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1 | // Underscore.js 1.7.0 |
2 | // http://underscorejs.org | |
3 | // (c) 2009-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors | |
4 | // Underscore may be freely distributed under the MIT license. | |
5 | ||
6 | (function() { | |
7 | ||
8 | // Baseline setup | |
9 | // -------------- | |
10 | ||
11 | // Establish the root object, `window` in the browser, or `exports` on the server. | |
12 | var root = this; | |
13 | ||
14 | // Save the previous value of the `_` variable. | |
15 | var previousUnderscore = root._; | |
16 | ||
17 | // Save bytes in the minified (but not gzipped) version: | |
18 | var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; | |
19 | ||
20 | // Create quick reference variables for speed access to core prototypes. | |
21 | var | |
22 | push = ArrayProto.push, | |
23 | slice = ArrayProto.slice, | |
24 | concat = ArrayProto.concat, | |
25 | toString = ObjProto.toString, | |
26 | hasOwnProperty = ObjProto.hasOwnProperty; | |
27 | ||
28 | // All **ECMAScript 5** native function implementations that we hope to use | |
29 | // are declared here. | |
30 | var | |
31 | nativeIsArray = Array.isArray, | |
32 | nativeKeys = Object.keys, | |
33 | nativeBind = FuncProto.bind; | |
34 | ||
35 | // Create a safe reference to the Underscore object for use below. | |
36 | var _ = function(obj) { | |
37 | if (obj instanceof _) return obj; | |
38 | if (!(this instanceof _)) return new _(obj); | |
39 | this._wrapped = obj; | |
40 | }; | |
41 | ||
42 | // Export the Underscore object for **Node.js**, with | |
43 | // backwards-compatibility for the old `require()` API. If we're in | |
44 | // the browser, add `_` as a global object. | |
45 | if (typeof exports !== 'undefined') { | |
46 | if (typeof module !== 'undefined' && module.exports) { | |
47 | exports = module.exports = _; | |
48 | } | |
49 | exports._ = _; | |
50 | } else { | |
51 | root._ = _; | |
52 | } | |
53 | ||
54 | // Current version. | |
55 | _.VERSION = '1.7.0'; | |
56 | ||
57 | // Internal function that returns an efficient (for current engines) version | |
58 | // of the passed-in callback, to be repeatedly applied in other Underscore | |
59 | // functions. | |
60 | var createCallback = function(func, context, argCount) { | |
61 | if (context === void 0) return func; | |
62 | switch (argCount == null ? 3 : argCount) { | |
63 | case 1: return function(value) { | |
64 | return func.call(context, value); | |
65 | }; | |
66 | case 2: return function(value, other) { | |
67 | return func.call(context, value, other); | |
68 | }; | |
69 | case 3: return function(value, index, collection) { | |
70 | return func.call(context, value, index, collection); | |
71 | }; | |
72 | case 4: return function(accumulator, value, index, collection) { | |
73 | return func.call(context, accumulator, value, index, collection); | |
74 | }; | |
75 | } | |
76 | return function() { | |
77 | return func.apply(context, arguments); | |
78 | }; | |
79 | }; | |
80 | ||
81 | // A mostly-internal function to generate callbacks that can be applied | |
82 | // to each element in a collection, returning the desired result — either | |
83 | // identity, an arbitrary callback, a property matcher, or a property accessor. | |
84 | _.iteratee = function(value, context, argCount) { | |
85 | if (value == null) return _.identity; | |
86 | if (_.isFunction(value)) return createCallback(value, context, argCount); | |
87 | if (_.isObject(value)) return _.matches(value); | |
88 | return _.property(value); | |
89 | }; | |
90 | ||
91 | // Collection Functions | |
92 | // -------------------- | |
93 | ||
94 | // The cornerstone, an `each` implementation, aka `forEach`. | |
95 | // Handles raw objects in addition to array-likes. Treats all | |
96 | // sparse array-likes as if they were dense. | |
97 | _.each = _.forEach = function(obj, iteratee, context) { | |
98 | if (obj == null) return obj; | |
99 | iteratee = createCallback(iteratee, context); | |
100 | var i, length = obj.length; | |
101 | if (length === +length) { | |
102 | for (i = 0; i < length; i++) { | |
103 | iteratee(obj[i], i, obj); | |
104 | } | |
105 | } else { | |
106 | var keys = _.keys(obj); | |
107 | for (i = 0, length = keys.length; i < length; i++) { | |
108 | iteratee(obj[keys[i]], keys[i], obj); | |
109 | } | |
110 | } | |
111 | return obj; | |
112 | }; | |
113 | ||
114 | // Return the results of applying the iteratee to each element. | |
115 | _.map = _.collect = function(obj, iteratee, context) { | |
116 | if (obj == null) return []; | |
117 | iteratee = _.iteratee(iteratee, context); | |
118 | var keys = obj.length !== +obj.length && _.keys(obj), | |
119 | length = (keys || obj).length, | |
120 | results = Array(length), | |
121 | currentKey; | |
122 | for (var index = 0; index < length; index++) { | |
123 | currentKey = keys ? keys[index] : index; | |
124 | results[index] = iteratee(obj[currentKey], currentKey, obj); | |
125 | } | |
126 | return results; | |
127 | }; | |
128 | ||
129 | var reduceError = 'Reduce of empty array with no initial value'; | |
130 | ||
131 | // **Reduce** builds up a single result from a list of values, aka `inject`, | |
132 | // or `foldl`. | |
133 | _.reduce = _.foldl = _.inject = function(obj, iteratee, memo, context) { | |
134 | if (obj == null) obj = []; | |
135 | iteratee = createCallback(iteratee, context, 4); | |
136 | var keys = obj.length !== +obj.length && _.keys(obj), | |
137 | length = (keys || obj).length, | |
138 | index = 0, currentKey; | |
139 | if (arguments.length < 3) { | |
140 | if (!length) throw new TypeError(reduceError); | |
141 | memo = obj[keys ? keys[index++] : index++]; | |
142 | } | |
143 | for (; index < length; index++) { | |
144 | currentKey = keys ? keys[index] : index; | |
145 | memo = iteratee(memo, obj[currentKey], currentKey, obj); | |
146 | } | |
147 | return memo; | |
148 | }; | |
149 | ||
150 | // The right-associative version of reduce, also known as `foldr`. | |
151 | _.reduceRight = _.foldr = function(obj, iteratee, memo, context) { | |
152 | if (obj == null) obj = []; | |
153 | iteratee = createCallback(iteratee, context, 4); | |
154 | var keys = obj.length !== + obj.length && _.keys(obj), | |
155 | index = (keys || obj).length, | |
156 | currentKey; | |
157 | if (arguments.length < 3) { | |
158 | if (!index) throw new TypeError(reduceError); | |
159 | memo = obj[keys ? keys[--index] : --index]; | |
160 | } | |
161 | while (index--) { | |
162 | currentKey = keys ? keys[index] : index; | |
163 | memo = iteratee(memo, obj[currentKey], currentKey, obj); | |
164 | } | |
165 | return memo; | |
166 | }; | |
167 | ||
168 | // Return the first value which passes a truth test. Aliased as `detect`. | |
169 | _.find = _.detect = function(obj, predicate, context) { | |
170 | var result; | |
171 | predicate = _.iteratee(predicate, context); | |
172 | _.some(obj, function(value, index, list) { | |
173 | if (predicate(value, index, list)) { | |
174 | result = value; | |
