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ampersand/template/shared/test/assets/underscore.js
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68.45
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1218
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// Underscore.js 1.4.4 // =================== // > http://underscorejs.org // > (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc. // > Underscore may be freely distributed under the MIT license. // Baseline setup // -------------- (function() { // Establish the root object, `window` in the browser, or `global` on the server. var root = this; // Save the previous value of the `_` variable. var previousUnderscore = root._; // Establish the object that gets returned to break out of a loop iteration. var breaker = {}; // Save bytes in the minified (but not gzipped) version: var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; // Create quick reference variables for speed access to core prototypes. var push = ArrayProto.push, slice = ArrayProto.slice, concat = ArrayProto.concat, toString = ObjProto.toString, hasOwnProperty = ObjProto.hasOwnProperty; // All **ECMAScript 5** native function implementations that we hope to use // are declared here. var nativeForEach = ArrayProto.forEach, nativeMap = ArrayProto.map, nativeReduce = ArrayProto.reduce, nativeReduceRight = ArrayProto.reduceRight, nativeFilter = ArrayProto.filter, nativeEvery = ArrayProto.every, nativeSome = ArrayProto.some, nativeIndexOf = ArrayProto.indexOf, nativeLastIndexOf = ArrayProto.lastIndexOf, nativeIsArray = Array.isArray, nativeKeys = Object.keys, nativeBind = FuncProto.bind; // Create a safe reference to the Underscore object for use below. var _ = function(obj) { if (obj instanceof _) return obj; if (!(this instanceof _)) return new _(obj); this._wrapped = obj; }; // Export the Underscore object for **Node.js**, with // backwards-compatibility for the old `require()` API. If we're in // the browser, add `_` as a global object via a string identifier, // for Closure Compiler "advanced" mode. if (typeof exports !== 'undefined') { if (typeof module !== 'undefined' && module.exports) { exports = module.exports = _; } exports._ = _; } else { root._ = _; } // Current version. _.VERSION = '1.4.4'; // Collection Functions // -------------------- // The cornerstone, an `each` implementation, aka `forEach`. // Handles objects with the built-in `forEach`, arrays, and raw objects. // Delegates to **ECMAScript 5**'s native `forEach` if available. var each = _.each = _.forEach = function(obj, iterator, context) { if (obj == null) return; if (nativeForEach && obj.forEach === nativeForEach) { obj.forEach(iterator, context); } else if (obj.length === +obj.length) { for (var i = 0, l = obj.length; i < l; i++) { if (iterator.call(context, obj[i], i, obj) === breaker) return; } } else { for (var key in obj) { if (_.has(obj, key)) { if (iterator.call(context, obj[key], key, obj) === breaker) return; } } } }; // Return the results of applying the iterator to each element. // Delegates to **ECMAScript 5**'s native `map` if available. _.map = _.collect = function(obj, iterator, context) { var results = []; if (obj == null) return results; if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context); each(obj, function(value, index, list) { results[results.length] = iterator.call(context, value, index, list); }); return results; }; var reduceError = 'Reduce of empty array with no initial value'; // **Reduce** builds up a single result from a list of values, aka `inject`, // or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available. _.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) { var initial = arguments.length > 2; if (obj == null) obj = []; if (nativeReduce && obj.reduce === nativeReduce) { if (context) iterator = _.bind(iterator, context); return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator); } each(obj, function(value, index, list) { if (!initial) { memo = value; initial = true; } else { memo = iterator.call(context, memo, value, index, list); } }); if (!initial) throw new TypeError(reduceError); return memo; }; // The right-associative version of reduce, also known as `foldr`. // Delegates to **ECMAScript 5**'s native `reduceRight` if available. _.reduceRight = _.foldr = function(obj, iterator, memo, context) { var initial = arguments.length > 2; if (obj == null) obj = []; if (nativeReduceRight && obj.reduceRight === nativeReduceRight) { if (context) iterator = _.bind(iterator, context); return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator); } var length = obj.length; if (length !