<!DOCTYPE html> <html> <head> <title>underscore.js</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <link rel="stylesheet" media="all" href="docco.css" /> </head> <body> <div id="container"> <div id="background"></div> <table cellpadding="0" cellspacing="0"> <thead> <tr> <th class="docs"> <h1> underscore.js </h1> </th> <th class="code"> </th> </tr> </thead> <tbody> <tr id="section-1"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-1">¶</a> </div> <pre><code>Underscore.js 1.2.0
(c) 2011 Jeremy Ashkenas, DocumentCloud Inc.
Underscore is freely distributable under the MIT license.
Portions of Underscore are inspired or borrowed from Prototype,
Oliver Steele's Functional, and John Resig's Micro-Templating.
For all details and documentation:
http://documentcloud.github.com/underscore
</code></pre> </td> <td class="code"> <div class="highlight"><pre><span class="p">(</span><span class="kd">function</span><span class="p">()</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-2"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-2">¶</a> </div> <h2>Baseline setup</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-3"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-3">¶</a> </div> <p>Establish the root object, <code>window</code> in the browser, or <code>global</code> on the server.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">root</span> <span class="o">=</span> <span class="k">this</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-4"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-4">¶</a> </div> <p>Save the previous value of the <code>_</code> variable.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">previousUnderscore</span> <span class="o">=</span> <span class="nx">root</span><span class="p">.</span><span class="nx">_</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-5"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-5">¶</a> </div> <p>Establish the object that gets returned to break out of a loop iteration.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">breaker</span> <span class="o">=</span> <span class="p">{};</span></pre></div> </td> </tr> <tr id="section-6"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-6">¶</a> </div> <p>Save bytes in the minified (but not gzipped) version:</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">ArrayProto</span> <span class="o">=</span> <span class="nb">Array</span><span class="p">.</span><span class="nx">prototype</span><span class="p">,</span> <span class="nx">ObjProto</span> <span class="o">=</span> <span class="nb">Object</span><span class="p">.</span><span class="nx">prototype</span><span class="p">,</span> <span class="nx">FuncProto</span> <span class="o">=</span> <span class="nb">Function</span><span class="p">.</span><span class="nx">prototype</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-7"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-7">¶</a> </div> <p>Create quick reference variables for speed access to core prototypes.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">slice</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">slice</span><span class="p">,</span>
<span class="nx">unshift</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">unshift</span><span class="p">,</span>
<span class="nx">toString</span> <span class="o">=</span> <span class="nx">ObjProto</span><span class="p">.</span><span class="nx">toString</span><span class="p">,</span>
<span class="nx">hasOwnProperty</span> <span class="o">=</span> <span class="nx">ObjProto</span><span class="p">.</span><span class="nx">hasOwnProperty</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-8"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-8">¶</a> </div> <p>All <strong>ECMAScript 5</strong> native function implementations that we hope to use
are declared here.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span>
<span class="nx">nativeForEach</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">forEach</span><span class="p">,</span>
<span class="nx">nativeMap</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">map</span><span class="p">,</span>
<span class="nx">nativeReduce</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">reduce</span><span class="p">,</span>
<span class="nx">nativeReduceRight</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">reduceRight</span><span class="p">,</span>
<span class="nx">nativeFilter</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">filter</span><span class="p">,</span>
<span class="nx">nativeEvery</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">every</span><span class="p">,</span>
<span class="nx">nativeSome</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">some</span><span class="p">,</span>
<span class="nx">nativeIndexOf</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">,</span>
<span class="nx">nativeLastIndexOf</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">.</span><span class="nx">lastIndexOf</span><span class="p">,</span>
<span class="nx">nativeIsArray</span> <span class="o">=</span> <span class="nb">Array</span><span class="p">.</span><span class="nx">isArray</span><span class="p">,</span>
<span class="nx">nativeKeys</span> <span class="o">=</span> <span class="nb">Object</span><span class="p">.</span><span class="nx">keys</span><span class="p">,</span>
<span class="nx">nativeBind</span> <span class="o">=</span> <span class="nx">FuncProto</span><span class="p">.</span><span class="nx">bind</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-9"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-9">¶</a> </div> <p>Create a safe reference to the Underscore object for use below.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span> <span class="k">return</span> <span class="k">new</span> <span class="nx">wrapper</span><span class="p">(</span><span class="nx">obj</span><span class="p">);</span> <span class="p">};</span></pre></div> </td> </tr> <tr id="section-10"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-10">¶</a> </div> <p>Export the Underscore object for <strong>CommonJS</strong>, with backwards-compatibility
for the old <code>require()</code> API. If we're not in CommonJS, add <code>_</code> to the
global object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="k">typeof</span> <span class="nx">module</span> <span class="o">!==</span> <span class="s1">'undefined'</span> <span class="o">&&</span> <span class="nx">module</span><span class="p">.</span><span class="nx">exports</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">module</span><span class="p">.</span><span class="nx">exports</span> <span class="o">=</span> <span class="nx">_</span><span class="p">;</span>
<span class="nx">_</span><span class="p">.</span><span class="nx">_</span> <span class="o">=</span> <span class="nx">_</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-11"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-11">¶</a> </div> <p>Exported as a string, for Closure Compiler "advanced" mode.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">root</span><span class="p">[</span><span class="s1">'_'</span><span class="p">]</span> <span class="o">=</span> <span class="nx">_</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-12"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-12">¶</a> </div> <p>Current version.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">VERSION</span> <span class="o">=</span> <span class="s1">'1.2.0'</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-13"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-13">¶</a> </div> <h2>Collection Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-14"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-14">¶</a> </div> <p>The cornerstone, an <code>each</code> implementation, aka <code>forEach</code>.
Handles objects with the built-in <code>forEach</code>, arrays, and raw objects.
Delegates to <strong>ECMAScript 5</strong>'s native <code>forEach</code> if available.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">each</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">each</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">forEach</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeForEach</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">forEach</span> <span class="o">===</span> <span class="nx">nativeForEach</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">obj</span><span class="p">.</span><span class="nx">forEach</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">obj</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="o">+</span><span class="nx">obj</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">l</span> <span class="o">=</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">l</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">i</span> <span class="k">in</span> <span class="nx">obj</span> <span class="o">&&</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">i</span><span class="p">],</span> <span class="nx">i</span><span class="p">,</span> <span class="nx">obj</span><span class="p">)</span> <span class="o">===</span> <span class="nx">breaker</span><span class="p">)</span> <span class="k">return</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">key</span> <span class="k">in</span> <span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">key</span><span class="p">))</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">key</span><span class="p">],</span> <span class="nx">key</span><span class="p">,</span> <span class="nx">obj</span><span class="p">)</span> <span class="o">===</span> <span class="nx">breaker</span><span class="p">)</span> <span class="k">return</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-15"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-15">¶</a> </div> <p>Return the results of applying the iterator to each element.
Delegates to <strong>ECMAScript 5</strong>'s native <code>map</code> if available.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">map</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">results</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeMap</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">map</span> <span class="o">===</span> <span class="nx">nativeMap</span><span class="p">)</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">results</span><span class="p">[</span><span class="nx">results</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">);</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-16"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-16">¶</a> </div> <p><strong>Reduce</strong> builds up a single result from a list of values, aka <code>inject</code>,
or <code>foldl</code>. Delegates to <strong>ECMAScript 5</strong>'s native <code>reduce</code> if available.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">reduce</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">foldl</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">inject</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">memo</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">initial</span> <span class="o">=</span> <span class="nx">memo</span> <span class="o">!==</span> <span class="k">void</span> <span class="mi">0</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">obj</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeReduce</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduce</span> <span class="o">===</span> <span class="nx">nativeReduce</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">context</span><span class="p">)</span> <span class="nx">iterator</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">bind</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">initial</span> <span class="o">?</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduce</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">memo</span><span class="p">)</span> <span class="o">:</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduce</span><span class="p">(</span><span class="nx">iterator</span><span class="p">);</span>
<span class="p">}</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">initial</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">memo</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="nx">initial</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="nx">memo</span> <span class="o">=</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">memo</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">initial</span><span class="p">)</span> <span class="k">throw</span> <span class="k">new</span> <span class="nx">TypeError</span><span class="p">(</span><span class="s2">"Reduce of empty array with no initial value"</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">memo</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-17"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-17">¶</a> </div> <p>The right-associative version of reduce, also known as <code>foldr</code>.