175 | return true; | |
176 | } | |
177 | }); | |
178 | return result; | |
179 | }; | |
180 | ||
181 | // Return all the elements that pass a truth test. | |
182 | // Aliased as `select`. | |
183 | _.filter = _.select = function(obj, predicate, context) { | |
184 | var results = []; | |
185 | if (obj == null) return results; | |
186 | predicate = _.iteratee(predicate, context); | |
187 | _.each(obj, function(value, index, list) { | |
188 | if (predicate(value, index, list)) results.push(value); | |
189 | }); | |
190 | return results; | |
191 | }; | |
192 | ||
193 | // Return all the elements for which a truth test fails. | |
194 | _.reject = function(obj, predicate, context) { | |
195 | return _.filter(obj, _.negate(_.iteratee(predicate)), context); | |
196 | }; | |
197 | ||
198 | // Determine whether all of the elements match a truth test. | |
199 | // Aliased as `all`. | |
200 | _.every = _.all = function(obj, predicate, context) { | |
201 | if (obj == null) return true; | |
202 | predicate = _.iteratee(predicate, context); | |
203 | var keys = obj.length !== +obj.length && _.keys(obj), | |
204 | length = (keys || obj).length, | |
205 | index, currentKey; | |
206 | for (index = 0; index < length; index++) { | |
207 | currentKey = keys ? keys[index] : index; | |
208 | if (!predicate(obj[currentKey], currentKey, obj)) return false; | |
209 | } | |
210 | return true; | |
211 | }; | |
212 | ||
213 | // Determine if at least one element in the object matches a truth test. | |
214 | // Aliased as `any`. | |
215 | _.some = _.any = function(obj, predicate, context) { | |
216 | if (obj == null) return false; | |
217 | predicate = _.iteratee(predicate, context); | |
218 | var keys = obj.length !== +obj.length && _.keys(obj), | |
219 | length = (keys || obj).length, | |
220 | index, currentKey; | |
221 | for (index = 0; index < length; index++) { | |
222 | currentKey = keys ? keys[index] : index; | |
223 | if (predicate(obj[currentKey], currentKey, obj)) return true; | |
224 | } | |
225 | return false; | |
226 | }; | |
227 | ||
228 | // Determine if the array or object contains a given value (using `===`). | |
229 | // Aliased as `include`. | |
230 | _.contains = _.include = function(obj, target) { | |
231 | if (obj == null) return false; | |
232 | if (obj.length !== +obj.length) obj = _.values(obj); | |
233 | return _.indexOf(obj, target) >= 0; | |
234 | }; | |
235 | ||
236 | // Invoke a method (with arguments) on every item in a collection. | |
237 | _.invoke = function(obj, method) { | |
238 | var args = slice.call(arguments, 2); | |
239 | var isFunc = _.isFunction(method); | |
240 | return _.map(obj, function(value) { | |
241 | return (isFunc ? method : value[method]).apply(value, args); | |
242 | }); | |
243 | }; | |
244 | ||
245 | // Convenience version of a common use case of `map`: fetching a property. | |
246 | _.pluck = function(obj, key) { | |
247 | return _.map(obj, _.property(key)); | |
248 | }; | |
249 | ||
250 | // Convenience version of a common use case of `filter`: selecting only objects | |
251 | // containing specific `key:value` pairs. | |
252 | _.where = function(obj, attrs) { | |
253 | return _.filter(obj, _.matches(attrs)); | |
254 | }; | |
255 | ||
256 | // Convenience version of a common use case of `find`: getting the first object | |
257 | // containing specific `key:value` pairs. | |
258 | _.findWhere = function(obj, attrs) { | |
259 | return _.find(obj, _.matches(attrs)); | |
260 | }; | |
261 | ||
262 | // Return the maximum element (or element-based computation). | |
263 | _.max = function(obj, iteratee, context) { | |
264 | var result = -Infinity, lastComputed = -Infinity, | |
265 | value, computed; | |
266 | if (iteratee == null && obj != null) { | |
267 | obj = obj.length === +obj.length ? obj : _.values(obj); | |
268 | for (var i = 0, length = obj.length; i < length; i++) { | |
269 | value = obj[i]; | |
270 | if (value > result) { | |
271 | result = value; | |
272 | } | |
273 | } | |
274 | } else { | |
275 | iteratee = _.iteratee(iteratee, context); | |
276 | _.each(obj, function(value, index, list) { | |
277 | computed = iteratee(value, index, list); | |
278 | if (computed > lastComputed || computed === -Infinity && result === -Infinity) { | |
279 | result = value; | |
280 | lastComputed = computed; | |
281 | } | |
282 | }); | |
283 | } | |
284 | return result; | |
285 | }; | |
286 | ||
287 | // Return the minimum element (or element-based computation). | |
288 | _.min = function(obj, iteratee, context) { | |
289 | var result = Infinity, lastComputed = Infinity, | |
290 | value, computed; | |
291 | if (iteratee == null && obj != null) { | |
292 | obj = obj.length === +obj.length ? obj : _.values(obj); | |
293 | for (var i = 0, length = obj.length; i < length; i++) { | |
294 | value = obj[i]; | |
295 | if (value < result) { | |
296 | result = value; | |
297 | } | |
298 | } | |
299 | } else { | |
300 | iteratee = _.iteratee(iteratee, context); | |
301 | _.each(obj, function(value, index, list) { | |
302 | computed = iteratee(value, index, list); | |
303 | if (computed < lastComputed || computed === Infinity && result === Infinity) { | |
304 | result = value; | |
305 | lastComputed = computed; | |
306 | } | |
307 | }); | |
308 | } | |
309 | return result; | |
310 | }; | |
311 | ||
312 | // Shuffle a collection, using the modern version of the | |
313 | // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher–Yates_shuffle). | |
314 | _.shuffle = function(obj) { | |
315 | var set = obj && obj.length === +obj.length ? obj : _.values(obj); | |
316 | var length = set.length; | |
317 | var shuffled = Array(length); | |
318 | for (var index = 0, rand; index < length; index++) { | |
319 | rand = _.random(0, index); | |
320 | if (rand !== index) shuffled[index] = shuffled[rand]; | |
321 | shuffled[rand] = set[index]; | |
322 | } | |
323 | return shuffled; | |
324 | }; | |
325 | ||
326 | // Sample **n** random values from a collection. | |
327 | // If **n** is not specified, returns a single random element. | |
328 | // The internal `guard` argument allows it to work with `map`. | |
329 | _.sample = function(obj, n, guard) { | |
330 | if (n == null || guard) { | |
331 | if (obj.length !== +obj.length) obj = _.values(obj); | |
332 | return obj[_.random(obj.length - 1)]; | |
333 | } | |
334 | return _.shuffle(obj).slice(0, Math.max(0, n)); | |
335 | }; | |
336 | ||
337 | // Sort the object's values by a criterion produced by an iteratee. | |
338 | _.sortBy = function(obj, iteratee, context) { | |
339 | iteratee = _.iteratee(iteratee, context); | |
340 | return _.pluck(_.map(obj, function(value, index, list) { | |
341 | return { | |
342 | value: value, | |
343 | index: index, | |
344 | criteria: iteratee(value, index, list) | |
345 | }; | |
346 | }).sort(function(left, right) { | |
347 | var a = left.criteria; | |
348 | var b = right.criteria; | |
349 | if (a !== b) { | |
350 | if (a > b || a === void 0) return 1; | |
351 | if (a < b || b === void 0) return -1; | |
352 | } | |