== +length) { var keys = _.keys(obj); length = keys.length; } each(obj, function(value, index, list) { index = keys ? keys[--length] : --length; if (!initial) { memo = obj[index]; initial = true; } else { memo = iterator.call(context, memo, obj[index], index, list); } }); if (!initial) throw new TypeError(reduceError); return memo; }; // Return the first value which passes a truth test. Aliased as `detect`. _.find = _.detect = function(obj, iterator, context) { var result; any(obj, function(value, index, list) { if (iterator.call(context, value, index, list)) { result = value; return true; } }); return result; }; // Return all the elements that pass a truth test. // Delegates to **ECMAScript 5**'s native `filter` if available. // Aliased as `select`. _.filter = _.select = function(obj, iterator, context) { var results = []; if (obj == null) return results; if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context); each(obj, function(value, index, list) { if (iterator.call(context, value, index, list)) results[results.length] = value; }); return results; }; // Return all the elements for which a truth test fails. _.reject = function(obj, iterator, context) { return _.filter(obj, function(value, index, list) { return !iterator.call(context, value, index, list); }, context); }; // Determine whether all of the elements match a truth test. // Delegates to **ECMAScript 5**'s native `every` if available. // Aliased as `all`. _.every = _.all = function(obj, iterator, context) { iterator || (iterator = _.identity); var result = true; if (obj == null) return result; if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context); each(obj, function(value, index, list) { if (!(result = result && iterator.call(context, value, index, list))) return breaker; }); return !!result; }; // Determine if at least one element in the object matches a truth test. // Delegates to **ECMAScript 5**'s native `some` if available. // Aliased as `any`. var any = _.some = _.any = function(obj, iterator, context) { iterator || (iterator = _.identity); var result = false; if (obj == null) return result; if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context); each(obj, function(value, index, list) { if (result || (result = iterator.call(context, value, index, list))) return breaker; }); return !!result; }; // Determine if the array or object contains a given value (using `===`). // Aliased as `include`. _.contains = _.include = function(obj, target) { if (obj == null) return false; if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1; return any(obj, function(value) { return value === target; }); }; // Invoke a method (with arguments) on every item in a collection. _.invoke = function(obj, method) { var args = slice.call(arguments, 2); var isFunc = _.isFunction(method); return _.map(obj, function(value) { return (isFunc ? method : value[method]).apply(value, args); }); }; // Convenience version of a common use case of `map`: fetching a property. _.pluck = function(obj, key) { return _.map(obj, function(value){ return value[key]; }); }; // Convenience version of a common use case of `filter`: selecting only objects // containing specific `key:value` pairs. _.where = function(obj, attrs, first) { if (_.isEmpty(attrs)) return first ? null : []; return _[first ? 'find' : 'filter'](obj, function(value) { for (var key in attrs) { if (attrs[key] !== value[key]) return false; } return true; }); }; // Convenience version of a common use case of `find`: getting the first object // containing specific `key:value` pairs. _.findWhere = function(obj, attrs) { return _.where(obj, attrs, true); }; // Return the maximum element or (element-based computation). // Can't optimize arrays of integers longer than 65,535 elements. // See: https://bugs.webkit.org/show_bug.cgi?id=80797 _.max = function(obj, iterator, context) { if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) { return Math.max.apply(Math, obj); } if (!iterator && _.isEmpty(obj)) return -Infinity; var result = {computed : -Infinity, value: -Infinity}; each(obj, function(value, index, list) { var computed = iterator ? iterator.call(context, value, index, list) : value; computed >= result.computed && (result = {value : value, computed : computed}); }); return result.value; }; // Return the minimum element (or element-based computation). _.min = function(obj, iterator, context) { if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) { return Math.min.apply(Math, obj); } if (!iterator && _.isEmpty(obj)) return Infinity; var result = {computed : Infinity, value: Infinity}; each(obj, function(value, index, list) { var computed = iterator ? iterator.call(context, value, index, list) : value; computed < result.computed && (result = {value : value, computed : computed}); }); return result.value; }; // Shuffle an array. _.shuffle = function(obj) { var rand; var index = 0; var shuffled = []; each(obj, function(value) { rand = _.random(index++); shuffled[index - 1] = shuffled[rand]; shuffled[rand] = value; }); return shuffled; }; // An internal function to generate lookup iterators. var lookupIterator = function(value) { return _.isFunction(value) ? value : function(obj){ return obj[value]; }; }; // Sort the object's values by a criterion produced by an iterator. _.sortBy = function(obj, value, context) { var iterator = lookupIterator(value); return _.pluck(_.map(obj, function(value, index, list) { return { value : value, index : index, criteria : iterator.call(context, value, index, list) }; }).sort(function(left, right) { var a = left.criteria; var b = right.criteria; if (a !== b) { if (a > b || a === void 0) return 1; if (a < b || b === void 0) return -1; } return left.index < right.index ? -1 : 1; }), 'value'); }; // An internal function used for aggregate "group by" operations. var group = function(obj, value, context, behavior) { var result = {}; var iterator = lookupIterator(value || _.identity); each(obj, function(value, index) { var key = iterator.call(context, value, index, obj); behavior(result, key, value); }); return result; }; // Groups the object's values by a criterion. Pass either a string attribute // to group by, or a function that returns the criterion. _.groupBy = function(obj, value, context) { return group(obj, value, context, function(result, key, value) { (_.has(result, key) ? result[key] : (result[key] = [])).push(value); }); }; // Counts instances of an object that group by a certain criterion. Pass // either a string attribute to count by, or a function that returns the // criterion. _.countBy = function(obj, value, context) { return group(obj, value, context, function(result, key) { if (!_.has(result, key)) result[key] = 0; result[key]++; }); }; // Use a comparator function to figure out the smallest index at which // an object should be inserted so as to maintain order. Uses binary search. _.sortedIndex = function(array, obj, iterator, context) { iterator = iterator == null ? _.identity : lookupIterator(iterator); var value = iterator.call(context, obj); var low = 0, high = array.length; while (low < high) { var mid = (low + high) >>> 1; iterator.call(context, array[mid]) < value ? low = mid + 1 : high = mid; } return low; }; // Safely convert anything iterable into a real, live array. _.toArray = function(obj) { if (!obj) return []; if (_.isArray(obj)) return slice.call(obj); if (obj.length === +obj.length) return _.map(obj, _.identity); return _.values(obj); }; // Return the number of elements in an object. _.size = function(obj) { if (obj == null) return 0; return (obj.length === +obj.length) ? obj.length : _.keys(obj).length; }; // Array Functions // --------------- // Get the first element of an array. Passing **n** will return the first N // values in the array. Aliased as `head` and `take`. The **guard** check // allows it to work with `_.map`. _.first = _.head = _.take = function(array, n, guard) { if (array == null) return void 0; return (n != null) && !guard ? slice.call(array, 0, n) : array[0]; }; // Returns everything but the last entry of the array. Especially useful on // the arguments object. Passing **n** will return all the values in // the array, excluding the last N. The **guard** check allows it to work with // `_.map`. _.initial = function(array, n, guard) { return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n)); }; // Get the last element of an array. Passing **n** will return the last N // values in the array. The **guard** check allows it to work with `_.map`. _.last = function(array, n, guard) { if (array == null) return void 0; if ((n != null) && !guard) { return slice.call(array, Math.max(array.length - n, 0)); } else { return array[array.length - 1]; } }; // Returns everything but the first entry of the array. Aliased as `tail` and `drop`. // Especially useful on the arguments object. Passing an **n** will return // the rest N values in the array. The **guard** // check allows it to work with `_.map`. _.rest = _.tail = _.drop = function(array, n, guard) { return slice.call(array, (n == null) || guard ? 