1// Underscore.js 1.8.3 2// http://underscorejs.org 3// (c) 2009-2015 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 toString = ObjProto.toString, 25 hasOwnProperty = ObjProto.hasOwnProperty; 26 27 // All **ECMAScript 5** native function implementations that we hope to use 28 // are declared here. 29 var 30 nativeIsArray = Array.isArray, 31 nativeKeys = Object.keys, 32 nativeBind = FuncProto.bind, 33 nativeCreate = Object.create; 34 35 // Naked function reference for surrogate-prototype-swapping. 36 var Ctor = function(){}; 37 38 // Create a safe reference to the Underscore object for use below. 39 var _ = function(obj) { 40 if (obj instanceof _) return obj; 41 if (!(this instanceof _)) return new _(obj); 42 this._wrapped = obj; 43 }; 44 45 // Export the Underscore object for **Node.js**, with 46 // backwards-compatibility for the old `require()` API. If we're in 47 // the browser, add `_` as a global object. 48 if (typeof exports !== 'undefined') { 49 if (typeof module !== 'undefined' && module.exports) { 50 exports = module.exports = _; 51 } 52 exports._ = _; 53 } else { 54 root._ = _; 55 } 56 57 // Current version. 58 _.VERSION = '1.8.3'; 59 60 // Internal function that returns an efficient (for current engines) version 61 // of the passed-in callback, to be repeatedly applied in other Underscore 62 // functions. 63 var optimizeCb = function(func, context, argCount) { 64 if (context === void 0) return func; 65 switch (argCount == null ? 3 : argCount) { 66 case 1: return function(value) { 67 return func.call(context, value); 68 }; 69 case 2: return function(value, other) { 70 return func.call(context, value, other); 71 }; 72 case 3: return function(value, index, collection) { 73 return func.call(context, value, index, collection); 74 }; 75 case 4: return function(accumulator, value, index, collection) { 76 return func.call(context, accumulator, value, index, collection); 77 }; 78 } 79 return function() { 80 return func.apply(context, arguments); 81 }; 82 }; 83 84 // A mostly-internal function to generate callbacks that can be applied 85 // to each element in a collection, returning the desired result — either 86 // identity, an arbitrary callback, a property matcher, or a property accessor. 87 var cb = function(value, context, argCount) { 88 if (value == null) return _.identity; 89 if (_.isFunction(value)) return optimizeCb(value, context, argCount); 90 if (_.isObject(value)) return _.matcher(value); 91 return _.property(value); 92 }; 93 _.iteratee = function(value, context) { 94 return cb(value, context, Infinity); 95 }; 96 97 // An internal function for creating assigner functions. 98 var createAssigner = function(keysFunc, undefinedOnly) { 99 return function(obj) { 100 var length = arguments.length; 101 if (length < 2 || obj == null) return obj; 102 for (var index = 1; index < length; index++) { 103 var source = arguments[index], 104 keys = keysFunc(source), 105 l = keys.length; 106 for (var i = 0; i < l; i++) { 107 var key = keys[i]; 108 if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key]; 109 } 110 } 111 return obj; 112 }; 113 }; 114 115 // An internal function for creating a new object that inherits from another. 116 var baseCreate = function(prototype) { 117 if (!_.isObject(prototype)) return {}; 118 if (nativeCreate) return nativeCreate(prototype); 119 Ctor.prototype = prototype; 120 var result = new Ctor; 121 Ctor.prototype = null; 122 return result; 123 }; 124 125 var property = function(key) { 126 return function(obj) { 127 return obj == null ? void 0 : obj[key]; 128 }; 129 }; 130 131 // Helper for collection methods to determine whether a collection 132 // should be iterated as an array or as an object 133 // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength 134 // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094 135 var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1; 136 var getLength = property('length'); 137 var isArrayLike = function(collection) { 138 var length = getLength(collection); 139 return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX; 140 }; 141 142 // Collection Functions 143 // -------------------- 144 145 // The cornerstone, an `each` implementation, aka `forEach`. 146 // Handles raw objects in addition to array-likes. Treats all 147 // sparse array-likes as if they were dense. 148 _.each = _.forEach = function(obj, iteratee, context) { 149 iteratee = optimizeCb(iteratee, context); 150 var i, length; 151 if (isArrayLike(obj)) { 152 for (i = 0, length = obj.length; i < length; i++) { 153 iteratee(obj[i], i, obj); 154 } 155 } else { 156 var keys = _.keys(obj); 157 for (i = 0, length = keys.length; i < length; i++) { 158 iteratee(obj[keys[i]], keys[i], obj); 159 } 160 } 161 return obj; 162 }; 163 164 // Return the results of applying the iteratee to each element. 165 _.map = _.collect = function(obj, iteratee, context) { 166 iteratee = cb(iteratee, context); 167 var keys = !isArrayLike(obj) && _.keys(obj), 168 length = (keys || obj).length, 169 results = Array(length); 170 for (var index = 0; index < length; index++) { 171 var currentKey = keys ? keys[index] : index; 172 results[index] = iteratee(obj[currentKey], currentKey, obj); 173 } 174 return results; 175 }; 176 177 // Create a reducing function iterating left or right. 178 function createReduce(dir) { 179 // Optimized iterator function as using arguments.length 180 // in the main function will deoptimize the, see #1991. 181 function iterator(obj, iteratee, memo, keys, index, length) { 182 for (; index >= 0 && index < length; index += dir) { 183 var currentKey = keys ? keys[index] : index; 184 memo = iteratee(memo, obj[currentKey], currentKey, obj); 185 } 186 return memo; 187 } 188 189 return function(obj, iteratee, memo, context) { 190 iteratee = optimizeCb(iteratee, context, 4); 191 var keys = !isArrayLike(obj) && _.keys(obj), 192 length = (keys || obj).length, 193 index = dir > 0 ? 0 : length - 1; 194 // Determine the initial value if none is provided. 195 if (arguments.length < 3) { 196 memo = obj[keys ? keys[index] : index]; 197 index += dir; 198 } 199 return iterator(obj, iteratee, memo, keys, index, length); 200 }; 201 } 202 203 // **Reduce** builds up a single result from a list of values, aka `inject`, 204 // or `foldl`. 205 _.reduce = _.foldl = _.inject = createReduce(1); 206 207 // The right-associative version of reduce, also known as `foldr`. 208 _.reduceRight = _.foldr = createReduce(-1); 209 210 // Return the first value which passes a truth test. Aliased as `detect`. 