Delegates to <strong>ECMAScript 5</strong>'s native <code>reduceRight</code> if available.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">reduceRight</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">foldr</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">memo</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">obj</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeReduceRight</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduceRight</span> <span class="o">===</span> <span class="nx">nativeReduceRight</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">context</span><span class="p">)</span> <span class="nx">iterator</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">bind</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">memo</span> <span class="o">!==</span> <span class="k">void</span> <span class="mi">0</span> <span class="o">?</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduceRight</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">memo</span><span class="p">)</span> <span class="o">:</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">reduceRight</span><span class="p">(</span><span class="nx">iterator</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">reversed</span> <span class="o">=</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">?</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">slice</span><span class="p">()</span> <span class="o">:</span> <span class="nx">_</span><span class="p">.</span><span class="nx">toArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">)).</span><span class="nx">reverse</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">reduce</span><span class="p">(</span><span class="nx">reversed</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">memo</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-18"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-18">¶</a> </div> <p>Return the first value which passes a truth test. Aliased as <code>detect</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">find</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">detect</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">result</span><span class="p">;</span>
<span class="nx">any</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">))</span> <span class="p">{</span>
<span class="nx">result</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-19"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-19">¶</a> </div> <p>Return all the elements that pass a truth test.
Delegates to <strong>ECMAScript 5</strong>'s native <code>filter</code> if available.
Aliased as <code>select</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">filter</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">select</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">results</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeFilter</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">filter</span> <span class="o">===</span> <span class="nx">nativeFilter</span><span class="p">)</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">filter</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">))</span> <span class="nx">results</span><span class="p">[</span><span class="nx">results</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-20"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-20">¶</a> </div> <p>Return all the elements for which a truth test fails.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">reject</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">results</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">))</span> <span class="nx">results</span><span class="p">[</span><span class="nx">results</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-21"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-21">¶</a> </div> <p>Determine whether all of the elements match a truth test.
Delegates to <strong>ECMAScript 5</strong>'s native <code>every</code> if available.
Aliased as <code>all</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">every</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">all</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeEvery</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">every</span> <span class="o">===</span> <span class="nx">nativeEvery</span><span class="p">)</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">every</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="p">(</span><span class="nx">result</span> <span class="o">=</span> <span class="nx">result</span> <span class="o">&&</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)))</span> <span class="k">return</span> <span class="nx">breaker</span><span class="p">;</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-22"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-22">¶</a> </div> <p>Determine if at least one element in the object matches a truth test.
Delegates to <strong>ECMAScript 5</strong>'s native <code>some</code> if available.
Aliased as <code>any</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">any</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">some</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">any</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">iterator</span> <span class="o">=</span> <span class="nx">iterator</span> <span class="o">||</span> <span class="nx">_</span><span class="p">.</span><span class="nx">identity</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeSome</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">some</span> <span class="o">===</span> <span class="nx">nativeSome</span><span class="p">)</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">some</span><span class="p">(</span><span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">);</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">result</span> <span class="o">|=</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">))</span> <span class="k">return</span> <span class="nx">breaker</span><span class="p">;</span>
<span class="p">});</span>
<span class="k">return</span> <span class="o">!!</span><span class="nx">result</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-23"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-23">¶</a> </div> <p>Determine if a given value is included in the array or object using <code>===</code>.
Aliased as <code>contains</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">include</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">contains</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">target</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">found</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">found</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeIndexOf</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">indexOf</span> <span class="o">===</span> <span class="nx">nativeIndexOf</span><span class="p">)</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">target</span><span class="p">)</span> <span class="o">!=</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="nx">any</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">found</span> <span class="o">=</span> <span class="nx">value</span> <span class="o">===</span> <span class="nx">target</span><span class="p">)</span> <span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">found</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-24"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-24">¶</a> </div> <p>Invoke a method (with arguments) on every item in a collection.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">invoke</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">method</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">(</span><span class="nx">method</span><span class="p">.</span><span class="nx">call</span> <span class="o">?</span> <span class="nx">method</span> <span class="o">||</span> <span class="nx">value</span> <span class="o">:</span> <span class="nx">value</span><span class="p">[</span><span class="nx">method</span><span class="p">]).</span><span class="nx">apply</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">args</span><span class="p">);</span>
<span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-25"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-25">¶</a> </div> <p>Convenience version of a common use case of <code>map</code>: fetching a property.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">key</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">){</span> <span class="k">return</span> <span class="nx">value</span><span class="p">[</span><span class="nx">key</span><span class="p">];</span> <span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-26"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-26">¶</a> </div> <p>Return the maximum element or (element-based computation).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">max</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterator</span> <span class="o">&&</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">return</span> <span class="nb">Math</span><span class="p">.</span><span class="nx">max</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nb">Math</span><span class="p">,</span> <span class="nx">obj</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterator</span> <span class="o">&&</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">return</span> <span class="o">-</span><span class="kc">Infinity</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="p">{</span><span class="nx">computed</span> <span class="o">:</span> <span class="o">-</span><span class="kc">Infinity</span><span class="p">};</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">computed</span> <span class="o">=</span> <span class="nx">iterator</span> <span class="o">?</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="o">:</span> <span class="nx">value</span><span class="p">;</span>
<span class="nx">computed</span> <span class="o">>=</span> <span class="nx">result</span><span class="p">.</span><span class="nx">computed</span> <span class="o">&&</span> <span class="p">(</span><span class="nx">result</span> <span class="o">=</span> <span class="p">{</span><span class="nx">value</span> <span class="o">:</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">computed</span> <span class="o">:</span> <span class="nx">computed</span><span class="p">});</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">.</span><span class="nx">value</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-27"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-27">¶</a> </div> <p>Return the minimum element (or element-based computation).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">min</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterator</span> <span class="o">&&</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">return</span> <span class="nb">Math</span><span class="p">.</span><span class="nx">min</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nb">Math</span><span class="p">,</span> <span class="nx">obj</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterator</span> <span class="o">&&</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">return</span> <span class="kc">Infinity</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="p">{</span><span class="nx">computed</span> <span class="o">:</span> <span class="kc">Infinity</span><span class="p">};</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">computed</span> <span class="o">=</span> <span class="nx">iterator</span> <span class="o">?</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="o">:</span> <span class="nx">value</span><span class="p">;</span>
<span class="nx">computed</span> <span class="o"><</span> <span class="nx">result</span><span class="p">.</span><span class="nx">computed</span> <span class="o">&&</span> <span class="p">(</span><span class="nx">result</span> <span class="o">=</span> <span class="p">{</span><span class="nx">value</span> <span class="o">:</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">computed</span> <span class="o">:</span> <span class="nx">computed</span><span class="p">});</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">.</span><span class="nx">value</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-28"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-28">¶</a> </div> <p>Shuffle an array.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">shuffle</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">shuffled</span> <span class="o">=</span> <span class="p">[],</span> <span class="nx">rand</span><span class="p">;</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">index</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">shuffled</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="nx">rand</span> <span class="o">=</span> <span class="nb">Math</span><span class="p">.</span><span class="nx">floor</span><span class="p">(</span><span class="nb">Math</span><span class="p">.</span><span class="nx">random</span><span class="p">()</span> <span class="o">*</span> <span class="p">(</span><span class="nx">index</span> <span class="o">+</span> <span class="mi">1</span><span class="p">));</span>
