1 (function (global, factory) {
2 typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
3 typeof define === 'function' && define.amd ? define('underscore', factory) :
4 (global = typeof globalThis !== 'undefined' ? globalThis : global || self, (function () {
5 var current = global._;
6 var exports = global._ = factory();
7 exports.noConflict = function () { global._ = current; return exports; };
10 // Underscore.js 1.13.1
11 // https://underscorejs.org
12 // (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
13 // Underscore may be freely distributed under the MIT license.
16 var VERSION = '1.13.1';
18 // Establish the root object, `window` (`self`) in the browser, `global`
19 // on the server, or `this` in some virtual machines. We use `self`
20 // instead of `window` for `WebWorker` support.
21 var root = typeof self == 'object' && self.self === self && self ||
22 typeof global == 'object' && global.global === global && global ||
23 Function('return this')() ||
26 // Save bytes in the minified (but not gzipped) version:
27 var ArrayProto = Array.prototype, ObjProto = Object.prototype;
28 var SymbolProto = typeof Symbol !== 'undefined' ? Symbol.prototype : null;
30 // Create quick reference variables for speed access to core prototypes.
31 var push = ArrayProto.push,
32 slice = ArrayProto.slice,
33 toString = ObjProto.toString,
34 hasOwnProperty = ObjProto.hasOwnProperty;
36 // Modern feature detection.
37 var supportsArrayBuffer = typeof ArrayBuffer !== 'undefined',
38 supportsDataView = typeof DataView !== 'undefined';
40 // All **ECMAScript 5+** native function implementations that we hope to use
42 var nativeIsArray = Array.isArray,
43 nativeKeys = Object.keys,
44 nativeCreate = Object.create,
45 nativeIsView = supportsArrayBuffer && ArrayBuffer.isView;
47 // Create references to these builtin functions because we override them.
51 // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.
52 var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');
53 var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString',
54 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
56 // The largest integer that can be represented exactly.
57 var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
59 // Some functions take a variable number of arguments, or a few expected
60 // arguments at the beginning and then a variable number of values to operate
61 // on. This helper accumulates all remaining arguments past the function’s
62 // argument length (or an explicit `startIndex`), into an array that becomes
63 // the last argument. Similar to ES6’s "rest parameter".
64 function restArguments(func, startIndex) {
65 startIndex = startIndex == null ? func.length - 1 : +startIndex;
67 var length = Math.max(arguments.length - startIndex, 0),
70 for (; index < length; index++) {
71 rest[index] = arguments[index + startIndex];
74 case 0: return func.call(this, rest);
75 case 1: return func.call(this, arguments[0], rest);
76 case 2: return func.call(this, arguments[0], arguments[1], rest);
78 var args = Array(startIndex + 1);
79 for (index = 0; index < startIndex; index++) {
80 args[index] = arguments[index];
82 args[startIndex] = rest;
83 return func.apply(this, args);
87 // Is a given variable an object?
88 function isObject(obj) {
89 var type = typeof obj;
90 return type === 'function' || type === 'object' && !!obj;
93 // Is a given value equal to null?
94 function isNull(obj) {
98 // Is a given variable undefined?
99 function isUndefined(obj) {
100 return obj === void 0;
103 // Is a given value a boolean?
104 function isBoolean(obj) {
105 return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
108 // Is a given value a DOM element?
109 function isElement(obj) {
110 return !!(obj && obj.nodeType === 1);
113 // Internal function for creating a `toString`-based type tester.
114 function tagTester(name) {
115 var tag = '[object ' + name + ']';
116 return function(obj) {
117 return toString.call(obj) === tag;
121 var isString = tagTester('String');
123 var isNumber = tagTester('Number');
125 var isDate = tagTester('Date');
127 var isRegExp = tagTester('RegExp');
129 var isError = tagTester('Error');
131 var isSymbol = tagTester('Symbol');
133 var isArrayBuffer = tagTester('ArrayBuffer');
135 var isFunction = tagTester('Function');
137 // Optimize `isFunction` if appropriate. Work around some `typeof` bugs in old
138 // v8, IE 11 (#1621), Safari 8 (#1929), and PhantomJS (#2236).
139 var nodelist = root.document && root.document.childNodes;
140 if (typeof /./ != 'function' && typeof Int8Array != 'object' && typeof nodelist != 'function') {
141 isFunction = function(obj) {
142 return typeof obj == 'function' || false;
146 var isFunction$1 = isFunction;
148 var hasObjectTag = tagTester('Object');
150 // In IE 10 - Edge 13, `DataView` has string tag `'[object Object]'`.
151 // In IE 11, the most common among them, this problem also applies to
152 // `Map`, `WeakMap` and `Set`.
153 var hasStringTagBug = (
154 supportsDataView && hasObjectTag(new DataView(new ArrayBuffer(8)))
156 isIE11 = (typeof Map !== 'undefined' && hasObjectTag(new Map));
158 var isDataView = tagTester('DataView');
160 // In IE 10 - Edge 13, we need a different heuristic
161 // to determine whether an object is a `DataView`.
162 function ie10IsDataView(obj) {
163 return obj != null && isFunction$1(obj.getInt8) && isArrayBuffer(obj.buffer);
166 var isDataView$1 = (hasStringTagBug ? ie10IsDataView : isDataView);
168 // Is a given value an array?
169 // Delegates to ECMA5's native `Array.isArray`.
170 var isArray = nativeIsArray || tagTester('Array');
172 // Internal function to check whether `key` is an own property name of `obj`.
173 function has$1(obj, key) {
174 return obj != null && hasOwnProperty.call(obj, key);
177 var isArguments = tagTester('Arguments');
179 // Define a fallback version of the method in browsers (ahem, IE < 9), where
180 // there isn't any inspectable "Arguments" type.
182 if (!isArguments(arguments)) {
183 isArguments = function(obj) {
184 return has$1(obj, 'callee');
189 var isArguments$1 = isArguments;
191 // Is a given object a finite number?
192 function isFinite$1(obj) {
193 return !isSymbol(obj) && _isFinite(obj) && !isNaN(parseFloat(obj));
196 // Is the given value `NaN`?
197 function isNaN$1(obj) {
198 return isNumber(obj) && _isNaN(obj);
201 // Predicate-generating function. Often useful outside of Underscore.
202 function constant(value) {
208 // Common internal logic for `isArrayLike` and `isBufferLike`.
209 function createSizePropertyCheck(getSizeProperty) {
210 return function(collection) {
211 var sizeProperty = getSizeProperty(collection);
212 return typeof sizeProperty == 'number' && sizeProperty >= 0 && sizeProperty <= MAX_ARRAY_INDEX;
216 // Internal helper to generate a function to obtain property `key` from `obj`.
217 function shallowProperty(key) {
218 return function(obj) {
219 return obj == null ? void 0 : obj[key];
223 // Internal helper to obtain the `byteLength` property of an object.
224 var getByteLength = shallowProperty('byteLength');
226 // Internal helper to determine whether we should spend extensive checks against
227 // `ArrayBuffer` et al.
228 var isBufferLike = createSizePropertyCheck(getByteLength);
230 // Is a given value a typed array?