1 : n); }; // Trim out all falsy values from an array. _.compact = function(array) { return _.filter(array, _.identity); }; // Internal implementation of a recursive `flatten` function. var flatten = function(input, shallow, output) { each(input, function(value) { if (_.isArray(value)) { shallow ? push.apply(output, value) : flatten(value, shallow, output); } else { output.push(value); } }); return output; }; // Return a completely flattened version of an array. _.flatten = function(array, shallow) { return flatten(array, shallow, []); }; // Return a version of the array that does not contain the specified value(s). _.without = function(array) { return _.difference(array, slice.call(arguments, 1)); }; // Produce a duplicate-free version of the array. If the array has already // been sorted, you have the option of using a faster algorithm. // Aliased as `unique`. _.uniq = _.unique = function(array, isSorted, iterator, context) { if (_.isFunction(isSorted)) { context = iterator; iterator = isSorted; isSorted = false; } var initial = iterator ? _.map(array, iterator, context) : array; var results = []; var seen = []; each(initial, function(value, index) { if (isSorted ? (!index || seen[seen.length - 1] !== value) : !_.contains(seen, value)) { seen.push(value); results.push(array[index]); } }); return results; }; // Produce an array that contains the union: each distinct element from all of // the passed-in arrays. _.union = function() { return _.uniq(concat.apply(ArrayProto, arguments)); }; // Produce an array that contains every item shared between all the // passed-in arrays. _.intersection = function(array) { var rest = slice.call(arguments, 1); return _.filter(_.uniq(array), function(item) { return _.every(rest, function(other) { return _.indexOf(other, item) >= 0; }); }); }; // Take the difference between one array and a number of other arrays. // Only the elements present in just the first array will remain. _.difference = function(array) { var rest = concat.apply(ArrayProto, slice.call(arguments, 1)); return _.filter(array, function(value){ return !_.contains(rest, value); }); }; // Zip together multiple lists into a single array -- elements that share // an index go together. _.zip = function() { var args = slice.call(arguments); var length = _.max(_.pluck(args, 'length')); var results = new Array(length); for (var i = 0; i < length; i++) { results[i] = _.pluck(args, "" + i); } return results; }; // Converts lists into objects. Pass either a single array of `[key, value]` // pairs, or two parallel arrays of the same length -- one of keys, and one of // the corresponding values. _.object = function(list, values) { if (list == null) return {}; var result = {}; for (var i = 0, l = list.length; i < l; i++) { if (values) { result[list[i]] = values[i]; } else { result[list[i][0]] = list[i][1]; } } return result; }; // If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**), // we need this function. Return the position of the first occurrence of an // item in an array, or -1 if the item is not included in the array. // Delegates to **ECMAScript 5**'s native `indexOf` if available. // If the array is large and already in sort order, pass `true` // for **isSorted** to use binary search. _.indexOf = function(array, item, isSorted) { if (array == null) return -1; var i = 0, l = array.length; if (isSorted) { if (typeof isSorted == 'number') { i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted); } else { i = _.sortedIndex(array, item); return array[i] === item ? i : -1; } } if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted); for (; i < l; i++) if (array[i] === item) return i; return -1; }; // Delegates to **ECMAScript 5**'s native `lastIndexOf` if available. _.lastIndexOf = function(array, item, from) { if (array == null) return -1; var hasIndex = from != null; if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) { return hasIndex ? array.lastIndexOf(item, from) : array.lastIndexOf(item); } var i = (hasIndex ? from : array.length); while (i--) if (array[i] === item) return i; return -1; }; // Generate an integer Array containing an arithmetic progression. A port of // the native Python `range()` function. See // [the Python documentation](http://docs.python.org/library/functions.html#range). _.range = function(start, stop, step) { if (arguments.length <= 1) { stop = start || 0; start = 0; } step = arguments[2] || 1; var len = Math.max(Math.ceil((stop - start) / step), 0); var idx = 0; var range = new Array(len); while(idx < len) { range[idx++] = start; start += step; } return