211 _.find = _.detect = function(obj, predicate, context) { 212 var key; 213 if (isArrayLike(obj)) { 214 key = _.findIndex(obj, predicate, context); 215 } else { 216 key = _.findKey(obj, predicate, context); 217 } 218 if (key !== void 0 && key !== -1) return obj[key]; 219 }; 220 221 // Return all the elements that pass a truth test. 222 // Aliased as `select`. 223 _.filter = _.select = function(obj, predicate, context) { 224 var results = []; 225 predicate = cb(predicate, context); 226 _.each(obj, function(value, index, list) { 227 if (predicate(value, index, list)) results.push(value); 228 }); 229 return results; 230 }; 231 232 // Return all the elements for which a truth test fails. 233 _.reject = function(obj, predicate, context) { 234 return _.filter(obj, _.negate(cb(predicate)), context); 235 }; 236 237 // Determine whether all of the elements match a truth test. 238 // Aliased as `all`. 239 _.every = _.all = function(obj, predicate, context) { 240 predicate = cb(predicate, context); 241 var keys = !isArrayLike(obj) && _.keys(obj), 242 length = (keys || obj).length; 243 for (var index = 0; index < length; index++) { 244 var currentKey = keys ? keys[index] : index; 245 if (!predicate(obj[currentKey], currentKey, obj)) return false; 246 } 247 return true; 248 }; 249 250 // Determine if at least one element in the object matches a truth test. 251 // Aliased as `any`. 252 _.some = _.any = function(obj, predicate, context) { 253 predicate = cb(predicate, context); 254 var keys = !isArrayLike(obj) && _.keys(obj), 255 length = (keys || obj).length; 256 for (var index = 0; index < length; index++) { 257 var currentKey = keys ? keys[index] : index; 258 if (predicate(obj[currentKey], currentKey, obj)) return true; 259 } 260 return false; 261 }; 262 263 // Determine if the array or object contains a given item (using `===`). 264 // Aliased as `includes` and `include`. 265 _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) { 266 if (!isArrayLike(obj)) obj = _.values(obj); 267 if (typeof fromIndex != 'number' || guard) fromIndex = 0; 268 return _.indexOf(obj, item, fromIndex) >= 0; 269 }; 270 271 // Invoke a method (with arguments) on every item in a collection. 272 _.invoke = function(obj, method) { 273 var args = slice.call(arguments, 2); 274 var isFunc = _.isFunction(method); 275 return _.map(obj, function(value) { 276 var func = isFunc ? method : value[method]; 277 return func == null ? func : func.apply(value, args); 278 }); 279 }; 280 281 // Convenience version of a common use case of `map`: fetching a property. 282 _.pluck = function(obj, key) { 283 return _.map(obj, _.property(key)); 284 }; 285 286 // Convenience version of a common use case of `filter`: selecting only objects 287 // containing specific `key:value` pairs. 288 _.where = function(obj, attrs) { 289 return _.filter(obj, _.matcher(attrs)); 290 }; 291 292 // Convenience version of a common use case of `find`: getting the first object 293 // containing specific `key:value` pairs. 294 _.findWhere = function(obj, attrs) { 295 return _.find(obj, _.matcher(attrs)); 296 }; 297 298 // Return the maximum element (or element-based computation). 299 _.max = function(obj, iteratee, context) { 300 var result = -Infinity, lastComputed = -Infinity, 301 value, computed; 302 if (iteratee == null && obj != null) { 303 obj = isArrayLike(obj) ? obj : _.values(obj); 304 for (var i = 0, length = obj.length; i < length; i++) { 305 value = obj[i]; 306 if (value > result) { 307 result = value; 308 } 309 } 310 } else { 311 iteratee = cb(iteratee, context); 312 _.each(obj, function(value, index, list) { 313 computed = iteratee(value, index, list); 314 if (computed > lastComputed || computed === -Infinity && result === -Infinity) { 315 result = value; 316 lastComputed = computed; 317 } 318 }); 319 } 320 return result; 321 }; 322 323 // Return the minimum element (or element-based computation). 324 _.min = function(obj, iteratee, context) { 325 var result = Infinity, lastComputed = Infinity, 326 value, computed; 327 if (iteratee == null && obj != null) { 328 obj = isArrayLike(obj) ? obj : _.values(obj); 329 for (var i = 0, length = obj.length; i < length; i++) { 330 value = obj[i]; 331 if (value < result) { 332 result = value; 333 } 334 } 335 } else { 336 iteratee = cb(iteratee, context); 337 _.each(obj, function(value, index, list) { 338 computed = iteratee(value, index, list); 339 if (computed < lastComputed || computed === Infinity && result === Infinity) { 340 result = value; 341 lastComputed = computed; 342 } 343 }); 344 } 345 return result; 346 }; 347 348 // Shuffle a collection, using the modern version of the 349 // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher–Yates_shuffle). 350 _.shuffle = function(obj) { 351 var set = isArrayLike(obj) ? obj : _.values(obj); 352 var length = set.length; 353 var shuffled = Array(length); 354 for (var index = 0, rand; index < length; index++) { 355 rand = _.random(0, index); 356 if (rand !== index) shuffled[index] = shuffled[rand]; 357 shuffled[rand] = set[index]; 358 } 359 return shuffled; 360 }; 361 362 // Sample **n** random values from a collection. 363 // If **n** is not specified, returns a single random element. 364 // The internal `guard` argument allows it to work with `map`. 365 _.sample = function(obj, n, guard) { 366 if (n == null || guard) { 367 if (!isArrayLike(obj)) obj = _.values(obj); 368 return obj[_.random(obj.length - 1)]; 369 } 370 return _.shuffle(obj).slice(0, Math.max(0, n)); 371 }; 372 373 // Sort the object's values by a criterion produced by an iteratee. 374 _.sortBy = function(obj, iteratee, context) { 375 iteratee = cb(iteratee, context); 376 return _.pluck(_.map(obj, function(value, index, list) { 377 return { 378 value: value, 379 index: index, 380 criteria: iteratee(value, index, list) 381 }; 382 }).sort(function(left, right) { 383 var a = left.criteria; 384 var b = right.criteria; 385 if (a !== b) { 386 if (a > b || a === void 0) return 1; 387 if (a < b || b === void 0) return -1; 388 } 389 return left.index - right.index; 390 }), 'value'); 391 }; 392 393 // An internal function used for aggregate "group by" operations. 394 var group = function(behavior) { 395 return function(obj, iteratee, context) { 396 var result = {}; 397 iteratee = cb(iteratee, context); 398 _.each(obj, function(value, index) { 399 var key = iteratee(value, index, obj); 400 behavior(result, value, key); 401 }); 402 return result; 403 }; 404 }; 405 406 // Groups the object's values by a criterion. Pass either a string attribute 407 // to group by, or a function that returns the criterion. 