231 var typedArrayPattern = /\[object ((I|Ui)nt(8|16|32)|Float(32|64)|Uint8Clamped|Big(I|Ui)nt64)Array\]/;
232 function isTypedArray(obj) {
233 // `ArrayBuffer.isView` is the most future-proof, so use it when available.
234 // Otherwise, fall back on the above regular expression.
235 return nativeIsView ? (nativeIsView(obj) && !isDataView$1(obj)) :
236 isBufferLike(obj) && typedArrayPattern.test(toString.call(obj));
239 var isTypedArray$1 = supportsArrayBuffer ? isTypedArray : constant(false);
241 // Internal helper to obtain the `length` property of an object.
242 var getLength = shallowProperty('length');
244 // Internal helper to create a simple lookup structure.
245 // `collectNonEnumProps` used to depend on `_.contains`, but this led to
246 // circular imports. `emulatedSet` is a one-off solution that only works for
247 // arrays of strings.
248 function emulatedSet(keys) {
250 for (var l = keys.length, i = 0; i < l; ++i) hash[keys[i]] = true;
252 contains: function(key) { return hash[key]; },
253 push: function(key) {
255 return keys.push(key);
260 // Internal helper. Checks `keys` for the presence of keys in IE < 9 that won't
261 // be iterated by `for key in ...` and thus missed. Extends `keys` in place if
263 function collectNonEnumProps(obj, keys) {
264 keys = emulatedSet(keys);
265 var nonEnumIdx = nonEnumerableProps.length;
266 var constructor = obj.constructor;
267 var proto = isFunction$1(constructor) && constructor.prototype || ObjProto;
269 // Constructor is a special case.
270 var prop = 'constructor';
271 if (has$1(obj, prop) && !keys.contains(prop)) keys.push(prop);
273 while (nonEnumIdx--) {
274 prop = nonEnumerableProps[nonEnumIdx];
275 if (prop in obj && obj[prop] !== proto[prop] && !keys.contains(prop)) {
281 // Retrieve the names of an object's own properties.
282 // Delegates to **ECMAScript 5**'s native `Object.keys`.
284 if (!isObject(obj)) return [];
285 if (nativeKeys) return nativeKeys(obj);
287 for (var key in obj) if (has$1(obj, key)) keys.push(key);
289 if (hasEnumBug) collectNonEnumProps(obj, keys);
293 // Is a given array, string, or object empty?
294 // An "empty" object has no enumerable own-properties.
295 function isEmpty(obj) {
296 if (obj == null) return true;
297 // Skip the more expensive `toString`-based type checks if `obj` has no
299 var length = getLength(obj);
300 if (typeof length == 'number' && (
301 isArray(obj) || isString(obj) || isArguments$1(obj)
302 )) return length === 0;
303 return getLength(keys(obj)) === 0;
306 // Returns whether an object has a given set of `key:value` pairs.
307 function isMatch(object, attrs) {
308 var _keys = keys(attrs), length = _keys.length;
309 if (object == null) return !length;
310 var obj = Object(object);
311 for (var i = 0; i < length; i++) {
313 if (attrs[key] !== obj[key] || !(key in obj)) return false;
318 // If Underscore is called as a function, it returns a wrapped object that can
319 // be used OO-style. This wrapper holds altered versions of all functions added
320 // through `_.mixin`. Wrapped objects may be chained.
322 if (obj instanceof _$1) return obj;
323 if (!(this instanceof _$1)) return new _$1(obj);
327 _$1.VERSION = VERSION;
329 // Extracts the result from a wrapped and chained object.
330 _$1.prototype.value = function() {
331 return this._wrapped;
334 // Provide unwrapping proxies for some methods used in engine operations
335 // such as arithmetic and JSON stringification.
336 _$1.prototype.valueOf = _$1.prototype.toJSON = _$1.prototype.value;
338 _$1.prototype.toString = function() {
339 return String(this._wrapped);
342 // Internal function to wrap or shallow-copy an ArrayBuffer,
343 // typed array or DataView to a new view, reusing the buffer.
344 function toBufferView(bufferSource) {
345 return new Uint8Array(
346 bufferSource.buffer || bufferSource,
347 bufferSource.byteOffset || 0,
348 getByteLength(bufferSource)
352 // We use this string twice, so give it a name for minification.
353 var tagDataView = '[object DataView]';
355 // Internal recursive comparison function for `_.isEqual`.
356 function eq(a, b, aStack, bStack) {
357 // Identical objects are equal. `0 === -0`, but they aren't identical.
358 // See the [Harmony `egal` proposal](https://wiki.ecmascript.org/doku.php?id=harmony:egal).
359 if (a === b) return a !== 0 || 1 / a === 1 / b;
360 // `null` or `undefined` only equal to itself (strict comparison).
361 if (a == null || b == null) return false;
362 // `NaN`s are equivalent, but non-reflexive.
363 if (a !== a) return b !== b;
364 // Exhaust primitive checks
366 if (type !== 'function' && type !== 'object' && typeof b != 'object') return false;
367 return deepEq(a, b, aStack, bStack);
370 // Internal recursive comparison function for `_.isEqual`.
371 function deepEq(a, b, aStack, bStack) {
372 // Unwrap any wrapped objects.
373 if (a instanceof _$1) a = a._wrapped;
374 if (b instanceof _$1) b = b._wrapped;
375 // Compare `[[Class]]` names.
376 var className = toString.call(a);
377 if (className !== toString.call(b)) return false;
378 // Work around a bug in IE 10 - Edge 13.
379 if (hasStringTagBug && className == '[object Object]' && isDataView$1(a)) {
380 if (!isDataView$1(b)) return false;
381 className = tagDataView;
384 // These types are compared by value.
385 case '[object RegExp]':
386 // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')
387 case '[object String]':
388 // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
389 // equivalent to `new String("5")`.
390 return '' + a === '' + b;
391 case '[object Number]':
392 // `NaN`s are equivalent, but non-reflexive.
393 // Object(NaN) is equivalent to NaN.
394 if (+a !== +a) return +b !== +b;
395 // An `egal` comparison is performed for other numeric values.
396 return +a === 0 ? 1 / +a === 1 / b : +a === +b;
397 case '[object Date]':
398 case '[object Boolean]':
399 // Coerce dates and booleans to numeric primitive values. Dates are compared by their
400 // millisecond representations. Note that invalid dates with millisecond representations
401 // of `NaN` are not equivalent.
403 case '[object Symbol]':
404 return SymbolProto.valueOf.call(a) === SymbolProto.valueOf.call(b);
405 case '[object ArrayBuffer]':
407 // Coerce to typed array so we can fall through.
408 return deepEq(toBufferView(a), toBufferView(b), aStack, bStack);
411 var areArrays = className === '[object Array]';
412 if (!areArrays && isTypedArray$1(a)) {
413 var byteLength = getByteLength(a);
414 if (byteLength !== getByteLength(b)) return false;
415 if (a.buffer === b.buffer && a.byteOffset === b.byteOffset) return true;
419 if (typeof a != 'object' || typeof b != 'object') return false;
421 // Objects with different constructors are not equivalent, but `Object`s or `Array`s
422 // from different frames are.
423 var aCtor = a.constructor, bCtor = b.constructor;
424 if (aCtor !== bCtor && !(isFunction$1(aCtor) && aCtor instanceof aCtor &&
425 isFunction$1(bCtor) && bCtor instanceof bCtor)
426 && ('constructor' in a && 'constructor' in b)) {
430 // Assume equality for cyclic structures. The algorithm for detecting cyclic
431 // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
433 // Initializing stack of traversed objects.
