[659] | 1 | // Underscore.js 1.3.1 |
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| 2 | // (c) 2009-2012 Jeremy Ashkenas, DocumentCloud Inc. |
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| 3 | // Underscore is freely distributable under the MIT license. |
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| 4 | // Portions of Underscore are inspired or borrowed from Prototype, |
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| 5 | // Oliver Steele's Functional, and John Resig's Micro-Templating. |
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| 6 | // For all details and documentation: |
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| 7 | // http://documentcloud.github.com/underscore |
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| 8 | |
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| 9 | (function() { |
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| 10 | |
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| 11 | // Baseline setup |
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| 12 | // -------------- |
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| 13 | |
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| 14 | // Establish the root object, `window` in the browser, or `global` on the server. |
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| 15 | var root = this; |
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| 16 | |
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| 17 | // Save the previous value of the `_` variable. |
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| 18 | var previousUnderscore = root._; |
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| 19 | |
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| 20 | // Establish the object that gets returned to break out of a loop iteration. |
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| 21 | var breaker = {}; |
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| 22 | |
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| 23 | // Save bytes in the minified (but not gzipped) version: |
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| 24 | var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype; |
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| 25 | |
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| 26 | // Create quick reference variables for speed access to core prototypes. |
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| 27 | var slice = ArrayProto.slice, |
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| 28 | unshift = ArrayProto.unshift, |
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| 29 | toString = ObjProto.toString, |
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| 30 | hasOwnProperty = ObjProto.hasOwnProperty; |
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| 31 | |
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| 32 | // All **ECMAScript 5** native function implementations that we hope to use |
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| 33 | // are declared here. |
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| 34 | var |
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| 35 | nativeForEach = ArrayProto.forEach, |
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| 36 | nativeMap = ArrayProto.map, |
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| 37 | nativeReduce = ArrayProto.reduce, |
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| 38 | nativeReduceRight = ArrayProto.reduceRight, |
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| 39 | nativeFilter = ArrayProto.filter, |
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| 40 | nativeEvery = ArrayProto.every, |
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| 41 | nativeSome = ArrayProto.some, |
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| 42 | nativeIndexOf = ArrayProto.indexOf, |
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| 43 | nativeLastIndexOf = ArrayProto.lastIndexOf, |
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| 44 | nativeIsArray = Array.isArray, |
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| 45 | nativeKeys = Object.keys, |
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| 46 | nativeBind = FuncProto.bind; |
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| 47 | |
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| 48 | // Create a safe reference to the Underscore object for use below. |
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| 49 | var _ = function(obj) { return new wrapper(obj); }; |
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| 50 | |
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| 51 | // Export the Underscore object for **Node.js**, with |
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| 52 | // backwards-compatibility for the old `require()` API. If we're in |
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| 53 | // the browser, add `_` as a global object via a string identifier, |
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| 54 | // for Closure Compiler "advanced" mode. |
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| 55 | if (typeof exports !== 'undefined') { |
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| 56 | if (typeof module !== 'undefined' && module.exports) { |
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| 57 | exports = module.exports = _; |
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| 58 | } |
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| 59 | exports._ = _; |
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| 60 | } else { |
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| 61 | root['_'] = _; |
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| 62 | } |
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| 63 | |
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| 64 | // Current version. |
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| 65 | _.VERSION = '1.3.1'; |
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| 66 | |
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| 67 | // Collection Functions |
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| 68 | // -------------------- |
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| 69 | |
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| 70 | // The cornerstone, an `each` implementation, aka `forEach`. |
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| 71 | // Handles objects with the built-in `forEach`, arrays, and raw objects. |
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| 72 | // Delegates to **ECMAScript 5**'s native `forEach` if available. |
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| 73 | var each = _.each = _.forEach = function(obj, iterator, context) { |
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| 74 | if (obj == null) return; |
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| 75 | if (nativeForEach && obj.forEach === nativeForEach) { |
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| 76 | obj.forEach(iterator, context); |
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| 77 | } else if (obj.length === +obj.length) { |
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| 78 | for (var i = 0, l = obj.length; i < l; i++) { |
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| 79 | if (i in obj && iterator.call(context, obj[i], i, obj) === breaker) return; |
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| 80 | } |
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| 81 | } else { |
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| 82 | for (var key in obj) { |
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| 83 | if (_.has(obj, key)) { |
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| 84 | if (iterator.call(context, obj[key], key, obj) === breaker) return; |
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| 85 | } |
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| 86 | } |
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| 87 | } |
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| 88 | }; |
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| 89 | |
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| 90 | // Return the results of applying the iterator to each element. |
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| 91 | // Delegates to **ECMAScript 5**'s native `map` if available. |
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| 92 | _.map = _.collect = function(obj, iterator, context) { |
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| 93 | var results = []; |
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| 94 | if (obj == null) return results; |
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| 95 | if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context); |
