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 |
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448 | // the native Python `range()` function. See |
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449 | // [the Python documentation](http://docs.python.org/library/functions.html#range). |
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450 | _.range = function(start, stop, step) { |
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451 | if (arguments.length <= 1) { |
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452 | stop = start || 0; |
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453 | start = 0; |
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454 | } |
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455 | step = arguments[2] || 1; |
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456 | |
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457 | var len = Math.max(Math.ceil((stop - start) / step), 0); |
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458 | var idx = 0; |
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459 | var range = new Array(len); |
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460 | |
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461 | while(idx < len) { |
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462 | range[idx++] = start; |
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463 | start += step; |
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464 | } |
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465 | |
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466 | return range; |
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467 | }; |
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468 | |
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469 | // Function (ahem) Functions |
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470 | // ------------------ |
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471 | |
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472 | // Reusable constructor function for prototype setting. |
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473 | var ctor = function(){}; |
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474 | |
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475 | // Create a function bound to a given object (assigning `this`, and arguments, |
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476 | // optionally). Binding with arguments is also known as `curry`. |
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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);};' + |
---|
912 | 'with(obj||{}){__p.push(\'' + |
---|
913 | str.replace(/\\/g, '\\\\') |
---|
914 | .replace(/'/g, "\\'") |
---|
915 | .replace(c.escape || noMatch, function(match, code) { |
---|
916 | return "',_.escape(" + unescape(code) + "),'"; |
---|
917 | }) |
---|
918 | .replace(c.interpolate || noMatch, function(match, code) { |
---|
919 | return "'," + unescape(code) + ",'"; |
---|
920 | }) |
---|
921 | .replace(c.evaluate || noMatch, function(match, code) { |
---|
922 | return "');" + unescape(code).replace(/[\r\n\t]/g, ' ') + ";__p.push('"; |
---|
923 | }) |
---|
924 | .replace(/\r/g, '\\r') |
---|
925 | .replace(/\n/g, '\\n') |
---|
926 | .replace(/\t/g, '\\t') |
---|
927 | + "');}return __p.join('');"; |
---|
928 | var func = new Function('obj', '_', tmpl); |
---|
929 | if (data) return func(data, _); |
---|
930 | return function(data) { |
---|
931 | return func.call(this, data, _); |
---|
932 | }; |
---|
933 | }; |
---|
934 | |
---|
935 | // Add a "chain" function, which will delegate to the wrapper. |
---|
936 | _.chain = function(obj) { |
---|
937 | return _(obj).chain(); |
---|
938 | }; |
---|
939 | |
---|
940 | // The OOP Wrapper |
---|
941 | // --------------- |
---|
942 | |
---|
943 | // If Underscore is called as a function, it returns a wrapped object that |
---|
944 | // can be used OO-style. This wrapper holds altered versions of all the |
---|
945 | // underscore functions. Wrapped objects may be chained. |
---|
946 | var wrapper = function(obj) { this._wrapped = obj; }; |
---|
947 | |
---|
948 | // Expose `wrapper.prototype` as `_.prototype` |
---|
949 | _.prototype = wrapper.prototype; |
---|
950 | |
---|
951 | // Helper function to continue chaining intermediate results. |
---|
952 | var result = function(obj, chain) { |
---|
953 | return chain ? _(obj).chain() : obj; |
---|
954 | }; |
---|
955 | |
---|
956 | // A method to easily add functions to the OOP wrapper. |
---|
957 | var addToWrapper = function(name, func) { |
---|
958 | wrapper.prototype[name] = function() { |
---|
959 | var args = slice.call(arguments); |
---|
960 | unshift.call(args, this._wrapped); |
---|
961 | return result(func.apply(_, args), this._chain); |
---|
962 | }; |
---|
963 | }; |
---|
964 | |
---|
965 | // Add all of the Underscore functions to the wrapper object. |
---|
966 | _.mixin(_); |
---|
967 | |
---|
968 | // Add all mutator Array functions to the wrapper. |
---|
969 | each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) { |
---|
970 | var method = ArrayProto[name]; |
---|
971 | wrapper.prototype[name] = function() { |
---|
972 | var wrapped = this._wrapped; |
---|
973 | method.apply(wrapped, arguments); |
---|
974 | var length = wrapped.length; |
---|
975 | if ((name == 'shift' || name == 'splice') && length === 0) delete wrapped[0]; |
---|
976 | return result(wrapped, this._chain); |
---|
977 | }; |
---|
978 | }); |
---|
979 | |
---|
980 | // Add all accessor Array functions to the wrapper. |
---|
981 | each(['concat', 'join', 'slice'], function(name) { |
---|
982 | var method = ArrayProto[name]; |
---|
983 | wrapper.prototype[name] = function() { |
---|
984 | return result(method.apply(this._wrapped, arguments), this._chain); |
---|
985 | }; |
---|
986 | }); |
---|
987 | |
---|
988 | // Start chaining a wrapped Underscore object. |
---|
989 | wrapper.prototype.chain = function() { |
---|
990 | this._chain = true; |
---|
991 | return this; |
---|
992 | }; |
---|
993 | |
---|
994 | // Extracts the result from a wrapped and chained object. |
---|
995 | wrapper.prototype.value = function() { |
---|
996 | return this._wrapped; |
---|
997 | }; |
---|
998 | |
---|
999 | }).call(this); |
---|