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<!DOCTYPE html><meta charset="UTF-8"><meta http-equiv="Content-Language" content="en" /><title>iter.js</title><link href="../../../../dossier.css" rel="stylesheet" type="text/css"><div id="main-wrapper"><input type="checkbox" id="sidenav-toggle" /><main><header><h1>lib/goog/iter/iter.js</h1></header><pre><table class="srcfile"><tbody><tr><td><a name="l1" href="#l1">1</a><td>// Copyright 2007 The Closure Library Authors. All Rights Reserved.<tr><td><a name="l2" href="#l2">2</a><td>//<tr><td><a name="l3" href="#l3">3</a><td>// Licensed under the Apache License, Version 2.0 (the "License");<tr><td><a name="l4" href="#l4">4</a><td>// you may not use this file except in compliance with the License.<tr><td><a name="l5" href="#l5">5</a><td>// You may obtain a copy of the License at<tr><td><a name="l6" href="#l6">6</a><td>//<tr><td><a name="l7" href="#l7">7</a><td>// http://www.apache.org/licenses/LICENSE-2.0<tr><td><a name="l8" href="#l8">8</a><td>//<tr><td><a name="l9" href="#l9">9</a><td>// Unless required by applicable law or agreed to in writing, software<tr><td><a name="l10" href="#l10">10</a><td>// distributed under the License is distributed on an "AS-IS" BASIS,<tr><td><a name="l11" href="#l11">11</a><td>// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<tr><td><a name="l12" href="#l12">12</a><td>// See the License for the specific language governing permissions and<tr><td><a name="l13" href="#l13">13</a><td>// limitations under the License.<tr><td><a name="l14" href="#l14">14</a><td><tr><td><a name="l15" href="#l15">15</a><td>/**<tr><td><a name="l16" href="#l16">16</a><td> * @fileoverview Python style iteration utilities.<tr><td><a name="l17" href="#l17">17</a><td> * @author arv@google.com (Erik Arvidsson)<tr><td><a name="l18" href="#l18">18</a><td> */<tr><td><a name="l19" href="#l19">19</a><td><tr><td><a name="l20" href="#l20">20</a><td><tr><td><a name="l21" href="#l21">21</a><td>goog.provide('goog.iter');<tr><td><a name="l22" href="#l22">22</a><td>goog.provide('goog.iter.Iterable');<tr><td><a name="l23" href="#l23">23</a><td>goog.provide('goog.iter.Iterator');<tr><td><a name="l24" href="#l24">24</a><td>goog.provide('goog.iter.StopIteration');<tr><td><a name="l25" href="#l25">25</a><td><tr><td><a name="l26" href="#l26">26</a><td>goog.require('goog.array');<tr><td><a name="l27" href="#l27">27</a><td>goog.require('goog.asserts');<tr><td><a name="l28" href="#l28">28</a><td>goog.require('goog.functions');<tr><td><a name="l29" href="#l29">29</a><td>goog.require('goog.math');<tr><td><a name="l30" href="#l30">30</a><td><tr><td><a name="l31" href="#l31">31</a><td><tr><td><a name="l32" href="#l32">32</a><td>/**<tr><td><a name="l33" href="#l33">33</a><td> * @typedef {goog.iter.Iterator|{length:number}|{__iterator__}}<tr><td><a name="l34" href="#l34">34</a><td> */<tr><td><a name="l35" href="#l35">35</a><td>goog.iter.Iterable;<tr><td><a name="l36" href="#l36">36</a><td><tr><td><a name="l37" href="#l37">37</a><td><tr><td><a name="l38" href="#l38">38</a><td>// For script engines that already support iterators.<tr><td><a name="l39" href="#l39">39</a><td>if ('StopIteration' in goog.global) {<tr><td><a name="l40" href="#l40">40</a><td> /**<tr><td><a name="l41" href="#l41">41</a><td> * Singleton Error object that is used to terminate iterations.<tr><td><a name="l42" href="#l42">42</a><td> * @type {Error}<tr><td><a name="l43" href="#l43">43</a><td> */<tr><td><a name="l44" href="#l44">44</a><td> goog.iter.StopIteration = goog.global['StopIteration'];<tr><td><a name="l45" href="#l45">45</a><td>} else {<tr><td><a name="l46" href="#l46">46</a><td> /**<tr><td><a name="l47" href="#l47">47</a><td> * Singleton Error object that is used to terminate iterations.<tr><td><a name="l48" href="#l48">48</a><td> * @type {Error}<tr><td><a name="l49" href="#l49">49</a><td> * @suppress {duplicate}<tr><td><a name="l50" href="#l50">50</a><td> */<tr><td><a name="l51" href="#l51">51</a><td> goog.iter.StopIteration = Error('StopIteration');<tr><td><a name="l52" href="#l52">52</a><td>}<tr><td><a name="l53" href="#l53">53</a><td><tr><td><a name="l54" href="#l54">54</a><td><tr><td><a name="l55" href="#l55">55</a><td><tr><td><a name="l56" href="#l56">56</a><td>/**<tr><td><a name="l57" href="#l57">57</a><td> * Class/interface for iterators. An iterator needs to implement a {@code next}<tr><td><a name="l58" href="#l58">58</a><td> * method and it needs to throw a {@code goog.iter.StopIteration} when the<tr><td><a name="l59" href="#l59">59</a><td> * iteration passes beyond the end. Iterators have no {@code hasNext} method.<tr><td><a name="l60" href="#l60">60</a><td> * It is recommended to always use the helper functions to iterate over the<tr><td><a name="l61" href="#l61">61</a><td> * iterator or in case you are only targeting JavaScript 1.7 for in loops.<tr><td><a name="l62" href="#l62">62</a><td> * @constructor<tr><td><a name="l63" href="#l63">63</a><td> * @template VALUE<tr><td><a name="l64" href="#l64">64</a><td> */<tr><td><a name="l65" href="#l65">65</a><td>goog.iter.Iterator = function() {};<tr><td><a name="l66" href="#l66">66</a><td><tr><td><a name="l67" href="#l67">67</a><td><tr><td><a name="l68" href="#l68">68</a><td>/**<tr><td><a name="l69" href="#l69">69</a><td> * Returns the next value of the iteration. This will throw the object<tr><td><a name="l70" href="#l70">70</a><td> * {@see goog.iter#StopIteration} when the iteration passes the end.<tr><td><a name="l71" href="#l71">71</a><td> * @return {VALUE} Any object or value.<tr><td><a name="l72" href="#l72">72</a><td> */<tr><td><a name="l73" href="#l73">73</a><td>goog.iter.Iterator.prototype.next = function() {<tr><td><a name="l74" href="#l74">74</a><td> throw goog.iter.StopIteration;<tr><td><a name="l75" href="#l75">75</a><td>};<tr><td><a name="l76" href="#l76">76</a><td><tr><td><a name="l77" href="#l77">77</a><td><tr><td><a name="l78" href="#l78">78</a><td>/**<tr><td><a name="l79" href="#l79">79</a><td> * Returns the {@code Iterator} object itself. This is used to implement<tr><td><a name="l80" href="#l80">80</a><td> * the iterator protocol in JavaScript 1.7<tr><td><a name="l81" href="#l81">81</a><td> * @param {boolean=} opt_keys Whether to return the keys or values. Default is<tr><td><a name="l82" href="#l82">82</a><td> * to only return the values. This is being used by the for-in loop (true)<tr><td><a name="l83" href="#l83">83</a><td> * and the for-each-in loop (false). Even though the param gives a hint<tr><td><a name="l84" href="#l84">84</a><td> * about what the iterator will return there is no guarantee that it will<tr><td><a name="l85" href="#l85">85</a><td> * return the keys when true is passed.<tr><td><a name="l86" href="#l86">86</a><td> * @return {!goog.iter.Iterator.<VALUE>} The object itself.<tr><td><a name="l87" href="#l87">87</a><td> */<tr><td><a name="l88" href="#l88">88</a><td>goog.iter.Iterator.prototype.__iterator__ = function(opt_keys) {<tr><td><a name="l89" href="#l89">89</a><td> return this;<tr><td><a name="l90" href="#l90">90</a><td>};<tr><td><a name="l91" href="#l91">91</a><td><tr><td><a name="l92" href="#l92">92</a><td><tr><td><a name="l93" href="#l93">93</a><td>/**<tr><td><a name="l94" href="#l94">94</a><td> * Returns an iterator that knows how to iterate over the values in the object.<tr><td><a name="l95" href="#l95">95</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable If the<tr><td><a name="l96" href="#l96">96</a><td> * object is an iterator it will be returned as is. If the object has an<tr><td><a name="l97" href="#l97">97</a><td> * {@code __iterator__} method that will be called to get the value<tr><td><a name="l98" href="#l98">98</a><td> * iterator. If the object is an array-like object we create an iterator<tr><td><a name="l99" href="#l99">99</a><td> * for that.<tr><td><a name="l100" href="#l100">100</a><td> * @return {!goog.iter.Iterator.<VALUE>} An iterator that knows how to iterate<tr><td><a name="l101" href="#l101">101</a><td> * over the values in {@code iterable}.<tr><td><a name="l102" href="#l102">102</a><td> * @template VALUE<tr><td><a name="l103" href="#l103">103</a><td> */<tr><td><a name="l104" href="#l104">104</a><td>goog.iter.toIterator = function(iterable) {<tr><td><a name="l105" href="#l105">105</a><td> if (iterable instanceof goog.iter.Iterator) {<tr><td><a name="l106" href="#l106">106</a><td> return iterable;<tr><td><a name="l107" href="#l107">107</a><td> }<tr><td><a name="l108" href="#l108">108</a><td> if (typeof iterable.__iterator__ == 'function') {<tr><td><a name="l109" href="#l109">109</a><td> return iterable.__iterator__(false);<tr><td><a name="l110" href="#l110">110</a><td> }<tr><td><a name="l111" href="#l111">111</a><td> if (goog.isArrayLike(iterable)) {<tr><td><a name="l112" href="#l112">112</a><td> var i = 0;<tr><td><a name="l113" href="#l113">113</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l114" href="#l114">114</a><td> newIter.next = function() {<tr><td><a name="l115" href="#l115">115</a><td> while (true) {<tr><td><a name="l116" href="#l116">116</a><td> if (i >= iterable.length) {<tr><td><a name="l117" href="#l117">117</a><td> throw goog.iter.StopIteration;<tr><td><a name="l118" href="#l118">118</a><td> }<tr><td><a name="l119" href="#l119">119</a><td> // Don't include deleted elements.<tr><td><a name="l120" href="#l120">120</a><td> if (!(i in iterable)) {<tr><td><a name="l121" href="#l121">121</a><td> i++;<tr><td><a name="l122" href="#l122">122</a><td> continue;<tr><td><a name="l123" href="#l123">123</a><td> }<tr><td><a name="l124" href="#l124">124</a><td> return iterable[i++];<tr><td><a name="l125" href="#l125">125</a><td> }<tr><td><a name="l126" href="#l126">126</a><td> };<tr><td><a name="l127" href="#l127">127</a><td> return newIter;<tr><td><a name="l128" href="#l128">128</a><td> }<tr><td><a name="l129" href="#l129">129</a><td><tr><td><a name="l130" href="#l130">130</a><td><tr><td><a name="l131" href="#l131">131</a><td> // TODO(arv): Should we fall back on goog.structs.getValues()?<tr><td><a name="l132" href="#l132">132</a><td> throw Error('Not implemented');<tr><td><a name="l133" href="#l133">133</a><td>};<tr><td><a name="l134" href="#l134">134</a><td><tr><td><a name="l135" href="#l135">135</a><td><tr><td><a name="l136" href="#l136">136</a><td>/**<tr><td><a name="l137" href="#l137">137</a><td> * Calls a function for each element in the iterator with the element of the<tr><td><a name="l138" href="#l138">138</a><td> * iterator passed as argument.<tr><td><a name="l139" href="#l139">139</a><td> *<tr><td><a name="l140" href="#l140">140</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l141" href="#l141">141</a><td> * to iterate over. If the iterable is an object {@code toIterator} will be<tr><td><a name="l142" href="#l142">142</a><td> * called on it.<tr><td><a name="l143" href="#l143">143</a><td> * @param {function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>)|<tr><td><a name="l144" href="#l144">144</a><td> * function(this:THIS,number,undefined,goog.iter.Iterator.<VALUE>)} f<tr><td><a name="l145" href="#l145">145</a><td> * The function to call for every element. This function takes 3 arguments<tr><td><a name="l146" href="#l146">146</a><td> * (the element, undefined, and the iterator) and the return value is<tr><td><a name="l147" href="#l147">147</a><td> * irrelevant. The reason for passing undefined as the second argument is<tr><td><a name="l148" href="#l148">148</a><td> * so that the same function can be used in {@see goog.array#forEach} as<tr><td><a name="l149" href="#l149">149</a><td> * well as others.<tr><td><a name="l150" href="#l150">150</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l151" href="#l151">151</a><td> * {@code f}.<tr><td><a name="l152" href="#l152">152</a><td> * @template THIS, VALUE<tr><td><a name="l153" href="#l153">153</a><td> */<tr><td><a name="l154" href="#l154">154</a><td>goog.iter.forEach = function(iterable, f, opt_obj) {<tr><td><a name="l155" href="#l155">155</a><td> if (goog.isArrayLike(iterable)) {<tr><td><a name="l156" href="#l156">156</a><td> /** @preserveTry */<tr><td><a name="l157" href="#l157">157</a><td> try {<tr><td><a name="l158" href="#l158">158</a><td> // NOTES: this passes the index number to the second parameter<tr><td><a name="l159" href="#l159">159</a><td> // of the callback contrary to the documentation above.