353 | return left.index - right.index; | |
354 | }), 'value'); | |
355 | }; | |
356 | ||
357 | // An internal function used for aggregate "group by" operations. | |
358 | var group = function(behavior) { | |
359 | return function(obj, iteratee, context) { | |
360 | var result = {}; | |
361 | iteratee = _.iteratee(iteratee, context); | |
362 | _.each(obj, function(value, index) { | |
363 | var key = iteratee(value, index, obj); | |
364 | behavior(result, value, key); | |
365 | }); | |
366 | return result; | |
367 | }; | |
368 | }; | |
369 | ||
370 | // Groups the object's values by a criterion. Pass either a string attribute | |
371 | // to group by, or a function that returns the criterion. | |
372 | _.groupBy = group(function(result, value, key) { | |
373 | if (_.has(result, key)) result[key].push(value); else result[key] = [value]; | |
374 | }); | |
375 | ||
376 | // Indexes the object's values by a criterion, similar to `groupBy`, but for | |
377 | // when you know that your index values will be unique. | |
378 | _.indexBy = group(function(result, value, key) { | |
379 | result[key] = value; | |
380 | }); | |
381 | ||
382 | // Counts instances of an object that group by a certain criterion. Pass | |
383 | // either a string attribute to count by, or a function that returns the | |
384 | // criterion. | |
385 | _.countBy = group(function(result, value, key) { | |
386 | if (_.has(result, key)) result[key]++; else result[key] = 1; | |
387 | }); | |
388 | ||
389 | // Use a comparator function to figure out the smallest index at which | |
390 | // an object should be inserted so as to maintain order. Uses binary search. | |
391 | _.sortedIndex = function(array, obj, iteratee, context) { | |
392 | iteratee = _.iteratee(iteratee, context, 1); | |
393 | var value = iteratee(obj); | |
394 | var low = 0, high = array.length; | |
395 | while (low < high) { | |
396 | var mid = low + high >>> 1; | |
397 | if (iteratee(array[mid]) < value) low = mid + 1; else high = mid; | |
398 | } | |
399 | return low; | |
400 | }; | |
401 | ||
402 | // Safely create a real, live array from anything iterable. | |
403 | _.toArray = function(obj) { | |
404 | if (!obj) return []; | |
405 | if (_.isArray(obj)) return slice.call(obj); | |
406 | if (obj.length === +obj.length) return _.map(obj, _.identity); | |
407 | return _.values(obj); | |
408 | }; | |
409 | ||
410 | // Return the number of elements in an object. | |
411 | _.size = function(obj) { | |
412 | if (obj == null) return 0; | |
413 | return obj.length === +obj.length ? obj.length : _.keys(obj).length; | |
414 | }; | |
415 | ||
416 | // Split a collection into two arrays: one whose elements all satisfy the given | |
417 | // predicate, and one whose elements all do not satisfy the predicate. | |
418 | _.partition = function(obj, predicate, context) { | |
419 | predicate = _.iteratee(predicate, context); | |
420 | var pass = [], fail = []; | |
421 | _.each(obj, function(value, key, obj) { | |
422 | (predicate(value, key, obj) ? pass : fail).push(value); | |
423 | }); | |
424 | return [pass, fail]; | |
425 | }; | |
426 | ||
427 | // Array Functions | |
428 | // --------------- | |
429 | ||
430 | // Get the first element of an array. Passing **n** will return the first N | |
431 | // values in the array. Aliased as `head` and `take`. The **guard** check | |
432 | // allows it to work with `_.map`. | |
433 | _.first = _.head = _.take = function(array, n, guard) { | |
434 | if (array == null) return void 0; | |
435 | if (n == null || guard) return array[0]; | |
436 | if (n < 0) return []; | |
437 | return slice.call(array, 0, n); | |
438 | }; | |
439 | ||
440 | // Returns everything but the last entry of the array. Especially useful on | |
441 | // the arguments object. Passing **n** will return all the values in | |
442 | // the array, excluding the last N. The **guard** check allows it to work with | |
443 | // `_.map`. | |
444 | _.initial = function(array, n, guard) { | |
445 | return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n))); | |
446 | }; | |
447 | ||
448 | // Get the last element of an array. Passing **n** will return the last N | |
449 | // values in the array. The **guard** check allows it to work with `_.map`. | |
450 | _.last = function(array, n, guard) { | |
451 | if (array == null) return void 0; | |
452 | if (n == null || guard) return array[array.length - 1]; | |
453 | return slice.call(array, Math.max(array.length - n, 0)); | |
454 | }; | |
455 | ||
456 | // Returns everything but the first entry of the array. Aliased as `tail` and `drop`. | |
457 | // Especially useful on the arguments object. Passing an **n** will return | |
458 | // the rest N values in the array. The **guard** | |
459 | // check allows it to work with `_.map`. | |
460 | _.rest = _.tail = _.drop = function(array, n, guard) { | |
461 | return slice.call(array, n == null || guard ? 1 : n); | |
462 | }; | |
463 | ||
464 | // Trim out all falsy values from an array. | |
465 | _.compact = function(array) { | |
466 | return _.filter(array, _.identity); | |
467 | }; | |
468 | ||
469 | // Internal implementation of a recursive `flatten` function. | |
470 | var flatten = function(input, shallow, strict, output) { | |
471 | if (shallow && _.every(input, _.isArray)) { | |
472 | return concat.apply(output, input); | |
473 | } | |
474 | for (var i = 0, length = input.length; i < length; i++) { | |
475 | var value = input[i]; | |
476 | if (!_.isArray(value) && !_.isArguments(value)) { | |
477 | if (!strict) output.push(value); | |
478 | } else if (shallow) { | |
479 | push.apply(output, value); | |
480 | } else { | |
481 | flatten(value, shallow, strict, output); | |
482 | } | |
483 | } | |
484 | return output; | |
485 | }; | |
486 | ||
487 | // Flatten out an array, either recursively (by default), or just one level. | |
488 | _.flatten = function(array, shallow) { | |
489 | return flatten(array, shallow, false, []); | |
490 | }; | |
491 | ||
492 | // Return a version of the array that does not contain the specified value(s). | |
493 | _.without = function(array) { | |
494 | return _.difference(array, slice.call(arguments, 1)); | |
495 | }; | |
496 | ||
497 | // Produce a duplicate-free version of the array. If the array has already | |
498 | // been sorted, you have the option of using a faster algorithm. | |
499 | // Aliased as `unique`. | |
500 | _.uniq = _.unique = function(array, isSorted, iteratee, context) { | |
501 | if (array == null) return []; | |
502 | if (!_.isBoolean(isSorted)) { | |
503 | context = iteratee; | |
504 | iteratee = isSorted; | |
505 | isSorted = false; | |
506 | } | |
507 | if (iteratee != null) iteratee = _.iteratee(iteratee, context); | |
508 | var result = []; | |
509 | var seen = []; | |
510 | for (var i = 0, length = array.length; i < length; i++) { | |
511 | var value = array[i]; | |
512 | if (isSorted) { | |
513 | if (!i || seen !== value) result.push(value); | |
514 | seen = value; | |
515 | } else if (iteratee) { | |
516 | var computed = iteratee(value, i, array); | |
