5510	exports.setImmediate = setImmediate$1;
5511	exports.some = some;
5512	exports.someLimit = someLimit;
5513	exports.someSeries = someSeries;
5514	exports.sortBy = sortBy;
5515	exports.timeout = timeout;
5516	exports.times = times;
5517	exports.timesLimit = timeLimit;
5518	exports.timesSeries = timesSeries;
5519	exports.transform = transform;
5520	exports.tryEach = tryEach;
5521	exports.unmemoize = unmemoize;
5522	exports.until = until;
5523	exports.waterfall = waterfall;
5524	exports.whilst = whilst;
5525	exports.all = every;
5526	exports.allLimit = everyLimit;
5527	exports.allSeries = everySeries;
5528	exports.any = some;
5529	exports.anyLimit = someLimit;
5530	exports.anySeries = someSeries;
5531	exports.find = detect;
5532	exports.findLimit = detectLimit;
5533	exports.findSeries = detectSeries;
5534	exports.forEach = eachLimit;
5535	exports.forEachSeries = eachSeries;
5536	exports.forEachLimit = eachLimit$1;
5537	exports.forEachOf = eachOf;
5538	exports.forEachOfSeries = eachOfSeries;
5539	exports.forEachOfLimit = eachOfLimit;
5540	exports.inject = reduce;
5541	exports.foldl = reduce;
5542	exports.foldr = reduceRight;
5543	exports.select = filter;
5544	exports.selectLimit = filterLimit;
5545	exports.selectSeries = filterSeries;
5546	exports.wrapSync = asyncify;
5547
5548	Object.defineProperty(exports, '__esModule', { value: true });
5549
5550	})));
5551