408 _.groupBy = group(function(result, value, key) { 409 if (_.has(result, key)) result[key].push(value); else result[key] = [value]; 410 }); 411 412 // Indexes the object's values by a criterion, similar to `groupBy`, but for 413 // when you know that your index values will be unique. 414 _.indexBy = group(function(result, value, key) { 415 result[key] = value; 416 }); 417 418 // Counts instances of an object that group by a certain criterion. Pass 419 // either a string attribute to count by, or a function that returns the 420 // criterion. 421 _.countBy = group(function(result, value, key) { 422 if (_.has(result, key)) result[key]++; else result[key] = 1; 423 }); 424 425 // Safely create a real, live array from anything iterable. 426 _.toArray = function(obj) { 427 if (!obj) return []; 428 if (_.isArray(obj)) return slice.call(obj); 429 if (isArrayLike(obj)) return _.map(obj, _.identity); 430 return _.values(obj); 431 }; 432 433 // Return the number of elements in an object. 434 _.size = function(obj) { 435 if (obj == null) return 0; 436 return isArrayLike(obj) ? obj.length : _.keys(obj).length; 437 }; 438 439 // Split a collection into two arrays: one whose elements all satisfy the given 440 // predicate, and one whose elements all do not satisfy the predicate. 441 _.partition = function(obj, predicate, context) { 442 predicate = cb(predicate, context); 443 var pass = [], fail = []; 444 _.each(obj, function(value, key, obj) { 445 (predicate(value, key, obj) ? pass : fail).push(value); 446 }); 447 return [pass, fail]; 448 }; 449 450 // Array Functions 451 // --------------- 452 453 // Get the first element of an array. Passing **n** will return the first N 454 // values in the array. Aliased as `head` and `take`. The **guard** check 455 // allows it to work with `_.map`. 456 _.first = _.head = _.take = function(array, n, guard) { 457 if (array == null) return void 0; 458 if (n == null || guard) return array[0]; 459 return _.initial(array, array.length - n); 460 }; 461 462 // Returns everything but the last entry of the array. Especially useful on 463 // the arguments object. Passing **n** will return all the values in 464 // the array, excluding the last N. 465 _.initial = function(array, n, guard) { 466 return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n))); 467 }; 468 469 // Get the last element of an array. Passing **n** will return the last N 470 // values in the array. 471 _.last = function(array, n, guard) { 472 if (array == null) return void 0; 473 if (n == null || guard) return array[array.length - 1]; 474 return _.rest(array, Math.max(0, array.length - n)); 475 }; 476 477 // Returns everything but the first entry of the array. Aliased as `tail` and `drop`. 478 // Especially useful on the arguments object. Passing an **n** will return 479 // the rest N values in the array. 480 _.rest = _.tail = _.drop = function(array, n, guard) { 481 return slice.call(array, n == null || guard ? 1 : n); 482 }; 483 484 // Trim out all falsy values from an array. 485 _.compact = function(array) { 486 return _.filter(array, _.identity); 487 }; 488 489 // Internal implementation of a recursive `flatten` function. 490 var flatten = function(input, shallow, strict, startIndex) { 491 var output = [], idx = 0; 492 for (var i = startIndex || 0, length = getLength(input); i < length; i++) { 493 var value = input[i]; 494 if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) { 495 //flatten current level of array or arguments object 496 if (!shallow) value = flatten(value, shallow, strict); 497 var j = 0, len = value.length; 498 output.length += len; 499 while (j < len) { 500 output[idx++] = value[j++]; 501 } 502 } else if (!strict) { 503 output[idx++] = value; 504 } 505 } 506 return output; 507 }; 508 509 // Flatten out an array, either recursively (by default), or just one level. 510 _.flatten = function(array, shallow) { 511 return flatten(array, shallow, false); 512 }; 513 514 // Return a version of the array that does not contain the specified value(s). 515 _.without = function(array) { 516 return _.difference(array, slice.call(arguments, 1)); 517 }; 518 519 // Produce a duplicate-free version of the array. If the array has already 520 // been sorted, you have the option of using a faster algorithm. 521 // Aliased as `unique`. 522 _.uniq = _.unique = function(array, isSorted, iteratee, context) { 523 if (!_.isBoolean(isSorted)) { 524 context = iteratee; 525 iteratee = isSorted; 526 isSorted = false; 527 } 528 if (iteratee != null) iteratee = cb(iteratee, context); 529 var result = []; 530 var seen = []; 531 for (var i = 0, length = getLength(array); i < length; i++) { 532 var value = array[i], 533 computed = iteratee ? iteratee(value, i, array) : value; 534 if (isSorted) { 535 if (!i || seen !== computed) result.push(value); 536 seen = computed; 537 } else if (iteratee) { 538 if (!_.contains(seen, computed)) { 539 seen.push(computed); 540 result.push(value); 541 } 542 } else if (!_.contains(result, value)) { 543 result.push(value); 544 } 545 } 546 return result; 547 }; 548 549 // Produce an array that contains the union: each distinct element from all of 550 // the passed-in arrays. 551 _.union = function() { 552 return _.uniq(flatten(arguments, true, true)); 553 }; 554 555 // Produce an array that contains every item shared between all the 556 // passed-in arrays. 557 _.intersection = function(array) { 558 var result = []; 559 var argsLength = arguments.length; 560 for (var i = 0, length = getLength(array); i < length; i++) { 561 var item = array[i]; 562 if (_.contains(result, item)) continue; 563 for (var j = 1; j < argsLength; j++) { 564 if (!_.contains(arguments[j], item)) break; 565 } 566 if (j === argsLength) result.push(item); 567 } 568 return result; 569 }; 570 571 // Take the difference between one array and a number of other arrays. 572 // Only the elements present in just the first array will remain. 573 _.difference = function(array) { 574 var rest = flatten(arguments, true, true, 1); 575 return _.filter(array, function(value){ 576 return !_.contains(rest, value); 577 }); 578 }; 579 580 // Zip together multiple lists into a single array -- elements that share 581 // an index go together. 