<span class="nx">shuffled</span><span class="p">[</span><span class="nx">index</span><span class="p">]</span> <span class="o">=</span> <span class="nx">shuffled</span><span class="p">[</span><span class="nx">rand</span><span class="p">];</span>
<span class="nx">shuffled</span><span class="p">[</span><span class="nx">rand</span><span class="p">]</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">shuffled</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-29"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-29">¶</a> </div> <p>Sort the object's values by a criterion produced by an iterator.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">sortBy</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">{</span>
<span class="nx">value</span> <span class="o">:</span> <span class="nx">value</span><span class="p">,</span>
<span class="nx">criteria</span> <span class="o">:</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">list</span><span class="p">)</span>
<span class="p">};</span>
<span class="p">}).</span><span class="nx">sort</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">left</span><span class="p">,</span> <span class="nx">right</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">a</span> <span class="o">=</span> <span class="nx">left</span><span class="p">.</span><span class="nx">criteria</span><span class="p">,</span> <span class="nx">b</span> <span class="o">=</span> <span class="nx">right</span><span class="p">.</span><span class="nx">criteria</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">a</span> <span class="o"><</span> <span class="nx">b</span> <span class="o">?</span> <span class="o">-</span><span class="mi">1</span> <span class="o">:</span> <span class="nx">a</span> <span class="o">></span> <span class="nx">b</span> <span class="o">?</span> <span class="mi">1</span> <span class="o">:</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">}),</span> <span class="s1">'value'</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-30"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-30">¶</a> </div> <p>Groups the object's values by a criterion produced by an iterator</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">groupBy</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="p">{};</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">key</span> <span class="o">=</span> <span class="nx">iterator</span><span class="p">(</span><span class="nx">value</span><span class="p">,</span> <span class="nx">index</span><span class="p">);</span>
<span class="p">(</span><span class="nx">result</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">||</span> <span class="p">(</span><span class="nx">result</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">=</span> <span class="p">[])).</span><span class="nx">push</span><span class="p">(</span><span class="nx">value</span><span class="p">);</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-31"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-31">¶</a> </div> <p>Use a comparator function to figure out at what index an object should
be inserted so as to maintain order. Uses binary search.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">sortedIndex</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">obj</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">iterator</span> <span class="o">||</span> <span class="p">(</span><span class="nx">iterator</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">identity</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">low</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">high</span> <span class="o">=</span> <span class="nx">array</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">low</span> <span class="o"><</span> <span class="nx">high</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">mid</span> <span class="o">=</span> <span class="p">(</span><span class="nx">low</span> <span class="o">+</span> <span class="nx">high</span><span class="p">)</span> <span class="o">>></span> <span class="mi">1</span><span class="p">;</span>
<span class="nx">iterator</span><span class="p">(</span><span class="nx">array</span><span class="p">[</span><span class="nx">mid</span><span class="p">])</span> <span class="o"><</span> <span class="nx">iterator</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">?</span> <span class="nx">low</span> <span class="o">=</span> <span class="nx">mid</span> <span class="o">+</span> <span class="mi">1</span> <span class="o">:</span> <span class="nx">high</span> <span class="o">=</span> <span class="nx">mid</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">low</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-32"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-32">¶</a> </div> <p>Safely convert anything iterable into a real, live array.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">toArray</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">iterable</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">iterable</span><span class="p">)</span> <span class="k">return</span> <span class="p">[];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">iterable</span><span class="p">.</span><span class="nx">toArray</span><span class="p">)</span> <span class="k">return</span> <span class="nx">iterable</span><span class="p">.</span><span class="nx">toArray</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">iterable</span><span class="p">))</span> <span class="k">return</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">iterable</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isArguments</span><span class="p">(</span><span class="nx">iterable</span><span class="p">))</span> <span class="k">return</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">iterable</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">values</span><span class="p">(</span><span class="nx">iterable</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-33"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-33">¶</a> </div> <p>Return the number of elements in an object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">size</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">toArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">).</span><span class="nx">length</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-34"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-34">¶</a> </div> <h2>Array Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-35"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-35">¶</a> </div> <p>Get the first element of an array. Passing <strong>n</strong> will return the first N
values in the array. Aliased as <code>head</code>. The <strong>guard</strong> check allows it to work
with <code>_.map</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">first</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">head</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">n</span><span class="p">,</span> <span class="nx">guard</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">(</span><span class="nx">n</span> <span class="o">!=</span> <span class="kc">null</span><span class="p">)</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">guard</span> <span class="o">?</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">n</span><span class="p">)</span> <span class="o">:</span> <span class="nx">array</span><span class="p">[</span><span class="mi">0</span><span class="p">];</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-36"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-36">¶</a> </div> <p>Returns everything but the last entry of the array. Especcialy useful on
the arguments object. Passing <strong>n</strong> will return all the values in
the array, excluding the last N. The <strong>guard</strong> check allows it to work with
<code>_.map</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">initial</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">n</span><span class="p">,</span> <span class="nx">guard</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">array</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="p">((</span><span class="nx">n</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="o">||</span> <span class="nx">guard</span> <span class="o">?</span> <span class="mi">1</span> <span class="o">:</span> <span class="nx">n</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-37"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-37">¶</a> </div> <p>Get the last element of an array. Passing <strong>n</strong> will return the last N
values in the array. The <strong>guard</strong> check allows it to work with <code>_.map</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">last</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">n</span><span class="p">,</span> <span class="nx">guard</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">(</span><span class="nx">n</span> <span class="o">!=</span> <span class="kc">null</span><span class="p">)</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">guard</span> <span class="o">?</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">array</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="nx">n</span><span class="p">)</span> <span class="o">:</span> <span class="nx">array</span><span class="p">[</span><span class="nx">array</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">];</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-38"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-38">¶</a> </div> <p>Returns everything but the first entry of the array. Aliased as <code>tail</code>.
Especially useful on the arguments object. Passing an <strong>index</strong> will return
the rest of the values in the array from that index onward. The <strong>guard</strong>
check allows it to work with <code>_.map</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">rest</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">tail</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">index</span><span class="p">,</span> <span class="nx">guard</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="p">(</span><span class="nx">index</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="o">||</span> <span class="nx">guard</span> <span class="o">?</span> <span class="mi">1</span> <span class="o">:</span> <span class="nx">index</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-39"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-39">¶</a> </div> <p>Trim out all falsy values from an array.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">compact</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">filter</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">){</span> <span class="k">return</span> <span class="o">!!</span><span class="nx">value</span><span class="p">;</span> <span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-40"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-40">¶</a> </div> <p>Return a completely flattened version of an array.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">flatten</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">reduce</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">memo</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">value</span><span class="p">))</span> <span class="k">return</span> <span class="nx">memo</span><span class="p">.</span><span class="nx">concat</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">flatten</span><span class="p">(</span><span class="nx">value</span><span class="p">));</span>
<span class="nx">memo</span><span class="p">[</span><span class="nx">memo</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">value</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">memo</span><span class="p">;</span>
<span class="p">},</span> <span class="p">[]);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-41"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-41">¶</a> </div> <p>Return a version of the array that does not contain the specified value(s).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">without</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">difference</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-42"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-42">¶</a> </div> <p>Produce a duplicate-free version of the array. If the array has already
been sorted, you have the option of using a faster algorithm.