517 | if (_.indexOf(seen, computed) < 0) { | |
518 | seen.push(computed); | |
519 | result.push(value); | |
520 | } | |
521 | } else if (_.indexOf(result, value) < 0) { | |
522 | result.push(value); | |
523 | } | |
524 | } | |
525 | return result; | |
526 | }; | |
527 | ||
528 | // Produce an array that contains the union: each distinct element from all of | |
529 | // the passed-in arrays. | |
530 | _.union = function() { | |
531 | return _.uniq(flatten(arguments, true, true, [])); | |
532 | }; | |
533 | ||
534 | // Produce an array that contains every item shared between all the | |
535 | // passed-in arrays. | |
536 | _.intersection = function(array) { | |
537 | if (array == null) return []; | |
538 | var result = []; | |
539 | var argsLength = arguments.length; | |
540 | for (var i = 0, length = array.length; i < length; i++) { | |
541 | var item = array[i]; | |
542 | if (_.contains(result, item)) continue; | |
543 | for (var j = 1; j < argsLength; j++) { | |
544 | if (!_.contains(arguments[j], item)) break; | |
545 | } | |
546 | if (j === argsLength) result.push(item); | |
547 | } | |
548 | return result; | |
549 | }; | |
550 | ||
551 | // Take the difference between one array and a number of other arrays. | |
552 | // Only the elements present in just the first array will remain. | |
553 | _.difference = function(array) { | |
554 | var rest = flatten(slice.call(arguments, 1), true, true, []); | |
555 | return _.filter(array, function(value){ | |
556 | return !_.contains(rest, value); | |
557 | }); | |
558 | }; | |
559 | ||
560 | // Zip together multiple lists into a single array -- elements that share | |
561 | // an index go together. | |
562 | _.zip = function(array) { | |
563 | if (array == null) return []; | |
564 | var length = _.max(arguments, 'length').length; | |
565 | var results = Array(length); | |
566 | for (var i = 0; i < length; i++) { | |
567 | results[i] = _.pluck(arguments, i); | |
568 | } | |
569 | return results; | |
570 | }; | |
571 | ||
572 | // Converts lists into objects. Pass either a single array of `[key, value]` | |
573 | // pairs, or two parallel arrays of the same length -- one of keys, and one of | |
574 | // the corresponding values. | |
575 | _.object = function(list, values) { | |
576 | if (list == null) return {}; | |
577 | var result = {}; | |
578 | for (var i = 0, length = list.length; i < length; i++) { | |
579 | if (values) { | |
580 | result[list[i]] = values[i]; | |
581 | } else { | |
582 | result[list[i][0]] = list[i][1]; | |
583 | } | |
584 | } | |
585 | return result; | |
586 | }; | |
587 | ||
588 | // Return the position of the first occurrence of an item in an array, | |
589 | // or -1 if the item is not included in the array. | |
590 | // If the array is large and already in sort order, pass `true` | |
591 | // for **isSorted** to use binary search. | |
592 | _.indexOf = function(array, item, isSorted) { | |
593 | if (array == null) return -1; | |
594 | var i = 0, length = array.length; | |
595 | if (isSorted) { | |
596 | if (typeof isSorted == 'number') { | |
597 | i = isSorted < 0 ? Math.max(0, length + isSorted) : isSorted; | |
598 | } else { | |
599 | i = _.sortedIndex(array, item); | |
600 | return array[i] === item ? i : -1; | |
601 | } | |
602 | } | |
603 | for (; i < length; i++) if (array[i] === item) return i; | |
604 | return -1; | |
605 | }; | |
606 | ||
607 | _.lastIndexOf = function(array, item, from) { | |
608 | if (array == null) return -1; | |
609 | var idx = array.length; | |
610 | if (typeof from == 'number') { | |
611 | idx = from < 0 ? idx + from + 1 : Math.min(idx, from + 1); | |
612 | } | |
613 | while (--idx >= 0) if (array[idx] === item) return idx; | |
614 | return -1; | |
615 | }; | |
616 | ||
617 | // Generate an integer Array containing an arithmetic progression. A port of | |
618 | // the native Python `range()` function. See | |
619 | // [the Python documentation](http://docs.python.org/library/functions.html#range). | |
620 | _.range = function(start, stop, step) { | |
621 | if (arguments.length <= 1) { | |
622 | stop = start || 0; | |
623 | start = 0; | |
624 | } | |
625 | step = step || 1; | |
626 | ||
627 | var length = Math.max(Math.ceil((stop - start) / step), 0); | |
628 | var range = Array(length); | |
629 | ||
630 | for (var idx = 0; idx < length; idx++, start += step) { | |
631 | range[idx] = start; | |
632 | } | |
633 | ||
634 | return range; | |
635 | }; | |
636 | ||
637 | // Function (ahem) Functions | |
638 | // ------------------ | |
639 | ||
640 | // Reusable constructor function for prototype setting. | |
641 | var Ctor = function(){}; | |
642 | ||
643 | // Create a function bound to a given object (assigning `this`, and arguments, | |
644 | // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if | |
645 | // available. | |
646 | _.bind = function(func, context) { | |
647 | var args, bound; | |
648 | if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); | |
649 | if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function'); | |
650 | args = slice.call(arguments, 2); | |
651 | bound = function() { | |
652 | if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments))); | |
653 | Ctor.prototype = func.prototype; | |
654 | var self = new Ctor; | |
655 | Ctor.prototype = null; | |
656 | var result = func.apply(self, args.concat(slice.call(arguments))); | |
657 | if (_.isObject(result)) return result; | |
658 | return self; | |
659 | }; | |
660 | return bound; | |
661 | }; | |
662 | ||
663 | // Partially apply a function by creating a version that has had some of its | |
664 | // arguments pre-filled, without changing its dynamic `this` context. _ acts | |
665 | // as a placeholder, allowing any combination of arguments to be pre-filled. | |
666 | _.partial = function(func) { | |
667 | var boundArgs = slice.call(arguments, 1); | |
668 | return function() { | |
669 | var position = 0; | |
670 | var args = boundArgs.slice(); | |
671 | for (var i = 0, length = args.length; i < length; i++) { | |
672 | if (args[i] === _) args[i] = arguments[position++]; | |
673 | } | |
674 | while (position < arguments.length) args.push(arguments[position++]); | |
675 | return func.apply(this, args); | |
676 | }; | |
677 | }; | |
678 | ||
679 | // Bind a number of an object's methods to that object. Remaining arguments | |
680 | // are the method names to be bound. Useful for ensuring that all callbacks | |
681 | // defined on an object belong to it. | |
682 | _.bindAll = function(obj) { | |
683 | var i, length = arguments.length, key; | |
684 | if (length <= 1) throw new Error('bindAll must be passed function names'); | |
685 | for (i = 1; i < length; i++) { | |
686 | key = arguments[i]; | |
687 | obj[key] = _.bind(obj[key], obj); | |
688 | } | |
689 | return obj; | |
690 | }; | |
691 | ||
692 | // Memoize an expensive function by storing its results. | |
693 | _.memoize = function(func, hasher) { | |
694 | var memoize = function(key) { | |
695 | var cache = memoize.cache; | |