434 // It's done here since we only need them for objects and arrays comparison.
435 aStack = aStack || [];
436 bStack = bStack || [];
437 var length = aStack.length;
439 // Linear search. Performance is inversely proportional to the number of
440 // unique nested structures.
441 if (aStack[length] === a) return bStack[length] === b;
444 // Add the first object to the stack of traversed objects.
448 // Recursively compare objects and arrays.
450 // Compare array lengths to determine if a deep comparison is necessary.
452 if (length !== b.length) return false;
453 // Deep compare the contents, ignoring non-numeric properties.
455 if (!eq(a[length], b[length], aStack, bStack)) return false;
458 // Deep compare objects.
459 var _keys = keys(a), key;
460 length = _keys.length;
461 // Ensure that both objects contain the same number of properties before comparing deep equality.
462 if (keys(b).length !== length) return false;
464 // Deep compare each member
466 if (!(has$1(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
469 // Remove the first object from the stack of traversed objects.
475 // Perform a deep comparison to check if two objects are equal.
476 function isEqual(a, b) {
480 // Retrieve all the enumerable property names of an object.
481 function allKeys(obj) {
482 if (!isObject(obj)) return [];
484 for (var key in obj) keys.push(key);
486 if (hasEnumBug) collectNonEnumProps(obj, keys);
490 // Since the regular `Object.prototype.toString` type tests don't work for
491 // some types in IE 11, we use a fingerprinting heuristic instead, based
492 // on the methods. It's not great, but it's the best we got.
493 // The fingerprint method lists are defined below.
494 function ie11fingerprint(methods) {
495 var length = getLength(methods);
496 return function(obj) {
497 if (obj == null) return false;
498 // `Map`, `WeakMap` and `Set` have no enumerable keys.
499 var keys = allKeys(obj);
500 if (getLength(keys)) return false;
501 for (var i = 0; i < length; i++) {
502 if (!isFunction$1(obj[methods[i]])) return false;
504 // If we are testing against `WeakMap`, we need to ensure that
505 // `obj` doesn't have a `forEach` method in order to distinguish
506 // it from a regular `Map`.
507 return methods !== weakMapMethods || !isFunction$1(obj[forEachName]);
511 // In the interest of compact minification, we write
512 // each string in the fingerprints only once.
513 var forEachName = 'forEach',
515 commonInit = ['clear', 'delete'],
516 mapTail = ['get', hasName, 'set'];
518 // `Map`, `WeakMap` and `Set` each have slightly different
519 // combinations of the above sublists.
520 var mapMethods = commonInit.concat(forEachName, mapTail),
521 weakMapMethods = commonInit.concat(mapTail),
522 setMethods = ['add'].concat(commonInit, forEachName, hasName);
524 var isMap = isIE11 ? ie11fingerprint(mapMethods) : tagTester('Map');
526 var isWeakMap = isIE11 ? ie11fingerprint(weakMapMethods) : tagTester('WeakMap');
528 var isSet = isIE11 ? ie11fingerprint(setMethods) : tagTester('Set');
530 var isWeakSet = tagTester('WeakSet');
532 // Retrieve the values of an object's properties.
533 function values(obj) {
534 var _keys = keys(obj);
535 var length = _keys.length;
536 var values = Array(length);
537 for (var i = 0; i < length; i++) {
538 values[i] = obj[_keys[i]];
543 // Convert an object into a list of `[key, value]` pairs.
544 // The opposite of `_.object` with one argument.
545 function pairs(obj) {
546 var _keys = keys(obj);
547 var length = _keys.length;
548 var pairs = Array(length);
549 for (var i = 0; i < length; i++) {
550 pairs[i] = [_keys[i], obj[_keys[i]]];
555 // Invert the keys and values of an object. The values must be serializable.
556 function invert(obj) {
558 var _keys = keys(obj);
559 for (var i = 0, length = _keys.length; i < length; i++) {
560 result[obj[_keys[i]]] = _keys[i];
565 // Return a sorted list of the function names available on the object.
566 function functions(obj) {
568 for (var key in obj) {
569 if (isFunction$1(obj[key])) names.push(key);
574 // An internal function for creating assigner functions.
575 function createAssigner(keysFunc, defaults) {
576 return function(obj) {
577 var length = arguments.length;
578 if (defaults) obj = Object(obj);
579 if (length < 2 || obj == null) return obj;
580 for (var index = 1; index < length; index++) {
581 var source = arguments[index],
582 keys = keysFunc(source),
584 for (var i = 0; i < l; i++) {
586 if (!defaults || obj[key] === void 0) obj[key] = source[key];
593 // Extend a given object with all the properties in passed-in object(s).
594 var extend = createAssigner(allKeys);
596 // Assigns a given object with all the own properties in the passed-in
598 // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)
599 var extendOwn = createAssigner(keys);
601 // Fill in a given object with default properties.
602 var defaults = createAssigner(allKeys, true);
604 // Create a naked function reference for surrogate-prototype-swapping.
609 // An internal function for creating a new object that inherits from another.
610 function baseCreate(prototype) {
611 if (!isObject(prototype)) return {};
612 if (nativeCreate) return nativeCreate(prototype);
614 Ctor.prototype = prototype;
615 var result = new Ctor;
616 Ctor.prototype = null;
620 // Creates an object that inherits from the given prototype object.
621 // If additional properties are provided then they will be added to the
623 function create(prototype, props) {
624 var result = baseCreate(prototype);
625 if (props) extendOwn(result, props);
629 // Create a (shallow-cloned) duplicate of an object.
630 function clone(obj) {
631 if (!isObject(obj)) return obj;
632 return isArray(obj) ? obj.slice() : extend({}, obj);
635 // Invokes `interceptor` with the `obj` and then returns `obj`.
636 // The primary purpose of this method is to "tap into" a method chain, in
637 // order to perform operations on intermediate results within the chain.
638 function tap(obj, interceptor) {
643 // Normalize a (deep) property `path` to array.
644 // Like `_.iteratee`, this function can be customized.
645 function toPath$1(path) {
646 return isArray(path) ? path : [path];
648 _$1.toPath = toPath$1;
650 // Internal wrapper for `_.toPath` to enable minification.
651 // Similar to `cb` for `_.iteratee`.
652 function toPath(path) {
653 return _$1.toPath(path);
656 // Internal function to obtain a nested property in `obj` along `path`.
657 function deepGet(obj, path) {
658 var length = path.length;
659 for (var i = 0; i < length; i++) {
660 if (obj == null) return void 0;
663 return length ? obj : void 0;
666 // Get the value of the (deep) property on `path` from `object`.
667 // If any property in `path` does not exist or if the value is
668 // `undefined`, return `defaultValue` instead.
669 // The `path` is normalized through `_.toPath`.
670 function get(object, path, defaultValue) {
671 var value = deepGet(object, toPath(path));
672 return isUndefined(value) ? defaultValue : value;
675 // Shortcut function for checking if an object has a given property directly on
676 // itself (in other words, not on a prototype). Unlike the internal `has`
677 // function, this public version can also traverse nested properties.