<tr><td><a name="l160" href="#l160">160</a><td> goog.array.forEach(/** @type {goog.array.ArrayLike} */(iterable), f,<tr><td><a name="l161" href="#l161">161</a><td> opt_obj);<tr><td><a name="l162" href="#l162">162</a><td> } catch (ex) {<tr><td><a name="l163" href="#l163">163</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l164" href="#l164">164</a><td> throw ex;<tr><td><a name="l165" href="#l165">165</a><td> }<tr><td><a name="l166" href="#l166">166</a><td> }<tr><td><a name="l167" href="#l167">167</a><td> } else {<tr><td><a name="l168" href="#l168">168</a><td> iterable = goog.iter.toIterator(iterable);<tr><td><a name="l169" href="#l169">169</a><td> /** @preserveTry */<tr><td><a name="l170" href="#l170">170</a><td> try {<tr><td><a name="l171" href="#l171">171</a><td> while (true) {<tr><td><a name="l172" href="#l172">172</a><td> f.call(opt_obj, iterable.next(), undefined, iterable);<tr><td><a name="l173" href="#l173">173</a><td> }<tr><td><a name="l174" href="#l174">174</a><td> } catch (ex) {<tr><td><a name="l175" href="#l175">175</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l176" href="#l176">176</a><td> throw ex;<tr><td><a name="l177" href="#l177">177</a><td> }<tr><td><a name="l178" href="#l178">178</a><td> }<tr><td><a name="l179" href="#l179">179</a><td> }<tr><td><a name="l180" href="#l180">180</a><td>};<tr><td><a name="l181" href="#l181">181</a><td><tr><td><a name="l182" href="#l182">182</a><td><tr><td><a name="l183" href="#l183">183</a><td>/**<tr><td><a name="l184" href="#l184">184</a><td> * Calls a function for every element in the iterator, and if the function<tr><td><a name="l185" href="#l185">185</a><td> * returns true adds the element to a new iterator.<tr><td><a name="l186" href="#l186">186</a><td> *<tr><td><a name="l187" href="#l187">187</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l188" href="#l188">188</a><td> * to iterate over.<tr><td><a name="l189" href="#l189">189</a><td> * @param {<tr><td><a name="l190" href="#l190">190</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l191" href="#l191">191</a><td> * The function to call for every element. This function takes 3 arguments<tr><td><a name="l192" href="#l192">192</a><td> * (the element, undefined, and the iterator) and should return a boolean.<tr><td><a name="l193" href="#l193">193</a><td> * If the return value is true the element will be included in the returned<tr><td><a name="l194" href="#l194">194</a><td> * iterator. If it is false the element is not included.<tr><td><a name="l195" href="#l195">195</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l196" href="#l196">196</a><td> * {@code f}.<tr><td><a name="l197" href="#l197">197</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator in which only elements<tr><td><a name="l198" href="#l198">198</a><td> * that passed the test are present.<tr><td><a name="l199" href="#l199">199</a><td> * @template THIS, VALUE<tr><td><a name="l200" href="#l200">200</a><td> */<tr><td><a name="l201" href="#l201">201</a><td>goog.iter.filter = function(iterable, f, opt_obj) {<tr><td><a name="l202" href="#l202">202</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l203" href="#l203">203</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l204" href="#l204">204</a><td> newIter.next = function() {<tr><td><a name="l205" href="#l205">205</a><td> while (true) {<tr><td><a name="l206" href="#l206">206</a><td> var val = iterator.next();<tr><td><a name="l207" href="#l207">207</a><td> if (f.call(opt_obj, val, undefined, iterator)) {<tr><td><a name="l208" href="#l208">208</a><td> return val;<tr><td><a name="l209" href="#l209">209</a><td> }<tr><td><a name="l210" href="#l210">210</a><td> }<tr><td><a name="l211" href="#l211">211</a><td> };<tr><td><a name="l212" href="#l212">212</a><td> return newIter;<tr><td><a name="l213" href="#l213">213</a><td>};<tr><td><a name="l214" href="#l214">214</a><td><tr><td><a name="l215" href="#l215">215</a><td><tr><td><a name="l216" href="#l216">216</a><td>/**<tr><td><a name="l217" href="#l217">217</a><td> * Calls a function for every element in the iterator, and if the function<tr><td><a name="l218" href="#l218">218</a><td> * returns false adds the element to a new iterator.<tr><td><a name="l219" href="#l219">219</a><td> *<tr><td><a name="l220" href="#l220">220</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l221" href="#l221">221</a><td> * to iterate over.<tr><td><a name="l222" href="#l222">222</a><td> * @param {<tr><td><a name="l223" href="#l223">223</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l224" href="#l224">224</a><td> * The function to call for every element. This function takes 3 arguments<tr><td><a name="l225" href="#l225">225</a><td> * (the element, undefined, and the iterator) and should return a boolean.<tr><td><a name="l226" href="#l226">226</a><td> * If the return value is false the element will be included in the returned<tr><td><a name="l227" href="#l227">227</a><td> * iterator. If it is true the element is not included.<tr><td><a name="l228" href="#l228">228</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l229" href="#l229">229</a><td> * {@code f}.<tr><td><a name="l230" href="#l230">230</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator in which only elements<tr><td><a name="l231" href="#l231">231</a><td> * that did not pass the test are present.<tr><td><a name="l232" href="#l232">232</a><td> * @template THIS, VALUE<tr><td><a name="l233" href="#l233">233</a><td> */<tr><td><a name="l234" href="#l234">234</a><td>goog.iter.filterFalse = function(iterable, f, opt_obj) {<tr><td><a name="l235" href="#l235">235</a><td> return goog.iter.filter(iterable, goog.functions.not(f), opt_obj);<tr><td><a name="l236" href="#l236">236</a><td>};<tr><td><a name="l237" href="#l237">237</a><td><tr><td><a name="l238" href="#l238">238</a><td><tr><td><a name="l239" href="#l239">239</a><td>/**<tr><td><a name="l240" href="#l240">240</a><td> * Creates a new iterator that returns the values in a range. This function<tr><td><a name="l241" href="#l241">241</a><td> * can take 1, 2 or 3 arguments:<tr><td><a name="l242" href="#l242">242</a><td> * <pre><tr><td><a name="l243" href="#l243">243</a><td> * range(5) same as range(0, 5, 1)<tr><td><a name="l244" href="#l244">244</a><td> * range(2, 5) same as range(2, 5, 1)<tr><td><a name="l245" href="#l245">245</a><td> * </pre><tr><td><a name="l246" href="#l246">246</a><td> *<tr><td><a name="l247" href="#l247">247</a><td> * @param {number} startOrStop The stop value if only one argument is provided.<tr><td><a name="l248" href="#l248">248</a><td> * The start value if 2 or more arguments are provided. If only one<tr><td><a name="l249" href="#l249">249</a><td> * argument is used the start value is 0.<tr><td><a name="l250" href="#l250">250</a><td> * @param {number=} opt_stop The stop value. If left out then the first<tr><td><a name="l251" href="#l251">251</a><td> * argument is used as the stop value.<tr><td><a name="l252" href="#l252">252</a><td> * @param {number=} opt_step The number to increment with between each call to<tr><td><a name="l253" href="#l253">253</a><td> * next. This can be negative.<tr><td><a name="l254" href="#l254">254</a><td> * @return {!goog.iter.Iterator.<number>} A new iterator that returns the values<tr><td><a name="l255" href="#l255">255</a><td> * in the range.<tr><td><a name="l256" href="#l256">256</a><td> */<tr><td><a name="l257" href="#l257">257</a><td>goog.iter.range = function(startOrStop, opt_stop, opt_step) {<tr><td><a name="l258" href="#l258">258</a><td> var start = 0;<tr><td><a name="l259" href="#l259">259</a><td> var stop = startOrStop;<tr><td><a name="l260" href="#l260">260</a><td> var step = opt_step || 1;<tr><td><a name="l261" href="#l261">261</a><td> if (arguments.length > 1) {<tr><td><a name="l262" href="#l262">262</a><td> start = startOrStop;<tr><td><a name="l263" href="#l263">263</a><td> stop = opt_stop;<tr><td><a name="l264" href="#l264">264</a><td> }<tr><td><a name="l265" href="#l265">265</a><td> if (step == 0) {<tr><td><a name="l266" href="#l266">266</a><td> throw Error('Range step argument must not be zero');<tr><td><a name="l267" href="#l267">267</a><td> }<tr><td><a name="l268" href="#l268">268</a><td><tr><td><a name="l269" href="#l269">269</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l270" href="#l270">270</a><td> newIter.next = function() {<tr><td><a name="l271" href="#l271">271</a><td> if (step > 0 && start >= stop || step < 0 && start <= stop) {<tr><td><a name="l272" href="#l272">272</a><td> throw goog.iter.StopIteration;<tr><td><a name="l273" href="#l273">273</a><td> }<tr><td><a name="l274" href="#l274">274</a><td> var rv = start;<tr><td><a name="l275" href="#l275">275</a><td> start += step;<tr><td><a name="l276" href="#l276">276</a><td> return rv;<tr><td><a name="l277" href="#l277">277</a><td> };<tr><td><a name="l278" href="#l278">278</a><td> return newIter;<tr><td><a name="l279" href="#l279">279</a><td>};<tr><td><a name="l280" href="#l280">280</a><td><tr><td><a name="l281" href="#l281">281</a><td><tr><td><a name="l282" href="#l282">282</a><td>/**<tr><td><a name="l283" href="#l283">283</a><td> * Joins the values in a iterator with a delimiter.<tr><td><a name="l284" href="#l284">284</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l285" href="#l285">285</a><td> * to get the values from.<tr><td><a name="l286" href="#l286">286</a><td> * @param {string} deliminator The text to put between the values.<tr><td><a name="l287" href="#l287">287</a><td> * @return {string} The joined value string.<tr><td><a name="l288" href="#l288">288</a><td> * @template VALUE<tr><td><a name="l289" href="#l289">289</a><td> */<tr><td><a name="l290" href="#l290">290</a><td>goog.iter.join = function(iterable, deliminator) {<tr><td><a name="l291" href="#l291">291</a><td> return goog.iter.toArray(iterable).join(deliminator);<tr><td><a name="l292" href="#l292">292</a><td>};<tr><td><a name="l293" href="#l293">293</a><td><tr><td><a name="l294" href="#l294">294</a><td><tr><td><a name="l295" href="#l295">295</a><td>/**<tr><td><a name="l296" href="#l296">296</a><td> * For every element in the iterator call a function and return a new iterator<tr><td><a name="l297" href="#l297">297</a><td> * with that value.<tr><td><a name="l298" href="#l298">298</a><td> *<tr><td><a name="l299" href="#l299">299</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l300" href="#l300">300</a><td> * iterator to iterate over.<tr><td><a name="l301" href="#l301">301</a><td> * @param {<tr><td><a name="l302" href="#l302">302</a><td> * function(this:THIS,VALUE,undefined,!goog.iter.Iterator.<VALUE>):RESULT} f<tr><td><a name="l303" href="#l303">303</a><td> * The function to call for every element. This function takes 3 arguments<tr><td><a name="l304" href="#l304">304</a><td> * (the element, undefined, and the iterator) and should return a new value.<tr><td><a name="l305" href="#l305">305</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l306" href="#l306">306</a><td> * {@code f}.<tr><td><a name="l307" href="#l307">307</a><td> * @return {!goog.iter.Iterator.<RESULT>} A new iterator that returns the<tr><td><a name="l308" href="#l308">308</a><td> * results of applying the function to each element in the original<tr><td><a name="l309" href="#l309">309</a><td> * iterator.<tr><td><a name="l310" href="#l310">310</a><td> * @template THIS, VALUE, RESULT<tr><td><a name="l311" href="#l311">311</a><td> */<tr><td><a name="l312" href="#l312">312</a><td>goog.iter.map = function(iterable, f, opt_obj) {<tr><td><a name="l313" href="#l313">313</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l314" href="#l314">314</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l315" href="#l315">315</a><td> newIter.next = function() {<tr><td><a name="l316" href="#l316">316</a><td> var val = iterator.next();<tr><td><a name="l317" href="#l317">317</a><td> return f.call(opt_obj, val, undefined, iterator);<tr><td><a name="l318" href="#l318">318</a><td> };<tr><td><a name="l319" href="#l319">319</a><td> return newIter;<tr><td><a name="l320" href="#l320">320</a><td>};<tr><td><a name="l321" href="#l321">321</a><td><tr><td><a name="l322" href="#l322">322</a><td><tr><td><a name="l323" href="#l323">323</a><td>/**<tr><td><a name="l324" href="#l324">324</a><td> * Passes every element of an iterator into a function and accumulates the<tr><td><a name="l325" href="#l325">325</a><td> * result.<tr><td><a name="l326" href="#l326">326</a><td> *<tr><td><a name="l327" href="#l327">327</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l328" href="#l328">328</a><td> * to iterate over.<tr><td><a name="l329" href="#l329">329</a><td> * @param {function(this:THIS,VALUE,VALUE):VALUE} f The function to call for<tr><td><a name="l330" href="#l330">330</a><td> * every element. This function takes 2 arguments (the function's previous<tr><td><a name="l331" href="#l331">331</a><td> * result or the initial value, and the value of the current element).<tr><td><a name="l332" href="#l332">332</a><td> * function(previousValue, currentElement) : newValue.<tr><td><a name="l333" href="#l333">333</a><td> * @param {VALUE} val The initial value to pass into the function on the first<tr><td><a name="l334" href="#l334">334</a><td> * call.