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| 96 | each(obj, function(value, index, list) { |
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| 97 | results[results.length] = iterator.call(context, value, index, list); |
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| 98 | }); |
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| 99 | if (obj.length === +obj.length) results.length = obj.length; |
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| 100 | return results; |
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| 101 | }; |
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| 102 | |
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| 103 | // **Reduce** builds up a single result from a list of values, aka `inject`, |
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| 104 | // or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available. |
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| 105 | _.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) { |
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| 106 | var initial = arguments.length > 2; |
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| 107 | if (obj == null) obj = []; |
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| 108 | if (nativeReduce && obj.reduce === nativeReduce) { |
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| 109 | if (context) iterator = _.bind(iterator, context); |
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| 110 | return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator); |
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| 111 | } |
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| 112 | each(obj, function(value, index, list) { |
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| 113 | if (!initial) { |
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| 114 | memo = value; |
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| 115 | initial = true; |
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| 116 | } else { |
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| 117 | memo = iterator.call(context, memo, value, index, list); |
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| 118 | } |
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| 119 | }); |
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| 120 | if (!initial) throw new TypeError('Reduce of empty array with no initial value'); |
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| 121 | return memo; |
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| 122 | }; |
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| 123 | |
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| 124 | // The right-associative version of reduce, also known as `foldr`. |
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| 125 | // Delegates to **ECMAScript 5**'s native `reduceRight` if available. |
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| 126 | _.reduceRight = _.foldr = function(obj, iterator, memo, context) { |
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| 127 | var initial = arguments.length > 2; |
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| 128 | if (obj == null) obj = []; |
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| 129 | if (nativeReduceRight && obj.reduceRight === nativeReduceRight) { |
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| 130 | if (context) iterator = _.bind(iterator, context); |
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| 131 | return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator); |
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| 132 | } |
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| 133 | var reversed = _.toArray(obj).reverse(); |
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| 134 | if (context && !initial) iterator = _.bind(iterator, context); |
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| 135 | return initial ? _.reduce(reversed, iterator, memo, context) : _.reduce(reversed, iterator); |
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| 136 | }; |
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| 137 | |
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| 138 | // Return the first value which passes a truth test. Aliased as `detect`. |
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| 139 | _.find = _.detect = function(obj, iterator, context) { |
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| 140 | var result; |
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| 141 | any(obj, function(value, index, list) { |
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| 142 | if (iterator.call(context, value, index, list)) { |
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| 143 | result = value; |
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| 144 | return true; |
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| 145 | } |
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| 146 | }); |
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| 147 | return result; |
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| 148 | }; |
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| 149 | |
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| 150 | // Return all the elements that pass a truth test. |
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| 151 | // Delegates to **ECMAScript 5**'s native `filter` if available. |
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| 152 | // Aliased as `select`. |
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| 153 | _.filter = _.select = function(obj, iterator, context) { |
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| 154 | var results = []; |
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| 155 | if (obj == null) return results; |
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| 156 | if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context); |
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| 157 | each(obj, function(value, index, list) { |
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| 158 | if (iterator.call(context, value, index, list)) results[results.length] = value; |
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| 159 | }); |
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| 160 | return results; |
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| 161 | }; |
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| 162 | |
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| 163 | // Return all the elements for which a truth test fails. |
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| 164 | _.reject = function(obj, iterator, context) { |
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| 165 | var results = []; |
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| 166 | if (obj == null) return results; |
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| 167 | each(obj, function(value, index, list) { |
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| 168 | if (!iterator.call(context, value, index, list)) results[results.length] = value; |
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| 169 | }); |
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| 170 | return results; |
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| 171 | }; |
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| 172 | |
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| 173 | // Determine whether all of the elements match a truth test. |
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| 174 | // Delegates to **ECMAScript 5**'s native `every` if available. |
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| 175 | // Aliased as `all`. |
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| 176 | _.every = _.all = function(obj, iterator, context) { |
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| 177 | var result = true; |
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| 178 | if (obj == null) return result; |
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| 179 | if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context); |
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| 180 | each(obj, function(value, index, list) { |
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| 181 | if (!(result = result && iterator.call(context, value, index, list))) return breaker; |
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| 182 | }); |
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| 183 | return result; |
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| 184 | }; |
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| 185 | |
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| 186 | // Determine if at least one element in the object matches a truth test. |
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| 187 | // Delegates to **ECMAScript 5**'s native `some` if available. |