696 | var address = hasher ? hasher.apply(this, arguments) : key; | |
697 | if (!_.has(cache, address)) cache[address] = func.apply(this, arguments); | |
698 | return cache[address]; | |
699 | }; | |
700 | memoize.cache = {}; | |
701 | return memoize; | |
702 | }; | |
703 | ||
704 | // Delays a function for the given number of milliseconds, and then calls | |
705 | // it with the arguments supplied. | |
706 | _.delay = function(func, wait) { | |
707 | var args = slice.call(arguments, 2); | |
708 | return setTimeout(function(){ | |
709 | return func.apply(null, args); | |
710 | }, wait); | |
711 | }; | |
712 | ||
713 | // Defers a function, scheduling it to run after the current call stack has | |
714 | // cleared. | |
715 | _.defer = function(func) { | |
716 | return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1))); | |
717 | }; | |
718 | ||
719 | // Returns a function, that, when invoked, will only be triggered at most once | |
720 | // during a given window of time. Normally, the throttled function will run | |
721 | // as much as it can, without ever going more than once per `wait` duration; | |
722 | // but if you'd like to disable the execution on the leading edge, pass | |
723 | // `{leading: false}`. To disable execution on the trailing edge, ditto. | |
724 | _.throttle = function(func, wait, options) { | |
725 | var context, args, result; | |
726 | var timeout = null; | |
727 | var previous = 0; | |
728 | if (!options) options = {}; | |
729 | var later = function() { | |
730 | previous = options.leading === false ? 0 : _.now(); | |
731 | timeout = null; | |
732 | result = func.apply(context, args); | |
733 | if (!timeout) context = args = null; | |
734 | }; | |
735 | return function() { | |
736 | var now = _.now(); | |
737 | if (!previous && options.leading === false) previous = now; | |
738 | var remaining = wait - (now - previous); | |
739 | context = this; | |
740 | args = arguments; | |
741 | if (remaining <= 0 || remaining > wait) { | |
742 | clearTimeout(timeout); | |
743 | timeout = null; | |
744 | previous = now; | |
745 | result = func.apply(context, args); | |
746 | if (!timeout) context = args = null; | |
747 | } else if (!timeout && options.trailing !== false) { | |
748 | timeout = setTimeout(later, remaining); | |
749 | } | |
750 | return result; | |
751 | }; | |
752 | }; | |
753 | ||
754 | // Returns a function, that, as long as it continues to be invoked, will not | |
755 | // be triggered. The function will be called after it stops being called for | |
756 | // N milliseconds. If `immediate` is passed, trigger the function on the | |
757 | // leading edge, instead of the trailing. | |
758 | _.debounce = function(func, wait, immediate) { | |
759 | var timeout, args, context, timestamp, result; | |
760 | ||
761 | var later = function() { | |
762 | var last = _.now() - timestamp; | |
763 | ||
764 | if (last < wait && last > 0) { | |
765 | timeout = setTimeout(later, wait - last); | |
766 | } else { | |
767 | timeout = null; | |
768 | if (!immediate) { | |
769 | result = func.apply(context, args); | |
770 | if (!timeout) context = args = null; | |
771 | } | |
772 | } | |
773 | }; | |
774 | ||
775 | return function() { | |
776 | context = this; | |
777 | args = arguments; | |
778 | timestamp = _.now(); | |
779 | var callNow = immediate && !timeout; | |
780 | if (!timeout) timeout = setTimeout(later, wait); | |
781 | if (callNow) { | |
782 | result = func.apply(context, args); | |
783 | context = args = null; | |
784 | } | |
785 | ||
786 | return result; | |
787 | }; | |
788 | }; | |
789 | ||
790 | // Returns the first function passed as an argument to the second, | |
791 | // allowing you to adjust arguments, run code before and after, and | |
792 | // conditionally execute the original function. | |
793 | _.wrap = function(func, wrapper) { | |
794 | return _.partial(wrapper, func); | |
795 | }; | |
796 | ||
797 | // Returns a negated version of the passed-in predicate. | |
798 | _.negate = function(predicate) { | |
799 | return function() { | |
800 | return !predicate.apply(this, arguments); | |
801 | }; | |
802 | }; | |
803 | ||
804 | // Returns a function that is the composition of a list of functions, each | |
805 | // consuming the return value of the function that follows. | |
806 | _.compose = function() { | |
807 | var args = arguments; | |
808 | var start = args.length - 1; | |
809 | return function() { | |
810 | var i = start; | |
811 | var result = args[start].apply(this, arguments); | |
812 | while (i--) result = args[i].call(this, result); | |
813 | return result; | |
814 | }; | |
815 | }; | |
816 | ||
817 | // Returns a function that will only be executed after being called N times. | |
818 | _.after = function(times, func) { | |
819 | return function() { | |
820 | if (--times < 1) { | |
821 | return func.apply(this, arguments); | |
822 | } | |
823 | }; | |
824 | }; | |
825 | ||
826 | // Returns a function that will only be executed before being called N times. | |
827 | _.before = function(times, func) { | |
828 | var memo; | |
829 | return function() { | |
830 | if (--times > 0) { | |
831 | memo = func.apply(this, arguments); | |
832 | } else { | |
833 | func = null; | |
834 | } | |
835 | return memo; | |
836 | }; | |
837 | }; | |
838 | ||
839 | // Returns a function that will be executed at most one time, no matter how | |
840 | // often you call it. Useful for lazy initialization. | |
841 | _.once = _.partial(_.before, 2); | |
842 | ||
843 | // Object Functions | |
844 | // ---------------- | |
845 | ||
846 | // Retrieve the names of an object's properties. | |
847 | // Delegates to **ECMAScript 5**'s native `Object.keys` | |
848 | _.keys = function(obj) { | |
849 | if (!_.isObject(obj)) return []; | |
850 | if (nativeKeys) return nativeKeys(obj); | |
851 | var keys = []; | |
852 | for (var key in obj) if (_.has(obj, key)) keys.push(key); | |
853 | return keys; | |
854 | }; | |
855 | ||
856 | // Retrieve the values of an object's properties. | |
857 | _.values = function(obj) { | |
858 | var keys = _.keys(obj); | |
859 | var length = keys.length; | |
860 | var values = Array(length); | |
861 | for (var i = 0; i < length; i++) { | |
862 | values[i] = obj[keys[i]]; | |
863 | } | |
864 | return values; | |
865 | }; | |
866 | ||
867 | // Convert an object into a list of `[key, value]` pairs. | |
868 | _.pairs = function(obj) { | |
869 | var keys = _.keys(obj); | |
870 | var length = keys.length; | |
871 | var pairs = Array(length); | |
872 | for (var i = 0; i < length; i++) { | |
873 | pairs[i] = [keys[i], obj[keys[i]]]; | |
874 | } | |
875 | return pairs; | |
876 | }; | |
877 | ||
878 | // Invert the keys and values of an object. The values must be serializable. | |
879 | _.invert = function(obj) { | |
880 | var result = {}; | |
881 | var keys = _.keys(obj); | |
882 | for (var i = 0, length = keys.length; i < length; i++) { | |
883 | result[obj[keys[i]]] = keys[i]; | |
884 | } | |
885 | return result; | |
886 | }; | |
887 | ||