678 function has(obj, path) {
680 var length = path.length;
681 for (var i = 0; i < length; i++) {
683 if (!has$1(obj, key)) return false;
689 // Keep the identity function around for default iteratees.
690 function identity(value) {
694 // Returns a predicate for checking whether an object has a given set of
695 // `key:value` pairs.
696 function matcher(attrs) {
697 attrs = extendOwn({}, attrs);
698 return function(obj) {
699 return isMatch(obj, attrs);
703 // Creates a function that, when passed an object, will traverse that object’s
704 // properties down the given `path`, specified as an array of keys or indices.
705 function property(path) {
707 return function(obj) {
708 return deepGet(obj, path);
712 // Internal function that returns an efficient (for current engines) version
713 // of the passed-in callback, to be repeatedly applied in other Underscore
715 function optimizeCb(func, context, argCount) {
716 if (context === void 0) return func;
717 switch (argCount == null ? 3 : argCount) {
718 case 1: return function(value) {
719 return func.call(context, value);
721 // The 2-argument case is omitted because we’re not using it.
722 case 3: return function(value, index, collection) {
723 return func.call(context, value, index, collection);
725 case 4: return function(accumulator, value, index, collection) {
726 return func.call(context, accumulator, value, index, collection);
730 return func.apply(context, arguments);
734 // An internal function to generate callbacks that can be applied to each
735 // element in a collection, returning the desired result — either `_.identity`,
736 // an arbitrary callback, a property matcher, or a property accessor.
737 function baseIteratee(value, context, argCount) {
738 if (value == null) return identity;
739 if (isFunction$1(value)) return optimizeCb(value, context, argCount);
740 if (isObject(value) && !isArray(value)) return matcher(value);
741 return property(value);
744 // External wrapper for our callback generator. Users may customize
745 // `_.iteratee` if they want additional predicate/iteratee shorthand styles.
746 // This abstraction hides the internal-only `argCount` argument.
747 function iteratee(value, context) {
748 return baseIteratee(value, context, Infinity);
750 _$1.iteratee = iteratee;
752 // The function we call internally to generate a callback. It invokes
753 // `_.iteratee` if overridden, otherwise `baseIteratee`.
754 function cb(value, context, argCount) {
755 if (_$1.iteratee !== iteratee) return _$1.iteratee(value, context);
756 return baseIteratee(value, context, argCount);
759 // Returns the results of applying the `iteratee` to each element of `obj`.
760 // In contrast to `_.map` it returns an object.
761 function mapObject(obj, iteratee, context) {
762 iteratee = cb(iteratee, context);
763 var _keys = keys(obj),
764 length = _keys.length,
766 for (var index = 0; index < length; index++) {
767 var currentKey = _keys[index];
768 results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
773 // Predicate-generating function. Often useful outside of Underscore.
776 // Generates a function for a given object that returns a given property.
777 function propertyOf(obj) {
778 if (obj == null) return noop;
779 return function(path) {
780 return get(obj, path);
784 // Run a function **n** times.
785 function times(n, iteratee, context) {
786 var accum = Array(Math.max(0, n));
787 iteratee = optimizeCb(iteratee, context, 1);
788 for (var i = 0; i < n; i++) accum[i] = iteratee(i);
792 // Return a random integer between `min` and `max` (inclusive).
793 function random(min, max) {
798 return min + Math.floor(Math.random() * (max - min + 1));
801 // A (possibly faster) way to get the current timestamp as an integer.
802 var now = Date.now || function() {
803 return new Date().getTime();
806 // Internal helper to generate functions for escaping and unescaping strings
807 // to/from HTML interpolation.
808 function createEscaper(map) {
809 var escaper = function(match) {
812 // Regexes for identifying a key that needs to be escaped.
813 var source = '(?:' + keys(map).join('|') + ')';
814 var testRegexp = RegExp(source);
815 var replaceRegexp = RegExp(source, 'g');
816 return function(string) {
817 string = string == null ? '' : '' + string;
818 return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;
822 // Internal list of HTML entities for escaping.
832 // Function for escaping strings to HTML interpolation.
833 var _escape = createEscaper(escapeMap);
835 // Internal list of HTML entities for unescaping.
836 var unescapeMap = invert(escapeMap);
838 // Function for unescaping strings from HTML interpolation.
839 var _unescape = createEscaper(unescapeMap);
841 // By default, Underscore uses ERB-style template delimiters. Change the
842 // following template settings to use alternative delimiters.
843 var templateSettings = _$1.templateSettings = {
844 evaluate: /<%([\s\S]+?)%>/g,
845 interpolate: /<%=([\s\S]+?)%>/g,
846 escape: /<%-([\s\S]+?)%>/g
849 // When customizing `_.templateSettings`, if you don't want to define an
850 // interpolation, evaluation or escaping regex, we need one that is
851 // guaranteed not to match.
852 var noMatch = /(.)^/;
854 // Certain characters need to be escaped so that they can be put into a
865 var escapeRegExp = /\\|'|\r|\n|\u2028|\u2029/g;
867 function escapeChar(match) {
868 return '\\' + escapes[match];
871 // In order to prevent third-party code injection through
872 // `_.templateSettings.variable`, we test it against the following regular
873 // expression. It is intentionally a bit more liberal than just matching valid
874 // identifiers, but still prevents possible loopholes through defaults or
875 // destructuring assignment.
876 var bareIdentifier = /^\s*(\w|\$)+\s*$/;
878 // JavaScript micro-templating, similar to John Resig's implementation.
879 // Underscore templating handles arbitrary delimiters, preserves whitespace,
880 // and correctly escapes quotes within interpolated code.
881 // NB: `oldSettings` only exists for backwards compatibility.
882 function template(text, settings, oldSettings) {
883 if (!settings && oldSettings) settings = oldSettings;
884 settings = defaults({}, settings, _$1.templateSettings);
886 // Combine delimiters into one regular expression via alternation.
887 var matcher = RegExp([
888 (settings.escape || noMatch).source,
889 (settings.interpolate || noMatch).source,
890 (settings.evaluate || noMatch).source
891 ].join('|') + '|$', 'g');
893 // Compile the template source, escaping string literals appropriately.
895 var source = "__p+='";
896 text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
897 source += text.slice(index, offset).replace(escapeRegExp, escapeChar);
898 index = offset + match.length;
901 source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
902 } else if (interpolate) {
903 source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
904 } else if (evaluate) {
905 source += "';\n" + evaluate + "\n__p+='";
908 // Adobe VMs need the match returned to produce the correct offset.
913 var argument = settings.variable;
915 // Insure against third-party code injection. (CVE-2021-23358)
916 if (!bareIdentifier.test(argument)) throw new Error(
917 'variable is not a bare identifier: ' + argument
920 // If a variable is not specified, place data values in local scope.
921 source = 'with(obj||{}){\n' + source + '}\n';
925 source = "var __t,__p='',__j=Array.prototype.join," +
926 "print=function(){__p+=__j.call(arguments,'');};\n" +
927 source + 'return __p;\n';
931 render = new Function(argument, '_', source);
937 var template = function(data) {
938 return render.call(this, data, _$1);
941 // Provide the compiled source as a convenience for precompilation.