<tr><td><a name="l335" href="#l335">335</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l336" href="#l336">336</a><td> * f.<tr><td><a name="l337" href="#l337">337</a><td> * @return {VALUE} Result of evaluating f repeatedly across the values of<tr><td><a name="l338" href="#l338">338</a><td> * the iterator.<tr><td><a name="l339" href="#l339">339</a><td> * @template THIS, VALUE<tr><td><a name="l340" href="#l340">340</a><td> */<tr><td><a name="l341" href="#l341">341</a><td>goog.iter.reduce = function(iterable, f, val, opt_obj) {<tr><td><a name="l342" href="#l342">342</a><td> var rval = val;<tr><td><a name="l343" href="#l343">343</a><td> goog.iter.forEach(iterable, function(val) {<tr><td><a name="l344" href="#l344">344</a><td> rval = f.call(opt_obj, rval, val);<tr><td><a name="l345" href="#l345">345</a><td> });<tr><td><a name="l346" href="#l346">346</a><td> return rval;<tr><td><a name="l347" href="#l347">347</a><td>};<tr><td><a name="l348" href="#l348">348</a><td><tr><td><a name="l349" href="#l349">349</a><td><tr><td><a name="l350" href="#l350">350</a><td>/**<tr><td><a name="l351" href="#l351">351</a><td> * Goes through the values in the iterator. Calls f for each of these, and if<tr><td><a name="l352" href="#l352">352</a><td> * any of them returns true, this returns true (without checking the rest). If<tr><td><a name="l353" href="#l353">353</a><td> * all return false this will return false.<tr><td><a name="l354" href="#l354">354</a><td> *<tr><td><a name="l355" href="#l355">355</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l356" href="#l356">356</a><td> * object.<tr><td><a name="l357" href="#l357">357</a><td> * @param {<tr><td><a name="l358" href="#l358">358</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l359" href="#l359">359</a><td> * The function to call for every value. This function takes 3 arguments<tr><td><a name="l360" href="#l360">360</a><td> * (the value, undefined, and the iterator) and should return a boolean.<tr><td><a name="l361" href="#l361">361</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l362" href="#l362">362</a><td> * {@code f}.<tr><td><a name="l363" href="#l363">363</a><td> * @return {boolean} true if any value passes the test.<tr><td><a name="l364" href="#l364">364</a><td> * @template THIS, VALUE<tr><td><a name="l365" href="#l365">365</a><td> */<tr><td><a name="l366" href="#l366">366</a><td>goog.iter.some = function(iterable, f, opt_obj) {<tr><td><a name="l367" href="#l367">367</a><td> iterable = goog.iter.toIterator(iterable);<tr><td><a name="l368" href="#l368">368</a><td> /** @preserveTry */<tr><td><a name="l369" href="#l369">369</a><td> try {<tr><td><a name="l370" href="#l370">370</a><td> while (true) {<tr><td><a name="l371" href="#l371">371</a><td> if (f.call(opt_obj, iterable.next(), undefined, iterable)) {<tr><td><a name="l372" href="#l372">372</a><td> return true;<tr><td><a name="l373" href="#l373">373</a><td> }<tr><td><a name="l374" href="#l374">374</a><td> }<tr><td><a name="l375" href="#l375">375</a><td> } catch (ex) {<tr><td><a name="l376" href="#l376">376</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l377" href="#l377">377</a><td> throw ex;<tr><td><a name="l378" href="#l378">378</a><td> }<tr><td><a name="l379" href="#l379">379</a><td> }<tr><td><a name="l380" href="#l380">380</a><td> return false;<tr><td><a name="l381" href="#l381">381</a><td>};<tr><td><a name="l382" href="#l382">382</a><td><tr><td><a name="l383" href="#l383">383</a><td><tr><td><a name="l384" href="#l384">384</a><td>/**<tr><td><a name="l385" href="#l385">385</a><td> * Goes through the values in the iterator. Calls f for each of these and if any<tr><td><a name="l386" href="#l386">386</a><td> * of them returns false this returns false (without checking the rest). If all<tr><td><a name="l387" href="#l387">387</a><td> * return true this will return true.<tr><td><a name="l388" href="#l388">388</a><td> *<tr><td><a name="l389" href="#l389">389</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l390" href="#l390">390</a><td> * object.<tr><td><a name="l391" href="#l391">391</a><td> * @param {<tr><td><a name="l392" href="#l392">392</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l393" href="#l393">393</a><td> * The function to call for every value. This function takes 3 arguments<tr><td><a name="l394" href="#l394">394</a><td> * (the value, undefined, and the iterator) and should return a boolean.<tr><td><a name="l395" href="#l395">395</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l396" href="#l396">396</a><td> * {@code f}.<tr><td><a name="l397" href="#l397">397</a><td> * @return {boolean} true if every value passes the test.<tr><td><a name="l398" href="#l398">398</a><td> * @template THIS, VALUE<tr><td><a name="l399" href="#l399">399</a><td> */<tr><td><a name="l400" href="#l400">400</a><td>goog.iter.every = function(iterable, f, opt_obj) {<tr><td><a name="l401" href="#l401">401</a><td> iterable = goog.iter.toIterator(iterable);<tr><td><a name="l402" href="#l402">402</a><td> /** @preserveTry */<tr><td><a name="l403" href="#l403">403</a><td> try {<tr><td><a name="l404" href="#l404">404</a><td> while (true) {<tr><td><a name="l405" href="#l405">405</a><td> if (!f.call(opt_obj, iterable.next(), undefined, iterable)) {<tr><td><a name="l406" href="#l406">406</a><td> return false;<tr><td><a name="l407" href="#l407">407</a><td> }<tr><td><a name="l408" href="#l408">408</a><td> }<tr><td><a name="l409" href="#l409">409</a><td> } catch (ex) {<tr><td><a name="l410" href="#l410">410</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l411" href="#l411">411</a><td> throw ex;<tr><td><a name="l412" href="#l412">412</a><td> }<tr><td><a name="l413" href="#l413">413</a><td> }<tr><td><a name="l414" href="#l414">414</a><td> return true;<tr><td><a name="l415" href="#l415">415</a><td>};<tr><td><a name="l416" href="#l416">416</a><td><tr><td><a name="l417" href="#l417">417</a><td><tr><td><a name="l418" href="#l418">418</a><td>/**<tr><td><a name="l419" href="#l419">419</a><td> * Takes zero or more iterables and returns one iterator that will iterate over<tr><td><a name="l420" href="#l420">420</a><td> * them in the order chained.<tr><td><a name="l421" href="#l421">421</a><td> * @param {...!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} var_args Any<tr><td><a name="l422" href="#l422">422</a><td> * number of iterable objects.<tr><td><a name="l423" href="#l423">423</a><td> * @return {!goog.iter.Iterator.<VALUE>} Returns a new iterator that will<tr><td><a name="l424" href="#l424">424</a><td> * iterate over all the given iterables' contents.<tr><td><a name="l425" href="#l425">425</a><td> * @template VALUE<tr><td><a name="l426" href="#l426">426</a><td> */<tr><td><a name="l427" href="#l427">427</a><td>goog.iter.chain = function(var_args) {<tr><td><a name="l428" href="#l428">428</a><td> var iterator = goog.iter.toIterator(arguments);<tr><td><a name="l429" href="#l429">429</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l430" href="#l430">430</a><td> var current = null;<tr><td><a name="l431" href="#l431">431</a><td><tr><td><a name="l432" href="#l432">432</a><td> iter.next = function() {<tr><td><a name="l433" href="#l433">433</a><td> while (true) {<tr><td><a name="l434" href="#l434">434</a><td> if (current == null) {<tr><td><a name="l435" href="#l435">435</a><td> var it = iterator.next();<tr><td><a name="l436" href="#l436">436</a><td> current = goog.iter.toIterator(it);<tr><td><a name="l437" href="#l437">437</a><td> }<tr><td><a name="l438" href="#l438">438</a><td> try {<tr><td><a name="l439" href="#l439">439</a><td> return current.next();<tr><td><a name="l440" href="#l440">440</a><td> } catch (ex) {<tr><td><a name="l441" href="#l441">441</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l442" href="#l442">442</a><td> throw ex;<tr><td><a name="l443" href="#l443">443</a><td> }<tr><td><a name="l444" href="#l444">444</a><td> current = null;<tr><td><a name="l445" href="#l445">445</a><td> }<tr><td><a name="l446" href="#l446">446</a><td> }<tr><td><a name="l447" href="#l447">447</a><td> };<tr><td><a name="l448" href="#l448">448</a><td><tr><td><a name="l449" href="#l449">449</a><td> return iter;<tr><td><a name="l450" href="#l450">450</a><td>};<tr><td><a name="l451" href="#l451">451</a><td><tr><td><a name="l452" href="#l452">452</a><td><tr><td><a name="l453" href="#l453">453</a><td>/**<tr><td><a name="l454" href="#l454">454</a><td> * Takes a single iterable containing zero or more iterables and returns one<tr><td><a name="l455" href="#l455">455</a><td> * iterator that will iterate over each one in the order given.<tr><td><a name="l456" href="#l456">456</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.chain.from_iterable<tr><td><a name="l457" href="#l457">457</a><td> * @param {goog.iter.Iterable} iterable The iterable of iterables to chain.<tr><td><a name="l458" href="#l458">458</a><td> * @return {!goog.iter.Iterator.<VALUE>} Returns a new iterator that will<tr><td><a name="l459" href="#l459">459</a><td> * iterate over all the contents of the iterables contained within<tr><td><a name="l460" href="#l460">460</a><td> * {@code iterable}.<tr><td><a name="l461" href="#l461">461</a><td> * @template VALUE<tr><td><a name="l462" href="#l462">462</a><td> */<tr><td><a name="l463" href="#l463">463</a><td>goog.iter.chainFromIterable = function(iterable) {<tr><td><a name="l464" href="#l464">464</a><td> return goog.iter.chain.apply(undefined, iterable);<tr><td><a name="l465" href="#l465">465</a><td>};<tr><td><a name="l466" href="#l466">466</a><td><tr><td><a name="l467" href="#l467">467</a><td><tr><td><a name="l468" href="#l468">468</a><td>/**<tr><td><a name="l469" href="#l469">469</a><td> * Builds a new iterator that iterates over the original, but skips elements as<tr><td><a name="l470" href="#l470">470</a><td> * long as a supplied function returns true.<tr><td><a name="l471" href="#l471">471</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l472" href="#l472">472</a><td> * object.<tr><td><a name="l473" href="#l473">473</a><td> * @param {<tr><td><a name="l474" href="#l474">474</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l475" href="#l475">475</a><td> * The function to call for every value. This function takes 3 arguments<tr><td><a name="l476" href="#l476">476</a><td> * (the value, undefined, and the iterator) and should return a boolean.<tr><td><a name="l477" href="#l477">477</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l478" href="#l478">478</a><td> * {@code f}.<tr><td><a name="l479" href="#l479">479</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator that drops elements from<tr><td><a name="l480" href="#l480">480</a><td> * the original iterator as long as {@code f} is true.<tr><td><a name="l481" href="#l481">481</a><td> * @template THIS, VALUE<tr><td><a name="l482" href="#l482">482</a><td> */<tr><td><a name="l483" href="#l483">483</a><td>goog.iter.dropWhile = function(iterable, f, opt_obj) {<tr><td><a name="l484" href="#l484">484</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l485" href="#l485">485</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l486" href="#l486">486</a><td> var dropping = true;<tr><td><a name="l487" href="#l487">487</a><td> newIter.next = function() {<tr><td><a name="l488" href="#l488">488</a><td> while (true) {<tr><td><a name="l489" href="#l489">489</a><td> var val = iterator.next();<tr><td><a name="l490" href="#l490">490</a><td> if (dropping && f.call(opt_obj, val, undefined, iterator)) {<tr><td><a name="l491" href="#l491">491</a><td> continue;<tr><td><a name="l492" href="#l492">492</a><td> } else {<tr><td><a name="l493" href="#l493">493</a><td> dropping = false;<tr><td><a name="l494" href="#l494">494</a><td> }<tr><td><a name="l495" href="#l495">495</a><td> return val;<tr><td><a name="l496" href="#l496">496</a><td> }<tr><td><a name="l497" href="#l497">497</a><td> };<tr><td><a name="l498" href="#l498">498</a><td> return newIter;<tr><td><a name="l499" href="#l499">499</a><td>};<tr><td><a name="l500" href="#l500">500</a><td><tr><td><a name="l501" href="#l501">501</a><td><tr><td><a name="l502" href="#l502">502</a><td>/**<tr><td><a name="l503" href="#l503">503</a><td> * Builds a new iterator that iterates over the original, but only as long as a<tr><td><a name="l504" href="#l504">504</a><td> * supplied function returns true.<tr><td><a name="l505" href="#l505">505</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l506" href="#l506">506</a><td> * object.<tr><td><a name="l507" href="#l507">507</a><td> * @param {<tr><td><a name="l508" href="#l508">508</a><td> * function(this:THIS,VALUE,undefined,goog.iter.Iterator.<VALUE>):boolean} f<tr><td><a name="l509" href="#l509">509</a><td> * The function to call for every value. This function takes 3 arguments<tr><td><a name="l510" href="#l510">510</a><td> * (the value, undefined, and the iterator) and should return a boolean.