Aliased as <code>unique</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">uniq</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">unique</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">isSorted</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">initial</span> <span class="o">=</span> <span class="nx">iterator</span> <span class="o">?</span> <span class="nx">_</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">)</span> <span class="o">:</span> <span class="nx">array</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="p">[];</span>
<span class="nx">_</span><span class="p">.</span><span class="nx">reduce</span><span class="p">(</span><span class="nx">initial</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">memo</span><span class="p">,</span> <span class="nx">el</span><span class="p">,</span> <span class="nx">i</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="mi">0</span> <span class="o">==</span> <span class="nx">i</span> <span class="o">||</span> <span class="p">(</span><span class="nx">isSorted</span> <span class="o">===</span> <span class="kc">true</span> <span class="o">?</span> <span class="nx">_</span><span class="p">.</span><span class="nx">last</span><span class="p">(</span><span class="nx">memo</span><span class="p">)</span> <span class="o">!=</span> <span class="nx">el</span> <span class="o">:</span> <span class="o">!</span><span class="nx">_</span><span class="p">.</span><span class="nx">include</span><span class="p">(</span><span class="nx">memo</span><span class="p">,</span> <span class="nx">el</span><span class="p">)))</span> <span class="p">{</span>
<span class="nx">memo</span><span class="p">[</span><span class="nx">memo</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">el</span><span class="p">;</span>
<span class="nx">result</span><span class="p">[</span><span class="nx">result</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">array</span><span class="p">[</span><span class="nx">i</span><span class="p">];</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">memo</span><span class="p">;</span>
<span class="p">},</span> <span class="p">[]);</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-43"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-43">¶</a> </div> <p>Produce an array that contains the union: each distinct element from all of
the passed-in arrays.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">union</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">uniq</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">flatten</span><span class="p">(</span><span class="nx">arguments</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-44"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-44">¶</a> </div> <p>Produce an array that contains every item shared between all the
passed-in arrays. (Aliased as "intersect" for back-compat.)</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">intersection</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">intersect</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">rest</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">filter</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">uniq</span><span class="p">(</span><span class="nx">array</span><span class="p">),</span> <span class="kd">function</span><span class="p">(</span><span class="nx">item</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">every</span><span class="p">(</span><span class="nx">rest</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">other</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">other</span><span class="p">,</span> <span class="nx">item</span><span class="p">)</span> <span class="o">>=</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">});</span>
<span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-45"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-45">¶</a> </div> <p>Take the difference between one array and another.
Only the elements present in just the first array will remain.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">difference</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">other</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">filter</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">){</span> <span class="k">return</span> <span class="o">!</span><span class="nx">_</span><span class="p">.</span><span class="nx">include</span><span class="p">(</span><span class="nx">other</span><span class="p">,</span> <span class="nx">value</span><span class="p">);</span> <span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-46"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-46">¶</a> </div> <p>Zip together multiple lists into a single array -- elements that share
an index go together.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">zip</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">length</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">max</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span><span class="p">(</span><span class="nx">args</span><span class="p">,</span> <span class="s1">'length'</span><span class="p">));</span>
<span class="kd">var</span> <span class="nx">results</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">Array</span><span class="p">(</span><span class="nx">length</span><span class="p">);</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">length</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="nx">results</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span><span class="p">(</span><span class="nx">args</span><span class="p">,</span> <span class="s2">""</span> <span class="o">+</span> <span class="nx">i</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">results</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-47"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-47">¶</a> </div> <p>If the browser doesn't supply us with indexOf (I'm looking at you, <strong>MSIE</strong>),
we need this function. Return the position of the first occurrence of an
item in an array, or -1 if the item is not included in the array.
Delegates to <strong>ECMAScript 5</strong>'s native <code>indexOf</code> if available.
If the array is large and already in sort order, pass <code>true</code>
for <strong>isSorted</strong> to use binary search.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">indexOf</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">item</span><span class="p">,</span> <span class="nx">isSorted</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">array</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">i</span><span class="p">,</span> <span class="nx">l</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isSorted</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">i</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">sortedIndex</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">item</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">array</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span> <span class="o">===</span> <span class="nx">item</span> <span class="o">?</span> <span class="nx">i</span> <span class="o">:</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeIndexOf</span> <span class="o">&&</span> <span class="nx">array</span><span class="p">.</span><span class="nx">indexOf</span> <span class="o">===</span> <span class="nx">nativeIndexOf</span><span class="p">)</span> <span class="k">return</span> <span class="nx">array</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="nx">item</span><span class="p">);</span>
<span class="k">for</span> <span class="p">(</span><span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">l</span> <span class="o">=</span> <span class="nx">array</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">l</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="k">if</span> <span class="p">(</span><span class="nx">array</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span> <span class="o">===</span> <span class="nx">item</span><span class="p">)</span> <span class="k">return</span> <span class="nx">i</span><span class="p">;</span>
<span class="k">return</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-48"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-48">¶</a> </div> <p>Delegates to <strong>ECMAScript 5</strong>'s native <code>lastIndexOf</code> if available.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">lastIndexOf</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">array</span><span class="p">,</span> <span class="nx">item</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">array</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">nativeLastIndexOf</span> <span class="o">&&</span> <span class="nx">array</span><span class="p">.</span><span class="nx">lastIndexOf</span> <span class="o">===</span> <span class="nx">nativeLastIndexOf</span><span class="p">)</span> <span class="k">return</span> <span class="nx">array</span><span class="p">.</span><span class="nx">lastIndexOf</span><span class="p">(</span><span class="nx">item</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="nx">array</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">i</span><span class="o">--</span><span class="p">)</span> <span class="k">if</span> <span class="p">(</span><span class="nx">array</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span> <span class="o">===</span> <span class="nx">item</span><span class="p">)</span> <span class="k">return</span> <span class="nx">i</span><span class="p">;</span>
<span class="k">return</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-49"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-49">¶</a> </div> <p>Generate an integer Array containing an arithmetic progression. A port of
the native Python <code>range()</code> function. See
<a href="http://docs.python.org/library/functions.html#range">the Python documentation</a>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">range</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">stop</span><span class="p">,</span> <span class="nx">step</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">arguments</span><span class="p">.</span><span class="nx">length</span> <span class="o"><=</span> <span class="mi">1</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">stop</span> <span class="o">=</span> <span class="nx">start</span> <span class="o">||</span> <span class="mi">0</span><span class="p">;</span>
<span class="nx">start</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">step</span> <span class="o">=</span> <span class="nx">arguments</span><span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="o">||</span> <span class="mi">1</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">len</span> <span class="o">=</span> <span class="nb">Math</span><span class="p">.</span><span class="nx">max</span><span class="p">(</span><span class="nb">Math</span><span class="p">.</span><span class="nx">ceil</span><span class="p">((</span><span class="nx">stop</span> <span class="o">-</span> <span class="nx">start</span><span class="p">)</span> <span class="o">/</span> <span class="nx">step</span><span class="p">),</span> <span class="mi">0</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">idx</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">range</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">Array</span><span class="p">(</span><span class="nx">len</span><span class="p">);</span>
<span class="k">while</span><span class="p">(</span><span class="nx">idx</span> <span class="o"><</span> <span class="nx">len</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">range</span><span class="p">[</span><span class="nx">idx</span><span class="o">++</span><span class="p">]</span> <span class="o">=</span> <span class="nx">start</span><span class="p">;</span>
<span class="nx">start</span> <span class="o">+=</span> <span class="nx">step</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">range</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-50"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-50">¶</a> </div> <h2>Function (ahem) Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-51"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-51">¶</a> </div> <p>Create a function bound to a given object (assigning <code>this</code>, and arguments,
optionally). Binding with arguments is also known as <code>curry</code>.
Delegates to <strong>ECMAScript 5</strong>'s native <code>Function.bind</code> if available.