582 _.zip = function() { 583 return _.unzip(arguments); 584 }; 585 586 // Complement of _.zip. Unzip accepts an array of arrays and groups 587 // each array's elements on shared indices 588 _.unzip = function(array) { 589 var length = array && _.max(array, getLength).length || 0; 590 var result = Array(length); 591 592 for (var index = 0; index < length; index++) { 593 result[index] = _.pluck(array, index); 594 } 595 return result; 596 }; 597 598 // Converts lists into objects. Pass either a single array of `[key, value]` 599 // pairs, or two parallel arrays of the same length -- one of keys, and one of 600 // the corresponding values. 601 _.object = function(list, values) { 602 var result = {}; 603 for (var i = 0, length = getLength(list); i < length; i++) { 604 if (values) { 605 result[list[i]] = values[i]; 606 } else { 607 result[list[i][0]] = list[i][1]; 608 } 609 } 610 return result; 611 }; 612 613 // Generator function to create the findIndex and findLastIndex functions 614 function createPredicateIndexFinder(dir) { 615 return function(array, predicate, context) { 616 predicate = cb(predicate, context); 617 var length = getLength(array); 618 var index = dir > 0 ? 0 : length - 1; 619 for (; index >= 0 && index < length; index += dir) { 620 if (predicate(array[index], index, array)) return index; 621 } 622 return -1; 623 }; 624 } 625 626 // Returns the first index on an array-like that passes a predicate test 627 _.findIndex = createPredicateIndexFinder(1); 628 _.findLastIndex = createPredicateIndexFinder(-1); 629 630 // Use a comparator function to figure out the smallest index at which 631 // an object should be inserted so as to maintain order. Uses binary search. 632 _.sortedIndex = function(array, obj, iteratee, context) { 633 iteratee = cb(iteratee, context, 1); 634 var value = iteratee(obj); 635 var low = 0, high = getLength(array); 636 while (low < high) { 637 var mid = Math.floor((low + high) / 2); 638 if (iteratee(array[mid]) < value) low = mid + 1; else high = mid; 639 } 640 return low; 641 }; 642 643 // Generator function to create the indexOf and lastIndexOf functions 644 function createIndexFinder(dir, predicateFind, sortedIndex) { 645 return function(array, item, idx) { 646 var i = 0, length = getLength(array); 647 if (typeof idx == 'number') { 648 if (dir > 0) { 649 i = idx >= 0 ? idx : Math.max(idx + length, i); 650 } else { 651 length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1; 652 } 653 } else if (sortedIndex && idx && length) { 654 idx = sortedIndex(array, item); 655 return array[idx] === item ? idx : -1; 656 } 657 if (item !== item) { 658 idx = predicateFind(slice.call(array, i, length), _.isNaN); 659 return idx >= 0 ? idx + i : -1; 660 } 661 for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) { 662 if (array[idx] === item) return idx; 663 } 664 return -1; 665 }; 666 } 667 668 // Return the position of the first occurrence of an item in an array, 669 // or -1 if the item is not included in the array. 670 // If the array is large and already in sort order, pass `true` 671 // for **isSorted** to use binary search. 672 _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex); 673 _.lastIndexOf = createIndexFinder(-1, _.findLastIndex); 674 675 // Generate an integer Array containing an arithmetic progression. A port of 676 // the native Python `range()` function. See 677 // [the Python documentation](http://docs.python.org/library/functions.html#range). 678 _.range = function(start, stop, step) { 679 if (stop == null) { 680 stop = start || 0; 681 start = 0; 682 } 683 step = step || 1; 684 685 var length = Math.max(Math.ceil((stop - start) / step), 0); 686 var range = Array(length); 687 688 for (var idx = 0; idx < length; idx++, start += step) { 689 range[idx] = start; 690 } 691 692 return range; 693 }; 694 695 // Function (ahem) Functions 696 // ------------------ 697 698 // Determines whether to execute a function as a constructor 699 // or a normal function with the provided arguments 700 var executeBound = function(sourceFunc, boundFunc, context, callingContext, args) { 701 if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args); 702 var self = baseCreate(sourceFunc.prototype); 703 var result = sourceFunc.apply(self, args); 704 if (_.isObject(result)) return result; 705 return self; 706 }; 707 708 // Create a function bound to a given object (assigning `this`, and arguments, 709 // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if 710 // available. 711 _.bind = function(func, context) { 712 if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); 713 if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function'); 714 var args = slice.call(arguments, 2); 715 var bound = function() { 716 return executeBound(func, bound, context, this, args.concat(slice.call(arguments))); 717 }; 718 return bound; 719 }; 720 721 // Partially apply a function by creating a version that has had some of its 722 // arguments pre-filled, without changing its dynamic `this` context. _ acts 723 // as a placeholder, allowing any combination of arguments to be pre-filled. 724 _.partial = function(func) { 725 var boundArgs = slice.call(arguments, 1); 726 var bound = function() { 727 var position = 0, length = boundArgs.length; 728 var args = Array(length); 729 for (var i = 0; i < length; i++) { 730 args[i] = boundArgs[i] === _ ? arguments[position++] : boundArgs[i]; 731 } 732 while (position < arguments.length) args.push(arguments[position++]); 733 return executeBound(func, bound, this, this, args); 734 }; 735 return bound; 736 }; 737 738 // Bind a number of an object's methods to that object. Remaining arguments 739 // are the method names to be bound. Useful for ensuring that all callbacks 740 // defined on an object belong to it. 741 _.bindAll = function(obj) { 742 var i, length = arguments.length, key; 743 if (length <= 1) throw new Error('bindAll must be passed function names'); 744 for (i = 1; i < length; i++) { 745 key = arguments[i]; 746 obj[key] = _.bind(obj[key], obj); 747 } 748 return obj; 749 }; 750 751 // Memoize an expensive function by storing its results. 752 _.memoize = function(func, hasher) { 753 var memoize = function(key) { 754 var cache = memoize.cache; 755 var address = '' + (hasher ? hasher.apply(this, arguments) : key); 756 if (!_.has(cache, address)) cache[address] = func.apply(this, arguments); 757 return cache[address]; 758 }; 759 memoize.cache = {}; 760 return memoize; 761 }; 762 763 // Delays a function for the given number of milliseconds, and then calls 764 // it with the arguments supplied. 765 _.delay = function(func, wait) { 766 var args = slice.call(arguments, 2); 767 return setTimeout(function(){ 768 return func.apply(null, args); 769 }, wait); 770 }; 771 772 // Defers a function, scheduling it to run after the current call stack has 773 // cleared. 