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| 188 | // Aliased as `any`. |
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| 189 | var any = _.some = _.any = function(obj, iterator, context) { |
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| 190 | iterator || (iterator = _.identity); |
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| 191 | var result = false; |
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| 192 | if (obj == null) return result; |
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| 193 | if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context); |
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| 194 | each(obj, function(value, index, list) { |
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| 195 | if (result || (result = iterator.call(context, value, index, list))) return breaker; |
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| 196 | }); |
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| 197 | return !!result; |
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| 198 | }; |
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| 199 | |
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| 200 | // Determine if a given value is included in the array or object using `===`. |
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| 201 | // Aliased as `contains`. |
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| 202 | _.include = _.contains = function(obj, target) { |
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| 203 | var found = false; |
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| 204 | if (obj == null) return found; |
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| 205 | if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1; |
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| 206 | found = any(obj, function(value) { |
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| 207 | return value === target; |
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| 208 | }); |
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| 209 | return found; |
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| 210 | }; |
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| 211 | |
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| 212 | // Invoke a method (with arguments) on every item in a collection. |
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| 213 | _.invoke = function(obj, method) { |
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| 214 | var args = slice.call(arguments, 2); |
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| 215 | return _.map(obj, function(value) { |
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| 216 | return (_.isFunction(method) ? method || value : value[method]).apply(value, args); |
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| 217 | }); |
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| 218 | }; |
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| 219 | |
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| 220 | // Convenience version of a common use case of `map`: fetching a property. |
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| 221 | _.pluck = function(obj, key) { |
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| 222 | return _.map(obj, function(value){ return value[key]; }); |
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| 223 | }; |
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| 224 | |
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| 225 | // Return the maximum element or (element-based computation). |
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| 226 | _.max = function(obj, iterator, context) { |
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| 227 | if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj); |
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| 228 | if (!iterator && _.isEmpty(obj)) return -Infinity; |
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| 229 | var result = {computed : -Infinity}; |
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| 230 | each(obj, function(value, index, list) { |
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| 231 | var computed = iterator ? iterator.call(context, value, index, list) : value; |
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| 232 | computed >= result.computed && (result = {value : value, computed : computed}); |
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| 233 | }); |
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| 234 | return result.value; |
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| 235 | }; |
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| 236 | |
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| 237 | // Return the minimum element (or element-based computation). |
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| 238 | _.min = function(obj, iterator, context) { |
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| 239 | if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj); |
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| 240 | if (!iterator && _.isEmpty(obj)) return Infinity; |
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| 241 | var result = {computed : Infinity}; |
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| 242 | each(obj, function(value, index, list) { |
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| 243 | var computed = iterator ? iterator.call(context, value, index, list) : value; |
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| 244 | computed < result.computed && (result = {value : value, computed : computed}); |
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| 245 | }); |
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| 246 | return result.value; |
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| 247 | }; |
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| 248 | |
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| 249 | // Shuffle an array. |
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| 250 | _.shuffle = function(obj) { |
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| 251 | var shuffled = [], rand; |
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| 252 | each(obj, function(value, index, list) { |
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| 253 | if (index == 0) { |
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| 254 | shuffled[0] = value; |
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| 255 | } else { |
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| 256 | rand = Math.floor(Math.random() * (index + 1)); |
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| 257 | shuffled[index] = shuffled[rand]; |
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| 258 | shuffled[rand] = value; |
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| 259 | } |
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| 260 | }); |
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| 261 | return shuffled; |
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| 262 | }; |
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| 263 | |
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| 264 | // Sort the object's values by a criterion produced by an iterator. |
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| 265 | _.sortBy = function(obj, iterator, context) { |
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| 266 | return _.pluck(_.map(obj, function(value, index, list) { |
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| 267 | return { |
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| 268 | value : value, |
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| 269 | criteria : iterator.call(context, value, index, list) |
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| 270 | }; |
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| 271 | }).sort(function(left, right) { |
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| 272 | var a = left.criteria, b = right.criteria; |
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| 273 | return a < b ? -1 : a > b ? 1 : 0; |
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| 274 | }), 'value'); |
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| 275 | }; |
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| 276 | |
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| 277 | // Groups the object's values by a criterion. Pass either a string attribute |
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| 278 | // to group by, or a function that returns the criterion. |
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| 279 | _.groupBy = function(obj, val) { |
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| 280 | var result = {}; |
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| 281 | var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; }; |