942 template.source = 'function(' + argument + '){\n' + source + '}';
947 // Traverses the children of `obj` along `path`. If a child is a function, it
948 // is invoked with its parent as context. Returns the value of the final
949 // child, or `fallback` if any child is undefined.
950 function result(obj, path, fallback) {
952 var length = path.length;
954 return isFunction$1(fallback) ? fallback.call(obj) : fallback;
956 for (var i = 0; i < length; i++) {
957 var prop = obj == null ? void 0 : obj[path[i]];
958 if (prop === void 0) {
960 i = length; // Ensure we don't continue iterating.
962 obj = isFunction$1(prop) ? prop.call(obj) : prop;
967 // Generate a unique integer id (unique within the entire client session).
968 // Useful for temporary DOM ids.
970 function uniqueId(prefix) {
971 var id = ++idCounter + '';
972 return prefix ? prefix + id : id;
975 // Start chaining a wrapped Underscore object.
976 function chain(obj) {
977 var instance = _$1(obj);
978 instance._chain = true;
982 // Internal function to execute `sourceFunc` bound to `context` with optional
983 // `args`. Determines whether to execute a function as a constructor or as a
985 function executeBound(sourceFunc, boundFunc, context, callingContext, args) {
986 if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
987 var self = baseCreate(sourceFunc.prototype);
988 var result = sourceFunc.apply(self, args);
989 if (isObject(result)) return result;
993 // Partially apply a function by creating a version that has had some of its
994 // arguments pre-filled, without changing its dynamic `this` context. `_` acts
995 // as a placeholder by default, allowing any combination of arguments to be
996 // pre-filled. Set `_.partial.placeholder` for a custom placeholder argument.
997 var partial = restArguments(function(func, boundArgs) {
998 var placeholder = partial.placeholder;
999 var bound = function() {
1000 var position = 0, length = boundArgs.length;
1001 var args = Array(length);
1002 for (var i = 0; i < length; i++) {
1003 args[i] = boundArgs[i] === placeholder ? arguments[position++] : boundArgs[i];
1005 while (position < arguments.length) args.push(arguments[position++]);
1006 return executeBound(func, bound, this, this, args);
1011 partial.placeholder = _$1;
1013 // Create a function bound to a given object (assigning `this`, and arguments,
1015 var bind = restArguments(function(func, context, args) {
1016 if (!isFunction$1(func)) throw new TypeError('Bind must be called on a function');
1017 var bound = restArguments(function(callArgs) {
1018 return executeBound(func, bound, context, this, args.concat(callArgs));
1023 // Internal helper for collection methods to determine whether a collection
1024 // should be iterated as an array or as an object.
1025 // Related: https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
1026 // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
1027 var isArrayLike = createSizePropertyCheck(getLength);
1029 // Internal implementation of a recursive `flatten` function.
1030 function flatten$1(input, depth, strict, output) {
1031 output = output || [];
1032 if (!depth && depth !== 0) {
1034 } else if (depth <= 0) {
1035 return output.concat(input);
1037 var idx = output.length;
1038 for (var i = 0, length = getLength(input); i < length; i++) {
1039 var value = input[i];
1040 if (isArrayLike(value) && (isArray(value) || isArguments$1(value))) {
1041 // Flatten current level of array or arguments object.
1043 flatten$1(value, depth - 1, strict, output);
1044 idx = output.length;
1046 var j = 0, len = value.length;
1047 while (j < len) output[idx++] = value[j++];
1049 } else if (!strict) {
1050 output[idx++] = value;
1056 // Bind a number of an object's methods to that object. Remaining arguments
1057 // are the method names to be bound. Useful for ensuring that all callbacks
1058 // defined on an object belong to it.
1059 var bindAll = restArguments(function(obj, keys) {
1060 keys = flatten$1(keys, false, false);
1061 var index = keys.length;
1062 if (index < 1) throw new Error('bindAll must be passed function names');
1064 var key = keys[index];
1065 obj[key] = bind(obj[key], obj);
1070 // Memoize an expensive function by storing its results.
1071 function memoize(func, hasher) {
1072 var memoize = function(key) {
1073 var cache = memoize.cache;
1074 var address = '' + (hasher ? hasher.apply(this, arguments) : key);
1075 if (!has$1(cache, address)) cache[address] = func.apply(this, arguments);
1076 return cache[address];
1082 // Delays a function for the given number of milliseconds, and then calls
1083 // it with the arguments supplied.
1084 var delay = restArguments(function(func, wait, args) {
1085 return setTimeout(function() {
1086 return func.apply(null, args);
1090 // Defers a function, scheduling it to run after the current call stack has
1092 var defer = partial(delay, _$1, 1);
1094 // Returns a function, that, when invoked, will only be triggered at most once
1095 // during a given window of time. Normally, the throttled function will run
1096 // as much as it can, without ever going more than once per `wait` duration;
1097 // but if you'd like to disable the execution on the leading edge, pass
1098 // `{leading: false}`. To disable execution on the trailing edge, ditto.
1099 function throttle(func, wait, options) {
1100 var timeout, context, args, result;
1102 if (!options) options = {};
1104 var later = function() {
1105 previous = options.leading === false ? 0 : now();
1107 result = func.apply(context, args);
1108 if (!timeout) context = args = null;
1111 var throttled = function() {
1113 if (!previous && options.leading === false) previous = _now;
1114 var remaining = wait - (_now - previous);
1117 if (remaining <= 0 || remaining > wait) {
1119 clearTimeout(timeout);
1123 result = func.apply(context, args);
1124 if (!timeout) context = args = null;
1125 } else if (!timeout && options.trailing !== false) {
1126 timeout = setTimeout(later, remaining);
1131 throttled.cancel = function() {
1132 clearTimeout(timeout);
1134 timeout = context = args = null;
1140 // When a sequence of calls of the returned function ends, the argument
1141 // function is triggered. The end of a sequence is defined by the `wait`
1142 // parameter. If `immediate` is passed, the argument function will be
1143 // triggered at the beginning of the sequence instead of at the end.
1144 function debounce(func, wait, immediate) {
1145 var timeout, previous, args, result, context;
1147 var later = function() {
1148 var passed = now() - previous;
1149 if (wait > passed) {
1150 timeout = setTimeout(later, wait - passed);
1153 if (!immediate) result = func.apply(context, args);
1154 // This check is needed because `func` can recursively invoke `debounced`.
1155 if (!timeout) args = context = null;
1159 var debounced = restArguments(function(_args) {
1164 timeout = setTimeout(later, wait);
1165 if (immediate) result = func.apply(context, args);
1170 debounced.cancel = function() {
1171 clearTimeout(timeout);
1172 timeout = args = context = null;
1178 // Returns the first function passed as an argument to the second,
1179 // allowing you to adjust arguments, run code before and after, and
1180 // conditionally execute the original function.
1181 function wrap(func, wrapper) {
1182 return partial(wrapper, func);
1185 // Returns a negated version of the passed-in predicate.
1186 function negate(predicate) {
1188 return !predicate.apply(this, arguments);
1192 // Returns a function that is the composition of a list of functions, each
1193 // consuming the return value of the function that follows.
1194 function compose() {
1195 var args = arguments;
1196 var start = args.length - 1;
1199 var result = args[start].apply(this, arguments);
1200 while (i--) result = args[i].call(this, result);
1205 // Returns a function that will only be executed on and after the Nth call.