<tr><td><a name="l511" href="#l511">511</a><td> * @param {THIS=} opt_obj This is used as the 'this' object in f when called.<tr><td><a name="l512" href="#l512">512</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator that keeps elements in<tr><td><a name="l513" href="#l513">513</a><td> * the original iterator as long as the function is true.<tr><td><a name="l514" href="#l514">514</a><td> * @template THIS, VALUE<tr><td><a name="l515" href="#l515">515</a><td> */<tr><td><a name="l516" href="#l516">516</a><td>goog.iter.takeWhile = function(iterable, f, opt_obj) {<tr><td><a name="l517" href="#l517">517</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l518" href="#l518">518</a><td> var newIter = new goog.iter.Iterator;<tr><td><a name="l519" href="#l519">519</a><td> var taking = true;<tr><td><a name="l520" href="#l520">520</a><td> newIter.next = function() {<tr><td><a name="l521" href="#l521">521</a><td> while (true) {<tr><td><a name="l522" href="#l522">522</a><td> if (taking) {<tr><td><a name="l523" href="#l523">523</a><td> var val = iterator.next();<tr><td><a name="l524" href="#l524">524</a><td> if (f.call(opt_obj, val, undefined, iterator)) {<tr><td><a name="l525" href="#l525">525</a><td> return val;<tr><td><a name="l526" href="#l526">526</a><td> } else {<tr><td><a name="l527" href="#l527">527</a><td> taking = false;<tr><td><a name="l528" href="#l528">528</a><td> }<tr><td><a name="l529" href="#l529">529</a><td> } else {<tr><td><a name="l530" href="#l530">530</a><td> throw goog.iter.StopIteration;<tr><td><a name="l531" href="#l531">531</a><td> }<tr><td><a name="l532" href="#l532">532</a><td> }<tr><td><a name="l533" href="#l533">533</a><td> };<tr><td><a name="l534" href="#l534">534</a><td> return newIter;<tr><td><a name="l535" href="#l535">535</a><td>};<tr><td><a name="l536" href="#l536">536</a><td><tr><td><a name="l537" href="#l537">537</a><td><tr><td><a name="l538" href="#l538">538</a><td>/**<tr><td><a name="l539" href="#l539">539</a><td> * Converts the iterator to an array<tr><td><a name="l540" href="#l540">540</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterator<tr><td><a name="l541" href="#l541">541</a><td> * to convert to an array.<tr><td><a name="l542" href="#l542">542</a><td> * @return {!Array.<VALUE>} An array of the elements the iterator iterates over.<tr><td><a name="l543" href="#l543">543</a><td> * @template VALUE<tr><td><a name="l544" href="#l544">544</a><td> */<tr><td><a name="l545" href="#l545">545</a><td>goog.iter.toArray = function(iterable) {<tr><td><a name="l546" href="#l546">546</a><td> // Fast path for array-like.<tr><td><a name="l547" href="#l547">547</a><td> if (goog.isArrayLike(iterable)) {<tr><td><a name="l548" href="#l548">548</a><td> return goog.array.toArray(/** @type {!goog.array.ArrayLike} */(iterable));<tr><td><a name="l549" href="#l549">549</a><td> }<tr><td><a name="l550" href="#l550">550</a><td> iterable = goog.iter.toIterator(iterable);<tr><td><a name="l551" href="#l551">551</a><td> var array = [];<tr><td><a name="l552" href="#l552">552</a><td> goog.iter.forEach(iterable, function(val) {<tr><td><a name="l553" href="#l553">553</a><td> array.push(val);<tr><td><a name="l554" href="#l554">554</a><td> });<tr><td><a name="l555" href="#l555">555</a><td> return array;<tr><td><a name="l556" href="#l556">556</a><td>};<tr><td><a name="l557" href="#l557">557</a><td><tr><td><a name="l558" href="#l558">558</a><td><tr><td><a name="l559" href="#l559">559</a><td>/**<tr><td><a name="l560" href="#l560">560</a><td> * Iterates over two iterables and returns true if they contain the same<tr><td><a name="l561" href="#l561">561</a><td> * sequence of elements and have the same length.<tr><td><a name="l562" href="#l562">562</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable1 The first<tr><td><a name="l563" href="#l563">563</a><td> * iterable object.<tr><td><a name="l564" href="#l564">564</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable2 The second<tr><td><a name="l565" href="#l565">565</a><td> * iterable object.<tr><td><a name="l566" href="#l566">566</a><td> * @return {boolean} true if the iterables contain the same sequence of elements<tr><td><a name="l567" href="#l567">567</a><td> * and have the same length.<tr><td><a name="l568" href="#l568">568</a><td> * @template VALUE<tr><td><a name="l569" href="#l569">569</a><td> */<tr><td><a name="l570" href="#l570">570</a><td>goog.iter.equals = function(iterable1, iterable2) {<tr><td><a name="l571" href="#l571">571</a><td> var fillValue = {};<tr><td><a name="l572" href="#l572">572</a><td> var pairs = goog.iter.zipLongest(fillValue, iterable1, iterable2);<tr><td><a name="l573" href="#l573">573</a><td> return goog.iter.every(pairs, function(pair) {<tr><td><a name="l574" href="#l574">574</a><td> return pair[0] == pair[1];<tr><td><a name="l575" href="#l575">575</a><td> });<tr><td><a name="l576" href="#l576">576</a><td>};<tr><td><a name="l577" href="#l577">577</a><td><tr><td><a name="l578" href="#l578">578</a><td><tr><td><a name="l579" href="#l579">579</a><td>/**<tr><td><a name="l580" href="#l580">580</a><td> * Advances the iterator to the next position, returning the given default value<tr><td><a name="l581" href="#l581">581</a><td> * instead of throwing an exception if the iterator has no more entries.<tr><td><a name="l582" href="#l582">582</a><td> * @param {goog.iter.Iterator.<VALUE>|goog.iter.Iterable} iterable The iterable<tr><td><a name="l583" href="#l583">583</a><td> * object.<tr><td><a name="l584" href="#l584">584</a><td> * @param {VALUE} defaultValue The value to return if the iterator is empty.<tr><td><a name="l585" href="#l585">585</a><td> * @return {VALUE} The next item in the iteration, or defaultValue if the<tr><td><a name="l586" href="#l586">586</a><td> * iterator was empty.<tr><td><a name="l587" href="#l587">587</a><td> * @template VALUE<tr><td><a name="l588" href="#l588">588</a><td> */<tr><td><a name="l589" href="#l589">589</a><td>goog.iter.nextOrValue = function(iterable, defaultValue) {<tr><td><a name="l590" href="#l590">590</a><td> try {<tr><td><a name="l591" href="#l591">591</a><td> return goog.iter.toIterator(iterable).next();<tr><td><a name="l592" href="#l592">592</a><td> } catch (e) {<tr><td><a name="l593" href="#l593">593</a><td> if (e != goog.iter.StopIteration) {<tr><td><a name="l594" href="#l594">594</a><td> throw e;<tr><td><a name="l595" href="#l595">595</a><td> }<tr><td><a name="l596" href="#l596">596</a><td> return defaultValue;<tr><td><a name="l597" href="#l597">597</a><td> }<tr><td><a name="l598" href="#l598">598</a><td>};<tr><td><a name="l599" href="#l599">599</a><td><tr><td><a name="l600" href="#l600">600</a><td><tr><td><a name="l601" href="#l601">601</a><td>/**<tr><td><a name="l602" href="#l602">602</a><td> * Cartesian product of zero or more sets. Gives an iterator that gives every<tr><td><a name="l603" href="#l603">603</a><td> * combination of one element chosen from each set. For example,<tr><td><a name="l604" href="#l604">604</a><td> * ([1, 2], [3, 4]) gives ([1, 3], [1, 4], [2, 3], [2, 4]).<tr><td><a name="l605" href="#l605">605</a><td> * @see http://docs.python.org/library/itertools.html#itertools.product<tr><td><a name="l606" href="#l606">606</a><td> * @param {...!goog.array.ArrayLike.<VALUE>} var_args Zero or more sets, as<tr><td><a name="l607" href="#l607">607</a><td> * arrays.<tr><td><a name="l608" href="#l608">608</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} An iterator that gives each<tr><td><a name="l609" href="#l609">609</a><td> * n-tuple (as an array).<tr><td><a name="l610" href="#l610">610</a><td> * @template VALUE<tr><td><a name="l611" href="#l611">611</a><td> */<tr><td><a name="l612" href="#l612">612</a><td>goog.iter.product = function(var_args) {<tr><td><a name="l613" href="#l613">613</a><td> var someArrayEmpty = goog.array.some(arguments, function(arr) {<tr><td><a name="l614" href="#l614">614</a><td> return !arr.length;<tr><td><a name="l615" href="#l615">615</a><td> });<tr><td><a name="l616" href="#l616">616</a><td><tr><td><a name="l617" href="#l617">617</a><td> // An empty set in a cartesian product gives an empty set.<tr><td><a name="l618" href="#l618">618</a><td> if (someArrayEmpty || !arguments.length) {<tr><td><a name="l619" href="#l619">619</a><td> return new goog.iter.Iterator();<tr><td><a name="l620" href="#l620">620</a><td> }<tr><td><a name="l621" href="#l621">621</a><td><tr><td><a name="l622" href="#l622">622</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l623" href="#l623">623</a><td> var arrays = arguments;<tr><td><a name="l624" href="#l624">624</a><td><tr><td><a name="l625" href="#l625">625</a><td> // The first indices are [0, 0, ...]<tr><td><a name="l626" href="#l626">626</a><td> var indicies = goog.array.repeat(0, arrays.length);<tr><td><a name="l627" href="#l627">627</a><td><tr><td><a name="l628" href="#l628">628</a><td> iter.next = function() {<tr><td><a name="l629" href="#l629">629</a><td><tr><td><a name="l630" href="#l630">630</a><td> if (indicies) {<tr><td><a name="l631" href="#l631">631</a><td> var retVal = goog.array.map(indicies, function(valueIndex, arrayIndex) {<tr><td><a name="l632" href="#l632">632</a><td> return arrays[arrayIndex][valueIndex];<tr><td><a name="l633" href="#l633">633</a><td> });<tr><td><a name="l634" href="#l634">634</a><td><tr><td><a name="l635" href="#l635">635</a><td> // Generate the next-largest indices for the next call.<tr><td><a name="l636" href="#l636">636</a><td> // Increase the rightmost index. If it goes over, increase the next<tr><td><a name="l637" href="#l637">637</a><td> // rightmost (like carry-over addition).<tr><td><a name="l638" href="#l638">638</a><td> for (var i = indicies.length - 1; i >= 0; i--) {<tr><td><a name="l639" href="#l639">639</a><td> // Assertion prevents compiler warning below.<tr><td><a name="l640" href="#l640">640</a><td> goog.asserts.assert(indicies);<tr><td><a name="l641" href="#l641">641</a><td> if (indicies[i] < arrays[i].length - 1) {<tr><td><a name="l642" href="#l642">642</a><td> indicies[i]++;<tr><td><a name="l643" href="#l643">643</a><td> break;<tr><td><a name="l644" href="#l644">644</a><td> }<tr><td><a name="l645" href="#l645">645</a><td><tr><td><a name="l646" href="#l646">646</a><td> // We're at the last indices (the last element of every array), so<tr><td><a name="l647" href="#l647">647</a><td> // the iteration is over on the next call.<tr><td><a name="l648" href="#l648">648</a><td> if (i == 0) {<tr><td><a name="l649" href="#l649">649</a><td> indicies = null;<tr><td><a name="l650" href="#l650">650</a><td> break;<tr><td><a name="l651" href="#l651">651</a><td> }<tr><td><a name="l652" href="#l652">652</a><td> // Reset the index in this column and loop back to increment the<tr><td><a name="l653" href="#l653">653</a><td> // next one.<tr><td><a name="l654" href="#l654">654</a><td> indicies[i] = 0;<tr><td><a name="l655" href="#l655">655</a><td> }<tr><td><a name="l656" href="#l656">656</a><td> return retVal;<tr><td><a name="l657" href="#l657">657</a><td> }<tr><td><a name="l658" href="#l658">658</a><td><tr><td><a name="l659" href="#l659">659</a><td> throw goog.iter.StopIteration;<tr><td><a name="l660" href="#l660">660</a><td> };<tr><td><a name="l661" href="#l661">661</a><td><tr><td><a name="l662" href="#l662">662</a><td> return iter;<tr><td><a name="l663" href="#l663">663</a><td>};<tr><td><a name="l664" href="#l664">664</a><td><tr><td><a name="l665" href="#l665">665</a><td><tr><td><a name="l666" href="#l666">666</a><td>/**<tr><td><a name="l667" href="#l667">667</a><td> * Create an iterator to cycle over the iterable's elements indefinitely.<tr><td><a name="l668" href="#l668">668</a><td> * For example, ([1, 2, 3]) would return : 1, 2, 3, 1, 2, 3, ...<tr><td><a name="l669" href="#l669">669</a><td> * @see: http://docs.python.org/library/itertools.html#itertools.cycle.<tr><td><a name="l670" href="#l670">670</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l671" href="#l671">671</a><td> * iterable object.<tr><td><a name="l672" href="#l672">672</a><td> * @return {!goog.iter.Iterator.<VALUE>} An iterator that iterates indefinitely<tr><td><a name="l673" href="#l673">673</a><td> * over the values in {@code iterable}.<tr><td><a name="l674" href="#l674">674</a><td> * @template VALUE<tr><td><a name="l675" href="#l675">675</a><td> */<tr><td><a name="l676" href="#l676">676</a><td>goog.iter.cycle = function(iterable) {<tr><td><a name="l677" href="#l677">677</a><td> var baseIterator = goog.iter.toIterator(iterable);<tr><td><a name="l678" href="#l678">678</a><td><tr><td><a name="l679" href="#l679">679</a><td> // We maintain a cache to store the iterable elements as we iterate<tr><td><a name="l680" href="#l680">680</a><td> // over them. The cache is used to return elements once we have<tr><td><a name="l681" href="#l681">681</a><td> // iterated over the iterable once.