| // Underscore.js | |
| // (c) 2009 Jeremy Ashkenas, DocumentCloud Inc. | |
| // Underscore is freely distributable under the terms of the MIT license. | |
| // Portions of Underscore are inspired by or borrowed from Prototype.js, | |
| // Oliver Steele's Functional, and John Resig's Micro-Templating. | |
| // For all details and documentation: | |
| // http://documentcloud.github.com/underscore/ | |
| (function() { | |
| /*------------------------- Baseline setup ---------------------------------*/ | |
| // 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._; | |
| // 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. | |
| var wrapper = function(obj) { this._wrapped = obj; }; | |
| // Establish the object that gets thrown to break out of a loop iteration. | |
| var breaker = typeof StopIteration !== 'undefined' ? StopIteration : '__break__'; | |
| // Create a safe reference to the Underscore object for reference below. | |
| var _ = root._ = function(obj) { return new wrapper(obj); }; | |
| // Export the Underscore object for CommonJS. | |
| if (typeof exports !== 'undefined') exports._ = _; | |
| // Current version. | |
| _.VERSION = '0.4.3'; | |
| /*------------------------ Collection Functions: ---------------------------*/ | |
| // The cornerstone, an each implementation. | |
| // Handles objects implementing forEach, arrays, and raw objects. | |
| _.each = function(obj, iterator, context) { | |
| var index = 0; | |
| try { | |
| if (obj.forEach) { | |
| obj.forEach(iterator, context); | |
| } else if (obj.length) { | |
| for (var i=0, l = obj.length; i<l; i++) iterator.call(context, obj[i], i, obj); | |
| } else { | |
| for (var key in obj) if (Object.prototype.hasOwnProperty.call(obj, key)) { | |
| iterator.call(context, obj[key], key, obj); | |
| } | |
| } | |
| } catch(e) { | |
| if (e != breaker) throw e; | |
| } | |
| return obj; | |
| }; | |
| // Return the results of applying the iterator to each element. Use JavaScript | |
| // 1.6's version of map, if possible. | |
| _.map = function(obj, iterator, context) { | |
| if (obj && obj.map) return obj.map(iterator, context); | |
| var results = []; | |
| _.each(obj, function(value, index, list) { | |
| results.push(iterator.call(context, value, index, list)); | |
| }); | |
| return results; | |
| }; | |
| // Reduce builds up a single result from a list of values. Also known as | |
| // inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible. | |
| _.reduce = function(obj, memo, iterator, context) { | |
| if (obj && obj.reduce) return obj.reduce(_.bind(iterator, context), memo); | |
| _.each(obj, function(value, index, list) { | |
| memo = iterator.call(context, memo, value, index, list); | |
| }); | |
| return memo; | |
| }; | |
| // The right-associative version of reduce, also known as foldr. Uses | |
| // JavaScript 1.8's version of reduceRight, if available. | |
| _.reduceRight = function(obj, memo, iterator, context) { | |
| if (obj && obj.reduceRight) return obj.reduceRight(_.bind(iterator, context), memo); | |
| var reversed = _.clone(_.toArray(obj)).reverse(); | |
| _.each(reversed, function(value, index) { | |
| memo = iterator.call(context, memo, value, index, obj); | |
| }); | |
| return memo; | |
| }; | |
| // Return the first value which passes a truth test. | |
| _.detect = function(obj, iterator, context) { | |
| var result; | |
| _.each(obj, function(value, index, list) { | |
| if (iterator.call(context, value, index, list)) { | |
| result = value; | |
| _.breakLoop(); | |
| } | |
| }); | |
| return result; | |
| }; | |
| // Return all the elements that pass a truth test. Use JavaScript 1.6's | |
| // filter(), if it exists. | |
| _.select = function(obj, iterator, context) { | |
| if (obj.filter) return obj.filter(iterator, context); | |
| var results = []; | |
| _.each(obj, function(value, index, list) { | |
| iterator.call(context, value, index, list) && results.push(value); | |
| }); | |
| return results; | |
| }; | |
| // Return all the elements for which a truth test fails. | |
| _.reject = function(obj, iterator, context) { | |
| var results = []; | |
| _.each(obj, function(value, index, list) { | |
| !iterator.call(context, value, index, list) && results.push(value); | |
| }); | |
| return results; | |
| }; | |
| // Determine whether all of the elements match a truth test. Delegate to | |
| // JavaScript 1.6's every(), if it is present. | |
| _.all = function(obj, iterator, context) { | |
| iterator = iterator || _.identity; | |
| if (obj.every) return obj.every(iterator, context); | |
| var result = true; | |
| _.each(obj, function(value, index, list) { | |
| if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop(); | |
| }); | |
| return result; | |
| }; | |
| // Determine if at least one element in the object matches a truth test. Use | |
| // JavaScript 1.6's some(), if it exists. | |
| _.any = function(obj, iterator, context) { | |
| iterator = iterator || _.identity; | |
| if (obj.some) return obj.some(iterator, context); | |
| var result = false; | |
| _.each(obj, function(value, index, list) { | |
| if (result = iterator.call(context, value, index, list)) _.breakLoop(); | |
| }); | |
| return result; | |
| }; | |
| // Determine if a given value is included in the array or object, | |
| // based on '==='. | |
| _.include = function(obj, target) { | |
| if (_.isArray(obj)) return _.indexOf(obj, target) != -1; | |
| var found = false; | |
| _.each(obj, function(value) { | |
| if (found = value === target) _.breakLoop(); | |
| }); | |
| return found; | |
| }; | |
| // Invoke a method with arguments on every item in a collection. | |
| _.invoke = function(obj, method) { | |
| var args = _.toArray(arguments).slice(2); | |
| return _.map(obj, function(value) { | |
| return (method ? value[method] : value).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]; }); | |
| }; | |