888 | // Return a sorted list of the function names available on the object. | |
889 | // Aliased as `methods` | |
890 | _.functions = _.methods = function(obj) { | |
891 | var names = []; | |
892 | for (var key in obj) { | |
893 | if (_.isFunction(obj[key])) names.push(key); | |
894 | } | |
895 | return names.sort(); | |
896 | }; | |
897 | ||
898 | // Extend a given object with all the properties in passed-in object(s). | |
899 | _.extend = function(obj) { | |
900 | if (!_.isObject(obj)) return obj; | |
901 | var source, prop; | |
902 | for (var i = 1, length = arguments.length; i < length; i++) { | |
903 | source = arguments[i]; | |
904 | for (prop in source) { | |
905 | if (hasOwnProperty.call(source, prop)) { | |
906 | obj[prop] = source[prop]; | |
907 | } | |
908 | } | |
909 | } | |
910 | return obj; | |
911 | }; | |
912 | ||
913 | // Return a copy of the object only containing the whitelisted properties. | |
914 | _.pick = function(obj, iteratee, context) { | |
915 | var result = {}, key; | |
916 | if (obj == null) return result; | |
917 | if (_.isFunction(iteratee)) { | |
918 | iteratee = createCallback(iteratee, context); | |
919 | for (key in obj) { | |
920 | var value = obj[key]; | |
921 | if (iteratee(value, key, obj)) result[key] = value; | |
922 | } | |
923 | } else { | |
924 | var keys = concat.apply([], slice.call(arguments, 1)); | |
925 | obj = new Object(obj); | |
926 | for (var i = 0, length = keys.length; i < length; i++) { | |
927 | key = keys[i]; | |
928 | if (key in obj) result[key] = obj[key]; | |
929 | } | |
930 | } | |
931 | return result; | |
932 | }; | |
933 | ||
934 | // Return a copy of the object without the blacklisted properties. | |
935 | _.omit = function(obj, iteratee, context) { | |
936 | if (_.isFunction(iteratee)) { | |
937 | iteratee = _.negate(iteratee); | |
938 | } else { | |
939 | var keys = _.map(concat.apply([], slice.call(arguments, 1)), String); | |
940 | iteratee = function(value, key) { | |
941 | return !_.contains(keys, key); | |
942 | }; | |
943 | } | |
944 | return _.pick(obj, iteratee, context); | |
945 | }; | |
946 | ||
947 | // Fill in a given object with default properties. | |
948 | _.defaults = function(obj) { | |
949 | if (!_.isObject(obj)) return obj; | |
950 | for (var i = 1, length = arguments.length; i < length; i++) { | |
951 | var source = arguments[i]; | |
952 | for (var prop in source) { | |
953 | if (obj[prop] === void 0) obj[prop] = source[prop]; | |
954 | } | |
955 | } | |
956 | return obj; | |
957 | }; | |
958 | ||
959 | // Create a (shallow-cloned) duplicate of an object. | |
960 | _.clone = function(obj) { | |
961 | if (!_.isObject(obj)) return obj; | |
962 | return _.isArray(obj) ? obj.slice() : _.extend({}, obj); | |
963 | }; | |
964 | ||
965 | // Invokes interceptor with the obj, and then returns obj. | |
966 | // The primary purpose of this method is to "tap into" a method chain, in | |
967 | // order to perform operations on intermediate results within the chain. | |
968 | _.tap = function(obj, interceptor) { | |
969 | interceptor(obj); | |
970 | return obj; | |
971 | }; | |
972 | ||
973 | // Internal recursive comparison function for `isEqual`. | |
974 | var eq = function(a, b, aStack, bStack) { | |
975 | // Identical objects are equal. `0 === -0`, but they aren't identical. | |
976 | // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal). | |
977 | if (a === b) return a !== 0 || 1 / a === 1 / b; | |
978 | // A strict comparison is necessary because `null == undefined`. | |
979 | if (a == null || b == null) return a === b; | |
980 | // Unwrap any wrapped objects. | |
981 | if (a instanceof _) a = a._wrapped; | |
982 | if (b instanceof _) b = b._wrapped; | |
983 | // Compare `[[Class]]` names. | |
984 | var className = toString.call(a); | |
985 | if (className !== toString.call(b)) return false; | |
986 | switch (className) { | |
987 | // Strings, numbers, regular expressions, dates, and booleans are compared by value. | |
988 | case '[object RegExp]': | |
989 | // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i') | |
990 | case '[object String]': | |
991 | // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is | |
992 | // equivalent to `new String("5")`. | |
993 | return '' + a === '' + b; | |
994 | case '[object Number]': | |
995 | // `NaN`s are equivalent, but non-reflexive. | |
996 | // Object(NaN) is equivalent to NaN | |
997 | if (+a !== +a) return +b !== +b; | |
998 | // An `egal` comparison is performed for other numeric values. | |
999 | return +a === 0 ? 1 / +a === 1 / b : +a === +b; | |
1000 | case '[object Date]': | |
1001 | case '[object Boolean]': | |
1002 | // Coerce dates and booleans to numeric primitive values. Dates are compared by their | |
1003 | // millisecond representations. Note that invalid dates with millisecond representations | |
1004 | // of `NaN` are not equivalent. | |
1005 | return +a === +b; | |
1006 | } | |
1007 | if (typeof a != 'object' || typeof b != 'object') return false; | |
1008 | // Assume equality for cyclic structures. The algorithm for detecting cyclic | |
1009 | // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`. | |
1010 | var length = aStack.length; | |
1011 | while (length--) { | |
1012 | // Linear search. Performance is inversely proportional to the number of | |
1013 | // unique nested structures. | |
1014 | if (aStack[length] === a) return bStack[length] === b; | |
1015 | } | |
1016 | // Objects with different constructors are not equivalent, but `Object`s | |
1017 | // from different frames are. | |
1018 | var aCtor = a.constructor, bCtor = b.constructor; | |
1019 | if ( | |
1020 | aCtor !== bCtor && | |
1021 | // Handle Object.create(x) cases | |
1022 | 'constructor' in a && 'constructor' in b && | |
1023 | !(_.isFunction(aCtor) && aCtor instanceof aCtor && | |
1024 | _.isFunction(bCtor) && bCtor instanceof bCtor) | |
1025 | ) { | |
1026 | return false; | |
1027 | } | |
1028 | // Add the first object to the stack of traversed objects. | |
1029 | aStack.push(a); | |
1030 | bStack.push(b); | |
1031 | var size, result; | |
1032 | // Recursively compare objects and arrays. | |
1033 | if (className === '[object Array]') { | |
1034 | // Compare array lengths to determine if a deep comparison is necessary. | |
1035 | size = a.length; | |
1036 | result = size === b.length; | |
1037 | if (result) { | |
1038 | // Deep compare the contents, ignoring non-numeric properties. | |
1039 | while (size--) { | |
1040 | if (!(result = eq(a[size], b[size], aStack, bStack))) break; | |
1041 | } | |
1042 | } | |
1043 | } else { | |
1044 | // Deep compare objects. | |
1045 | var keys = _.keys(a), key; | |
1046 | size = keys.length; | |
1047 | // Ensure that both objects contain the same number of properties before comparing deep equality. | |
1048 | result = _.keys(b).length === size; | |
1049 | if (result) { | |
1050 | while (size--) { | |
1051 | // Deep compare each member | |
1052 | key = keys[size]; | |
1053 | if (!(result = _.has(b, key) && eq(a[key], b[key], aStack, bStack))) break; | |