range; }; // Function (ahem) Functions // ------------------ // Create a function bound to a given object (assigning `this`, and arguments, // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if // available. _.bind = function(func, context) { if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); var args = slice.call(arguments, 2); return function() { return func.apply(context, args.concat(slice.call(arguments))); }; }; // Partially apply a function by creating a version that has had some of its // arguments pre-filled, without changing its dynamic `this` context. _.partial = function(func) { var args = slice.call(arguments, 1); return function() { return func.apply(this, args.concat(slice.call(arguments))); }; }; // Bind all of an object's methods to that object. Useful for ensuring that // all callbacks defined on an object belong to it. _.bindAll = function(obj) { var funcs = slice.call(arguments, 1); if (funcs.length === 0) funcs = _.functions(obj); each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); }); return obj; }; // Memoize an expensive function by storing its results. _.memoize = function(func, hasher) { var memo = {}; hasher || (hasher = _.identity); return function() { var key = hasher.apply(this, arguments); return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments)); }; }; // Delays a function for the given number of milliseconds, and then calls // it with the arguments supplied. _.delay = function(func, wait) { var args = slice.call(arguments, 2); return setTimeout(function(){ return func.apply(null, args); }, wait); }; // Defers a function, scheduling it to run after the current call stack has // cleared. _.defer = function(func) { return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1))); }; // Returns a function, that, when invoked, will only be triggered at most once // during a given window of time. _.throttle = function(func, wait) { var context, args, timeout, result; var previous = 0; var later = function() { previous = new Date; timeout = null; result = func.apply(context, args); }; return function() { var now = new Date; var remaining = wait - (now - previous); context = this; args = arguments; if (remaining <= 0) { clearTimeout(timeout); timeout = null; previous = now; result = func.apply(context, args); } else if (!timeout) { timeout = setTimeout(later, remaining); } return result; }; }; // Returns a function, that, as long as it continues to be invoked, will not // be triggered. The function will be called after it stops being called for // N milliseconds. If `immediate` is passed, trigger the function on the // leading edge, instead of the trailing. _.debounce = function(func, wait, immediate) { var timeout, result; return function() { var context = this, args = arguments; var later = function() { timeout = null; if (!immediate) result = func.apply(context, args); }; var callNow = immediate && !timeout; clearTimeout(timeout); timeout = setTimeout(later, wait); if (callNow) result = func.apply(context, args); return result; }; }; // Returns a function that will be executed at most one time, no matter how // often you call it. Useful for lazy initialization. _.once = function(func) { var ran = false, memo; return function() { if (ran) return memo; ran = true; memo = func.apply(this, arguments); func = null; return memo; }; }; // Returns the first function passed as an argument to the second, // allowing you to adjust arguments, run code before and after, and // conditionally execute the original function. _.wrap = function(func, wrapper) { return function() { var args = [func]; push.apply(args, arguments); return wrapper.apply(this, args); }; }; // Returns a function that is the composition of a list of functions, each // consuming the return value of the function that follows. _.compose = function() { var funcs = arguments; return function() { var args = arguments; for (var i = funcs.length - 1; i >= 0; i--) { args = [funcs[i].apply(this, args)]; } return args[0]; }; }; // Returns a function that will only be executed after being called N times. _.after = function(times, func) { if (times <= 0) return func(); return function() { if (--times < 1) { return func.apply(this, arguments); } }; }; // Object Functions // ---------------- // Retrieve the names of an object's properties. // Delegates to **ECMAScript 5**'s native `Object.keys` _.keys = nativeKeys || function(obj) { if (obj !