1206 function after(times, func) {
1209 return func.apply(this, arguments);
1214 // Returns a function that will only be executed up to (but not including) the
1216 function before(times, func) {
1220 memo = func.apply(this, arguments);
1222 if (times <= 1) func = null;
1227 // Returns a function that will be executed at most one time, no matter how
1228 // often you call it. Useful for lazy initialization.
1229 var once = partial(before, 2);
1231 // Returns the first key on an object that passes a truth test.
1232 function findKey(obj, predicate, context) {
1233 predicate = cb(predicate, context);
1234 var _keys = keys(obj), key;
1235 for (var i = 0, length = _keys.length; i < length; i++) {
1237 if (predicate(obj[key], key, obj)) return key;
1241 // Internal function to generate `_.findIndex` and `_.findLastIndex`.
1242 function createPredicateIndexFinder(dir) {
1243 return function(array, predicate, context) {
1244 predicate = cb(predicate, context);
1245 var length = getLength(array);
1246 var index = dir > 0 ? 0 : length - 1;
1247 for (; index >= 0 && index < length; index += dir) {
1248 if (predicate(array[index], index, array)) return index;
1254 // Returns the first index on an array-like that passes a truth test.
1255 var findIndex = createPredicateIndexFinder(1);
1257 // Returns the last index on an array-like that passes a truth test.
1258 var findLastIndex = createPredicateIndexFinder(-1);
1260 // Use a comparator function to figure out the smallest index at which
1261 // an object should be inserted so as to maintain order. Uses binary search.
1262 function sortedIndex(array, obj, iteratee, context) {
1263 iteratee = cb(iteratee, context, 1);
1264 var value = iteratee(obj);
1265 var low = 0, high = getLength(array);
1266 while (low < high) {
1267 var mid = Math.floor((low + high) / 2);
1268 if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
1273 // Internal function to generate the `_.indexOf` and `_.lastIndexOf` functions.
1274 function createIndexFinder(dir, predicateFind, sortedIndex) {
1275 return function(array, item, idx) {
1276 var i = 0, length = getLength(array);
1277 if (typeof idx == 'number') {
1279 i = idx >= 0 ? idx : Math.max(idx + length, i);
1281 length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
1283 } else if (sortedIndex && idx && length) {
1284 idx = sortedIndex(array, item);
1285 return array[idx] === item ? idx : -1;
1287 if (item !== item) {
1288 idx = predicateFind(slice.call(array, i, length), isNaN$1);
1289 return idx >= 0 ? idx + i : -1;
1291 for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
1292 if (array[idx] === item) return idx;
1298 // Return the position of the first occurrence of an item in an array,
1299 // or -1 if the item is not included in the array.
1300 // If the array is large and already in sort order, pass `true`
1301 // for **isSorted** to use binary search.
1302 var indexOf = createIndexFinder(1, findIndex, sortedIndex);
1304 // Return the position of the last occurrence of an item in an array,
1305 // or -1 if the item is not included in the array.
1306 var lastIndexOf = createIndexFinder(-1, findLastIndex);
1308 // Return the first value which passes a truth test.
1309 function find(obj, predicate, context) {
1310 var keyFinder = isArrayLike(obj) ? findIndex : findKey;
1311 var key = keyFinder(obj, predicate, context);
1312 if (key !== void 0 && key !== -1) return obj[key];
1315 // Convenience version of a common use case of `_.find`: getting the first
1316 // object containing specific `key:value` pairs.
1317 function findWhere(obj, attrs) {
1318 return find(obj, matcher(attrs));
1321 // The cornerstone for collection functions, an `each`
1322 // implementation, aka `forEach`.
1323 // Handles raw objects in addition to array-likes. Treats all
1324 // sparse array-likes as if they were dense.
1325 function each(obj, iteratee, context) {
1326 iteratee = optimizeCb(iteratee, context);
1328 if (isArrayLike(obj)) {
1329 for (i = 0, length = obj.length; i < length; i++) {
1330 iteratee(obj[i], i, obj);
1333 var _keys = keys(obj);
1334 for (i = 0, length = _keys.length; i < length; i++) {
1335 iteratee(obj[_keys[i]], _keys[i], obj);
1341 // Return the results of applying the iteratee to each element.
1342 function map(obj, iteratee, context) {
1343 iteratee = cb(iteratee, context);
1344 var _keys = !isArrayLike(obj) && keys(obj),
1345 length = (_keys || obj).length,
1346 results = Array(length);
1347 for (var index = 0; index < length; index++) {
1348 var currentKey = _keys ? _keys[index] : index;
1349 results[index] = iteratee(obj[currentKey], currentKey, obj);
1354 // Internal helper to create a reducing function, iterating left or right.
1355 function createReduce(dir) {
1356 // Wrap code that reassigns argument variables in a separate function than
1357 // the one that accesses `arguments.length` to avoid a perf hit. (#1991)
1358 var reducer = function(obj, iteratee, memo, initial) {
1359 var _keys = !isArrayLike(obj) && keys(obj),
1360 length = (_keys || obj).length,
1361 index = dir > 0 ? 0 : length - 1;
1363 memo = obj[_keys ? _keys[index] : index];
1366 for (; index >= 0 && index < length; index += dir) {
1367 var currentKey = _keys ? _keys[index] : index;
1368 memo = iteratee(memo, obj[currentKey], currentKey, obj);
1373 return function(obj, iteratee, memo, context) {
1374 var initial = arguments.length >= 3;
1375 return reducer(obj, optimizeCb(iteratee, context, 4), memo, initial);
1379 // **Reduce** builds up a single result from a list of values, aka `inject`,
1381 var reduce = createReduce(1);
1383 // The right-associative version of reduce, also known as `foldr`.
1384 var reduceRight = createReduce(-1);
1386 // Return all the elements that pass a truth test.
1387 function filter(obj, predicate, context) {
1389 predicate = cb(predicate, context);
1390 each(obj, function(value, index, list) {
1391 if (predicate(value, index, list)) results.push(value);
1396 // Return all the elements for which a truth test fails.
1397 function reject(obj, predicate, context) {
1398 return filter(obj, negate(cb(predicate)), context);
1401 // Determine whether all of the elements pass a truth test.
1402 function every(obj, predicate, context) {
1403 predicate = cb(predicate, context);
1404 var _keys = !isArrayLike(obj) && keys(obj),
1405 length = (_keys || obj).length;
1406 for (var index = 0; index < length; index++) {
1407 var currentKey = _keys ? _keys[index] : index;
1408 if (!predicate(obj[currentKey], currentKey, obj)) return false;
1413 // Determine if at least one element in the object passes a truth test.
1414 function some(obj, predicate, context) {
1415 predicate = cb(predicate, context);
1416 var _keys = !isArrayLike(obj) && keys(obj),
1417 length = (_keys || obj).length;
1418 for (var index = 0; index < length; index++) {
1419 var currentKey = _keys ? _keys[index] : index;
1420 if (predicate(obj[currentKey], currentKey, obj)) return true;
1425 // Determine if the array or object contains a given item (using `===`).
1426 function contains(obj, item, fromIndex, guard) {
1427 if (!isArrayLike(obj)) obj = values(obj);
1428 if (typeof fromIndex != 'number' || guard) fromIndex = 0;
1429 return indexOf(obj, item, fromIndex) >= 0;
1432 // Invoke a method (with arguments) on every item in a collection.