774 _.defer = _.partial(_.delay, _, 1); 775 776 // Returns a function, that, when invoked, will only be triggered at most once 777 // during a given window of time. Normally, the throttled function will run 778 // as much as it can, without ever going more than once per `wait` duration; 779 // but if you'd like to disable the execution on the leading edge, pass 780 // `{leading: false}`. To disable execution on the trailing edge, ditto. 781 _.throttle = function(func, wait, options) { 782 var context, args, result; 783 var timeout = null; 784 var previous = 0; 785 if (!options) options = {}; 786 var later = function() { 787 previous = options.leading === false ? 0 : _.now(); 788 timeout = null; 789 result = func.apply(context, args); 790 if (!timeout) context = args = null; 791 }; 792 return function() { 793 var now = _.now(); 794 if (!previous && options.leading === false) previous = now; 795 var remaining = wait - (now - previous); 796 context = this; 797 args = arguments; 798 if (remaining <= 0 || remaining > wait) { 799 if (timeout) { 800 clearTimeout(timeout); 801 timeout = null; 802 } 803 previous = now; 804 result = func.apply(context, args); 805 if (!timeout) context = args = null; 806 } else if (!timeout && options.trailing !== false) { 807 timeout = setTimeout(later, remaining); 808 } 809 return result; 810 }; 811 }; 812 813 // Returns a function, that, as long as it continues to be invoked, will not 814 // be triggered. The function will be called after it stops being called for 815 // N milliseconds. If `immediate` is passed, trigger the function on the 816 // leading edge, instead of the trailing. 817 _.debounce = function(func, wait, immediate) { 818 var timeout, args, context, timestamp, result; 819 820 var later = function() { 821 var last = _.now() - timestamp; 822 823 if (last < wait && last >= 0) { 824 timeout = setTimeout(later, wait - last); 825 } else { 826 timeout = null; 827 if (!immediate) { 828 result = func.apply(context, args); 829 if (!timeout) context = args = null; 830 } 831 } 832 }; 833 834 return function() { 835 context = this; 836 args = arguments; 837 timestamp = _.now(); 838 var callNow = immediate && !timeout; 839 if (!timeout) timeout = setTimeout(later, wait); 840 if (callNow) { 841 result = func.apply(context, args); 842 context = args = null; 843 } 844 845 return result; 846 }; 847 }; 848 849 // Returns the first function passed as an argument to the second, 850 // allowing you to adjust arguments, run code before and after, and 851 // conditionally execute the original function. 852 _.wrap = function(func, wrapper) { 853 return _.partial(wrapper, func); 854 }; 855 856 // Returns a negated version of the passed-in predicate. 857 _.negate = function(predicate) { 858 return function() { 859 return !predicate.apply(this, arguments); 860 }; 861 }; 862 863 // Returns a function that is the composition of a list of functions, each 864 // consuming the return value of the function that follows. 865 _.compose = function() { 866 var args = arguments; 867 var start = args.length - 1; 868 return function() { 869 var i = start; 870 var result = args[start].apply(this, arguments); 871 while (i--) result = args[i].call(this, result); 872 return result; 873 }; 874 }; 875 876 // Returns a function that will only be executed on and after the Nth call. 877 _.after = function(times, func) { 878 return function() { 879 if (--times < 1) { 880 return func.apply(this, arguments); 881 } 882 }; 883 }; 884 885 // Returns a function that will only be executed up to (but not including) the Nth call. 886 _.before = function(times, func) { 887 var memo; 888 return function() { 889 if (--times > 0) { 890 memo = func.apply(this, arguments); 891 } 892 if (times <= 1) func = null; 893 return memo; 894 }; 895 }; 896 897 // Returns a function that will be executed at most one time, no matter how 898 // often you call it. Useful for lazy initialization. 899 _.once = _.partial(_.before, 2); 900 901 // Object Functions 902 // ---------------- 903 904 // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed. 905 var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString'); 906 var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString', 907 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString']; 908 909 function collectNonEnumProps(obj, keys) { 910 var nonEnumIdx = nonEnumerableProps.length; 911 var constructor = obj.constructor; 912 var proto = (_.isFunction(constructor) && constructor.prototype) || ObjProto; 913 914 // Constructor is a special case. 915 var prop = 'constructor'; 916 if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop); 917 918 while (nonEnumIdx--) { 919 prop = nonEnumerableProps[nonEnumIdx]; 920 if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) { 921 keys.push(prop); 922 } 923 } 924 } 925 926 // Retrieve the names of an object's own properties. 927 // Delegates to **ECMAScript 5**'s native `Object.keys` 928 _.keys = function(obj) { 929 if (!_.isObject(obj)) return []; 930 if (nativeKeys) return nativeKeys(obj); 931 var keys = []; 932 for (var key in obj) if (_.has(obj, key)) keys.push(key); 933 // Ahem, IE < 9. 934 if (hasEnumBug) collectNonEnumProps(obj, keys); 935 return keys; 936 }; 937 938 // Retrieve all the property names of an object. 939 _.allKeys = function(obj) { 940 if (!_.isObject(obj)) return []; 941 var keys = []; 942 for (var key in obj) keys.push(key); 943 // Ahem, IE < 9. 944 if (hasEnumBug) collectNonEnumProps(obj, keys); 945 return keys; 946 }; 947 948 // Retrieve the values of an object's properties. 949 _.values = function(obj) { 950 var keys = _.keys(obj); 951 var length = keys.length; 952 var values = Array(length); 953 for (var i = 0; i < length; i++) { 954 values[i] = obj[keys[i]]; 955 } 956 return values; 957 }; 958 959 // Returns the results of applying the iteratee to each element of the object 960 // In contrast to _.map it returns an object 961 _.mapObject = function(obj, iteratee, context) { 962 iteratee = cb(iteratee, context); 963 var keys = _.keys(obj), 964 length = keys.length, 965 results = {}, 966 currentKey; 967 for (var index = 0; index < length; index++) { 968 currentKey = keys[index]; 969 results[currentKey] = iteratee(obj[currentKey], currentKey, obj); 970 } 971 return results; 972 }; 973 974 // Convert an object into a list of `[key, value]` pairs. 975 _.pairs = function(obj) { 976 var keys = _.keys(obj); 977 var length = keys.length; 978 var pairs = Array(length); 979 for (var i = 0; i < length; i++) { 980 pairs[i] = [keys[i], obj[keys[i]]]; 981 } 982 return pairs; 983 }; 984 985 // Invert the keys and values of an object. The values must be serializable. 