== Object(obj)) throw new TypeError('Invalid object'); var keys = []; for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key; return keys; }; // Retrieve the values of an object's properties. _.values = function(obj) { var values = []; for (var key in obj) if (_.has(obj, key)) values.push(obj[key]); return values; }; // Convert an object into a list of `[key, value]` pairs. _.pairs = function(obj) { var pairs = []; for (var key in obj) if (_.has(obj, key)) pairs.push([key, obj[key]]); return pairs; }; // Invert the keys and values of an object. The values must be serializable. _.invert = function(obj) { var result = {}; for (var key in obj) if (_.has(obj, key)) result[obj[key]] = key; return result; }; // Return a sorted list of the function names available on the object. // Aliased as `methods` _.functions = _.methods = function(obj) { var names = []; for (var key in obj) { if (_.isFunction(obj[key])) names.push(key); } return names.sort(); }; // Extend a given object with all the properties in passed-in object(s). _.extend = function(obj) { each(slice.call(arguments, 1), function(source) { if (source) { for (var prop in source) { obj[prop] = source[prop]; } } }); return obj; }; // Return a copy of the object only containing the whitelisted properties. _.pick = function(obj) { var copy = {}; var keys = concat.apply(ArrayProto, slice.call(arguments, 1)); each(keys, function(key) { if (key in obj) copy[key] = obj[key]; }); return copy; }; // Return a copy of the object without the blacklisted properties. _.omit = function(obj) { var copy = {}; var keys = concat.apply(ArrayProto, slice.call(arguments, 1)); for (var key in obj) { if (!_.contains(keys, key)) copy[key] = obj[key]; } return copy; }; // Fill in a given object with default properties. _.defaults = function(obj) { each(slice.call(arguments, 1), function(source) { if (source) { for (var prop in source) { if (obj[prop] == null) obj[prop] = source[prop]; } } }); return obj; }; // Create a (shallow-cloned) duplicate of an object. _.clone = function(obj) { if (!_.isObject(obj)) return obj; return _.isArray(obj) ? obj.slice() : _.extend({}, obj); }; // Invokes interceptor with the obj, and then returns obj. // The primary purpose of this method is to "tap into" a method chain, in // order to perform operations on intermediate results within the chain. _.tap = function(obj, interceptor) { interceptor(obj); return obj; }; // Internal recursive comparison function for `isEqual`. var eq = function(a, b, aStack, bStack) { // Identical objects are equal. `0 === -0`, but they aren't identical. // See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal. if (a === b) return a !== 0 || 1 / a == 1 / b; // A strict comparison is necessary because `null == undefined`. if (a == null || b == null) return a === b; // Unwrap any wrapped objects. if (a instanceof _) a = a._wrapped; if (b instanceof _) b = b._wrapped; // Compare `[[Class]]` names. var className = toString.call(a); if (className != toString.call(b)) return false; switch (className) { // Strings, numbers, dates, and booleans are compared by value. case '[object String]': // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is // equivalent to `new String("5")`. return a == String(b); case '[object Number]': // `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for // other numeric values. return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b); case '[object Date]': case '[object Boolean]': // Coerce dates and booleans to numeric primitive values. Dates are compared by their // millisecond representations. Note that invalid dates with millisecond representations // of `NaN` are not equivalent. return +a == +b; // RegExps are compared by their source patterns and flags. case '[object RegExp]': return a.source == b.source && a.global == b.global && a.multiline == b.multiline && a.ignoreCase == b.ignoreCase; } if (typeof a != 'object' || typeof b != 'object') return false; // Assume equality for cyclic structures. The algorithm for detecting cyclic // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`. var length = aStack.length; while (length--) { // Linear search. Performance is inversely proportional to the number of // unique nested structures. if (aStack[length] == a) return bStack[length] == b; } // Add the first object to the stack of traversed objects. aStack.push(a); bStack.push(b); var size = 0, result = true; // Recursively compare objects and arrays. if (className == '[object Array]') { // Compare array lengths to determine if a deep comparison is necessary. size = a.length; result = size == b.length; if (result) { // Deep compare the contents, ignoring non-numeric properties. while (size--) { if (!