<tr><td><a name="l682" href="#l682">682</a><td> var cache = [];<tr><td><a name="l683" href="#l683">683</a><td> var cacheIndex = 0;<tr><td><a name="l684" href="#l684">684</a><td><tr><td><a name="l685" href="#l685">685</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l686" href="#l686">686</a><td><tr><td><a name="l687" href="#l687">687</a><td> // This flag is set after the iterable is iterated over once<tr><td><a name="l688" href="#l688">688</a><td> var useCache = false;<tr><td><a name="l689" href="#l689">689</a><td><tr><td><a name="l690" href="#l690">690</a><td> iter.next = function() {<tr><td><a name="l691" href="#l691">691</a><td> var returnElement = null;<tr><td><a name="l692" href="#l692">692</a><td><tr><td><a name="l693" href="#l693">693</a><td> // Pull elements off the original iterator if not using cache<tr><td><a name="l694" href="#l694">694</a><td> if (!useCache) {<tr><td><a name="l695" href="#l695">695</a><td> try {<tr><td><a name="l696" href="#l696">696</a><td> // Return the element from the iterable<tr><td><a name="l697" href="#l697">697</a><td> returnElement = baseIterator.next();<tr><td><a name="l698" href="#l698">698</a><td> cache.push(returnElement);<tr><td><a name="l699" href="#l699">699</a><td> return returnElement;<tr><td><a name="l700" href="#l700">700</a><td> } catch (e) {<tr><td><a name="l701" href="#l701">701</a><td> // If an exception other than StopIteration is thrown<tr><td><a name="l702" href="#l702">702</a><td> // or if there are no elements to iterate over (the iterable was empty)<tr><td><a name="l703" href="#l703">703</a><td> // throw an exception<tr><td><a name="l704" href="#l704">704</a><td> if (e != goog.iter.StopIteration || goog.array.isEmpty(cache)) {<tr><td><a name="l705" href="#l705">705</a><td> throw e;<tr><td><a name="l706" href="#l706">706</a><td> }<tr><td><a name="l707" href="#l707">707</a><td> // set useCache to true after we know that a 'StopIteration' exception<tr><td><a name="l708" href="#l708">708</a><td> // was thrown and the cache is not empty (to handle the 'empty iterable'<tr><td><a name="l709" href="#l709">709</a><td> // use case)<tr><td><a name="l710" href="#l710">710</a><td> useCache = true;<tr><td><a name="l711" href="#l711">711</a><td> }<tr><td><a name="l712" href="#l712">712</a><td> }<tr><td><a name="l713" href="#l713">713</a><td><tr><td><a name="l714" href="#l714">714</a><td> returnElement = cache[cacheIndex];<tr><td><a name="l715" href="#l715">715</a><td> cacheIndex = (cacheIndex + 1) % cache.length;<tr><td><a name="l716" href="#l716">716</a><td><tr><td><a name="l717" href="#l717">717</a><td> return returnElement;<tr><td><a name="l718" href="#l718">718</a><td> };<tr><td><a name="l719" href="#l719">719</a><td><tr><td><a name="l720" href="#l720">720</a><td> return iter;<tr><td><a name="l721" href="#l721">721</a><td>};<tr><td><a name="l722" href="#l722">722</a><td><tr><td><a name="l723" href="#l723">723</a><td><tr><td><a name="l724" href="#l724">724</a><td>/**<tr><td><a name="l725" href="#l725">725</a><td> * Creates an iterator that counts indefinitely from a starting value.<tr><td><a name="l726" href="#l726">726</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.count<tr><td><a name="l727" href="#l727">727</a><td> * @param {number=} opt_start The starting value. Default is 0.<tr><td><a name="l728" href="#l728">728</a><td> * @param {number=} opt_step The number to increment with between each call to<tr><td><a name="l729" href="#l729">729</a><td> * next. Negative and floating point numbers are allowed. Default is 1.<tr><td><a name="l730" href="#l730">730</a><td> * @return {!goog.iter.Iterator.<number>} A new iterator that returns the values<tr><td><a name="l731" href="#l731">731</a><td> * in the series.<tr><td><a name="l732" href="#l732">732</a><td> */<tr><td><a name="l733" href="#l733">733</a><td>goog.iter.count = function(opt_start, opt_step) {<tr><td><a name="l734" href="#l734">734</a><td> var counter = opt_start || 0;<tr><td><a name="l735" href="#l735">735</a><td> var step = goog.isDef(opt_step) ? opt_step : 1;<tr><td><a name="l736" href="#l736">736</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l737" href="#l737">737</a><td><tr><td><a name="l738" href="#l738">738</a><td> iter.next = function() {<tr><td><a name="l739" href="#l739">739</a><td> var returnValue = counter;<tr><td><a name="l740" href="#l740">740</a><td> counter += step;<tr><td><a name="l741" href="#l741">741</a><td> return returnValue;<tr><td><a name="l742" href="#l742">742</a><td> };<tr><td><a name="l743" href="#l743">743</a><td><tr><td><a name="l744" href="#l744">744</a><td> return iter;<tr><td><a name="l745" href="#l745">745</a><td>};<tr><td><a name="l746" href="#l746">746</a><td><tr><td><a name="l747" href="#l747">747</a><td><tr><td><a name="l748" href="#l748">748</a><td>/**<tr><td><a name="l749" href="#l749">749</a><td> * Creates an iterator that returns the same object or value repeatedly.<tr><td><a name="l750" href="#l750">750</a><td> * @param {VALUE} value Any object or value to repeat.<tr><td><a name="l751" href="#l751">751</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator that returns the<tr><td><a name="l752" href="#l752">752</a><td> * repeated value.<tr><td><a name="l753" href="#l753">753</a><td> * @template VALUE<tr><td><a name="l754" href="#l754">754</a><td> */<tr><td><a name="l755" href="#l755">755</a><td>goog.iter.repeat = function(value) {<tr><td><a name="l756" href="#l756">756</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l757" href="#l757">757</a><td><tr><td><a name="l758" href="#l758">758</a><td> iter.next = goog.functions.constant(value);<tr><td><a name="l759" href="#l759">759</a><td><tr><td><a name="l760" href="#l760">760</a><td> return iter;<tr><td><a name="l761" href="#l761">761</a><td>};<tr><td><a name="l762" href="#l762">762</a><td><tr><td><a name="l763" href="#l763">763</a><td><tr><td><a name="l764" href="#l764">764</a><td>/**<tr><td><a name="l765" href="#l765">765</a><td> * Creates an iterator that returns running totals from the numbers in<tr><td><a name="l766" href="#l766">766</a><td> * {@code iterable}. For example, the array {@code [1, 2, 3, 4, 5]} yields<tr><td><a name="l767" href="#l767">767</a><td> * {@code 1 -> 3 -> 6 -> 10 -> 15}.<tr><td><a name="l768" href="#l768">768</a><td> * @see http://docs.python.org/3.2/library/itertools.html#itertools.accumulate<tr><td><a name="l769" href="#l769">769</a><td> * @param {!goog.iter.Iterable.<number>} iterable The iterable of numbers to<tr><td><a name="l770" href="#l770">770</a><td> * accumulate.<tr><td><a name="l771" href="#l771">771</a><td> * @return {!goog.iter.Iterator.<number>} A new iterator that returns the<tr><td><a name="l772" href="#l772">772</a><td> * numbers in the series.<tr><td><a name="l773" href="#l773">773</a><td> */<tr><td><a name="l774" href="#l774">774</a><td>goog.iter.accumulate = function(iterable) {<tr><td><a name="l775" href="#l775">775</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l776" href="#l776">776</a><td> var total = 0;<tr><td><a name="l777" href="#l777">777</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l778" href="#l778">778</a><td><tr><td><a name="l779" href="#l779">779</a><td> iter.next = function() {<tr><td><a name="l780" href="#l780">780</a><td> total += iterator.next();<tr><td><a name="l781" href="#l781">781</a><td> return total;<tr><td><a name="l782" href="#l782">782</a><td> };<tr><td><a name="l783" href="#l783">783</a><td><tr><td><a name="l784" href="#l784">784</a><td> return iter;<tr><td><a name="l785" href="#l785">785</a><td>};<tr><td><a name="l786" href="#l786">786</a><td><tr><td><a name="l787" href="#l787">787</a><td><tr><td><a name="l788" href="#l788">788</a><td>/**<tr><td><a name="l789" href="#l789">789</a><td> * Creates an iterator that returns arrays containing the ith elements from the<tr><td><a name="l790" href="#l790">790</a><td> * provided iterables. The returned arrays will be the same size as the number<tr><td><a name="l791" href="#l791">791</a><td> * of iterables given in {@code var_args}. Once the shortest iterable is<tr><td><a name="l792" href="#l792">792</a><td> * exhausted, subsequent calls to {@code next()} will throw<tr><td><a name="l793" href="#l793">793</a><td> * {@code goog.iter.StopIteration}.<tr><td><a name="l794" href="#l794">794</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.izip<tr><td><a name="l795" href="#l795">795</a><td> * @param {...!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} var_args Any<tr><td><a name="l796" href="#l796">796</a><td> * number of iterable objects.<tr><td><a name="l797" href="#l797">797</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} A new iterator that returns<tr><td><a name="l798" href="#l798">798</a><td> * arrays of elements from the provided iterables.<tr><td><a name="l799" href="#l799">799</a><td> * @template VALUE<tr><td><a name="l800" href="#l800">800</a><td> */<tr><td><a name="l801" href="#l801">801</a><td>goog.iter.zip = function(var_args) {<tr><td><a name="l802" href="#l802">802</a><td> var args = arguments;<tr><td><a name="l803" href="#l803">803</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l804" href="#l804">804</a><td><tr><td><a name="l805" href="#l805">805</a><td> if (args.length > 0) {<tr><td><a name="l806" href="#l806">806</a><td> var iterators = goog.array.map(args, goog.iter.toIterator);<tr><td><a name="l807" href="#l807">807</a><td> iter.next = function() {<tr><td><a name="l808" href="#l808">808</a><td> var arr = goog.array.map(iterators, function(it) {<tr><td><a name="l809" href="#l809">809</a><td> return it.next();<tr><td><a name="l810" href="#l810">810</a><td> });<tr><td><a name="l811" href="#l811">811</a><td> return arr;<tr><td><a name="l812" href="#l812">812</a><td> };<tr><td><a name="l813" href="#l813">813</a><td> }<tr><td><a name="l814" href="#l814">814</a><td><tr><td><a name="l815" href="#l815">815</a><td> return iter;<tr><td><a name="l816" href="#l816">816</a><td>};<tr><td><a name="l817" href="#l817">817</a><td><tr><td><a name="l818" href="#l818">818</a><td><tr><td><a name="l819" href="#l819">819</a><td>/**<tr><td><a name="l820" href="#l820">820</a><td> * Creates an iterator that returns arrays containing the ith elements from the<tr><td><a name="l821" href="#l821">821</a><td> * provided iterables. The returned arrays will be the same size as the number<tr><td><a name="l822" href="#l822">822</a><td> * of iterables given in {@code var_args}. Shorter iterables will be extended<tr><td><a name="l823" href="#l823">823</a><td> * with {@code fillValue}. Once the longest iterable is exhausted, subsequent<tr><td><a name="l824" href="#l824">824</a><td> * calls to {@code next()} will throw {@code goog.iter.StopIteration}.<tr><td><a name="l825" href="#l825">825</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.izip_longest<tr><td><a name="l826" href="#l826">826</a><td> * @param {VALUE} fillValue The object or value used to fill shorter iterables.<tr><td><a name="l827" href="#l827">827</a><td> * @param {...!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} var_args Any<tr><td><a name="l828" href="#l828">828</a><td> * number of iterable objects.<tr><td><a name="l829" href="#l829">829</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} A new iterator that returns<tr><td><a name="l830" href="#l830">830</a><td> * arrays of elements from the provided iterables.<tr><td><a name="l831" href="#l831">831</a><td> * @template VALUE<tr><td><a name="l832" href="#l832">832</a><td> */<tr><td><a name="l833" href="#l833">833</a><td>goog.iter.zipLongest = function(fillValue, var_args) {<tr><td><a name="l834" href="#l834">834</a><td> var args = goog.array.slice(arguments, 1);<tr><td><a name="l835" href="#l835">835</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l836" href="#l836">836</a><td><tr><td><a name="l837" href="#l837">837</a><td> if (args.length > 0) {<tr><td><a name="l838" href="#l838">838</a><td> var iterators = goog.array.map(args, goog.iter.toIterator);<tr><td><a name="l839" href="#l839">839</a><td><tr><td><a name="l840" href="#l840">840</a><td> iter.next = function() {<tr><td><a name="l841" href="#l841">841</a><td> var iteratorsHaveValues = false; // false when all iterators are empty.<tr><td><a name="l842" href="#l842">842</a><td> var arr = goog.array.map(iterators, function(it) {<tr><td><a name="l843" href="#l843">843</a><td> var returnValue;<tr><td><a name="l844" href="#l844">844</a><td> try {<tr><td><a name="l845" href="#l845">845</a><td> returnValue = it.next();<tr><td><a name="l846" href="#l846">846</a><td> // Iterator had a value, so we've not exhausted the iterators.<tr><td><a name="l847" href="#l847">847</a><td> // Set flag accordingly.