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| 282 | each(obj, function(value, index) { |
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| 283 | var key = iterator(value, index); |
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| 284 | (result[key] || (result[key] = [])).push(value); |
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| 285 | }); |
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| 286 | return result; |
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| 287 | }; |
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| 288 | |
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| 289 | // Use a comparator function to figure out at what index an object should |
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| 290 | // be inserted so as to maintain order. Uses binary search. |
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| 291 | _.sortedIndex = function(array, obj, iterator) { |
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| 292 | iterator || (iterator = _.identity); |
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| 293 | var low = 0, high = array.length; |
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| 294 | while (low < high) { |
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| 295 | var mid = (low + high) >> 1; |
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| 296 | iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid; |
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| 297 | } |
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| 298 | return low; |
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| 299 | }; |
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| 300 | |
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| 301 | // Safely convert anything iterable into a real, live array. |
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| 302 | _.toArray = function(iterable) { |
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| 303 | if (!iterable) return []; |
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| 304 | if (iterable.toArray) return iterable.toArray(); |
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| 305 | if (_.isArray(iterable)) return slice.call(iterable); |
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| 306 | if (_.isArguments(iterable)) return slice.call(iterable); |
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| 307 | return _.values(iterable); |
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| 308 | }; |
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| 309 | |
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| 310 | // Return the number of elements in an object. |
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| 311 | _.size = function(obj) { |
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| 312 | return _.toArray(obj).length; |
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| 313 | }; |
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| 314 | |
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| 315 | // Array Functions |
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| 316 | // --------------- |
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| 317 | |
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| 318 | // Get the first element of an array. Passing **n** will return the first N |
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| 319 | // values in the array. Aliased as `head`. The **guard** check allows it to work |
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| 320 | // with `_.map`. |
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| 321 | _.first = _.head = function(array, n, guard) { |
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| 322 | return (n != null) && !guard ? slice.call(array, 0, n) : array[0]; |
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| 323 | }; |
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| 324 | |
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| 325 | // Returns everything but the last entry of the array. Especcialy useful on |
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| 326 | // the arguments object. Passing **n** will return all the values in |
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| 327 | // the array, excluding the last N. The **guard** check allows it to work with |
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| 328 | // `_.map`. |
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| 329 | _.initial = function(array, n, guard) { |
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| 330 | return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n)); |
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| 331 | }; |
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| 332 | |
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| 333 | // Get the last element of an array. Passing **n** will return the last N |
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| 334 | // values in the array. The **guard** check allows it to work with `_.map`. |
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| 335 | _.last = function(array, n, guard) { |
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| 336 | if ((n != null) && !guard) { |
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| 337 | return slice.call(array, Math.max(array.length - n, 0)); |
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| 338 | } else { |
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| 339 | return array[array.length - 1]; |
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| 340 | } |
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| 341 | }; |
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| 342 | |
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| 343 | // Returns everything but the first entry of the array. Aliased as `tail`. |
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| 344 | // Especially useful on the arguments object. Passing an **index** will return |
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| 345 | // the rest of the values in the array from that index onward. The **guard** |
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| 346 | // check allows it to work with `_.map`. |
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| 347 | _.rest = _.tail = function(array, index, guard) { |
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| 348 | return slice.call(array, (index == null) || guard ? 1 : index); |
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| 349 | }; |
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| 350 | |
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| 351 | // Trim out all falsy values from an array. |
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| 352 | _.compact = function(array) { |
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| 353 | return _.filter(array, function(value){ return !!value; }); |
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| 354 | }; |
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| 355 | |
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| 356 | // Return a completely flattened version of an array. |
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| 357 | _.flatten = function(array, shallow) { |
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| 358 | return _.reduce(array, function(memo, value) { |
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| 359 | if (_.isArray(value)) return memo.concat(shallow ? value : _.flatten(value)); |
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| 360 | memo[memo.length] = value; |
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| 361 | return memo; |
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| 362 | }, []); |
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| 363 | }; |
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| 364 | |
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| 365 | // Return a version of the array that does not contain the specified value(s). |
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| 366 | _.without = function(array) { |
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| 367 | return _.difference(array, slice.call(arguments, 1)); |
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| 368 | }; |
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| 369 | |
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| 370 | // Produce a duplicate-free version of the array. If the array has already |
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| 371 | // been sorted, you have the option of using a faster algorithm. |
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| 372 | // Aliased as `unique`. |
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| 373 | _.uniq = _.unique = function(array, isSorted, iterator) { |