(result = eq(a[size], b[size], aStack, bStack))) break; } } } else { // Objects with different constructors are not equivalent, but `Object`s // from different frames are. var aCtor = a.constructor, bCtor = b.constructor; if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) && _.isFunction(bCtor) && (bCtor instanceof bCtor))) { return false; } // Deep compare objects. for (var key in a) { if (_.has(a, key)) { // Count the expected number of properties. size++; // Deep compare each member. if (!(result = _.has(b, key) && eq(a[key], b[key], aStack, bStack))) break; } } // Ensure that both objects contain the same number of properties. if (result) { for (key in b) { if (_.has(b, key) && !(size--)) break; } result = !size; } } // Remove the first object from the stack of traversed objects. aStack.pop(); bStack.pop(); return result; }; // Perform a deep comparison to check if two objects are equal. _.isEqual = function(a, b) { return eq(a, b, [], []); }; // Is a given array, string, or object empty? // An "empty" object has no enumerable own-properties. _.isEmpty = function(obj) { if (obj == null) return true; if (_.isArray(obj) || _.isString(obj)) return obj.length === 0; for (var key in obj) if (_.has(obj, key)) return false; return true; }; // Is a given value a DOM element? _.isElement = function(obj) { return !!(obj && obj.nodeType === 1); }; // Is a given value an array? // Delegates to ECMA5's native Array.isArray _.isArray = nativeIsArray || function(obj) { return toString.call(obj) == '[object Array]'; }; // Is a given variable an object? _.isObject = function(obj) { return obj === Object(obj); }; // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp. each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp'], function(name) { _['is' + name] = function(obj) { return toString.call(obj) == '[object ' + name + ']'; }; }); // Define a fallback version of the method in browsers (ahem, IE), where // there isn't any inspectable "Arguments" type. if (!_.isArguments(arguments)) { _.isArguments = function(obj) { return !!(obj && _.has(obj, 'callee')); }; } // Optimize `isFunction` if appropriate. if (typeof (/./) !== 'function') { _.isFunction = function(obj) { return typeof obj === 'function'; }; } // Is a given object a finite number? _.isFinite = function(obj) { return isFinite(obj) && !isNaN(parseFloat(obj)); }; // Is the given value `NaN`? (NaN is the only number which does not equal itself). _.isNaN = function(obj) { return _.isNumber(obj) && obj != +obj; }; // Is a given value a boolean? _.isBoolean = function(obj) { return obj === true || obj === false || toString.call(obj) == '[object Boolean]'; }; // Is a given value equal to null? _.isNull = function(obj) { return obj === null; }; // Is a given variable undefined? _.isUndefined = function(obj) { return obj === void 0; }; // Shortcut function for checking if an object has a given property directly // on itself (in other words, not on a prototype). _.has = function(obj, key) { return hasOwnProperty.call(obj, key); }; // Utility Functions // ----------------- // Run Underscore.js in *noConflict* mode, returning the `_` variable to its // previous owner. Returns a reference to the Underscore object. _.noConflict = function() { root._ = previousUnderscore; return this; }; // Keep the identity function around for default iterators. _.identity = function(value) { return value; }; // Run a function **n** times. _.times = function(n, iterator, context) { var accum = Array(n); for (var i = 0; i < n; i++) accum[i] = iterator.call(context, i); return accum; }; // Return a random integer between min and max (inclusive). _.random = function(min, max) { if (max == null) { max = min; min = 0; } return min + Math.floor(Math.random() * (max - min + 1)); }; // List of HTML entities for escaping. var entityMap = { escape: { '&': '&', '<': '<', '>': '>', '"': '"', "'": ''', '/': '/' } }; entityMap.unescape = _.invert(entityMap.escape); // Regexes containing the keys and values listed immediately above. var entityRegexes = { escape: new RegExp('[' + _.keys(entityMap.escape).join('') + ']', 'g'), unescape: new RegExp('(' + _.keys(entityMap.unescape).join('|') + ')', 'g') }; // Functions for escaping and unescaping strings to/from HTML interpolation. _.each(['escape', 'unescape'], function(method) { _[method] = function(string) { if (string == null) return ''; return ('' + string).replace(entityRegexes[method], function(match) { return entityMap[method][match]; }); }; }); // If the value of the named property is a function then invoke it; // otherwise, return