<tr><td><a name="l848" href="#l848">848</a><td> iteratorsHaveValues = true;<tr><td><a name="l849" href="#l849">849</a><td> } catch (ex) {<tr><td><a name="l850" href="#l850">850</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l851" href="#l851">851</a><td> throw ex;<tr><td><a name="l852" href="#l852">852</a><td> }<tr><td><a name="l853" href="#l853">853</a><td> returnValue = fillValue;<tr><td><a name="l854" href="#l854">854</a><td> }<tr><td><a name="l855" href="#l855">855</a><td> return returnValue;<tr><td><a name="l856" href="#l856">856</a><td> });<tr><td><a name="l857" href="#l857">857</a><td><tr><td><a name="l858" href="#l858">858</a><td> if (!iteratorsHaveValues) {<tr><td><a name="l859" href="#l859">859</a><td> throw goog.iter.StopIteration;<tr><td><a name="l860" href="#l860">860</a><td> }<tr><td><a name="l861" href="#l861">861</a><td> return arr;<tr><td><a name="l862" href="#l862">862</a><td> };<tr><td><a name="l863" href="#l863">863</a><td> }<tr><td><a name="l864" href="#l864">864</a><td><tr><td><a name="l865" href="#l865">865</a><td> return iter;<tr><td><a name="l866" href="#l866">866</a><td>};<tr><td><a name="l867" href="#l867">867</a><td><tr><td><a name="l868" href="#l868">868</a><td><tr><td><a name="l869" href="#l869">869</a><td>/**<tr><td><a name="l870" href="#l870">870</a><td> * Creates an iterator that filters {@code iterable} based on a series of<tr><td><a name="l871" href="#l871">871</a><td> * {@code selectors}. On each call to {@code next()}, one item is taken from<tr><td><a name="l872" href="#l872">872</a><td> * both the {@code iterable} and {@code selectors} iterators. If the item from<tr><td><a name="l873" href="#l873">873</a><td> * {@code selectors} evaluates to true, the item from {@code iterable} is given.<tr><td><a name="l874" href="#l874">874</a><td> * Otherwise, it is skipped. Once either {@code iterable} or {@code selectors}<tr><td><a name="l875" href="#l875">875</a><td> * is exhausted, subsequent calls to {@code next()} will throw<tr><td><a name="l876" href="#l876">876</a><td> * {@code goog.iter.StopIteration}.<tr><td><a name="l877" href="#l877">877</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.compress<tr><td><a name="l878" href="#l878">878</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l879" href="#l879">879</a><td> * iterable to filter.<tr><td><a name="l880" href="#l880">880</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} selectors An<tr><td><a name="l881" href="#l881">881</a><td> * iterable of items to be evaluated in a boolean context to determine if<tr><td><a name="l882" href="#l882">882</a><td> * the corresponding element in {@code iterable} should be included in the<tr><td><a name="l883" href="#l883">883</a><td> * result.<tr><td><a name="l884" href="#l884">884</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator that returns the<tr><td><a name="l885" href="#l885">885</a><td> * filtered values.<tr><td><a name="l886" href="#l886">886</a><td> * @template VALUE<tr><td><a name="l887" href="#l887">887</a><td> */<tr><td><a name="l888" href="#l888">888</a><td>goog.iter.compress = function(iterable, selectors) {<tr><td><a name="l889" href="#l889">889</a><td> var selectorIterator = goog.iter.toIterator(selectors);<tr><td><a name="l890" href="#l890">890</a><td><tr><td><a name="l891" href="#l891">891</a><td> return goog.iter.filter(iterable, function() {<tr><td><a name="l892" href="#l892">892</a><td> return !!selectorIterator.next();<tr><td><a name="l893" href="#l893">893</a><td> });<tr><td><a name="l894" href="#l894">894</a><td>};<tr><td><a name="l895" href="#l895">895</a><td><tr><td><a name="l896" href="#l896">896</a><td><tr><td><a name="l897" href="#l897">897</a><td><tr><td><a name="l898" href="#l898">898</a><td>/**<tr><td><a name="l899" href="#l899">899</a><td> * Implements the {@code goog.iter.groupBy} iterator.<tr><td><a name="l900" href="#l900">900</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l901" href="#l901">901</a><td> * iterable to group.<tr><td><a name="l902" href="#l902">902</a><td> * @param {function(...[VALUE]): KEY=} opt_keyFunc Optional function for<tr><td><a name="l903" href="#l903">903</a><td> * determining the key value for each group in the {@code iterable}. Default<tr><td><a name="l904" href="#l904">904</a><td> * is the identity function.<tr><td><a name="l905" href="#l905">905</a><td> * @constructor<tr><td><a name="l906" href="#l906">906</a><td> * @extends {goog.iter.Iterator.<!Array>}<tr><td><a name="l907" href="#l907">907</a><td> * @template KEY, VALUE<tr><td><a name="l908" href="#l908">908</a><td> * @private<tr><td><a name="l909" href="#l909">909</a><td> */<tr><td><a name="l910" href="#l910">910</a><td>goog.iter.GroupByIterator_ = function(iterable, opt_keyFunc) {<tr><td><a name="l911" href="#l911">911</a><td><tr><td><a name="l912" href="#l912">912</a><td> /**<tr><td><a name="l913" href="#l913">913</a><td> * The iterable to group, coerced to an iterator.<tr><td><a name="l914" href="#l914">914</a><td> * @type {!goog.iter.Iterator}<tr><td><a name="l915" href="#l915">915</a><td> */<tr><td><a name="l916" href="#l916">916</a><td> this.iterator = goog.iter.toIterator(iterable);<tr><td><a name="l917" href="#l917">917</a><td><tr><td><a name="l918" href="#l918">918</a><td> /**<tr><td><a name="l919" href="#l919">919</a><td> * A function for determining the key value for each element in the iterable.<tr><td><a name="l920" href="#l920">920</a><td> * If no function is provided, the identity function is used and returns the<tr><td><a name="l921" href="#l921">921</a><td> * element unchanged.<tr><td><a name="l922" href="#l922">922</a><td> * @type {function(...[VALUE]): KEY}<tr><td><a name="l923" href="#l923">923</a><td> */<tr><td><a name="l924" href="#l924">924</a><td> this.keyFunc = opt_keyFunc || goog.functions.identity;<tr><td><a name="l925" href="#l925">925</a><td><tr><td><a name="l926" href="#l926">926</a><td> /**<tr><td><a name="l927" href="#l927">927</a><td> * The target key for determining the start of a group.<tr><td><a name="l928" href="#l928">928</a><td> * @type {KEY}<tr><td><a name="l929" href="#l929">929</a><td> */<tr><td><a name="l930" href="#l930">930</a><td> this.targetKey;<tr><td><a name="l931" href="#l931">931</a><td><tr><td><a name="l932" href="#l932">932</a><td> /**<tr><td><a name="l933" href="#l933">933</a><td> * The current key visited during iteration.<tr><td><a name="l934" href="#l934">934</a><td> * @type {KEY}<tr><td><a name="l935" href="#l935">935</a><td> */<tr><td><a name="l936" href="#l936">936</a><td> this.currentKey;<tr><td><a name="l937" href="#l937">937</a><td><tr><td><a name="l938" href="#l938">938</a><td> /**<tr><td><a name="l939" href="#l939">939</a><td> * The current value being added to the group.<tr><td><a name="l940" href="#l940">940</a><td> * @type {VALUE}<tr><td><a name="l941" href="#l941">941</a><td> */<tr><td><a name="l942" href="#l942">942</a><td> this.currentValue;<tr><td><a name="l943" href="#l943">943</a><td>};<tr><td><a name="l944" href="#l944">944</a><td>goog.inherits(goog.iter.GroupByIterator_, goog.iter.Iterator);<tr><td><a name="l945" href="#l945">945</a><td><tr><td><a name="l946" href="#l946">946</a><td><tr><td><a name="l947" href="#l947">947</a><td>/** @override */<tr><td><a name="l948" href="#l948">948</a><td>goog.iter.GroupByIterator_.prototype.next = function() {<tr><td><a name="l949" href="#l949">949</a><td> while (this.currentKey == this.targetKey) {<tr><td><a name="l950" href="#l950">950</a><td> this.currentValue = this.iterator.next(); // Exits on StopIteration<tr><td><a name="l951" href="#l951">951</a><td> this.currentKey = this.keyFunc(this.currentValue);<tr><td><a name="l952" href="#l952">952</a><td> }<tr><td><a name="l953" href="#l953">953</a><td> this.targetKey = this.currentKey;<tr><td><a name="l954" href="#l954">954</a><td> return [this.currentKey, this.groupItems_(this.targetKey)];<tr><td><a name="l955" href="#l955">955</a><td>};<tr><td><a name="l956" href="#l956">956</a><td><tr><td><a name="l957" href="#l957">957</a><td><tr><td><a name="l958" href="#l958">958</a><td>/**<tr><td><a name="l959" href="#l959">959</a><td> * Performs the grouping of objects using the given key.<tr><td><a name="l960" href="#l960">960</a><td> * @param {KEY} targetKey The target key object for the group.<tr><td><a name="l961" href="#l961">961</a><td> * @return {!Array.<VALUE>} An array of grouped objects.<tr><td><a name="l962" href="#l962">962</a><td> * @private<tr><td><a name="l963" href="#l963">963</a><td> */<tr><td><a name="l964" href="#l964">964</a><td>goog.iter.GroupByIterator_.prototype.groupItems_ = function(targetKey) {<tr><td><a name="l965" href="#l965">965</a><td> var arr = [];<tr><td><a name="l966" href="#l966">966</a><td> while (this.currentKey == targetKey) {<tr><td><a name="l967" href="#l967">967</a><td> arr.push(this.currentValue);<tr><td><a name="l968" href="#l968">968</a><td> try {<tr><td><a name="l969" href="#l969">969</a><td> this.currentValue = this.iterator.next();<tr><td><a name="l970" href="#l970">970</a><td> } catch (ex) {<tr><td><a name="l971" href="#l971">971</a><td> if (ex !== goog.iter.StopIteration) {<tr><td><a name="l972" href="#l972">972</a><td> throw ex;<tr><td><a name="l973" href="#l973">973</a><td> }<tr><td><a name="l974" href="#l974">974</a><td> break;<tr><td><a name="l975" href="#l975">975</a><td> }<tr><td><a name="l976" href="#l976">976</a><td> this.currentKey = this.keyFunc(this.currentValue);<tr><td><a name="l977" href="#l977">977</a><td> }<tr><td><a name="l978" href="#l978">978</a><td> return arr;<tr><td><a name="l979" href="#l979">979</a><td>};<tr><td><a name="l980" href="#l980">980</a><td><tr><td><a name="l981" href="#l981">981</a><td><tr><td><a name="l982" href="#l982">982</a><td>/**<tr><td><a name="l983" href="#l983">983</a><td> * Creates an iterator that returns arrays containing elements from the<tr><td><a name="l984" href="#l984">984</a><td> * {@code iterable} grouped by a key value. For iterables with repeated<tr><td><a name="l985" href="#l985">985</a><td> * elements (i.e. sorted according to a particular key function), this function<tr><td><a name="l986" href="#l986">986</a><td> * has a {@code uniq}-like effect. For example, grouping the array:<tr><td><a name="l987" href="#l987">987</a><td> * {@code [A, B, B, C, C, A]} produces<tr><td><a name="l988" href="#l988">988</a><td> * {@code [A, [A]], [B, [B, B]], [C, [C, C]], [A, [A]]}.<tr><td><a name="l989" href="#l989">989</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.groupby<tr><td><a name="l990" href="#l990">990</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l991" href="#l991">991</a><td> * iterable to group.<tr><td><a name="l992" href="#l992">992</a><td> * @param {function(...[VALUE]): KEY=} opt_keyFunc Optional function for<tr><td><a name="l993" href="#l993">993</a><td> * determining the key value for each group in the {@code iterable}. Default<tr><td><a name="l994" href="#l994">994</a><td> * is the identity function.<tr><td><a name="l995" href="#l995">995</a><td> * @return {!goog.iter.Iterator.<!Array>} A new iterator that returns arrays of<tr><td><a name="l996" href="#l996">996</a><td> * consecutive key and groups.<tr><td><a name="l997" href="#l997">997</a><td> * @template KEY, VALUE<tr><td><a name="l998" href="#l998">998</a><td> */<tr><td><a name="l999" href="#l999">999</a><td>goog.iter.groupBy = function(iterable, opt_keyFunc) {<tr><td><a name="l1000" href="#l1000">1000</a><td> return new goog.iter.GroupByIterator_(iterable, opt_keyFunc);<tr><td><a name="l1001" href="#l1001">1001</a><td>};<tr><td><a name="l1002" href="#l1002">1002</a><td><tr><td><a name="l1003" href="#l1003">1003</a><td><tr><td><a name="l1004" href="#l1004">1004</a><td>/**<tr><td><a name="l1005" href="#l1005">1005</a><td> * Gives an iterator that gives the result of calling the given function<tr><td><a name="l1006" href="#l1006">1006</a><td> * <code>f</code> with the arguments taken from the next element from<tr><td><a name="l1007" href="#l1007">1007</a><td> * <code>iterable</code> (the elements are expected to also be iterables).<tr><td><a name="l1008" href="#l1008">1008</a><td> *<tr><td><a name="l1009" href="#l1009">1009</a><td> * Similar to {@see goog.iter#map} but allows the function to accept multiple<tr><td><a name="l1010" href="#l1010">1010</a><td> * arguments from the iterable.<tr><td><a name="l1011" href="#l1011">1011</a><td> *<tr><td><a name="l1012" href="#l1012">1012</a><td> * @param {!goog.iter.Iterable.<!goog.iter.Iterable>} iterable The iterable of<tr><td><a name="l1013" href="#l1013">1013</a><td> * iterables to iterate over.<tr><td><a name="l1014" href="#l1014">1014</a><td> * @param {function(this:THIS,...[*]):RESULT} f The function to call for every<tr><td><a name="l1015" href="#l1015">1015</a><td> * element. This function takes N+2 arguments, where N represents the<tr><td><a name="l1016" href="#l1016">1016</a><td> * number of items from the next element of the iterable. The two<tr><td><a name="l1017" href="#l1017">1017</a><td> * additional arguments passed to the function are undefined and the<tr><td><a name="l1018" href="#l1018">1018</a><td> * iterator itself. The function should return a new value.