We check for <code>func.bind</code> first, to fail fast when <code>func</code> is undefined.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">bind</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">func</span><span class="p">.</span><span class="nx">bind</span> <span class="o">===</span> <span class="nx">nativeBind</span> <span class="o">&&</span> <span class="nx">nativeBind</span><span class="p">)</span> <span class="k">return</span> <span class="nx">nativeBind</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">));</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">args</span><span class="p">.</span><span class="nx">concat</span><span class="p">(</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">)));</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-52"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-52">¶</a> </div> <p>Bind all of an object's methods to that object. Useful for ensuring that
all callbacks defined on an object belong to it.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">bindAll</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">funcs</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">funcs</span><span class="p">.</span><span class="nx">length</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span> <span class="nx">funcs</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">functions</span><span class="p">(</span><span class="nx">obj</span><span class="p">);</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">funcs</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">f</span><span class="p">)</span> <span class="p">{</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">f</span><span class="p">]</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">bind</span><span class="p">(</span><span class="nx">obj</span><span class="p">[</span><span class="nx">f</span><span class="p">],</span> <span class="nx">obj</span><span class="p">);</span> <span class="p">});</span>
<span class="k">return</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-53"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-53">¶</a> </div> <p>Memoize an expensive function by storing its results.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">memoize</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">hasher</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">memo</span> <span class="o">=</span> <span class="p">{};</span>
<span class="nx">hasher</span> <span class="o">||</span> <span class="p">(</span><span class="nx">hasher</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">identity</span><span class="p">);</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">key</span> <span class="o">=</span> <span class="nx">hasher</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">memo</span><span class="p">,</span> <span class="nx">key</span><span class="p">)</span> <span class="o">?</span> <span class="nx">memo</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">:</span> <span class="p">(</span><span class="nx">memo</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">=</span> <span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">));</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-54"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-54">¶</a> </div> <p>Delays a function for the given number of milliseconds, and then calls
it with the arguments supplied.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">delay</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">setTimeout</span><span class="p">(</span><span class="kd">function</span><span class="p">(){</span> <span class="k">return</span> <span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">args</span><span class="p">);</span> <span class="p">},</span> <span class="nx">wait</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-55"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-55">¶</a> </div> <p>Defers a function, scheduling it to run after the current call stack has
cleared.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">defer</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">delay</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">_</span><span class="p">,</span> <span class="p">[</span><span class="nx">func</span><span class="p">,</span> <span class="mi">1</span><span class="p">].</span><span class="nx">concat</span><span class="p">(</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">)));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-56"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-56">¶</a> </div> <p>Internal function used to implement <code>_.throttle</code> and <code>_.debounce</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">limit</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">,</span> <span class="nx">debounce</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">timeout</span><span class="p">;</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">context</span> <span class="o">=</span> <span class="k">this</span><span class="p">,</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">arguments</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">throttler</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">timeout</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">args</span><span class="p">);</span>
<span class="p">};</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">debounce</span><span class="p">)</span> <span class="nx">clearTimeout</span><span class="p">(</span><span class="nx">timeout</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">debounce</span> <span class="o">||</span> <span class="o">!</span><span class="nx">timeout</span><span class="p">)</span> <span class="nx">timeout</span> <span class="o">=</span> <span class="nx">setTimeout</span><span class="p">(</span><span class="nx">throttler</span><span class="p">,</span> <span class="nx">wait</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-57"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-57">¶</a> </div> <p>Returns a function, that, when invoked, will only be triggered at most once
during a given window of time.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">throttle</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">limit</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">,</span> <span class="kc">false</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-58"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-58">¶</a> </div> <p>Returns a function, that, as long as it continues to be invoked, will not
be triggered. The function will be called after it stops being called for
N milliseconds.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">debounce</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">limit</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wait</span><span class="p">,</span> <span class="kc">true</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-59"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-59">¶</a> </div> <p>Returns a function that will be executed at most one time, no matter how
often you call it. Useful for lazy initialization.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">once</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">ran</span> <span class="o">=</span> <span class="kc">false</span><span class="p">,</span> <span class="nx">memo</span><span class="p">;</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ran</span><span class="p">)</span> <span class="k">return</span> <span class="nx">memo</span><span class="p">;</span>
<span class="nx">ran</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">memo</span> <span class="o">=</span> <span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-60"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-60">¶</a> </div> <p>Returns the first function passed as an argument to the second,
allowing you to adjust arguments, run code before and after, and
conditionally execute the original function.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">wrap</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">func</span><span class="p">,</span> <span class="nx">wrapper</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="p">[</span><span class="nx">func</span><span class="p">].</span><span class="nx">concat</span><span class="p">(</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">));</span>
<span class="k">return</span> <span class="nx">wrapper</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">args</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-61"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-61">¶</a> </div> <p>Returns a function that is the composition of a list of functions, each
consuming the return value of the function that follows.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">compose</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">funcs</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">);</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">);</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="nx">funcs</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">;</span> <span class="nx">i</span> <span class="o">>=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span><span class="o">--</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">args</span> <span class="o">=</span> <span class="p">[</span><span class="nx">funcs</span><span class="p">[</span><span class="nx">i</span><span class="p">].</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">args</span><span class="p">)];</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">args</span><span class="p">[</span><span class="mi">0</span><span class="p">];</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-62"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-62">¶</a> </div> <p>Returns a function that will only be executed after being called N times.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">after</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">times</span><span class="p">,</span> <span class="nx">func</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">--</span><span class="nx">times</span> <span class="o"><</span> <span class="mi">1</span><span class="p">)</span> <span class="p">{</span> <span class="k">return</span> <span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">);</span> <span class="p">}</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-63"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-63">¶</a> </div> <h2>Object Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-64"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-64">¶</a> </div> <p>Retrieve the names of an object's properties.
Delegates to <strong>ECMAScript 5</strong>'s native <code>Object.keys</code></p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">keys</span> <span class="o">=</span> <span class="nx">nativeKeys</span> <span class="o">||</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">!==</span> <span class="nb">Object</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">throw</span> <span class="k">new</span> <span class="nx">TypeError</span><span class="p">(</span><span class="s1">'Invalid object'</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">keys</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">key</span> <span class="k">in</span> <span class="nx">obj</span><span class="p">)</span> <span class="k">if</span> <span class="p">(</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">key</span><span class="p">))</span> <span class="nx">keys</span><span class="p">[</span><span class="nx">keys</span><span class="p">.</span><span class="nx">length</span><span class="p">]</span> <span class="o">=</span> <span class="nx">key</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">keys</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-65"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-65">¶</a> </div> <p>Retrieve the values of an object's properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">values</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">_</span><span class="p">.</span><span class="nx">identity</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-66"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-66">¶</a> </div> <p>Return a sorted list of the function names available on the object.
Aliased as <code>methods</code></p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">functions</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">methods</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">names</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">key</span> <span class="k">in</span> <span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isFunction</span><span class="p">(</span><span class="nx">obj</span><span class="p">[</span><span class="nx">key</span><span class="p">]))</span> <span class="nx">names</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">key</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">names</span><span class="p">.</span><span class="nx">sort</span><span class="p">();</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-67"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-67">¶</a> </div> <p>Extend a given object with all the properties in passed-in object(s).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">extend</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">),</span> <span class="kd">function</span><span class="p">(</span><span class="nx">source</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">prop</span> <span class="k">in</span> <span class="nx">source</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">source</span><span class="p">[</span><span class="nx">prop</span><span class="p">]</span> <span class="o">!==</span> <span class="k">void</span> <span class="mi">0</span><span class="p">)</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">prop</span><span class="p">]</span> <span class="o">=</span> <span class="nx">source</span><span class="p">[</span><span class="nx">prop</span><span class="p">];</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-68"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-68">¶</a> </div> <p>Fill in a given object with default properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">defaults</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">,</span> <span class="mi">1</span><span class="p">),</span> <span class="kd">function</span><span class="p">(</span><span class="nx">source</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">prop</span> <span class="k">in</span> <span class="nx">source</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">obj</span><span class="p">[</span><span class="nx">prop</span><span class="p">]</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">prop</span><span class="p">]</span> <span class="o">=</span> <span class="nx">source</span><span class="p">[</span><span class="nx">prop</span><span class="p">];</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="k">return</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-69"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-69">¶</a> </div> <p>Create a (shallow-cloned) duplicate of an object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">clone</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">?</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">slice</span><span class="p">()</span> <span class="o">:</span> <span class="nx">_</span><span class="p">.</span><span class="nx">extend</span><span class="p">({},</span> <span class="nx">obj</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-70"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-70">¶</a> </div> <p>Invokes interceptor with the obj, and then returns obj.