1054 | } | |
1055 | } | |
1056 | } | |
1057 | // Remove the first object from the stack of traversed objects. | |
1058 | aStack.pop(); | |
1059 | bStack.pop(); | |
1060 | return result; | |
1061 | }; | |
1062 | ||
1063 | // Perform a deep comparison to check if two objects are equal. | |
1064 | _.isEqual = function(a, b) { | |
1065 | return eq(a, b, [], []); | |
1066 | }; | |
1067 | ||
1068 | // Is a given array, string, or object empty? | |
1069 | // An "empty" object has no enumerable own-properties. | |
1070 | _.isEmpty = function(obj) { | |
1071 | if (obj == null) return true; | |
1072 | if (_.isArray(obj) || _.isString(obj) || _.isArguments(obj)) return obj.length === 0; | |
1073 | for (var key in obj) if (_.has(obj, key)) return false; | |
1074 | return true; | |
1075 | }; | |
1076 | ||
1077 | // Is a given value a DOM element? | |
1078 | _.isElement = function(obj) { | |
1079 | return !!(obj && obj.nodeType === 1); | |
1080 | }; | |
1081 | ||
1082 | // Is a given value an array? | |
1083 | // Delegates to ECMA5's native Array.isArray | |
1084 | _.isArray = nativeIsArray || function(obj) { | |
1085 | return toString.call(obj) === '[object Array]'; | |
1086 | }; | |
1087 | ||
1088 | // Is a given variable an object? | |
1089 | _.isObject = function(obj) { | |
1090 | var type = typeof obj; | |
1091 | return type === 'function' || type === 'object' && !!obj; | |
1092 | }; | |
1093 | ||
1094 | // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp. | |
1095 | _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp'], function(name) { | |
1096 | _['is' + name] = function(obj) { | |
1097 | return toString.call(obj) === '[object ' + name + ']'; | |
1098 | }; | |
1099 | }); | |
1100 | ||
1101 | // Define a fallback version of the method in browsers (ahem, IE), where | |
1102 | // there isn't any inspectable "Arguments" type. | |
1103 | if (!_.isArguments(arguments)) { | |
1104 | _.isArguments = function(obj) { | |
1105 | return _.has(obj, 'callee'); | |
1106 | }; | |
1107 | } | |
1108 | ||
1109 | // Optimize `isFunction` if appropriate. Work around an IE 11 bug. | |
1110 | if (typeof /./ !== 'function') { | |
1111 | _.isFunction = function(obj) { | |
1112 | return typeof obj == 'function' || false; | |
1113 | }; | |
1114 | } | |
1115 | ||
1116 | // Is a given object a finite number? | |
1117 | _.isFinite = function(obj) { | |
1118 | return isFinite(obj) && !isNaN(parseFloat(obj)); | |
1119 | }; | |
1120 | ||
1121 | // Is the given value `NaN`? (NaN is the only number which does not equal itself). | |
1122 | _.isNaN = function(obj) { | |
1123 | return _.isNumber(obj) && obj !== +obj; | |
1124 | }; | |
1125 | ||
1126 | // Is a given value a boolean? | |
1127 | _.isBoolean = function(obj) { | |
1128 | return obj === true || obj === false || toString.call(obj) === '[object Boolean]'; | |
1129 | }; | |
1130 | ||
1131 | // Is a given value equal to null? | |
1132 | _.isNull = function(obj) { | |
1133 | return obj === null; | |
1134 | }; | |
1135 | ||
1136 | // Is a given variable undefined? | |
1137 | _.isUndefined = function(obj) { | |
1138 | return obj === void 0; | |
1139 | }; | |
1140 | ||
1141 | // Shortcut function for checking if an object has a given property directly | |
1142 | // on itself (in other words, not on a prototype). | |
1143 | _.has = function(obj, key) { | |
1144 | return obj != null && hasOwnProperty.call(obj, key); | |
1145 | }; | |
1146 | ||
1147 | // Utility Functions | |
1148 | // ----------------- | |
1149 | ||
1150 | // Run Underscore.js in *noConflict* mode, returning the `_` variable to its | |
1151 | // previous owner. Returns a reference to the Underscore object. | |
1152 | _.noConflict = function() { | |
1153 | root._ = previousUnderscore; | |
1154 | return this; | |
1155 | }; | |
1156 | ||
1157 | // Keep the identity function around for default iteratees. | |
1158 | _.identity = function(value) { | |
1159 | return value; | |
1160 | }; | |
1161 | ||
1162 | // Predicate-generating functions. Often useful outside of Underscore. | |
1163 | _.constant = function(value) { | |
1164 | return function() { | |
1165 | return value; | |
1166 | }; | |
1167 | }; | |
1168 | ||
1169 | _.noop = function(){}; | |
1170 | ||
1171 | _.property = function(key) { | |
1172 | return function(obj) { | |
1173 | return obj[key]; | |
1174 | }; | |
1175 | }; | |
1176 | ||
1177 | // Returns a predicate for checking whether an object has a given set of `key:value` pairs. | |
1178 | _.matches = function(attrs) { | |
1179 | var pairs = _.pairs(attrs), length = pairs.length; | |
1180 | return function(obj) { | |
1181 | if (obj == null) return !length; | |
1182 | obj = new Object(obj); | |
1183 | for (var i = 0; i < length; i++) { | |
1184 | var pair = pairs[i], key = pair[0]; | |
1185 | if (pair[1] !== obj[key] || !(key in obj)) return false; | |
1186 | } | |
1187 | return true; | |
1188 | }; | |
1189 | }; | |
1190 | ||
1191 | // Run a function **n** times. | |
1192 | _.times = function(n, iteratee, context) { | |
1193 | var accum = Array(Math.max(0, n)); | |
1194 | iteratee = createCallback(iteratee, context, 1); | |
1195 | for (var i = 0; i < n; i++) accum[i] = iteratee(i); | |
1196 | return accum; | |
1197 | }; | |
1198 | ||
1199 | // Return a random integer between min and max (inclusive). | |
1200 | _.random = function(min, max) { | |
1201 | if (max == null) { | |
1202 | max = min; | |
1203 | min = 0; | |
1204 | } | |
1205 | return min + Math.floor(Math.random() * (max - min + 1)); | |
1206 | }; | |
1207 | ||
1208 | // A (possibly faster) way to get the current timestamp as an integer. | |
1209 | _.now = Date.now || function() { | |
1210 | return new Date().getTime(); | |
1211 | }; | |
1212 | ||
1213 | // List of HTML entities for escaping. | |
1214 | var escapeMap = { | |
1215 | '&': '&', | |
1216 | '<': '<', | |
1217 | '>': '>', | |
1218 | '"': '"', | |
1219 | "'": ''', | |
1220 | '`': '`' | |
1221 | }; | |
1222 | var unescapeMap = _.invert(escapeMap); | |
1223 | ||
1224 | // Functions for escaping and unescaping strings to/from HTML interpolation. | |
1225 | var createEscaper = function(map) { | |
1226 | var escaper = function(match) { | |
1227 | return map[match]; | |
1228 | }; | |
1229 | // Regexes for identifying a key that needs to be escaped | |
1230 | var source = '(?:' + _.keys(map).join('|') + ')'; | |
1231 | var testRegexp = RegExp(source); | |
1232 | var replaceRegexp = RegExp(source, 'g'); | |
1233 | return function(string) { | |
1234 | string = string == null ? '' : '' + string; | |
1235 | return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string; | |
1236 | }; | |
1237 | }; | |
1238 | _.escape = createEscaper(escapeMap); | |
1239 | _.unescape = createEscaper(unescapeMap); | |
1240 | ||
1241 | // If the value of the named `property` is a function then invoke it with the | |
1242 | // `object` as context; otherwise, return it. | |
1243 | _.result = function(object, property) { | |
1244 | if (object == null) return void 0; | |
1245 | var value = object[property]; | |