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| 374 | var initial = iterator ? _.map(array, iterator) : array; |
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| 375 | var result = []; |
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| 376 | _.reduce(initial, function(memo, el, i) { |
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| 377 | if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) { |
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| 378 | memo[memo.length] = el; |
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| 379 | result[result.length] = array[i]; |
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| 380 | } |
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| 381 | return memo; |
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| 382 | }, []); |
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| 383 | return result; |
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| 384 | }; |
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| 385 | |
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| 386 | // Produce an array that contains the union: each distinct element from all of |
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| 387 | // the passed-in arrays. |
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| 388 | _.union = function() { |
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| 389 | return _.uniq(_.flatten(arguments, true)); |
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| 390 | }; |
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| 391 | |
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| 392 | // Produce an array that contains every item shared between all the |
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| 393 | // passed-in arrays. (Aliased as "intersect" for back-compat.) |
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| 394 | _.intersection = _.intersect = function(array) { |
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| 395 | var rest = slice.call(arguments, 1); |
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| 396 | return _.filter(_.uniq(array), function(item) { |
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| 397 | return _.every(rest, function(other) { |
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| 398 | return _.indexOf(other, item) >= 0; |
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| 399 | }); |
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| 400 | }); |
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| 401 | }; |
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| 402 | |
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| 403 | // Take the difference between one array and a number of other arrays. |
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| 404 | // Only the elements present in just the first array will remain. |
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| 405 | _.difference = function(array) { |
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| 406 | var rest = _.flatten(slice.call(arguments, 1)); |
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| 407 | return _.filter(array, function(value){ return !_.include(rest, value); }); |
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| 408 | }; |
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| 409 | |
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| 410 | // Zip together multiple lists into a single array -- elements that share |
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| 411 | // an index go together. |
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| 412 | _.zip = function() { |
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| 413 | var args = slice.call(arguments); |
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| 414 | var length = _.max(_.pluck(args, 'length')); |
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| 415 | var results = new Array(length); |
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| 416 | for (var i = 0; i < length; i++) results[i] = _.pluck(args, "" + i); |
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| 417 | return results; |
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| 418 | }; |
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| 419 | |
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| 420 | // If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**), |
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| 421 | // we need this function. Return the position of the first occurrence of an |
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| 422 | // item in an array, or -1 if the item is not included in the array. |
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| 423 | // Delegates to **ECMAScript 5**'s native `indexOf` if available. |
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| 424 | // If the array is large and already in sort order, pass `true` |
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| 425 | // for **isSorted** to use binary search. |
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| 426 | _.indexOf = function(array, item, isSorted) { |
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| 427 | if (array == null) return -1; |
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| 428 | var i, l; |
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| 429 | if (isSorted) { |
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| 430 | i = _.sortedIndex(array, item); |
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| 431 | return array[i] === item ? i : -1; |
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| 432 | } |
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| 433 | if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item); |
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| 434 | for (i = 0, l = array.length; i < l; i++) if (i in array && array[i] === item) return i; |
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| 435 | return -1; |
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| 436 | }; |
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| 437 | |
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| 438 | // Delegates to **ECMAScript 5**'s native `lastIndexOf` if available. |
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| 439 | _.lastIndexOf = function(array, item) { |
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| 440 | if (array == null) return -1; |
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| 441 | if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item); |
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| 442 | var i = array.length; |
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| 443 | while (i--) if (i in array && array[i] === item) return i; |
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| 444 | return -1; |
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| 445 | }; |
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| 446 | |
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| 447 | // Generate an integer Array containing an arithmetic progression. A port of |
---|
| 448 | // the native Python `range()` function. See |
---|
| 449 | // [the Python documentation](http://docs.python.org/library/functions.html#range). |
---|
| 450 | _.range = function(start, stop, step) { |
---|
| 451 | if (arguments.length <= 1) { |
---|
| 452 | stop = start || 0; |
---|
| 453 | start = 0; |
---|
| 454 | } |
---|
| 455 | step = arguments[2] || 1; |
---|
| 456 | |
---|
| 457 | var len = Math.max(Math.ceil((stop - start) / step), 0); |
---|
| 458 | var idx = 0; |
---|
| 459 | var range = new Array(len); |
---|
| 460 | |
---|
| 461 | while(idx < len) { |
---|
| 462 | range[idx++] = start; |
---|
| 463 | start += step; |
---|
| 464 | } |
---|
| 465 | |
---|
| 466 | return range; |
---|
| 467 | }; |
---|
| 468 | |
---|
| 469 | // Function (ahem) Functions |
---|
| 470 | // ------------------ |
---|
| 471 | |
---|
| 472 | // Reusable constructor function for prototype setting. |
---|
| 473 | var ctor = function(){}; |
---|
| 474 | |
---|
| 475 | // Create a function bound to a given object (assigning `this`, and arguments, |
---|
| 476 | // optionally). Binding with arguments is also known as `curry`. |
---|
| 477 | // Delegates to **ECMAScript 5**'s native `Function.bind` if available. |
---|
| 478 | // We check for `func.bind` first, to fail fast when `func` is undefined. |
---|
| 479 | _.bind = function bind(func, context) { |
---|
| 480 | var bound, args; |
---|
| 481 | if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1)); |
---|
| 482 | if (!_.isFunction(func)) throw new TypeError; |
---|
| 483 | args = slice.call(arguments, 2); |
---|
| 484 | return bound = function() { |
---|
| 485 | if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments))); |
---|
| 486 | ctor.prototype = func.prototype; |