The primary purpose of this method is to "tap into" a method chain, in
order to perform operations on intermediate results within the chain.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">tap</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">interceptor</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">interceptor</span><span class="p">(</span><span class="nx">obj</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-71"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-71">¶</a> </div> <p>Internal recursive comparison function.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">eq</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">b</span><span class="p">,</span> <span class="nx">stack</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-72"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-72">¶</a> </div> <p>Identical objects are equal. <code>0 === -0</code>, but they aren't identical.
See the Harmony <code>egal</code> proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">a</span> <span class="o">===</span> <span class="nx">b</span><span class="p">)</span> <span class="k">return</span> <span class="nx">a</span> <span class="o">!==</span> <span class="mi">0</span> <span class="o">||</span> <span class="mi">1</span> <span class="o">/</span> <span class="nx">a</span> <span class="o">==</span> <span class="mi">1</span> <span class="o">/</span> <span class="nx">b</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-73"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-73">¶</a> </div> <p>A strict comparison is necessary because <code>null == undefined</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">a</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">return</span> <span class="nx">a</span> <span class="o">===</span> <span class="nx">b</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-74"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-74">¶</a> </div> <p>Compare object types.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">typeA</span> <span class="o">=</span> <span class="k">typeof</span> <span class="nx">a</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">typeA</span> <span class="o">!=</span> <span class="k">typeof</span> <span class="nx">b</span><span class="p">)</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-75"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-75">¶</a> </div> <p>Optimization; ensure that both values are truthy or falsy.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">a</span> <span class="o">!=</span> <span class="o">!</span><span class="nx">b</span><span class="p">)</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-76"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-76">¶</a> </div> <p><code>NaN</code> values are equal.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nb">isNaN</span><span class="p">(</span><span class="nx">a</span><span class="p">))</span> <span class="k">return</span> <span class="nx">_</span><span class="p">.</span><span class="nb">isNaN</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-77"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-77">¶</a> </div> <p>Compare string objects by value.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isStringA</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isString</span><span class="p">(</span><span class="nx">a</span><span class="p">),</span> <span class="nx">isStringB</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isString</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isStringA</span> <span class="o">||</span> <span class="nx">isStringB</span><span class="p">)</span> <span class="k">return</span> <span class="nx">isStringA</span> <span class="o">&&</span> <span class="nx">isStringB</span> <span class="o">&&</span> <span class="nb">String</span><span class="p">(</span><span class="nx">a</span><span class="p">)</span> <span class="o">==</span> <span class="nb">String</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-78"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-78">¶</a> </div> <p>Compare number objects by value.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isNumberA</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isNumber</span><span class="p">(</span><span class="nx">a</span><span class="p">),</span> <span class="nx">isNumberB</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isNumber</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isNumberA</span> <span class="o">||</span> <span class="nx">isNumberB</span><span class="p">)</span> <span class="k">return</span> <span class="nx">isNumberA</span> <span class="o">&&</span> <span class="nx">isNumberB</span> <span class="o">&&</span> <span class="o">+</span><span class="nx">a</span> <span class="o">==</span> <span class="o">+</span><span class="nx">b</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-79"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-79">¶</a> </div> <p>Compare boolean objects by value. The value of <code>true</code> is 1; the value of <code>false</code> is 0.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isBooleanA</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isBoolean</span><span class="p">(</span><span class="nx">a</span><span class="p">),</span> <span class="nx">isBooleanB</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isBoolean</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isBooleanA</span> <span class="o">||</span> <span class="nx">isBooleanB</span><span class="p">)</span> <span class="k">return</span> <span class="nx">isBooleanA</span> <span class="o">&&</span> <span class="nx">isBooleanB</span> <span class="o">&&</span> <span class="o">+</span><span class="nx">a</span> <span class="o">==</span> <span class="o">+</span><span class="nx">b</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-80"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-80">¶</a> </div> <p>Compare dates by their millisecond values.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isDateA</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isDate</span><span class="p">(</span><span class="nx">a</span><span class="p">),</span> <span class="nx">isDateB</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isDate</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isDateA</span> <span class="o">||</span> <span class="nx">isDateB</span><span class="p">)</span> <span class="k">return</span> <span class="nx">isDateA</span> <span class="o">&&</span> <span class="nx">isDateB</span> <span class="o">&&</span> <span class="nx">a</span><span class="p">.</span><span class="nx">getTime</span><span class="p">()</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">getTime</span><span class="p">();</span></pre></div> </td> </tr> <tr id="section-81"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-81">¶</a> </div> <p>Compare RegExps by their source patterns and flags.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isRegExpA</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isRegExp</span><span class="p">(</span><span class="nx">a</span><span class="p">),</span> <span class="nx">isRegExpB</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isRegExp</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isRegExpA</span> <span class="o">||</span> <span class="nx">isRegExpB</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-82"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-82">¶</a> </div> <p>Ensure commutative equality for RegExps.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">return</span> <span class="nx">isRegExpA</span> <span class="o">&&</span> <span class="nx">isRegExpB</span> <span class="o">&&</span>
<span class="nx">a</span><span class="p">.</span><span class="nx">source</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">source</span> <span class="o">&&</span>
<span class="nx">a</span><span class="p">.</span><span class="nx">global</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">global</span> <span class="o">&&</span>
<span class="nx">a</span><span class="p">.</span><span class="nx">multiline</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">multiline</span> <span class="o">&&</span>
<span class="nx">a</span><span class="p">.</span><span class="nx">ignoreCase</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">ignoreCase</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-83"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-83">¶</a> </div> <p>Ensure that both values are objects.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">typeA</span> <span class="o">!=</span> <span class="s1">'object'</span><span class="p">)</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-84"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-84">¶</a> </div> <p>Unwrap any wrapped objects.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">a</span><span class="p">.</span><span class="nx">_chain</span><span class="p">)</span> <span class="nx">a</span> <span class="o">=</span> <span class="nx">a</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">b</span><span class="p">.</span><span class="nx">_chain</span><span class="p">)</span> <span class="nx">b</span> <span class="o">=</span> <span class="nx">b</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-85"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-85">¶</a> </div> <p>Invoke a custom <code>isEqual</code> method if one is provided.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isFunction</span><span class="p">(</span><span class="nx">a</span><span class="p">.</span><span class="nx">isEqual</span><span class="p">))</span> <span class="k">return</span> <span class="nx">a</span><span class="p">.</span><span class="nx">isEqual</span><span class="p">(</span><span class="nx">b</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-86"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-86">¶</a> </div> <p>Assume equality for cyclic structures. The algorithm for detecting cyclic structures is
adapted from ES 5.1 section 15.12.3, abstract operation <code>JO</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">length</span> <span class="o">=</span> <span class="nx">stack</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">length</span><span class="o">--</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-87"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-87">¶</a> </div> <p>Linear search. Performance is inversely proportional to the number of unique nested
structures.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">stack</span><span class="p">[</span><span class="nx">length</span><span class="p">]</span> <span class="o">==</span> <span class="nx">a</span><span class="p">)</span> <span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-88"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-88">¶</a> </div> <p>Add the first object to the stack of traversed objects.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">a</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">size</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">result</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">a</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="o">+</span><span class="nx">a</span><span class="p">.</span><span class="nx">length</span> <span class="o">||</span> <span class="nx">b</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="o">+</span><span class="nx">b</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-89"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-89">¶</a> </div> <p>Compare object lengths to determine if a deep comparison is necessary.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">size</span> <span class="o">=</span> <span class="nx">a</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="nx">result</span> <span class="o">=</span> <span class="nx">size</span> <span class="o">==</span> <span class="nx">b</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">result</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-90"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-90">¶</a> </div> <p>Deep compare array-like object contents, ignoring non-numeric properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">while</span> <span class="p">(</span><span class="nx">size</span><span class="o">--</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-91"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-91">¶</a> </div> <p>Ensure commutative equality for sparse arrays.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="p">(</span><span class="nx">result</span> <span class="o">=</span> <span class="nx">size</span> <span class="k">in</span> <span class="nx">a</span> <span class="o">==</span> <span class="nx">size</span> <span class="k">in</span> <span class="nx">b</span> <span class="o">&&</span> <span class="nx">eq</span><span class="p">(</span><span class="nx">a</span><span class="p">[</span><span class="nx">size</span><span class="p">],</span> <span class="nx">b</span><span class="p">[</span><span class="nx">size</span><span class="p">],</span> <span class="nx">stack</span><span class="p">)))</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-92"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-92">¶</a> </div> <p>Deep compare objects.