1246 | return _.isFunction(value) ? object[property]() : value; | |
1247 | }; | |
1248 | ||
1249 | // Generate a unique integer id (unique within the entire client session). | |
1250 | // Useful for temporary DOM ids. | |
1251 | var idCounter = 0; | |
1252 | _.uniqueId = function(prefix) { | |
1253 | var id = ++idCounter + ''; | |
1254 | return prefix ? prefix + id : id; | |
1255 | }; | |
1256 | ||
1257 | // By default, Underscore uses ERB-style template delimiters, change the | |
1258 | // following template settings to use alternative delimiters. | |
1259 | _.templateSettings = { | |
1260 | evaluate : /<%([\s\S]+?)%>/g, | |
1261 | interpolate : /<%=([\s\S]+?)%>/g, | |
1262 | escape : /<%-([\s\S]+?)%>/g | |
1263 | }; | |
1264 | ||
1265 | // When customizing `templateSettings`, if you don't want to define an | |
1266 | // interpolation, evaluation or escaping regex, we need one that is | |
1267 | // guaranteed not to match. | |
1268 | var noMatch = /(.)^/; | |
1269 | ||
1270 | // Certain characters need to be escaped so that they can be put into a | |
1271 | // string literal. | |
1272 | var escapes = { | |
1273 | "'": "'", | |
1274 | '\\': '\\', | |
1275 | '\r': 'r', | |
1276 | '\n': 'n', | |
1277 | '\u2028': 'u2028', | |
1278 | '\u2029': 'u2029' | |
1279 | }; | |
1280 | ||
1281 | var escaper = /\\|'|\r|\n|\u2028|\u2029/g; | |
1282 | ||
1283 | var escapeChar = function(match) { | |
1284 | return '\\' + escapes[match]; | |
1285 | }; | |
1286 | ||
1287 | // JavaScript micro-templating, similar to John Resig's implementation. | |
1288 | // Underscore templating handles arbitrary delimiters, preserves whitespace, | |
1289 | // and correctly escapes quotes within interpolated code. | |
1290 | // NB: `oldSettings` only exists for backwards compatibility. | |
1291 | _.template = function(text, settings, oldSettings) { | |
1292 | if (!settings && oldSettings) settings = oldSettings; | |
1293 | settings = _.defaults({}, settings, _.templateSettings); | |
1294 | ||
1295 | // Combine delimiters into one regular expression via alternation. | |
1296 | var matcher = RegExp([ | |
1297 | (settings.escape || noMatch).source, | |
1298 | (settings.interpolate || noMatch).source, | |
1299 | (settings.evaluate || noMatch).source | |
1300 | ].join('|') + '|$', 'g'); | |
1301 | ||
1302 | // Compile the template source, escaping string literals appropriately. | |
1303 | var index = 0; | |
1304 | var source = "__p+='"; | |
1305 | text.replace(matcher, function(match, escape, interpolate, evaluate, offset) { | |
1306 | source += text.slice(index, offset).replace(escaper, escapeChar); | |
1307 | index = offset + match.length; | |
1308 | ||
1309 | if (escape) { | |
1310 | source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'"; | |
1311 | } else if (interpolate) { | |
1312 | source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'"; | |
1313 | } else if (evaluate) { | |
1314 | source += "';\n" + evaluate + "\n__p+='"; | |
1315 | } | |
1316 | ||
1317 | // Adobe VMs need the match returned to produce the correct offest. | |
1318 | return match; | |
1319 | }); | |
1320 | source += "';\n"; | |
1321 | ||
1322 | // If a variable is not specified, place data values in local scope. | |
1323 | if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n'; | |
1324 | ||
1325 | source = "var __t,__p='',__j=Array.prototype.join," + | |
1326 | "print=function(){__p+=__j.call(arguments,'');};\n" + | |
1327 | source + 'return __p;\n'; | |
1328 | ||
1329 | try { | |
1330 | var render = new Function(settings.variable || 'obj', '_', source); | |
1331 | } catch (e) { | |
1332 | e.source = source; | |
1333 | throw e; | |
1334 | } | |
1335 | ||
1336 | var template = function(data) { | |
1337 | return render.call(this, data, _); | |
1338 | }; | |
1339 | ||
1340 | // Provide the compiled source as a convenience for precompilation. | |
1341 | var argument = settings.variable || 'obj'; | |
1342 | template.source = 'function(' + argument + '){\n' + source + '}'; | |
1343 | ||
1344 | return template; | |
1345 | }; | |
1346 | ||
1347 | // Add a "chain" function. Start chaining a wrapped Underscore object. | |
1348 | _.chain = function(obj) { | |
1349 | var instance = _(obj); | |
1350 | instance._chain = true; | |
1351 | return instance; | |
1352 | }; | |
1353 | ||
1354 | // OOP | |
1355 | // --------------- | |
1356 | // If Underscore is called as a function, it returns a wrapped object that | |
1357 | // can be used OO-style. This wrapper holds altered versions of all the | |
1358 | // underscore functions. Wrapped objects may be chained. | |
1359 | ||
1360 | // Helper function to continue chaining intermediate results. | |
1361 | var result = function(obj) { | |
1362 | return this._chain ? _(obj).chain() : obj; | |
1363 | }; | |
1364 | ||
1365 | // Add your own custom functions to the Underscore object. | |
1366 | _.mixin = function(obj) { | |
1367 | _.each(_.functions(obj), function(name) { | |
1368 | var func = _[name] = obj[name]; | |
1369 | _.prototype[name] = function() { | |
1370 | var args = [this._wrapped]; | |
1371 | push.apply(args, arguments); | |
1372 | return result.call(this, func.apply(_, args)); | |
1373 | }; | |
1374 | }); | |
1375 | }; | |
1376 | ||
1377 | // Add all of the Underscore functions to the wrapper object. | |
1378 | _.mixin(_); | |
1379 | ||
1380 | // Add all mutator Array functions to the wrapper. | |
1381 | _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { | |
1382 | var method = ArrayProto[name]; | |
1383 | _.prototype[name] = function() { | |
1384 | var obj = this._wrapped; | |
1385 | method.apply(obj, arguments); | |
1386 | if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0]; | |
1387 | return result.call(this, obj); | |
1388 | }; | |
1389 | }); | |
1390 | ||
1391 | // Add all accessor Array functions to the wrapper. | |
1392 | _.each(['concat', 'join', 'slice'], function(name) { | |
1393 | var method = ArrayProto[name]; | |
1394 | _.prototype[name] = function() { | |
1395 | return result.call(this, method.apply(this._wrapped, arguments)); | |
1396 | }; | |
1397 | }); | |
1398 | ||
1399 | // Extracts the result from a wrapped and chained object. | |
1400 | _.prototype.value = function() { | |
1401 | return this._wrapped; | |
1402 | }; | |
1403 | ||
1404 | // AMD registration happens at the end for compatibility with AMD loaders | |
1405 | // that may not enforce next-turn semantics on modules. Even though general | |
1406 | // practice for AMD registration is to be anonymous, underscore registers | |
1407 | // as a named module because, like jQuery, it is a base library that is | |
1408 | // popular enough to be bundled in a third party lib, but not be part of | |
1409 | // an AMD load request. Those cases could generate an error when an | |
1410 | // anonymous define() is called outside of a loader request. | |
1411 | if (typeof define === 'function' && define.amd) { | |
1412 | define('underscore', [], function() { | |
1413 | return _; | |
1414 | }); | |
1415 | } | |
1416 | }.call(this)); |