---|
| 487 | var self = new ctor; |
---|
| 488 | var result = func.apply(self, args.concat(slice.call(arguments))); |
---|
| 489 | if (Object(result) === result) return result; |
---|
| 490 | return self; |
---|
| 491 | }; |
---|
| 492 | }; |
---|
| 493 | |
---|
| 494 | // Bind all of an object's methods to that object. Useful for ensuring that |
---|
| 495 | // all callbacks defined on an object belong to it. |
---|
| 496 | _.bindAll = function(obj) { |
---|
| 497 | var funcs = slice.call(arguments, 1); |
---|
| 498 | if (funcs.length == 0) funcs = _.functions(obj); |
---|
| 499 | each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); }); |
---|
| 500 | return obj; |
---|
| 501 | }; |
---|
| 502 | |
---|
| 503 | // Memoize an expensive function by storing its results. |
---|
| 504 | _.memoize = function(func, hasher) { |
---|
| 505 | var memo = {}; |
---|
| 506 | hasher || (hasher = _.identity); |
---|
| 507 | return function() { |
---|
| 508 | var key = hasher.apply(this, arguments); |
---|
| 509 | return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments)); |
---|
| 510 | }; |
---|
| 511 | }; |
---|
| 512 | |
---|
| 513 | // Delays a function for the given number of milliseconds, and then calls |
---|
| 514 | // it with the arguments supplied. |
---|
| 515 | _.delay = function(func, wait) { |
---|
| 516 | var args = slice.call(arguments, 2); |
---|
| 517 | return setTimeout(function(){ return func.apply(func, args); }, wait); |
---|
| 518 | }; |
---|
| 519 | |
---|
| 520 | // Defers a function, scheduling it to run after the current call stack has |
---|
| 521 | // cleared. |
---|
| 522 | _.defer = function(func) { |
---|
| 523 | return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1))); |
---|
| 524 | }; |
---|
| 525 | |
---|
| 526 | // Returns a function, that, when invoked, will only be triggered at most once |
---|
| 527 | // during a given window of time. |
---|
| 528 | _.throttle = function(func, wait) { |
---|
| 529 | var context, args, timeout, throttling, more; |
---|
| 530 | var whenDone = _.debounce(function(){ more = throttling = false; }, wait); |
---|
| 531 | return function() { |
---|
| 532 | context = this; args = arguments; |
---|
| 533 | var later = function() { |
---|
| 534 | timeout = null; |
---|
| 535 | if (more) func.apply(context, args); |
---|
| 536 | whenDone(); |
---|
| 537 | }; |
---|
| 538 | if (!timeout) timeout = setTimeout(later, wait); |
---|
| 539 | if (throttling) { |
---|
| 540 | more = true; |
---|
| 541 | } else { |
---|
| 542 | func.apply(context, args); |
---|
| 543 | } |
---|
| 544 | whenDone(); |
---|
| 545 | throttling = true; |
---|
| 546 | }; |
---|
| 547 | }; |
---|
| 548 | |
---|
| 549 | // Returns a function, that, as long as it continues to be invoked, will not |
---|
| 550 | // be triggered. The function will be called after it stops being called for |
---|
| 551 | // N milliseconds. |
---|
| 552 | _.debounce = function(func, wait) { |
---|
| 553 | var timeout; |
---|
| 554 | return function() { |
---|
| 555 | var context = this, args = arguments; |
---|
| 556 | var later = function() { |
---|
| 557 | timeout = null; |
---|
| 558 | func.apply(context, args); |
---|
| 559 | }; |
---|
| 560 | clearTimeout(timeout); |
---|
| 561 | timeout = setTimeout(later, wait); |
---|
| 562 | }; |
---|
| 563 | }; |
---|
| 564 | |
---|
| 565 | // Returns a function that will be executed at most one time, no matter how |
---|
| 566 | // often you call it. Useful for lazy initialization. |
---|
| 567 | _.once = function(func) { |
---|
| 568 | var ran = false, memo; |
---|
| 569 | return function() { |
---|
| 570 | if (ran) return memo; |
---|
| 571 | ran = true; |
---|
| 572 | return memo = func.apply(this, arguments); |
---|
| 573 | }; |
---|
| 574 | }; |
---|
| 575 | |
---|
| 576 | // Returns the first function passed as an argument to the second, |
---|
| 577 | // allowing you to adjust arguments, run code before and after, and |
---|
| 578 | // conditionally execute the original function. |
---|
| 579 | _.wrap = function(func, wrapper) { |
---|
| 580 | return function() { |
---|
| 581 | var args = [func].concat(slice.call(arguments, 0)); |
---|
| 582 | return wrapper.apply(this, args); |
---|
| 583 | }; |
---|
| 584 | }; |
---|
| 585 | |
---|
| 586 | // Returns a function that is the composition of a list of functions, each |
---|
| 587 | // consuming the return value of the function that follows. |
---|
| 588 | _.compose = function() { |
---|
| 589 | var funcs = arguments; |
---|
| 590 | return function() { |
---|
| 591 | var args = arguments; |
---|
| 592 | for (var i = funcs.length - 1; i >= 0; i--) { |
---|
| 593 | args = [funcs[i].apply(this, args)]; |
---|
| 594 | } |
---|
| 595 | return args[0]; |
---|
| 596 | }; |
---|
| 597 | }; |
---|
| 598 | |
---|
| 599 | // Returns a function that will only be executed after being called N times. |
---|
| 600 | _.after = function(times, func) { |
---|
| 601 | if (times <= 0) return func(); |
---|
| 602 | return function() { |
---|
| 603 | if (--times < 1) { return func.apply(this, arguments); } |
---|
| 604 | }; |
---|
| 605 | }; |
---|
| 606 | |
---|
| 607 | // Object Functions |
---|
| 608 | // ---------------- |
---|
| 609 | |
---|
| 610 | // Retrieve the names of an object's properties. |
---|
| 611 | // Delegates to **ECMAScript 5**'s native `Object.keys` |
---|
| 612 | _.keys = nativeKeys || function(obj) { |
---|
| 613 | if (obj !== Object(obj)) throw new TypeError('Invalid object'); |
---|
| 614 | var keys = []; |
---|
| 615 | for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key; |
---|
| 616 | return keys; |
---|
| 617 | }; |
---|
| 618 | |
---|
| 619 | // Retrieve the values of an object's properties. |
---|
| 620 | _.values = function(obj) { |
---|
| 621 | return _.map(obj, _.identity); |
---|
| 622 | }; |
---|
| 623 | |
---|
| 624 | // Return a sorted list of the function names available on the object. |
---|
| 625 | // Aliased as `methods` |
---|
| 626 | _.functions = _.methods = function(obj) { |
---|
| 627 | var names = []; |
---|
| 628 | for (var key in obj) { |
---|
| 629 | if (_.isFunction(obj[key])) names.push(key); |
---|
| 630 | } |
---|
| 631 | return names.sort(); |
---|
| 632 | }; |
---|
| 633 | |
---|
| 634 | // Extend a given object with all the properties in passed-in object(s). |
---|
| 635 | _.extend = function(obj) { |
---|
| 636 | each(slice.call(arguments, 1), function(source) { |
---|
| 637 | for (var prop in source) { |
---|
| 638 | obj[prop] = source[prop]; |
---|
| 639 | } |
---|
| 640 | }); |
---|
| 641 | return obj; |
---|
| 642 | }; |
---|
| 643 | |
---|
| 644 | // Fill in a given object with default properties. |
---|
| 645 | _.defaults = function(obj) { |
---|
| 646 | each(slice.call(arguments, 1), function(source) { |
---|
| 647 | for (var prop in source) { |
---|
| 648 | if (obj[prop] == null) obj[prop] = source[prop]; |
---|
| 649 | } |
---|
| 650 | }); |
---|
| 651 | return obj; |
---|
| 652 | }; |
---|
| 653 | |
---|
| 654 | // Create a (shallow-cloned) duplicate of an object. |
---|
| 655 | _.clone = function(obj) { |
---|
| 656 | if (!_.isObject(obj)) return obj; |
---|
| 657 | return _.isArray(obj) ? obj.slice() : _.extend({}, obj); |
---|
| 658 | }; |
---|
| 659 | |
---|
| 660 | // Invokes interceptor with the obj, and then returns obj. |
---|
| 661 | // The primary purpose of this method is to "tap into" a method chain, in |
---|
| 662 | // order to perform operations on intermediate results within the chain. |
---|
| 663 | _.tap = function(obj, interceptor) { |
---|
| 664 | interceptor(obj); |
---|
| 665 | return obj; |
---|
| 666 | }; |
---|
| 667 | |
---|
| 668 | // Internal recursive comparison function. |
---|
| 669 | function eq(a, b, stack) { |
---|
| 670 | // Identical objects are equal. `0 === -0`, but they aren't identical. |
---|
| 671 | // See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal. |
---|
| 672 | if (a === b) return a !== 0 || 1 / a == 1 / b; |
---|
| 673 | // A strict comparison is necessary because `null == undefined`. |
---|
| 674 | if (a == null || b == null) return a === b; |
---|
| 675 | // Unwrap any wrapped objects. |
---|
| 676 | if (a._chain) a = a._wrapped; |
---|
| 677 | if (b._chain) b = b._wrapped; |
---|
| 678 | // Invoke a custom `isEqual` method if one is provided. |
---|
| 679 | if (a.isEqual && _.isFunction(a.isEqual)) return a.isEqual(b); |
---|
| 680 | if (b.isEqual && _.isFunction(b.isEqual)) return b.isEqual(a); |
---|
| 681 | // Compare `[[Class]]` names. |
---|
| 682 | var className = toString.call(a); |
---|
| 683 | if (className != toString.call(b)) return false; |
---|
| 684 | switch (className) { |
---|
| 685 | // Strings, numbers, dates, and booleans are compared by value. |
---|
| 686 | case '[object String]': |
---|
| 687 | // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is |
---|
| 688 | // equivalent to `new String("5")`. |
---|