| // Return the maximum item or (item-based computation). | |
| _.max = function(obj, iterator, context) { | |
| if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj); | |
| var result = {computed : -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)) return Math.min.apply(Math, obj); | |
| var result = {computed : 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; | |
| }; | |
| // Sort the object's values by a criteria produced by an iterator. | |
| _.sortBy = function(obj, iterator, context) { | |
| return _.pluck(_.map(obj, function(value, index, list) { | |
| return { | |
| value : value, | |
| criteria : iterator.call(context, value, index, list) | |
| }; | |
| }).sort(function(left, right) { | |
| var a = left.criteria, b = right.criteria; | |
| return a < b ? -1 : a > b ? 1 : 0; | |
| }), 'value'); | |
| }; | |
| // Use a comparator function to figure out at what index an object should | |
| // be inserted so as to maintain order. Uses binary search. | |
| _.sortedIndex = function(array, obj, iterator) { | |
| iterator = iterator || _.identity; | |
| var low = 0, high = array.length; | |
| while (low < high) { | |
| var mid = (low + high) >> 1; | |
| iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid; | |
| } | |
| return low; | |
| }; | |
| // Convert anything iterable into a real, live array. | |
| _.toArray = function(iterable) { | |
| if (!iterable) return []; | |
| if (_.isArray(iterable)) return iterable; | |
| return _.map(iterable, function(val){ return val; }); | |
| }; | |
| // Return the number of elements in an object. | |
| _.size = function(obj) { | |
| return _.toArray(obj).length; | |
| }; | |
| /*-------------------------- Array Functions: ------------------------------*/ | |
| // Get the first element of an array. | |
| _.first = function(array) { | |
| return array[0]; | |
| }; | |
| // Get the last element of an array. | |
| _.last = function(array) { | |
| return array[array.length - 1]; | |
| }; | |
| // Trim out all falsy values from an array. | |
| _.compact = function(array) { | |
| return _.select(array, function(value){ return !!value; }); | |
| }; | |
| // Return a completely flattened version of an array. | |
| _.flatten = function(array) { | |
| return _.reduce(array, [], function(memo, value) { | |
| if (_.isArray(value)) return memo.concat(_.flatten(value)); | |
| memo.push(value); | |
| return memo; | |
| }); | |
| }; | |
| // Return a version of the array that does not contain the specified value(s). | |
| _.without = function(array) { | |
| var values = array.slice.call(arguments, 0); | |
| return _.select(array, function(value){ return !_.include(values, value); }); | |
| }; | |
| // Produce a duplicate-free version of the array. If the array has already | |
| // been sorted, you have the option of using a faster algorithm. | |
| _.uniq = function(array, isSorted) { | |
| return _.reduce(array, [], function(memo, el, i) { | |
| if (0 == i || (isSorted ? _.last(memo) != el : !_.include(memo, el))) memo.push(el); | |
| return memo; | |
| }); | |
| }; | |
| // Produce an array that contains every item shared between all the | |
| // passed-in arrays. | |
| _.intersect = function(array) { | |
| var rest = _.toArray(arguments).slice(1); | |
| return _.select(_.uniq(array), function(item) { | |
| return _.all(rest, function(other) { | |
| return _.indexOf(other, item) >= 0; | |
| }); | |
| }); | |
| }; | |
| // Zip together multiple lists into a single array -- elements that share | |
| // an index go together. | |
| _.zip = function() { | |
| var args = _.toArray(arguments); | |
| var length = _.max(_.pluck(args, 'length')); | |
| var results = new Array(length); | |
| for (var i=0; i<length; i++) results[i] = _.pluck(args, String(i)); | |
| return results; | |
| }; | |
| // 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 occurence of an | |
| // item in an array, or -1 if the item is not included in the array. | |
| _.indexOf = function(array, item) { | |
| if (array.indexOf) return array.indexOf(item); | |
| for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i; | |
| return -1; | |
| }; | |
| // Provide JavaScript 1.6's lastIndexOf, delegating to the native function, | |
| // if possible. | |
| _.lastIndexOf = function(array, item) { | |
| if (array.lastIndexOf) return array.lastIndexOf(item); | |
| var i = array.length; | |
| while (i--) if (array[i] === item) return i; | |
| return -1; | |
| }; | |
| /* ----------------------- Function Functions: -----------------------------*/ | |
| // Create a function bound to a given object (assigning 'this', and arguments, | |
| // optionally). Binding with arguments is also known as 'curry'. | |
| _.bind = function(func, context) { | |
| context = context || root; | |
| var args = _.toArray(arguments).slice(2); | |
| return function() { | |
| var a = args.concat(_.toArray(arguments)); | |
| return func.apply(context, a); | |
| }; | |
| }; | |
| // 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() { | |
| var args = _.toArray(arguments); | |
| var context = args.pop(); | |
| _.each(args, function(methodName) { | |
| context[methodName] = _.bind(context[methodName], context); | |
| }); | |
| }; | |
| // Delays a function for the given number of milliseconds, and then calls | |
| // it with the arguments supplied. | |
| _.delay = function(func, wait) { | |
| var args = _.toArray(arguments).slice(2); | |
| return setTimeout(function(){ return func.apply(func, 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(_.toArray(arguments).slice(1))); | |
| }; | |
| // 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].concat(_.toArray(arguments)); | |
| return wrapper.apply(wrapper, 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 = _.toArray(arguments); | |
| return function() { | |
| for (var i=funcs.length-1; i >= 0; i--) { | |
| arguments = [funcs[i].apply(this, arguments)]; | |