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">key</span> <span class="k">in</span> <span class="nx">a</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">key</span><span class="p">))</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-93"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-93">¶</a> </div> <p>Count the expected number of properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">size</span><span class="o">++</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-94"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-94">¶</a> </div> <p>Deep compare each member.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="p">(</span><span class="nx">result</span> <span class="o">=</span> <span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">b</span><span class="p">,</span> <span class="nx">key</span><span class="p">)</span> <span class="o">&&</span> <span class="nx">eq</span><span class="p">(</span><span class="nx">a</span><span class="p">[</span><span class="nx">key</span><span class="p">],</span> <span class="nx">b</span><span class="p">[</span><span class="nx">key</span><span class="p">],</span> <span class="nx">stack</span><span class="p">)))</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-95"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-95">¶</a> </div> <p>Ensure that both objects contain the same number of properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">result</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="nx">key</span> <span class="k">in</span> <span class="nx">b</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">b</span><span class="p">,</span> <span class="nx">key</span><span class="p">)</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">size</span><span class="o">--</span><span class="p">)</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">result</span> <span class="o">=</span> <span class="o">!</span><span class="nx">size</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-96"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-96">¶</a> </div> <p>Remove the first object from the stack of traversed objects.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">stack</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-97"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-97">¶</a> </div> <p>Perform a deep comparison to check if two objects are equal.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isEqual</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">b</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">eq</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">b</span><span class="p">,</span> <span class="p">[]);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-98"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-98">¶</a> </div> <p>Is a given array or object empty?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isEmpty</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">||</span> <span class="nx">_</span><span class="p">.</span><span class="nx">isString</span><span class="p">(</span><span class="nx">obj</span><span class="p">))</span> <span class="k">return</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">0</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">key</span> <span class="k">in</span> <span class="nx">obj</span><span class="p">)</span> <span class="k">if</span> <span class="p">(</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">key</span><span class="p">))</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span>
<span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-99"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-99">¶</a> </div> <p>Is a given value a DOM element?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isElement</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">nodeType</span> <span class="o">==</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-100"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-100">¶</a> </div> <p>Is a given value an array?
Delegates to ECMA5's native Array.isArray</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isArray</span> <span class="o">=</span> <span class="nx">nativeIsArray</span> <span class="o">||</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">toString</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">===</span> <span class="s1">'[object Array]'</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-101"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-101">¶</a> </div> <p>Is a given variable an object?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isObject</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">obj</span> <span class="o">===</span> <span class="nb">Object</span><span class="p">(</span><span class="nx">obj</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-102"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-102">¶</a> </div> <p>Is a given variable an arguments object?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isArguments</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="s1">'callee'</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-103"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-103">¶</a> </div> <p>Is a given value a function?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isFunction</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">constructor</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">call</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">apply</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-104"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-104">¶</a> </div> <p>Is a given value a string?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isString</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">===</span> <span class="s1">''</span> <span class="o">||</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">charCodeAt</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">substr</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-105"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-105">¶</a> </div> <p>Is a given value a number?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isNumber</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">===</span> <span class="mi">0</span> <span class="o">||</span> <span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">toExponential</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">toFixed</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-106"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-106">¶</a> </div> <p>Is the given value <code>NaN</code>? <code>NaN</code> happens to be the only value in JavaScript
that does not equal itself.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nb">isNaN</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">obj</span> <span class="o">!==</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-107"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-107">¶</a> </div> <p>Is a given value a boolean?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isBoolean</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">obj</span> <span class="o">===</span> <span class="kc">true</span> <span class="o">||</span> <span class="nx">obj</span> <span class="o">===</span> <span class="kc">false</span> <span class="o">||</span> <span class="nx">toString</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="o">==</span> <span class="s1">'[object Boolean]'</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-108"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-108">¶</a> </div> <p>Is a given value a date?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isDate</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">getTimezoneOffset</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">setUTCFullYear</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-109"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-109">¶</a> </div> <p>Is the given value a regular expression?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isRegExp</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!!</span><span class="p">(</span><span class="nx">obj</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">test</span> <span class="o">&&</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">exec</span> <span class="o">&&</span> <span class="p">(</span><span class="nx">obj</span><span class="p">.</span><span class="nx">ignoreCase</span> <span class="o">||</span> <span class="nx">obj</span><span class="p">.</span><span class="nx">ignoreCase</span> <span class="o">===</span> <span class="kc">false</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-110"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-110">¶</a> </div> <p>Is a given value equal to null?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isNull</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">obj</span> <span class="o">===</span> <span class="kc">null</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-111"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-111">¶</a> </div> <p>Is a given variable undefined?</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">isUndefined</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">obj</span> <span class="o">===</span> <span class="k">void</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-112"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-112">¶</a> </div> <h2>Utility Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-113"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-113">¶</a> </div> <p>Run Underscore.js in <em>noConflict</em> mode, returning the <code>_</code> variable to its
previous owner. Returns a reference to the Underscore object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">noConflict</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">root</span><span class="p">.</span><span class="nx">_</span> <span class="o">=</span> <span class="nx">previousUnderscore</span><span class="p">;</span>
<span class="k">return</span> <span class="k">this</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-114"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-114">¶</a> </div> <p>Keep the identity function around for default iterators.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">identity</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">value</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-115"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-115">¶</a> </div> <p>Run a function <strong>n</strong> times.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">times</span> <span class="o">=</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">n</span><span class="p">,</span> <span class="nx">iterator</span><span class="p">,</span> <span class="nx">context</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">n</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="nx">iterator</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">context</span><span class="p">,</span> <span class="nx">i</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-116"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-116">¶</a> </div> <p>Escape a string for HTML interpolation.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">escape</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">string</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">(</span><span class="s1">''</span><span class="o">+</span><span class="nx">string</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/&(?!\w+;|#\d+;|#x[\da-f]+;)/gi</span><span class="p">,</span> <span class="s1">'&amp;'</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/</g</span><span class="p">,</span> <span class="s1">'&lt;'</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/>/g</span><span class="p">,</span> <span class="s1">'&gt;'</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/"/g</span><span class="p">,</span> <span class="s1">'&quot;'</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/'/g</span><span class="p">,</span> <span class="s1">'&#x27;'</span><span class="p">).</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\//g</span><span class="p">,</span><span class="s1">'&#x2F;'</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-117"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-117">¶</a> </div> <p>Add your own custom functions to the Underscore object, ensuring that
they're correctly added to the OOP wrapper as well.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">mixin</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">each</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">functions</span><span class="p">(</span><span class="nx">obj</span><span class="p">),</span> <span class="kd">function</span><span class="p">(</span><span class="nx">name</span><span class="p">){</span>
<span class="nx">addToWrapper</span><span class="p">(</span><span class="nx">name</span><span class="p">,</span> <span class="nx">_</span><span class="p">[</span><span class="nx">name</span><span class="p">]</span> <span class="o">=</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">name</span><span class="p">]);</span>
<span class="p">});</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-118"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-118">¶</a> </div> <p>Generate a unique integer id (unique within the entire client session).