986 _.invert = function(obj) { 987 var result = {}; 988 var keys = _.keys(obj); 989 for (var i = 0, length = keys.length; i < length; i++) { 990 result[obj[keys[i]]] = keys[i]; 991 } 992 return result; 993 }; 994 995 // Return a sorted list of the function names available on the object. 996 // Aliased as `methods` 997 _.functions = _.methods = function(obj) { 998 var names = []; 999 for (var key in obj) { 1000 if (_.isFunction(obj[key])) names.push(key); 1001 } 1002 return names.sort(); 1003 }; 1004 1005 // Extend a given object with all the properties in passed-in object(s). 1006 _.extend = createAssigner(_.allKeys); 1007 1008 // Assigns a given object with all the own properties in the passed-in object(s) 1009 // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign) 1010 _.extendOwn = _.assign = createAssigner(_.keys); 1011 1012 // Returns the first key on an object that passes a predicate test 1013 _.findKey = function(obj, predicate, context) { 1014 predicate = cb(predicate, context); 1015 var keys = _.keys(obj), key; 1016 for (var i = 0, length = keys.length; i < length; i++) { 1017 key = keys[i]; 1018 if (predicate(obj[key], key, obj)) return key; 1019 } 1020 }; 1021 1022 // Return a copy of the object only containing the whitelisted properties. 1023 _.pick = function(object, oiteratee, context) { 1024 var result = {}, obj = object, iteratee, keys; 1025 if (obj == null) return result; 1026 if (_.isFunction(oiteratee)) { 1027 keys = _.allKeys(obj); 1028 iteratee = optimizeCb(oiteratee, context); 1029 } else { 1030 keys = flatten(arguments, false, false, 1); 1031 iteratee = function(value, key, obj) { return key in obj; }; 1032 obj = Object(obj); 1033 } 1034 for (var i = 0, length = keys.length; i < length; i++) { 1035 var key = keys[i]; 1036 var value = obj[key]; 1037 if (iteratee(value, key, obj)) result[key] = value; 1038 } 1039 return result; 1040 }; 1041 1042 // Return a copy of the object without the blacklisted properties. 1043 _.omit = function(obj, iteratee, context) { 1044 if (_.isFunction(iteratee)) { 1045 iteratee = _.negate(iteratee); 1046 } else { 1047 var keys = _.map(flatten(arguments, false, false, 1), String); 1048 iteratee = function(value, key) { 1049 return !_.contains(keys, key); 1050 }; 1051 } 1052 return _.pick(obj, iteratee, context); 1053 }; 1054 1055 // Fill in a given object with default properties. 1056 _.defaults = createAssigner(_.allKeys, true); 1057 1058 // Creates an object that inherits from the given prototype object. 1059 // If additional properties are provided then they will be added to the 1060 // created object. 1061 _.create = function(prototype, props) { 1062 var result = baseCreate(prototype); 1063 if (props) _.extendOwn(result, props); 1064 return result; 1065 }; 1066 1067 // Create a (shallow-cloned) duplicate of an object. 1068 _.clone = function(obj) { 1069 if (!_.isObject(obj)) return obj; 1070 return _.isArray(obj) ? obj.slice() : _.extend({}, obj); 1071 }; 1072 1073 // Invokes interceptor with the obj, and then returns obj. 1074 // The primary purpose of this method is to "tap into" a method chain, in 1075 // order to perform operations on intermediate results within the chain. 1076 _.tap = function(obj, interceptor) { 1077 interceptor(obj); 1078 return obj; 1079 }; 1080 1081 // Returns whether an object has a given set of `key:value` pairs. 1082 _.isMatch = function(object, attrs) { 1083 var keys = _.keys(attrs), length = keys.length; 1084 if (object == null) return !length; 1085 var obj = Object(object); 1086 for (var i = 0; i < length; i++) { 1087 var key = keys[i]; 1088 if (attrs[key] !== obj[key] || !(key in obj)) return false; 1089 } 1090 return true; 1091 }; 1092 1093 1094 // Internal recursive comparison function for `isEqual`. 1095 var eq = function(a, b, aStack, bStack) { 1096 // Identical objects are equal. `0 === -0`, but they aren't identical. 1097 // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal). 1098 if (a === b) return a !== 0 || 1 / a === 1 / b; 1099 // A strict comparison is necessary because `null == undefined`. 1100 if (a == null || b == null) return a === b; 1101 // Unwrap any wrapped objects. 1102 if (a instanceof _) a = a._wrapped; 1103 if (b instanceof _) b = b._wrapped; 1104 // Compare `[[Class]]` names. 1105 var className = toString.call(a); 1106 if (className !== toString.call(b)) return false; 1107 switch (className) { 1108 // Strings, numbers, regular expressions, dates, and booleans are compared by value. 1109 case '[object RegExp]': 1110 // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i') 1111 case '[object String]': 1112 // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is 1113 // equivalent to `new String("5")`. 1114 return '' + a === '' + b; 1115 case '[object Number]': 1116 // `NaN`s are equivalent, but non-reflexive. 1117 // Object(NaN) is equivalent to NaN 1118 if (+a !== +a) return +b !== +b; 1119 // An `egal` comparison is performed for other numeric values. 1120 return +a === 0 ? 1 / +a === 1 / b : +a === +b; 1121 case '[object Date]': 1122 case '[object Boolean]': 1123 // Coerce dates and booleans to numeric primitive values. Dates are compared by their 1124 // millisecond representations. Note that invalid dates with millisecond representations 1125 // of `NaN` are not equivalent. 1126 return +a === +b; 1127 } 1128 1129 var areArrays = className === '[object Array]'; 1130 if (!areArrays) { 1131 if (typeof a != 'object' || typeof b != 'object') return false; 1132 1133 // Objects with different constructors are not equivalent, but `Object`s or `Array`s 1134 // from different frames are. 1135 var aCtor = a.constructor, bCtor = b.constructor; 1136 if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor && 1137 _.isFunction(bCtor) && bCtor instanceof bCtor) 1138 && ('constructor' in a && 'constructor' in b)) { 1139 return false; 1140 } 1141 } 1142 // Assume equality for cyclic structures. The algorithm for detecting cyclic 1143 // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`. 1144 1145 // Initializing stack of traversed objects. 1146 // It's done here since we only need them for objects and arrays comparison. 1147 aStack = aStack || []; 1148 bStack = bStack || []; 1149 var length = aStack.length; 1150 while (length--) { 1151 // Linear search. Performance is inversely proportional to the number of 1152 // unique nested structures. 