1433 var invoke = restArguments(function(obj, path, args) {
1434 var contextPath, func;
1435 if (isFunction$1(path)) {
1438 path = toPath(path);
1439 contextPath = path.slice(0, -1);
1440 path = path[path.length - 1];
1442 return map(obj, function(context) {
1445 if (contextPath && contextPath.length) {
1446 context = deepGet(context, contextPath);
1448 if (context == null) return void 0;
1449 method = context[path];
1451 return method == null ? method : method.apply(context, args);
1455 // Convenience version of a common use case of `_.map`: fetching a property.
1456 function pluck(obj, key) {
1457 return map(obj, property(key));
1460 // Convenience version of a common use case of `_.filter`: selecting only
1461 // objects containing specific `key:value` pairs.
1462 function where(obj, attrs) {
1463 return filter(obj, matcher(attrs));
1466 // Return the maximum element (or element-based computation).
1467 function max(obj, iteratee, context) {
1468 var result = -Infinity, lastComputed = -Infinity,
1470 if (iteratee == null || typeof iteratee == 'number' && typeof obj[0] != 'object' && obj != null) {
1471 obj = isArrayLike(obj) ? obj : values(obj);
1472 for (var i = 0, length = obj.length; i < length; i++) {
1474 if (value != null && value > result) {
1479 iteratee = cb(iteratee, context);
1480 each(obj, function(v, index, list) {
1481 computed = iteratee(v, index, list);
1482 if (computed > lastComputed || computed === -Infinity && result === -Infinity) {
1484 lastComputed = computed;
1491 // Return the minimum element (or element-based computation).
1492 function min(obj, iteratee, context) {
1493 var result = Infinity, lastComputed = Infinity,
1495 if (iteratee == null || typeof iteratee == 'number' && typeof obj[0] != 'object' && obj != null) {
1496 obj = isArrayLike(obj) ? obj : values(obj);
1497 for (var i = 0, length = obj.length; i < length; i++) {
1499 if (value != null && value < result) {
1504 iteratee = cb(iteratee, context);
1505 each(obj, function(v, index, list) {
1506 computed = iteratee(v, index, list);
1507 if (computed < lastComputed || computed === Infinity && result === Infinity) {
1509 lastComputed = computed;
1516 // Sample **n** random values from a collection using the modern version of the
1517 // [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher–Yates_shuffle).
1518 // If **n** is not specified, returns a single random element.
1519 // The internal `guard` argument allows it to work with `_.map`.
1520 function sample(obj, n, guard) {
1521 if (n == null || guard) {
1522 if (!isArrayLike(obj)) obj = values(obj);
1523 return obj[random(obj.length - 1)];
1525 var sample = isArrayLike(obj) ? clone(obj) : values(obj);
1526 var length = getLength(sample);
1527 n = Math.max(Math.min(n, length), 0);
1528 var last = length - 1;
1529 for (var index = 0; index < n; index++) {
1530 var rand = random(index, last);
1531 var temp = sample[index];
1532 sample[index] = sample[rand];
1533 sample[rand] = temp;
1535 return sample.slice(0, n);
1538 // Shuffle a collection.
1539 function shuffle(obj) {
1540 return sample(obj, Infinity);
1543 // Sort the object's values by a criterion produced by an iteratee.
1544 function sortBy(obj, iteratee, context) {
1546 iteratee = cb(iteratee, context);
1547 return pluck(map(obj, function(value, key, list) {
1551 criteria: iteratee(value, key, list)
1553 }).sort(function(left, right) {
1554 var a = left.criteria;
1555 var b = right.criteria;
1557 if (a > b || a === void 0) return 1;
1558 if (a < b || b === void 0) return -1;
1560 return left.index - right.index;
1564 // An internal function used for aggregate "group by" operations.
1565 function group(behavior, partition) {
1566 return function(obj, iteratee, context) {
1567 var result = partition ? [[], []] : {};
1568 iteratee = cb(iteratee, context);
1569 each(obj, function(value, index) {
1570 var key = iteratee(value, index, obj);
1571 behavior(result, value, key);
1577 // Groups the object's values by a criterion. Pass either a string attribute
1578 // to group by, or a function that returns the criterion.
1579 var groupBy = group(function(result, value, key) {
1580 if (has$1(result, key)) result[key].push(value); else result[key] = [value];
1583 // Indexes the object's values by a criterion, similar to `_.groupBy`, but for
1584 // when you know that your index values will be unique.
1585 var indexBy = group(function(result, value, key) {
1586 result[key] = value;
1589 // Counts instances of an object that group by a certain criterion. Pass
1590 // either a string attribute to count by, or a function that returns the
1592 var countBy = group(function(result, value, key) {
1593 if (has$1(result, key)) result[key]++; else result[key] = 1;
1596 // Split a collection into two arrays: one whose elements all pass the given
1597 // truth test, and one whose elements all do not pass the truth test.
1598 var partition = group(function(result, value, pass) {
1599 result[pass ? 0 : 1].push(value);
1602 // Safely create a real, live array from anything iterable.
1603 var reStrSymbol = /[^\ud800-\udfff]|[\ud800-\udbff][\udc00-\udfff]|[\ud800-\udfff]/g;
1604 function toArray(obj) {
1605 if (!obj) return [];
1606 if (isArray(obj)) return slice.call(obj);
1607 if (isString(obj)) {
1608 // Keep surrogate pair characters together.
1609 return obj.match(reStrSymbol);
1611 if (isArrayLike(obj)) return map(obj, identity);
1615 // Return the number of elements in a collection.
1616 function size(obj) {
1617 if (obj == null) return 0;
1618 return isArrayLike(obj) ? obj.length : keys(obj).length;
1621 // Internal `_.pick` helper function to determine whether `key` is an enumerable
1622 // property name of `obj`.
1623 function keyInObj(value, key, obj) {
1627 // Return a copy of the object only containing the allowed properties.
1628 var pick = restArguments(function(obj, keys) {
1629 var result = {}, iteratee = keys[0];
1630 if (obj == null) return result;
1631 if (isFunction$1(iteratee)) {
1632 if (keys.length > 1) iteratee = optimizeCb(iteratee, keys[1]);
1633 keys = allKeys(obj);
1635 iteratee = keyInObj;
1636 keys = flatten$1(keys, false, false);
1639 for (var i = 0, length = keys.length; i < length; i++) {
1641 var value = obj[key];
1642 if (iteratee(value, key, obj)) result[key] = value;
1647 // Return a copy of the object without the disallowed properties.
1648 var omit = restArguments(function(obj, keys) {
1649 var iteratee = keys[0], context;
1650 if (isFunction$1(iteratee)) {
1651 iteratee = negate(iteratee);
1652 if (keys.length > 1) context = keys[1];
1654 keys = map(flatten$1(keys, false, false), String);
1655 iteratee = function(value, key) {
1656 return !contains(keys, key);
1659 return pick(obj, iteratee, context);
1662 // Returns everything but the last entry of the array. Especially useful on
1663 // the arguments object. Passing **n** will return all the values in
1664 // the array, excluding the last N.