<tr><td><a name="l1019" href="#l1019">1019</a><td> * @param {THIS=} opt_obj The object to be used as the value of 'this' within<tr><td><a name="l1020" href="#l1020">1020</a><td> * {@code f}.<tr><td><a name="l1021" href="#l1021">1021</a><td> * @return {!goog.iter.Iterator.<RESULT>} A new iterator that returns the<tr><td><a name="l1022" href="#l1022">1022</a><td> * results of applying the function to each element in the original<tr><td><a name="l1023" href="#l1023">1023</a><td> * iterator.<tr><td><a name="l1024" href="#l1024">1024</a><td> * @template THIS, RESULT<tr><td><a name="l1025" href="#l1025">1025</a><td> */<tr><td><a name="l1026" href="#l1026">1026</a><td>goog.iter.starMap = function(iterable, f, opt_obj) {<tr><td><a name="l1027" href="#l1027">1027</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l1028" href="#l1028">1028</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l1029" href="#l1029">1029</a><td><tr><td><a name="l1030" href="#l1030">1030</a><td> iter.next = function() {<tr><td><a name="l1031" href="#l1031">1031</a><td> var args = goog.iter.toArray(iterator.next());<tr><td><a name="l1032" href="#l1032">1032</a><td> return f.apply(opt_obj, goog.array.concat(args, undefined, iterator));<tr><td><a name="l1033" href="#l1033">1033</a><td> };<tr><td><a name="l1034" href="#l1034">1034</a><td><tr><td><a name="l1035" href="#l1035">1035</a><td> return iter;<tr><td><a name="l1036" href="#l1036">1036</a><td>};<tr><td><a name="l1037" href="#l1037">1037</a><td><tr><td><a name="l1038" href="#l1038">1038</a><td><tr><td><a name="l1039" href="#l1039">1039</a><td>/**<tr><td><a name="l1040" href="#l1040">1040</a><td> * Returns an array of iterators each of which can iterate over the values in<tr><td><a name="l1041" href="#l1041">1041</a><td> * {@code iterable} without advancing the others.<tr><td><a name="l1042" href="#l1042">1042</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.tee<tr><td><a name="l1043" href="#l1043">1043</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1044" href="#l1044">1044</a><td> * iterable to tee.<tr><td><a name="l1045" href="#l1045">1045</a><td> * @param {number=} opt_num The number of iterators to create. Default is 2.<tr><td><a name="l1046" href="#l1046">1046</a><td> * @return {!Array.<goog.iter.Iterator.<VALUE>>} An array of iterators.<tr><td><a name="l1047" href="#l1047">1047</a><td> * @template VALUE<tr><td><a name="l1048" href="#l1048">1048</a><td> */<tr><td><a name="l1049" href="#l1049">1049</a><td>goog.iter.tee = function(iterable, opt_num) {<tr><td><a name="l1050" href="#l1050">1050</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l1051" href="#l1051">1051</a><td> var num = goog.isNumber(opt_num) ? opt_num : 2;<tr><td><a name="l1052" href="#l1052">1052</a><td> var buffers = goog.array.map(goog.array.range(num), function() {<tr><td><a name="l1053" href="#l1053">1053</a><td> return [];<tr><td><a name="l1054" href="#l1054">1054</a><td> });<tr><td><a name="l1055" href="#l1055">1055</a><td><tr><td><a name="l1056" href="#l1056">1056</a><td> var addNextIteratorValueToBuffers = function() {<tr><td><a name="l1057" href="#l1057">1057</a><td> var val = iterator.next();<tr><td><a name="l1058" href="#l1058">1058</a><td> goog.array.forEach(buffers, function(buffer) {<tr><td><a name="l1059" href="#l1059">1059</a><td> buffer.push(val);<tr><td><a name="l1060" href="#l1060">1060</a><td> });<tr><td><a name="l1061" href="#l1061">1061</a><td> };<tr><td><a name="l1062" href="#l1062">1062</a><td><tr><td><a name="l1063" href="#l1063">1063</a><td> var createIterator = function(buffer) {<tr><td><a name="l1064" href="#l1064">1064</a><td> // Each tee'd iterator has an associated buffer (initially empty). When a<tr><td><a name="l1065" href="#l1065">1065</a><td> // tee'd iterator's buffer is empty, it calls<tr><td><a name="l1066" href="#l1066">1066</a><td> // addNextIteratorValueToBuffers(), adding the next value to all tee'd<tr><td><a name="l1067" href="#l1067">1067</a><td> // iterators' buffers, and then returns that value. This allows each<tr><td><a name="l1068" href="#l1068">1068</a><td> // iterator to be advanced independently.<tr><td><a name="l1069" href="#l1069">1069</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l1070" href="#l1070">1070</a><td><tr><td><a name="l1071" href="#l1071">1071</a><td> iter.next = function() {<tr><td><a name="l1072" href="#l1072">1072</a><td> if (goog.array.isEmpty(buffer)) {<tr><td><a name="l1073" href="#l1073">1073</a><td> addNextIteratorValueToBuffers();<tr><td><a name="l1074" href="#l1074">1074</a><td> }<tr><td><a name="l1075" href="#l1075">1075</a><td> goog.asserts.assert(!goog.array.isEmpty(buffer));<tr><td><a name="l1076" href="#l1076">1076</a><td> return buffer.shift();<tr><td><a name="l1077" href="#l1077">1077</a><td> };<tr><td><a name="l1078" href="#l1078">1078</a><td><tr><td><a name="l1079" href="#l1079">1079</a><td> return iter;<tr><td><a name="l1080" href="#l1080">1080</a><td> };<tr><td><a name="l1081" href="#l1081">1081</a><td><tr><td><a name="l1082" href="#l1082">1082</a><td> return goog.array.map(buffers, createIterator);<tr><td><a name="l1083" href="#l1083">1083</a><td>};<tr><td><a name="l1084" href="#l1084">1084</a><td><tr><td><a name="l1085" href="#l1085">1085</a><td><tr><td><a name="l1086" href="#l1086">1086</a><td>/**<tr><td><a name="l1087" href="#l1087">1087</a><td> * Creates an iterator that returns arrays containing a count and an element<tr><td><a name="l1088" href="#l1088">1088</a><td> * obtained from the given {@code iterable}.<tr><td><a name="l1089" href="#l1089">1089</a><td> * @see http://docs.python.org/2/library/functions.html#enumerate<tr><td><a name="l1090" href="#l1090">1090</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1091" href="#l1091">1091</a><td> * iterable to enumerate.<tr><td><a name="l1092" href="#l1092">1092</a><td> * @param {number=} opt_start Optional starting value. Default is 0.<tr><td><a name="l1093" href="#l1093">1093</a><td> * @return {!goog.iter.Iterator.<!Array>} A new iterator containing count/item<tr><td><a name="l1094" href="#l1094">1094</a><td> * pairs.<tr><td><a name="l1095" href="#l1095">1095</a><td> * @template VALUE<tr><td><a name="l1096" href="#l1096">1096</a><td> */<tr><td><a name="l1097" href="#l1097">1097</a><td>goog.iter.enumerate = function(iterable, opt_start) {<tr><td><a name="l1098" href="#l1098">1098</a><td> return goog.iter.zip(goog.iter.count(opt_start), iterable);<tr><td><a name="l1099" href="#l1099">1099</a><td>};<tr><td><a name="l1100" href="#l1100">1100</a><td><tr><td><a name="l1101" href="#l1101">1101</a><td><tr><td><a name="l1102" href="#l1102">1102</a><td>/**<tr><td><a name="l1103" href="#l1103">1103</a><td> * Creates an iterator that returns the first {@code limitSize} elements from an<tr><td><a name="l1104" href="#l1104">1104</a><td> * iterable. If this number is greater than the number of elements in the<tr><td><a name="l1105" href="#l1105">1105</a><td> * iterable, all the elements are returned.<tr><td><a name="l1106" href="#l1106">1106</a><td> * @see http://goo.gl/V0sihp Inspired by the limit iterator in Guava.<tr><td><a name="l1107" href="#l1107">1107</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1108" href="#l1108">1108</a><td> * iterable to limit.<tr><td><a name="l1109" href="#l1109">1109</a><td> * @param {number} limitSize The maximum number of elements to return.<tr><td><a name="l1110" href="#l1110">1110</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator containing<tr><td><a name="l1111" href="#l1111">1111</a><td> * {@code limitSize} elements.<tr><td><a name="l1112" href="#l1112">1112</a><td> * @template VALUE<tr><td><a name="l1113" href="#l1113">1113</a><td> */<tr><td><a name="l1114" href="#l1114">1114</a><td>goog.iter.limit = function(iterable, limitSize) {<tr><td><a name="l1115" href="#l1115">1115</a><td> goog.asserts.assert(goog.math.isInt(limitSize) && limitSize >= 0);<tr><td><a name="l1116" href="#l1116">1116</a><td><tr><td><a name="l1117" href="#l1117">1117</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l1118" href="#l1118">1118</a><td><tr><td><a name="l1119" href="#l1119">1119</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l1120" href="#l1120">1120</a><td> var remaining = limitSize;<tr><td><a name="l1121" href="#l1121">1121</a><td><tr><td><a name="l1122" href="#l1122">1122</a><td> iter.next = function() {<tr><td><a name="l1123" href="#l1123">1123</a><td> if (remaining-- > 0) {<tr><td><a name="l1124" href="#l1124">1124</a><td> return iterator.next();<tr><td><a name="l1125" href="#l1125">1125</a><td> }<tr><td><a name="l1126" href="#l1126">1126</a><td> throw goog.iter.StopIteration;<tr><td><a name="l1127" href="#l1127">1127</a><td> };<tr><td><a name="l1128" href="#l1128">1128</a><td><tr><td><a name="l1129" href="#l1129">1129</a><td> return iter;<tr><td><a name="l1130" href="#l1130">1130</a><td>};<tr><td><a name="l1131" href="#l1131">1131</a><td><tr><td><a name="l1132" href="#l1132">1132</a><td><tr><td><a name="l1133" href="#l1133">1133</a><td>/**<tr><td><a name="l1134" href="#l1134">1134</a><td> * Creates an iterator that is advanced {@code count} steps ahead. Consumed<tr><td><a name="l1135" href="#l1135">1135</a><td> * values are silently discarded. If {@code count} is greater than the number<tr><td><a name="l1136" href="#l1136">1136</a><td> * of elements in {@code iterable}, an empty iterator is returned. Subsequent<tr><td><a name="l1137" href="#l1137">1137</a><td> * calls to {@code next()} will throw {@code goog.iter.StopIteration}.<tr><td><a name="l1138" href="#l1138">1138</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1139" href="#l1139">1139</a><td> * iterable to consume.<tr><td><a name="l1140" href="#l1140">1140</a><td> * @param {number} count The number of elements to consume from the iterator.<tr><td><a name="l1141" href="#l1141">1141</a><td> * @return {!goog.iter.Iterator.<VALUE>} An iterator advanced zero or more steps<tr><td><a name="l1142" href="#l1142">1142</a><td> * ahead.<tr><td><a name="l1143" href="#l1143">1143</a><td> * @template VALUE<tr><td><a name="l1144" href="#l1144">1144</a><td> */<tr><td><a name="l1145" href="#l1145">1145</a><td>goog.iter.consume = function(iterable, count) {<tr><td><a name="l1146" href="#l1146">1146</a><td> goog.asserts.assert(goog.math.isInt(count) && count >= 0);<tr><td><a name="l1147" href="#l1147">1147</a><td><tr><td><a name="l1148" href="#l1148">1148</a><td> var iterator = goog.iter.toIterator(iterable);<tr><td><a name="l1149" href="#l1149">1149</a><td><tr><td><a name="l1150" href="#l1150">1150</a><td> while (count-- > 0) {<tr><td><a name="l1151" href="#l1151">1151</a><td> goog.iter.nextOrValue(iterator, null);<tr><td><a name="l1152" href="#l1152">1152</a><td> }<tr><td><a name="l1153" href="#l1153">1153</a><td><tr><td><a name="l1154" href="#l1154">1154</a><td> return iterator;<tr><td><a name="l1155" href="#l1155">1155</a><td>};<tr><td><a name="l1156" href="#l1156">1156</a><td><tr><td><a name="l1157" href="#l1157">1157</a><td><tr><td><a name="l1158" href="#l1158">1158</a><td>/**<tr><td><a name="l1159" href="#l1159">1159</a><td> * Creates an iterator that returns a range of elements from an iterable.<tr><td><a name="l1160" href="#l1160">1160</a><td> * Similar to {@see goog.array#slice} but does not support negative indexes.<tr><td><a name="l1161" href="#l1161">1161</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1162" href="#l1162">1162</a><td> * iterable to slice.<tr><td><a name="l1163" href="#l1163">1163</a><td> * @param {number} start The index of the first element to return.<tr><td><a name="l1164" href="#l1164">1164</a><td> * @param {number=} opt_end The index after the last element to return. If<tr><td><a name="l1165" href="#l1165">1165</a><td> * defined, must be greater than or equal to {@code start}.<tr><td><a name="l1166" href="#l1166">1166</a><td> * @return {!goog.iter.Iterator.<VALUE>} A new iterator containing a slice of<tr><td><a name="l1167" href="#l1167">1167</a><td> * the original.