it. _.result = function(object, property) { if (object == null) return null; var value = object[property]; return _.isFunction(value) ? value.call(object) : value; }; // Add your own custom functions to the Underscore object. _.mixin = function(obj) { each(_.functions(obj), function(name){ var func = _[name] = obj[name]; _.prototype[name] = function() { var args = [this._wrapped]; push.apply(args, arguments); return result.call(this, func.apply(_, args)); }; }); }; // Generate a unique integer id (unique within the entire client session). // Useful for temporary DOM ids. var idCounter = 0; _.uniqueId = function(prefix) { var id = ++idCounter + ''; return prefix ? prefix + id : id; }; // By default, Underscore uses ERB-style template delimiters, change the // following template settings to use alternative delimiters. _.templateSettings = { evaluate : /<%([\s\S]+?)%>/g, interpolate : /<%=([\s\S]+?)%>/g, escape : /<%-([\s\S]+?)%>/g }; // When customizing `templateSettings`, if you don't want to define an // interpolation, evaluation or escaping regex, we need one that is // guaranteed not to match. var noMatch = /(.)^/; // Certain characters need to be escaped so that they can be put into a // string literal. var escapes = { "'": "'", '\\': '\\', '\r': 'r', '\n': 'n', '\t': 't', '\u2028': 'u2028', '\u2029': 'u2029' }; var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g; // JavaScript micro-templating, similar to John Resig's implementation. // Underscore templating handles arbitrary delimiters, preserves whitespace, // and correctly escapes quotes within interpolated code. _.template = function(text, data, settings) { var render; settings = _.defaults({}, settings, _.templateSettings); // Combine delimiters into one regular expression via alternation. var matcher = new RegExp([ (settings.escape || noMatch).source, (settings.interpolate || noMatch).source, (settings.evaluate || noMatch).source ].join('|') + '|$', 'g'); // Compile the template source, escaping string literals appropriately. var index = 0; var source = "__p+='"; text.replace(matcher, function(match, escape, interpolate, evaluate, offset) { source += text.slice(index, offset) .replace(escaper, function(match) { return '\\' + escapes[match]; }); if (escape) { source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'"; } if (interpolate) { source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'"; } if (evaluate) { source += "';\n" + evaluate + "\n__p+='"; } index = offset + match.length; return match; }); source += "';\n"; // If a variable is not specified, place data values in local scope. if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n'; source = "var __t,__p='',__j=Array.prototype.join," + "print=function(){__p+=__j.call(arguments,'');};\n" + source + "return __p;\n"; try { render = new Function(settings.variable || 'obj', '_', source); } catch (e) { e.source = source; throw e; } if (data) return render(data, _); var template = function(data) { return render.call(this, data, _); }; // Provide the compiled function source as a convenience for precompilation. template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}'; return template; }; // Add a "chain" function, which will delegate to the wrapper. _.chain = function(obj) { return _(obj).chain(); }; // OOP // --------------- // If Underscore is called as a function, it returns a wrapped object that // can be used OO-style. This wrapper holds altered versions of all the // underscore functions. Wrapped objects may be chained. // Helper function to continue chaining intermediate results. var result = function(obj) { return this._chain ? _(obj).chain() : obj; }; // Add all of the Underscore functions to the wrapper object. _.mixin(_); // Add all mutator Array functions to the wrapper. each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { var method = ArrayProto[name]; _.prototype[name] = function() { var obj = this._wrapped; method.apply(obj, arguments); if ((name == 'shift' || name == 'splice') && obj.length === 0) delete obj[0]; return result.call(this, obj); }; }); // Add all accessor Array functions to the wrapper. each(['concat', 'join', 'slice'], function(name) { var method = ArrayProto[name]; _.prototype[name] = function() { return result.call(this, method.apply(this._wrapped, arguments)); }; }); _.extend(_.prototype, { // Start chaining a wrapped Underscore object. chain: function() { this._chain = true; return this; }, // Extracts the result from a wrapped and chained object. value: function() { return this._wrapped; } }); }).call(this);