1153 if (aStack[length] === a) return bStack[length] === b; 1154 } 1155 1156 // Add the first object to the stack of traversed objects. 1157 aStack.push(a); 1158 bStack.push(b); 1159 1160 // Recursively compare objects and arrays. 1161 if (areArrays) { 1162 // Compare array lengths to determine if a deep comparison is necessary. 1163 length = a.length; 1164 if (length !== b.length) return false; 1165 // Deep compare the contents, ignoring non-numeric properties. 1166 while (length--) { 1167 if (!eq(a[length], b[length], aStack, bStack)) return false; 1168 } 1169 } else { 1170 // Deep compare objects. 1171 var keys = _.keys(a), key; 1172 length = keys.length; 1173 // Ensure that both objects contain the same number of properties before comparing deep equality. 1174 if (_.keys(b).length !== length) return false; 1175 while (length--) { 1176 // Deep compare each member 1177 key = keys[length]; 1178 if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false; 1179 } 1180 } 1181 // Remove the first object from the stack of traversed objects. 1182 aStack.pop(); 1183 bStack.pop(); 1184 return true; 1185 }; 1186 1187 // Perform a deep comparison to check if two objects are equal. 1188 _.isEqual = function(a, b) { 1189 return eq(a, b); 1190 }; 1191 1192 // Is a given array, string, or object empty? 1193 // An "empty" object has no enumerable own-properties. 1194 _.isEmpty = function(obj) { 1195 if (obj == null) return true; 1196 if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0; 1197 return _.keys(obj).length === 0; 1198 }; 1199 1200 // Is a given value a DOM element? 1201 _.isElement = function(obj) { 1202 return !!(obj && obj.nodeType === 1); 1203 }; 1204 1205 // Is a given value an array? 1206 // Delegates to ECMA5's native Array.isArray 1207 _.isArray = nativeIsArray || function(obj) { 1208 return toString.call(obj) === '[object Array]'; 1209 }; 1210 1211 // Is a given variable an object? 1212 _.isObject = function(obj) { 1213 var type = typeof obj; 1214 return type === 'function' || type === 'object' && !!obj; 1215 }; 1216 1217 // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError. 1218 _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function(name) { 1219 _['is' + name] = function(obj) { 1220 return toString.call(obj) === '[object ' + name + ']'; 1221 }; 1222 }); 1223 1224 // Define a fallback version of the method in browsers (ahem, IE < 9), where 1225 // there isn't any inspectable "Arguments" type. 1226 if (!_.isArguments(arguments)) { 1227 _.isArguments = function(obj) { 1228 return _.has(obj, 'callee'); 1229 }; 1230 } 1231 1232 // Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8, 1233 // IE 11 (#1621), and in Safari 8 (#1929). 1234 if (typeof /./ != 'function' && typeof Int8Array != 'object') { 1235 _.isFunction = function(obj) { 1236 return typeof obj == 'function' || false; 1237 }; 1238 } 1239 1240 // Is a given object a finite number? 1241 _.isFinite = function(obj) { 1242 return isFinite(obj) && !isNaN(parseFloat(obj)); 1243 }; 1244 1245 // Is the given value `NaN`? (NaN is the only number which does not equal itself). 1246 _.isNaN = function(obj) { 1247 return _.isNumber(obj) && obj !== +obj; 1248 }; 1249 1250 // Is a given value a boolean? 1251 _.isBoolean = function(obj) { 1252 return obj === true || obj === false || toString.call(obj) === '[object Boolean]'; 1253 }; 1254 1255 // Is a given value equal to null? 1256 _.isNull = function(obj) { 1257 return obj === null; 1258 }; 1259 1260 // Is a given variable undefined? 1261 _.isUndefined = function(obj) { 1262 return obj === void 0; 1263 }; 1264 1265 // Shortcut function for checking if an object has a given property directly 1266 // on itself (in other words, not on a prototype). 1267 _.has = function(obj, key) { 1268 return obj != null && hasOwnProperty.call(obj, key); 1269 }; 1270 1271 // Utility Functions 1272 // ----------------- 1273 1274 // Run Underscore.js in *noConflict* mode, returning the `_` variable to its 1275 // previous owner. Returns a reference to the Underscore object. 1276 _.noConflict = function() { 1277 root._ = previousUnderscore; 1278 return this; 1279 }; 1280 1281 // Keep the identity function around for default iteratees. 1282 _.identity = function(value) { 1283 return value; 1284 }; 1285 1286 // Predicate-generating functions. Often useful outside of Underscore. 1287 _.constant = function(value) { 1288 return function() { 1289 return value; 1290 }; 1291 }; 1292 1293 _.noop = function(){}; 1294 1295 _.property = property; 1296 1297 // Generates a function for a given object that returns a given property. 1298 _.propertyOf = function(obj) { 1299 return obj == null ? function(){} : function(key) { 1300 return obj[key]; 1301 }; 1302 }; 1303 1304 // Returns a predicate for checking whether an object has a given set of 1305 // `key:value` pairs. 1306 _.matcher = _.matches = function(attrs) { 1307 attrs = _.extendOwn({}, attrs); 1308 return function(obj) { 1309 return _.isMatch(obj, attrs); 1310 }; 1311 }; 1312 1313 // Run a function **n** times. 1314 _.times = function(n, iteratee, context) { 1315 var accum = Array(Math.max(0, n)); 1316 iteratee = optimizeCb(iteratee, context, 1); 1317 for (var i = 0; i < n; i++) accum[i] = iteratee(i); 1318 return accum; 1319 }; 1320 1321 // Return a random integer between min and max (inclusive). 1322 _.random = function(min, max) { 1323 if (max == null) { 1324 max = min; 1325 min = 0; 1326 } 1327 return min + Math.floor(Math.random() * (max - min + 1)); 1328 }; 1329 1330 // A (possibly faster) way to get the current timestamp as an integer. 1331 _.now = Date.now || function() { 1332 return new Date().getTime(); 1333 }; 1334 1335 // List of HTML entities for escaping. 1336 var escapeMap = { 1337 '&': '&', 1338 '<': '<', 1339 '>': '>', 1340 '"': '"', 1341 "'": ''', 1342 '`': '`' 1343 }; 1344 var unescapeMap = _.invert(escapeMap); 1345 1346 // Functions for escaping and unescaping strings to/from HTML interpolation. 1347 var createEscaper = function(map) { 1348 var escaper = function(match) { 1349 return map[match]; 1350 }; 1351 // Regexes for identifying a key that needs to be escaped 1352 var source = '(?:' + _.keys(map).join('|') + ')'; 1353 var testRegexp = RegExp(source); 1354 var replaceRegexp = RegExp(source, 'g'); 1355 return function(string) { 1356 string = string == null ? '' : '' + string; 1357 return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string; 1358 }; 1359 }; 1360 _.escape = createEscaper(escapeMap); 1361 _.unescape = createEscaper(unescapeMap); 1362 1363 // If the value of the named `property` is a function then invoke it with the 1364 // `object` as context; otherwise, return it. 1365 _.result = function(object, property, fallback) { 1366 var value = object == null ? void 0 : object[property]; 1367 if (value === void 0) { 1368 value = fallback; 1369 } 1370 return _.isFunction(value) ? value.call(object) : value; 1371 }; 1372 1373 // Generate a unique integer id (unique within the entire client session). 