| 689 | return a == String(b); |
---|
| 690 | case '[object Number]': |
---|
| 691 | // `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for |
---|
| 692 | // other numeric values. |
---|
| 693 | return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b); |
---|
| 694 | case '[object Date]': |
---|
| 695 | case '[object Boolean]': |
---|
| 696 | // Coerce dates and booleans to numeric primitive values. Dates are compared by their |
---|
| 697 | // millisecond representations. Note that invalid dates with millisecond representations |
---|
| 698 | // of `NaN` are not equivalent. |
---|
| 699 | return +a == +b; |
---|
| 700 | // RegExps are compared by their source patterns and flags. |
---|
| 701 | case '[object RegExp]': |
---|
| 702 | return a.source == b.source && |
---|
| 703 | a.global == b.global && |
---|
| 704 | a.multiline == b.multiline && |
---|
| 705 | a.ignoreCase == b.ignoreCase; |
---|
| 706 | } |
---|
| 707 | if (typeof a != 'object' || typeof b != 'object') return false; |
---|
| 708 | // Assume equality for cyclic structures. The algorithm for detecting cyclic |
---|
| 709 | // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`. |
---|
| 710 | var length = stack.length; |
---|
| 711 | while (length--) { |
---|
| 712 | // Linear search. Performance is inversely proportional to the number of |
---|
| 713 | // unique nested structures. |
---|
| 714 | if (stack[length] == a) return true; |
---|
| 715 | } |
---|
| 716 | // Add the first object to the stack of traversed objects. |
---|
| 717 | stack.push(a); |
---|
| 718 | var size = 0, result = true; |
---|
| 719 | // Recursively compare objects and arrays. |
---|
| 720 | if (className == '[object Array]') { |
---|
| 721 | // Compare array lengths to determine if a deep comparison is necessary. |
---|
| 722 | size = a.length; |
---|
| 723 | result = size == b.length; |
---|
| 724 | if (result) { |
---|
| 725 | // Deep compare the contents, ignoring non-numeric properties. |
---|
| 726 | while (size--) { |
---|
| 727 | // Ensure commutative equality for sparse arrays. |
---|
| 728 | if (!(result = size in a == size in b && eq(a[size], b[size], stack))) break; |
---|
| 729 | } |
---|
| 730 | } |
---|
| 731 | } else { |
---|
| 732 | // Objects with different constructors are not equivalent. |
---|
| 733 | if ('constructor' in a != 'constructor' in b || a.constructor != b.constructor) return false; |
---|
| 734 | // Deep compare objects. |
---|
| 735 | for (var key in a) { |
---|
| 736 | if (_.has(a, key)) { |
---|
| 737 | // Count the expected number of properties. |
---|
| 738 | size++; |
---|
| 739 | // Deep compare each member. |
---|
| 740 | if (!(result = _.has(b, key) && eq(a[key], b[key], stack))) break; |
---|
| 741 | } |
---|
| 742 | } |
---|
| 743 | // Ensure that both objects contain the same number of properties. |
---|
| 744 | if (result) { |
---|
| 745 | for (key in b) { |
---|
| 746 | if (_.has(b, key) && !(size--)) break; |
---|
| 747 | } |
---|
| 748 | result = !size; |
---|
| 749 | } |
---|
| 750 | } |
---|
| 751 | // Remove the first object from the stack of traversed objects. |
---|
| 752 | stack.pop(); |
---|
| 753 | return result; |
---|
| 754 | } |
---|
| 755 | |
---|
| 756 | // Perform a deep comparison to check if two objects are equal. |
---|
| 757 | _.isEqual = function(a, b) { |
---|
| 758 | return eq(a, b, []); |
---|
| 759 | }; |
---|
| 760 | |
---|
| 761 | // Is a given array, string, or object empty? |
---|
| 762 | // An "empty" object has no enumerable own-properties. |
---|
| 763 | _.isEmpty = function(obj) { |
---|
| 764 | if (_.isArray(obj) || _.isString(obj)) return obj.length === 0; |
---|
| 765 | for (var key in obj) if (_.has(obj, key)) return false; |
---|
| 766 | return true; |
---|
| 767 | }; |
---|
| 768 | |
---|
| 769 | // Is a given value a DOM element? |
---|
| 770 | _.isElement = function(obj) { |
---|
| 771 | return !!(obj && obj.nodeType == 1); |
---|
| 772 | }; |
---|
| 773 | |
---|
| 774 | // Is a given value an array? |
---|
| 775 | // Delegates to ECMA5's native Array.isArray |
---|
| 776 | _.isArray = nativeIsArray || function(obj) { |
---|
| 777 | return toString.call(obj) == '[object Array]'; |
---|
| 778 | }; |
---|
| 779 | |
---|
| 780 | // Is a given variable an object? |
---|
| 781 | _.isObject = function(obj) { |
---|
| 782 | return obj === Object(obj); |
---|
| 783 | }; |
---|
| 784 | |
---|
| 785 | // Is a given variable an arguments object? |
---|
| 786 | _.isArguments = function(obj) { |
---|
| 787 | return toString.call(obj) == '[object Arguments]'; |
---|
| 788 | }; |
---|
| 789 | if (!_.isArguments(arguments)) { |
---|
| 790 | _.isArguments = function(obj) { |
---|
| 791 | return !!(obj && _.has(obj, 'callee')); |
---|
| 792 | }; |
---|
| 793 | } |
---|
| 794 | |
---|
| 795 | // Is a given value a function? |
---|
| 796 | _.isFunction = function(obj) { |
---|
| 797 | return toString.call(obj) == '[object Function]'; |
---|
| 798 | }; |
---|
| 799 | |
---|
| 800 | // Is a given value a string? |
---|
| 801 | _.isString = function(obj) { |
---|
| 802 | return toString.call(obj) == '[object String]'; |
---|
| 803 | }; |
---|
| 804 | |
---|
| 805 | // Is a given value a number? |
---|
| 806 | _.isNumber = function(obj) { |
---|
| 807 | return toString.call(obj) == '[object Number]'; |
---|
| 808 | }; |
---|
| 809 | |
---|
| 810 | // Is the given value `NaN`? |
---|
| 811 | _.isNaN = function(obj) { |
---|
| 812 | // `NaN` is the only value for which `===` is not reflexive. |
---|
| 813 | return obj !== obj; |
---|
| 814 | }; |
---|
| 815 | |
---|
| 816 | // Is a given value a boolean? |
---|
| 817 | _.isBoolean = function(obj) { |
---|
| 818 | return obj === true || obj === false || toString.call(obj) == '[object Boolean]'; |
---|
| 819 | }; |
---|
| 820 | |
---|
| 821 | // Is a given value a date? |
---|
| 822 | _.isDate = function(obj) { |
---|
| 823 | return toString.call(obj) == '[object Date]'; |
---|
| 824 | }; |
---|
| 825 | |
---|
| 826 | // Is the given value a regular expression? |
---|
| 827 | _.isRegExp = function(obj) { |
---|
| 828 | return toString.call(obj) == '[object RegExp]'; |
---|
| 829 | }; |
---|
| 830 | |
---|
| 831 | // Is a given value equal to null? |
---|
| 832 | _.isNull = function(obj) { |
---|
| 833 | return obj === null; |
---|
| 834 | }; |
---|
| 835 | |
---|
| 836 | // Is a given variable undefined? |
---|
| 837 | _.isUndefined = function(obj) { |
---|
| 838 | return obj === void 0; |
---|
| 839 | }; |
---|
| 840 | |
---|
| 841 | // Has own property? |
---|
| 842 | _.has = function(obj, key) { |
---|
| 843 | return hasOwnProperty.call(obj, key); |
---|
| 844 | }; |
---|
| 845 | |
---|
| 846 | // Utility Functions |
---|
| 847 | // ----------------- |
---|
| 848 | |
---|
| 849 | // Run Underscore.js in *noConflict* mode, returning the `_` variable to its |
---|
| 850 | // previous owner. Returns a reference to the Underscore object. |
---|
| 851 | _.noConflict = function() { |
---|
| 852 | root._ = previousUnderscore; |
---|
| 853 | return this; |
---|
| 854 | }; |
---|
| 855 | |
---|
| 856 | // Keep the identity function around for default iterators. |
---|
| 857 | _.identity = function(value) { |
---|
| 858 | return value; |
---|
| 859 | }; |
---|
| 860 | |
---|
| 861 | // Run a function **n** times. |
---|
| 862 | _.times = function (n, iterator, context) { |
---|
| 863 | for (var i = 0; i < n; i++) iterator.call(context, i); |
---|
| 864 | }; |
---|
| 865 | |
---|
| 866 | // Escape a string for HTML interpolation. |
---|
| 867 | _.escape = function(string) { |
---|
| 868 | return (''+string).replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>').replace(/"/g, '"').replace(/'/g, ''').replace(/\//g,'/'); |
---|
| 869 | }; |
---|
| 870 | |
---|
| 871 | // Add your own custom functions to the Underscore object, ensuring that |
---|
| 872 | // they're correctly added to the OOP wrapper as well. |
---|
| 873 | _.mixin = function(obj) { |
---|
| 874 | each(_.functions(obj), function(name){ |
---|
| 875 | addToWrapper(name, _[name] = obj[name]); |
---|
| 876 | }); |
---|
| 877 | }; |
---|
| 878 | |
---|
| 879 | // Generate a unique integer id (unique within the entire client session). |
---|
| 880 | // Useful for temporary DOM ids. |
---|
| 881 | var idCounter = 0; |
---|
| 882 | _.uniqueId = function(prefix) { |
---|
| 883 | var id = idCounter++; |
---|
| 884 | return prefix ? prefix + id : id; |
---|
| 885 | }; |
---|
| 886 | |
---|
| 887 | // By default, Underscore uses ERB-style template delimiters, change the |
---|
| 888 | // following template settings to use alternative delimiters. |
---|
| 889 | _.templateSettings = { |
---|
| 890 | evaluate : /<%([\s\S]+?)%>/g, |
---|
| 891 | interpolate : /<%=([\s\S]+?)%>/g, |
---|
| 892 | escape : /<%-([\s\S]+?)%>/g |
---|
| 893 | }; |
---|
| 894 | |
---|
| 895 | // When customizing `templateSettings`, if you don't want to define an |
---|