<tr><td><a name="l1168" href="#l1168">1168</a><td> * @template VALUE<tr><td><a name="l1169" href="#l1169">1169</a><td> */<tr><td><a name="l1170" href="#l1170">1170</a><td>goog.iter.slice = function(iterable, start, opt_end) {<tr><td><a name="l1171" href="#l1171">1171</a><td> goog.asserts.assert(goog.math.isInt(start) && start >= 0);<tr><td><a name="l1172" href="#l1172">1172</a><td><tr><td><a name="l1173" href="#l1173">1173</a><td> var iterator = goog.iter.consume(iterable, start);<tr><td><a name="l1174" href="#l1174">1174</a><td><tr><td><a name="l1175" href="#l1175">1175</a><td> if (goog.isNumber(opt_end)) {<tr><td><a name="l1176" href="#l1176">1176</a><td> goog.asserts.assert(<tr><td><a name="l1177" href="#l1177">1177</a><td> goog.math.isInt(/** @type {number} */ (opt_end)) && opt_end >= start);<tr><td><a name="l1178" href="#l1178">1178</a><td> iterator = goog.iter.limit(iterator, opt_end - start /* limitSize */);<tr><td><a name="l1179" href="#l1179">1179</a><td> }<tr><td><a name="l1180" href="#l1180">1180</a><td><tr><td><a name="l1181" href="#l1181">1181</a><td> return iterator;<tr><td><a name="l1182" href="#l1182">1182</a><td>};<tr><td><a name="l1183" href="#l1183">1183</a><td><tr><td><a name="l1184" href="#l1184">1184</a><td><tr><td><a name="l1185" href="#l1185">1185</a><td>/**<tr><td><a name="l1186" href="#l1186">1186</a><td> * Checks an array for duplicate elements.<tr><td><a name="l1187" href="#l1187">1187</a><td> * @param {Array.<VALUE>|goog.array.ArrayLike} arr The array to check for<tr><td><a name="l1188" href="#l1188">1188</a><td> * duplicates.<tr><td><a name="l1189" href="#l1189">1189</a><td> * @return {boolean} True, if the array contains duplicates, false otherwise.<tr><td><a name="l1190" href="#l1190">1190</a><td> * @private<tr><td><a name="l1191" href="#l1191">1191</a><td> * @template VALUE<tr><td><a name="l1192" href="#l1192">1192</a><td> */<tr><td><a name="l1193" href="#l1193">1193</a><td>// TODO(user): Consider moving this into goog.array as a public function.<tr><td><a name="l1194" href="#l1194">1194</a><td>goog.iter.hasDuplicates_ = function(arr) {<tr><td><a name="l1195" href="#l1195">1195</a><td> var deduped = [];<tr><td><a name="l1196" href="#l1196">1196</a><td> goog.array.removeDuplicates(arr, deduped);<tr><td><a name="l1197" href="#l1197">1197</a><td> return arr.length != deduped.length;<tr><td><a name="l1198" href="#l1198">1198</a><td>};<tr><td><a name="l1199" href="#l1199">1199</a><td><tr><td><a name="l1200" href="#l1200">1200</a><td><tr><td><a name="l1201" href="#l1201">1201</a><td>/**<tr><td><a name="l1202" href="#l1202">1202</a><td> * Creates an iterator that returns permutations of elements in<tr><td><a name="l1203" href="#l1203">1203</a><td> * {@code iterable}.<tr><td><a name="l1204" href="#l1204">1204</a><td> *<tr><td><a name="l1205" href="#l1205">1205</a><td> * Permutations are obtained by taking the Cartesian product of<tr><td><a name="l1206" href="#l1206">1206</a><td> * {@code opt_length} iterables and filtering out those with repeated<tr><td><a name="l1207" href="#l1207">1207</a><td> * elements. For example, the permutations of {@code [1,2,3]} are<tr><td><a name="l1208" href="#l1208">1208</a><td> * {@code [[1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1]]}.<tr><td><a name="l1209" href="#l1209">1209</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.permutations<tr><td><a name="l1210" href="#l1210">1210</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1211" href="#l1211">1211</a><td> * iterable from which to generate permutations.<tr><td><a name="l1212" href="#l1212">1212</a><td> * @param {number=} opt_length Length of each permutation. If omitted, defaults<tr><td><a name="l1213" href="#l1213">1213</a><td> * to the length of {@code iterable}.<tr><td><a name="l1214" href="#l1214">1214</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} A new iterator containing the<tr><td><a name="l1215" href="#l1215">1215</a><td> * permutations of {@code iterable}.<tr><td><a name="l1216" href="#l1216">1216</a><td> * @template VALUE<tr><td><a name="l1217" href="#l1217">1217</a><td> */<tr><td><a name="l1218" href="#l1218">1218</a><td>goog.iter.permutations = function(iterable, opt_length) {<tr><td><a name="l1219" href="#l1219">1219</a><td> var elements = goog.iter.toArray(iterable);<tr><td><a name="l1220" href="#l1220">1220</a><td> var length = goog.isNumber(opt_length) ? opt_length : elements.length;<tr><td><a name="l1221" href="#l1221">1221</a><td><tr><td><a name="l1222" href="#l1222">1222</a><td> var sets = goog.array.repeat(elements, length);<tr><td><a name="l1223" href="#l1223">1223</a><td> var product = goog.iter.product.apply(undefined, sets);<tr><td><a name="l1224" href="#l1224">1224</a><td><tr><td><a name="l1225" href="#l1225">1225</a><td> return goog.iter.filter(product, function(arr) {<tr><td><a name="l1226" href="#l1226">1226</a><td> return !goog.iter.hasDuplicates_(arr);<tr><td><a name="l1227" href="#l1227">1227</a><td> });<tr><td><a name="l1228" href="#l1228">1228</a><td>};<tr><td><a name="l1229" href="#l1229">1229</a><td><tr><td><a name="l1230" href="#l1230">1230</a><td><tr><td><a name="l1231" href="#l1231">1231</a><td>/**<tr><td><a name="l1232" href="#l1232">1232</a><td> * Creates an iterator that returns combinations of elements from<tr><td><a name="l1233" href="#l1233">1233</a><td> * {@code iterable}.<tr><td><a name="l1234" href="#l1234">1234</a><td> *<tr><td><a name="l1235" href="#l1235">1235</a><td> * Combinations are obtained by taking the {@see goog.iter#permutations} of<tr><td><a name="l1236" href="#l1236">1236</a><td> * {@code iterable} and filtering those whose elements appear in the order they<tr><td><a name="l1237" href="#l1237">1237</a><td> * are encountered in {@code iterable}. For example, the 3-length combinations<tr><td><a name="l1238" href="#l1238">1238</a><td> * of {@code [0,1,2,3]} are {@code [[0,1,2], [0,1,3], [0,2,3], [1,2,3]]}.<tr><td><a name="l1239" href="#l1239">1239</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.combinations<tr><td><a name="l1240" href="#l1240">1240</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1241" href="#l1241">1241</a><td> * iterable from which to generate combinations.<tr><td><a name="l1242" href="#l1242">1242</a><td> * @param {number} length The length of each combination.<tr><td><a name="l1243" href="#l1243">1243</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} A new iterator containing<tr><td><a name="l1244" href="#l1244">1244</a><td> * combinations from the {@code iterable}.<tr><td><a name="l1245" href="#l1245">1245</a><td> * @template VALUE<tr><td><a name="l1246" href="#l1246">1246</a><td> */<tr><td><a name="l1247" href="#l1247">1247</a><td>goog.iter.combinations = function(iterable, length) {<tr><td><a name="l1248" href="#l1248">1248</a><td> var elements = goog.iter.toArray(iterable);<tr><td><a name="l1249" href="#l1249">1249</a><td> var indexes = goog.iter.range(elements.length);<tr><td><a name="l1250" href="#l1250">1250</a><td> var indexIterator = goog.iter.permutations(indexes, length);<tr><td><a name="l1251" href="#l1251">1251</a><td> // sortedIndexIterator will now give arrays of with the given length that<tr><td><a name="l1252" href="#l1252">1252</a><td> // indicate what indexes into "elements" should be returned on each iteration.<tr><td><a name="l1253" href="#l1253">1253</a><td> var sortedIndexIterator = goog.iter.filter(indexIterator, function(arr) {<tr><td><a name="l1254" href="#l1254">1254</a><td> return goog.array.isSorted(arr);<tr><td><a name="l1255" href="#l1255">1255</a><td> });<tr><td><a name="l1256" href="#l1256">1256</a><td><tr><td><a name="l1257" href="#l1257">1257</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l1258" href="#l1258">1258</a><td><tr><td><a name="l1259" href="#l1259">1259</a><td> function getIndexFromElements(index) {<tr><td><a name="l1260" href="#l1260">1260</a><td> return elements[index];<tr><td><a name="l1261" href="#l1261">1261</a><td> }<tr><td><a name="l1262" href="#l1262">1262</a><td><tr><td><a name="l1263" href="#l1263">1263</a><td> iter.next = function() {<tr><td><a name="l1264" href="#l1264">1264</a><td> return goog.array.map(<tr><td><a name="l1265" href="#l1265">1265</a><td> /** @type {!Array.<number>} */<tr><td><a name="l1266" href="#l1266">1266</a><td> (sortedIndexIterator.next()), getIndexFromElements);<tr><td><a name="l1267" href="#l1267">1267</a><td> };<tr><td><a name="l1268" href="#l1268">1268</a><td><tr><td><a name="l1269" href="#l1269">1269</a><td> return iter;<tr><td><a name="l1270" href="#l1270">1270</a><td>};<tr><td><a name="l1271" href="#l1271">1271</a><td><tr><td><a name="l1272" href="#l1272">1272</a><td><tr><td><a name="l1273" href="#l1273">1273</a><td>/**<tr><td><a name="l1274" href="#l1274">1274</a><td> * Creates an iterator that returns combinations of elements from<tr><td><a name="l1275" href="#l1275">1275</a><td> * {@code iterable}, with repeated elements possible.<tr><td><a name="l1276" href="#l1276">1276</a><td> *<tr><td><a name="l1277" href="#l1277">1277</a><td> * Combinations are obtained by taking the Cartesian product of {@code length}<tr><td><a name="l1278" href="#l1278">1278</a><td> * iterables and filtering those whose elements appear in the order they are<tr><td><a name="l1279" href="#l1279">1279</a><td> * encountered in {@code iterable}. For example, the 2-length combinations of<tr><td><a name="l1280" href="#l1280">1280</a><td> * {@code [1,2,3]} are {@code [[1,1], [1,2], [1,3], [2,2], [2,3], [3,3]]}.<tr><td><a name="l1281" href="#l1281">1281</a><td> * @see http://docs.python.org/2/library/itertools.html#itertools.combinations_with_replacement<tr><td><a name="l1282" href="#l1282">1282</a><td> * @see http://en.wikipedia.org/wiki/Combination#Number_of_combinations_with_repetition<tr><td><a name="l1283" href="#l1283">1283</a><td> * @param {!goog.iter.Iterator.<VALUE>|!goog.iter.Iterable} iterable The<tr><td><a name="l1284" href="#l1284">1284</a><td> * iterable to combine.<tr><td><a name="l1285" href="#l1285">1285</a><td> * @param {number} length The length of each combination.<tr><td><a name="l1286" href="#l1286">1286</a><td> * @return {!goog.iter.Iterator.<!Array.<VALUE>>} A new iterator containing<tr><td><a name="l1287" href="#l1287">1287</a><td> * combinations from the {@code iterable}.<tr><td><a name="l1288" href="#l1288">1288</a><td> * @template VALUE<tr><td><a name="l1289" href="#l1289">1289</a><td> */<tr><td><a name="l1290" href="#l1290">1290</a><td>goog.iter.combinationsWithReplacement = function(iterable, length) {<tr><td><a name="l1291" href="#l1291">1291</a><td> var elements = goog.iter.toArray(iterable);<tr><td><a name="l1292" href="#l1292">1292</a><td> var indexes = goog.array.range(elements.length);<tr><td><a name="l1293" href="#l1293">1293</a><td> var sets = goog.array.repeat(indexes, length);<tr><td><a name="l1294" href="#l1294">1294</a><td> var indexIterator = goog.iter.product.apply(undefined, sets);<tr><td><a name="l1295" href="#l1295">1295</a><td> // sortedIndexIterator will now give arrays of with the given length that<tr><td><a name="l1296" href="#l1296">1296</a><td> // indicate what indexes into "elements" should be returned on each iteration.<tr><td><a name="l1297" href="#l1297">1297</a><td> var sortedIndexIterator = goog.iter.filter(indexIterator, function(arr) {<tr><td><a name="l1298" href="#l1298">1298</a><td> return goog.array.isSorted(arr);<tr><td><a name="l1299" href="#l1299">1299</a><td> });<tr><td><a name="l1300" href="#l1300">1300</a><td><tr><td><a name="l1301" href="#l1301">1301</a><td> var iter = new goog.iter.Iterator();<tr><td><a name="l1302" href="#l1302">1302</a><td><tr><td><a name="l1303" href="#l1303">1303</a><td> function getIndexFromElements(index) {<tr><td><a name="l1304" href="#l1304">1304</a><td> return elements[index];<tr><td><a name="l1305" href="#l1305">1305</a><td> }<tr><td><a name="l1306" href="#l1306">1306</a><td><tr><td><a name="l1307" href="#l1307">1307</a><td> iter.next = function() {<tr><td><a name="l1308" href="#l1308">1308</a><td> return goog.array.map(<tr><td><a name="l1309" href="#l1309">1309</a><td> /** @type {!Array.<number>} */<tr><td><a name="l1310" href="#l1310">1310</a><td> (sortedIndexIterator.next()), getIndexFromElements);<tr><td><a name="l1311" href="#l1311">1311</a><td> };<tr><td><a name="l1312" href="#l1312">1312</a><td><tr><td><a name="l1313" href="#l1313">1313</a><td> return iter;<tr><td><a name="l1314" href="#l1314">1314</a><td>};</table></pre></main><nav id="topnav"><div><div id="menubutton"><label for="sidenav-toggle">Menu</label></div><form id="searchbox"><div><input type="search" placeholder="Search" tabindex="1"></div></form></div></nav><nav id="sidenav"><input type="checkbox" id="sidenav-types-ctrl" /><input type="checkbox" id="sidenav-files-ctrl" /><input type="checkbox" id="sidenav-modules-ctrl" /><a id="sidenav-overview"><div><h4>Overview</h4></div></a><div id="sidenav-types"><label for="sidenav-types-ctrl"><h4>Types</h4></label><i>No data</i></div><div id="sidenav-modules"><label for="sidenav-modules-ctrl"><h4>Modules</h4></label><i>No data</i></div><div id="sidenav-files"><label for="sidenav-files-ctrl"><h4>Files</h4></label><i>No data</i></div><a href="license.html"><div><h4>License</h4></div></a></nav><div id="push-footer"></div></div><footer><a href="https://github.com/jleyba/js-dossier">Generated by dossier</a></footer><script src="../../../../types.js"></script><script src="../../../../dossier.js"></script> |