1374 // Useful for temporary DOM ids. 1375 var idCounter = 0; 1376 _.uniqueId = function(prefix) { 1377 var id = ++idCounter + ''; 1378 return prefix ? prefix + id : id; 1379 }; 1380 1381 // By default, Underscore uses ERB-style template delimiters, change the 1382 // following template settings to use alternative delimiters. 1383 _.templateSettings = { 1384 evaluate : /<%([\s\S]+?)%>/g, 1385 interpolate : /<%=([\s\S]+?)%>/g, 1386 escape : /<%-([\s\S]+?)%>/g 1387 }; 1388 1389 // When customizing `templateSettings`, if you don't want to define an 1390 // interpolation, evaluation or escaping regex, we need one that is 1391 // guaranteed not to match. 1392 var noMatch = /(.)^/; 1393 1394 // Certain characters need to be escaped so that they can be put into a 1395 // string literal. 1396 var escapes = { 1397 "'": "'", 1398 '\\': '\\', 1399 '\r': 'r', 1400 '\n': 'n', 1401 '\u2028': 'u2028', 1402 '\u2029': 'u2029' 1403 }; 1404 1405 var escaper = /\\|'|\r|\n|\u2028|\u2029/g; 1406 1407 var escapeChar = function(match) { 1408 return '\\' + escapes[match]; 1409 }; 1410 1411 // JavaScript micro-templating, similar to John Resig's implementation. 1412 // Underscore templating handles arbitrary delimiters, preserves whitespace, 1413 // and correctly escapes quotes within interpolated code. 1414 // NB: `oldSettings` only exists for backwards compatibility. 1415 _.template = function(text, settings, oldSettings) { 1416 if (!settings && oldSettings) settings = oldSettings; 1417 settings = _.defaults({}, settings, _.templateSettings); 1418 1419 // Combine delimiters into one regular expression via alternation. 1420 var matcher = RegExp([ 1421 (settings.escape || noMatch).source, 1422 (settings.interpolate || noMatch).source, 1423 (settings.evaluate || noMatch).source 1424 ].join('|') + '|$', 'g'); 1425 1426 // Compile the template source, escaping string literals appropriately. 1427 var index = 0; 1428 var source = "__p+='"; 1429 text.replace(matcher, function(match, escape, interpolate, evaluate, offset) { 1430 source += text.slice(index, offset).replace(escaper, escapeChar); 1431 index = offset + match.length; 1432 1433 if (escape) { 1434 source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'"; 1435 } else if (interpolate) { 1436 source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'"; 1437 } else if (evaluate) { 1438 source += "';\n" + evaluate + "\n__p+='"; 1439 } 1440 1441 // Adobe VMs need the match returned to produce the correct offest. 1442 return match; 1443 }); 1444 source += "';\n"; 1445 1446 // If a variable is not specified, place data values in local scope. 1447 if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n'; 1448 1449 source = "var __t,__p='',__j=Array.prototype.join," + 1450 "print=function(){__p+=__j.call(arguments,'');};\n" + 1451 source + 'return __p;\n'; 1452 1453 try { 1454 var render = new Function(settings.variable || 'obj', '_', source); 1455 } catch (e) { 1456 e.source = source; 1457 throw e; 1458 } 1459 1460 var template = function(data) { 1461 return render.call(this, data, _); 1462 }; 1463 1464 // Provide the compiled source as a convenience for precompilation. 1465 var argument = settings.variable || 'obj'; 1466 template.source = 'function(' + argument + '){\n' + source + '}'; 1467 1468 return template; 1469 }; 1470 1471 // Add a "chain" function. Start chaining a wrapped Underscore object. 1472 _.chain = function(obj) { 1473 var instance = _(obj); 1474 instance._chain = true; 1475 return instance; 1476 }; 1477 1478 // OOP 1479 // --------------- 1480 // If Underscore is called as a function, it returns a wrapped object that 1481 // can be used OO-style. This wrapper holds altered versions of all the 1482 // underscore functions. Wrapped objects may be chained. 1483 1484 // Helper function to continue chaining intermediate results. 1485 var result = function(instance, obj) { 1486 return instance._chain ? _(obj).chain() : obj; 1487 }; 1488 1489 // Add your own custom functions to the Underscore object. 1490 _.mixin = function(obj) { 1491 _.each(_.functions(obj), function(name) { 1492 var func = _[name] = obj[name]; 1493 _.prototype[name] = function() { 1494 var args = [this._wrapped]; 1495 push.apply(args, arguments); 1496 return result(this, func.apply(_, args)); 1497 }; 1498 }); 1499 }; 1500 1501 // Add all of the Underscore functions to the wrapper object. 1502 _.mixin(_); 1503 1504 // Add all mutator Array functions to the wrapper. 1505 _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { 1506 var method = ArrayProto[name]; 1507 _.prototype[name] = function() { 1508 var obj = this._wrapped; 1509 method.apply(obj, arguments); 1510 if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0]; 1511 return result(this, obj); 1512 }; 1513 }); 1514 1515 // Add all accessor Array functions to the wrapper. 1516 _.each(['concat', 'join', 'slice'], function(name) { 1517 var method = ArrayProto[name]; 1518 _.prototype[name] = function() { 1519 return result(this, method.apply(this._wrapped, arguments)); 1520 }; 1521 }); 1522 1523 // Extracts the result from a wrapped and chained object. 1524 _.prototype.value = function() { 1525 return this._wrapped; 1526 }; 1527 1528 // Provide unwrapping proxy for some methods used in engine operations 1529 // such as arithmetic and JSON stringification. 1530 _.prototype.valueOf = _.prototype.toJSON = _.prototype.value; 1531 1532 _.prototype.toString = function() { 1533 return '' + this._wrapped; 1534 }; 1535 1536 // AMD registration happens at the end for compatibility with AMD loaders 1537 // that may not enforce next-turn semantics on modules. Even though general 1538 // practice for AMD registration is to be anonymous, underscore registers 1539 // as a named module because, like jQuery, it is a base library that is 1540 // popular enough to be bundled in a third party lib, but not be part of 1541 // an AMD load request. Those cases could generate an error when an 1542 // anonymous define() is called outside of a loader request. 1543 if (typeof define === 'function' && define.amd) { 1544 define('underscore', [], function() { 1545 return _; 1546 }); 1547 } 1548}.call(this)); 1549