1665 function initial(array, n, guard) {
1666 return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n)));
1669 // Get the first element of an array. Passing **n** will return the first N
1670 // values in the array. The **guard** check allows it to work with `_.map`.
1671 function first(array, n, guard) {
1672 if (array == null || array.length < 1) return n == null || guard ? void 0 : [];
1673 if (n == null || guard) return array[0];
1674 return initial(array, array.length - n);
1677 // Returns everything but the first entry of the `array`. Especially useful on
1678 // the `arguments` object. Passing an **n** will return the rest N values in the
1680 function rest(array, n, guard) {
1681 return slice.call(array, n == null || guard ? 1 : n);
1684 // Get the last element of an array. Passing **n** will return the last N
1685 // values in the array.
1686 function last(array, n, guard) {
1687 if (array == null || array.length < 1) return n == null || guard ? void 0 : [];
1688 if (n == null || guard) return array[array.length - 1];
1689 return rest(array, Math.max(0, array.length - n));
1692 // Trim out all falsy values from an array.
1693 function compact(array) {
1694 return filter(array, Boolean);
1697 // Flatten out an array, either recursively (by default), or up to `depth`.
1698 // Passing `true` or `false` as `depth` means `1` or `Infinity`, respectively.
1699 function flatten(array, depth) {
1700 return flatten$1(array, depth, false);
1703 // Take the difference between one array and a number of other arrays.
1704 // Only the elements present in just the first array will remain.
1705 var difference = restArguments(function(array, rest) {
1706 rest = flatten$1(rest, true, true);
1707 return filter(array, function(value){
1708 return !contains(rest, value);
1712 // Return a version of the array that does not contain the specified value(s).
1713 var without = restArguments(function(array, otherArrays) {
1714 return difference(array, otherArrays);
1717 // Produce a duplicate-free version of the array. If the array has already
1718 // been sorted, you have the option of using a faster algorithm.
1719 // The faster algorithm will not work with an iteratee if the iteratee
1720 // is not a one-to-one function, so providing an iteratee will disable
1721 // the faster algorithm.
1722 function uniq(array, isSorted, iteratee, context) {
1723 if (!isBoolean(isSorted)) {
1725 iteratee = isSorted;
1728 if (iteratee != null) iteratee = cb(iteratee, context);
1731 for (var i = 0, length = getLength(array); i < length; i++) {
1732 var value = array[i],
1733 computed = iteratee ? iteratee(value, i, array) : value;
1734 if (isSorted && !iteratee) {
1735 if (!i || seen !== computed) result.push(value);
1737 } else if (iteratee) {
1738 if (!contains(seen, computed)) {
1739 seen.push(computed);
1742 } else if (!contains(result, value)) {
1749 // Produce an array that contains the union: each distinct element from all of
1750 // the passed-in arrays.
1751 var union = restArguments(function(arrays) {
1752 return uniq(flatten$1(arrays, true, true));
1755 // Produce an array that contains every item shared between all the
1756 // passed-in arrays.
1757 function intersection(array) {
1759 var argsLength = arguments.length;
1760 for (var i = 0, length = getLength(array); i < length; i++) {
1761 var item = array[i];
1762 if (contains(result, item)) continue;
1764 for (j = 1; j < argsLength; j++) {
1765 if (!contains(arguments[j], item)) break;
1767 if (j === argsLength) result.push(item);
1772 // Complement of zip. Unzip accepts an array of arrays and groups
1773 // each array's elements on shared indices.
1774 function unzip(array) {
1775 var length = array && max(array, getLength).length || 0;
1776 var result = Array(length);
1778 for (var index = 0; index < length; index++) {
1779 result[index] = pluck(array, index);
1784 // Zip together multiple lists into a single array -- elements that share
1785 // an index go together.
1786 var zip = restArguments(unzip);
1788 // Converts lists into objects. Pass either a single array of `[key, value]`
1789 // pairs, or two parallel arrays of the same length -- one of keys, and one of
1790 // the corresponding values. Passing by pairs is the reverse of `_.pairs`.
1791 function object(list, values) {
1793 for (var i = 0, length = getLength(list); i < length; i++) {
1795 result[list[i]] = values[i];
1797 result[list[i][0]] = list[i][1];
1803 // Generate an integer Array containing an arithmetic progression. A port of
1804 // the native Python `range()` function. See
1805 // [the Python documentation](https://docs.python.org/library/functions.html#range).
1806 function range(start, stop, step) {
1812 step = stop < start ? -1 : 1;
1815 var length = Math.max(Math.ceil((stop - start) / step), 0);
1816 var range = Array(length);
1818 for (var idx = 0; idx < length; idx++, start += step) {
1825 // Chunk a single array into multiple arrays, each containing `count` or fewer
1827 function chunk(array, count) {
1828 if (count == null || count < 1) return [];
1830 var i = 0, length = array.length;
1831 while (i < length) {
1832 result.push(slice.call(array, i, i += count));
1837 // Helper function to continue chaining intermediate results.
1838 function chainResult(instance, obj) {
1839 return instance._chain ? _$1(obj).chain() : obj;
1842 // Add your own custom functions to the Underscore object.
1843 function mixin(obj) {
1844 each(functions(obj), function(name) {
1845 var func = _$1[name] = obj[name];
1846 _$1.prototype[name] = function() {
1847 var args = [this._wrapped];
1848 push.apply(args, arguments);
1849 return chainResult(this, func.apply(_$1, args));
1855 // Add all mutator `Array` functions to the wrapper.
1856 each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
1857 var method = ArrayProto[name];
1858 _$1.prototype[name] = function() {
1859 var obj = this._wrapped;
1861 method.apply(obj, arguments);
1862 if ((name === 'shift' || name === 'splice') && obj.length === 0) {
1866 return chainResult(this, obj);
1870 // Add all accessor `Array` functions to the wrapper.
1871 each(['concat', 'join', 'slice'], function(name) {
1872 var method = ArrayProto[name];
1873 _$1.prototype[name] = function() {
1874 var obj = this._wrapped;
1875 if (obj != null) obj = method.apply(obj, arguments);
1876 return chainResult(this, obj);
1885 restArguments: restArguments,
1888 isUndefined: isUndefined,
1889 isBoolean: isBoolean,
1890 isElement: isElement,
1897 isArrayBuffer: isArrayBuffer,
1898 isDataView: isDataView$1,
1900 isFunction: isFunction$1,
1901 isArguments: isArguments$1,
1902 isFinite: isFinite$1,
1904 isTypedArray: isTypedArray$1,
1909 isWeakMap: isWeakMap,
1911 isWeakSet: isWeakSet,
1917 functions: functions,
1920 extendOwn: extendOwn,
1928 mapObject: mapObject,
1934 propertyOf: propertyOf,
1941 unescape: _unescape,
1942 templateSettings: templateSettings,
1963 findIndex: findIndex,
1964 findLastIndex: findLastIndex,
1965 sortedIndex: sortedIndex,
1967 lastIndexOf: lastIndexOf,
1970 findWhere: findWhere,
1978 reduceRight: reduceRight,
2001 partition: partition,
2020 intersection: intersection,
2021 difference: difference,
2034 // Add all of the Underscore functions to the wrapper object.
2035 var _ = mixin(allExports);
2036 // Legacy Node.js API.
2042 //# sourceMappingURL=underscore-umd.js.map