| 896 | // interpolation, evaluation or escaping regex, we need one that is |
---|
| 897 | // guaranteed not to match. |
---|
| 898 | var noMatch = /.^/; |
---|
| 899 | |
---|
| 900 | // Within an interpolation, evaluation, or escaping, remove HTML escaping |
---|
| 901 | // that had been previously added. |
---|
| 902 | var unescape = function(code) { |
---|
| 903 | return code.replace(/\\\\/g, '\\').replace(/\\'/g, "'"); |
---|
| 904 | }; |
---|
| 905 | |
---|
| 906 | // JavaScript micro-templating, similar to John Resig's implementation. |
---|
| 907 | // Underscore templating handles arbitrary delimiters, preserves whitespace, |
---|
| 908 | // and correctly escapes quotes within interpolated code. |
---|
| 909 | _.template = function(str, data) { |
---|
| 910 | var c = _.templateSettings; |
---|
| 911 | var tmpl = 'var __p=[],print=function(){__p.push.apply(__p,arguments);};' + |
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| 912 | 'with(obj||{}){__p.push(\'' + |
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| 913 | str.replace(/\\/g, '\\\\') |
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| 914 | .replace(/'/g, "\\'") |
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| 915 | .replace(c.escape || noMatch, function(match, code) { |
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| 916 | return "',_.escape(" + unescape(code) + "),'"; |
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| 917 | }) |
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| 918 | .replace(c.interpolate || noMatch, function(match, code) { |
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| 919 | return "'," + unescape(code) + ",'"; |
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| 920 | }) |
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| 921 | .replace(c.evaluate || noMatch, function(match, code) { |
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| 922 | return "');" + unescape(code).replace(/[\r\n\t]/g, ' ') + ";__p.push('"; |
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| 923 | }) |
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| 924 | .replace(/\r/g, '\\r') |
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| 925 | .replace(/\n/g, '\\n') |
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| 926 | .replace(/\t/g, '\\t') |
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| 927 | + "');}return __p.join('');"; |
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| 928 | var func = new Function('obj', '_', tmpl); |
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| 929 | if (data) return func(data, _); |
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| 930 | return function(data) { |
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| 931 | return func.call(this, data, _); |
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| 932 | }; |
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| 933 | }; |
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| 934 | |
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| 935 | // Add a "chain" function, which will delegate to the wrapper. |
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| 936 | _.chain = function(obj) { |
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| 937 | return _(obj).chain(); |
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| 938 | }; |
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| 939 | |
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| 940 | // The OOP Wrapper |
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| 941 | // --------------- |
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| 942 | |
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| 943 | // If Underscore is called as a function, it returns a wrapped object that |
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| 944 | // can be used OO-style. This wrapper holds altered versions of all the |
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| 945 | // underscore functions. Wrapped objects may be chained. |
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| 946 | var wrapper = function(obj) { this._wrapped = obj; }; |
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| 947 | |
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| 948 | // Expose `wrapper.prototype` as `_.prototype` |
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| 949 | _.prototype = wrapper.prototype; |
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| 950 | |
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| 951 | // Helper function to continue chaining intermediate results. |
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| 952 | var result = function(obj, chain) { |
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| 953 | return chain ? _(obj).chain() : obj; |
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| 954 | }; |
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| 955 | |
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| 956 | // A method to easily add functions to the OOP wrapper. |
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| 957 | var addToWrapper = function(name, func) { |
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| 958 | wrapper.prototype[name] = function() { |
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| 959 | var args = slice.call(arguments); |
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| 960 | unshift.call(args, this._wrapped); |
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| 961 | return result(func.apply(_, args), this._chain); |
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| 962 | }; |
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| 963 | }; |
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| 964 | |
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| 965 | // Add all of the Underscore functions to the wrapper object. |
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| 966 | _.mixin(_); |
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| 967 | |
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| 968 | // Add all mutator Array functions to the wrapper. |
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| 969 | each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { |
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| 970 | var method = ArrayProto[name]; |
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| 971 | wrapper.prototype[name] = function() { |
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| 972 | var wrapped = this._wrapped; |
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| 973 | method.apply(wrapped, arguments); |
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| 974 | var length = wrapped.length; |
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| 975 | if ((name == 'shift' || name == 'splice') && length === 0) delete wrapped[0]; |
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| 976 | return result(wrapped, this._chain); |
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| 977 | }; |
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| 978 | }); |
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| 979 | |
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| 980 | // Add all accessor Array functions to the wrapper. |
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| 981 | each(['concat', 'join', 'slice'], function(name) { |
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| 982 | var method = ArrayProto[name]; |
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| 983 | wrapper.prototype[name] = function() { |
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| 984 | return result(method.apply(this._wrapped, arguments), this._chain); |
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| 985 | }; |
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| 986 | }); |
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| 987 | |
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| 988 | // Start chaining a wrapped Underscore object. |
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| 989 | wrapper.prototype.chain = function() { |
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| 990 | this._chain = true; |
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| 991 | return this; |
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| 992 | }; |
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| 993 | |
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| 994 | // Extracts the result from a wrapped and chained object. |
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| 995 | wrapper.prototype.value = function() { |
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| 996 | return this._wrapped; |
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| 997 | }; |
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| 998 | |
---|
| 999 | }).call(this); |
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