Useful for temporary DOM ids.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">idCounter</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="nx">_</span><span class="p">.</span><span class="nx">uniqueId</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">prefix</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">id</span> <span class="o">=</span> <span class="nx">idCounter</span><span class="o">++</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">prefix</span> <span class="o">?</span> <span class="nx">prefix</span> <span class="o">+</span> <span class="nx">id</span> <span class="o">:</span> <span class="nx">id</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-119"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-119">¶</a> </div> <p>By default, Underscore uses ERB-style template delimiters, change the
following template settings to use alternative delimiters.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">templateSettings</span> <span class="o">=</span> <span class="p">{</span>
<span class="nx">evaluate</span> <span class="o">:</span> <span class="sr">/<%([\s\S]+?)%>/g</span><span class="p">,</span>
<span class="nx">interpolate</span> <span class="o">:</span> <span class="sr">/<%=([\s\S]+?)%>/g</span><span class="p">,</span>
<span class="nx">escape</span> <span class="o">:</span> <span class="sr">/<%-([\s\S]+?)%>/g</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-120"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-120">¶</a> </div> <p>JavaScript micro-templating, similar to John Resig's implementation.
Underscore templating handles arbitrary delimiters, preserves whitespace,
and correctly escapes quotes within interpolated code.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">template</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">str</span><span class="p">,</span> <span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">c</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">templateSettings</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">tmpl</span> <span class="o">=</span> <span class="s1">'var __p=[],print=function(){__p.push.apply(__p,arguments);};'</span> <span class="o">+</span>
<span class="s1">'with(obj||{}){__p.push(\''</span> <span class="o">+</span>
<span class="nx">str</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\\/g</span><span class="p">,</span> <span class="s1">'\\\\'</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/'/g</span><span class="p">,</span> <span class="s2">"\\'"</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">c</span><span class="p">.</span><span class="nx">escape</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">match</span><span class="p">,</span> <span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="s2">"',_.escape("</span> <span class="o">+</span> <span class="nx">code</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\\'/g</span><span class="p">,</span> <span class="s2">"'"</span><span class="p">)</span> <span class="o">+</span> <span class="s2">"),'"</span><span class="p">;</span>
<span class="p">})</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">c</span><span class="p">.</span><span class="nx">interpolate</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">match</span><span class="p">,</span> <span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="s2">"',"</span> <span class="o">+</span> <span class="nx">code</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\\'/g</span><span class="p">,</span> <span class="s2">"'"</span><span class="p">)</span> <span class="o">+</span> <span class="s2">",'"</span><span class="p">;</span>
<span class="p">})</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="nx">c</span><span class="p">.</span><span class="nx">evaluate</span> <span class="o">||</span> <span class="kc">null</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">match</span><span class="p">,</span> <span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="s2">"');"</span> <span class="o">+</span> <span class="nx">code</span><span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\\'/g</span><span class="p">,</span> <span class="s2">"'"</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/[\r\n\t]/g</span><span class="p">,</span> <span class="s1">' '</span><span class="p">)</span> <span class="o">+</span> <span class="s2">"__p.push('"</span><span class="p">;</span>
<span class="p">})</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\r/g</span><span class="p">,</span> <span class="s1">'\\r'</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\n/g</span><span class="p">,</span> <span class="s1">'\\n'</span><span class="p">)</span>
<span class="p">.</span><span class="nx">replace</span><span class="p">(</span><span class="sr">/\t/g</span><span class="p">,</span> <span class="s1">'\\t'</span><span class="p">)</span>
<span class="o">+</span> <span class="s2">"');}return __p.join('');"</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">func</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">Function</span><span class="p">(</span><span class="s1">'obj'</span><span class="p">,</span> <span class="nx">tmpl</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">data</span> <span class="o">?</span> <span class="nx">func</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="o">:</span> <span class="nx">func</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-121"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-121">¶</a> </div> <h2>The OOP Wrapper</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-122"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-122">¶</a> </div> <p>If Underscore is called as a function, it returns a wrapped object that
can be used OO-style. This wrapper holds altered versions of all the
underscore functions. Wrapped objects may be chained.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">wrapper</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">)</span> <span class="p">{</span> <span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span> <span class="o">=</span> <span class="nx">obj</span><span class="p">;</span> <span class="p">};</span></pre></div> </td> </tr> <tr id="section-123"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-123">¶</a> </div> <p>Expose <code>wrapper.prototype</code> as <code>_.prototype</code></p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">prototype</span> <span class="o">=</span> <span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-124"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-124">¶</a> </div> <p>Helper function to continue chaining intermediate results.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">result</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">obj</span><span class="p">,</span> <span class="nx">chain</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">chain</span> <span class="o">?</span> <span class="nx">_</span><span class="p">(</span><span class="nx">obj</span><span class="p">).</span><span class="nx">chain</span><span class="p">()</span> <span class="o">:</span> <span class="nx">obj</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-125"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-125">¶</a> </div> <p>A method to easily add functions to the OOP wrapper.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">addToWrapper</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">name</span><span class="p">,</span> <span class="nx">func</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">[</span><span class="nx">name</span><span class="p">]</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">args</span> <span class="o">=</span> <span class="nx">slice</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">arguments</span><span class="p">);</span>
<span class="nx">unshift</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">args</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">(</span><span class="nx">func</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="nx">_</span><span class="p">,</span> <span class="nx">args</span><span class="p">),</span> <span class="k">this</span><span class="p">.</span><span class="nx">_chain</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-126"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-126">¶</a> </div> <p>Add all of the Underscore functions to the wrapper object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">_</span><span class="p">.</span><span class="nx">mixin</span><span class="p">(</span><span class="nx">_</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-127"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-127">¶</a> </div> <p>Add all mutator Array functions to the wrapper.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">each</span><span class="p">([</span><span class="s1">'pop'</span><span class="p">,</span> <span class="s1">'push'</span><span class="p">,</span> <span class="s1">'reverse'</span><span class="p">,</span> <span class="s1">'shift'</span><span class="p">,</span> <span class="s1">'sort'</span><span class="p">,</span> <span class="s1">'splice'</span><span class="p">,</span> <span class="s1">'unshift'</span><span class="p">],</span> <span class="kd">function</span><span class="p">(</span><span class="nx">name</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">method</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">[</span><span class="nx">name</span><span class="p">];</span>
<span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">[</span><span class="nx">name</span><span class="p">]</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">method</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">_chain</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">});</span></pre></div> </td> </tr> <tr id="section-128"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-128">¶</a> </div> <p>Add all accessor Array functions to the wrapper.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">each</span><span class="p">([</span><span class="s1">'concat'</span><span class="p">,</span> <span class="s1">'join'</span><span class="p">,</span> <span class="s1">'slice'</span><span class="p">],</span> <span class="kd">function</span><span class="p">(</span><span class="nx">name</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">method</span> <span class="o">=</span> <span class="nx">ArrayProto</span><span class="p">[</span><span class="nx">name</span><span class="p">];</span>
<span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">[</span><span class="nx">name</span><span class="p">]</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">result</span><span class="p">(</span><span class="nx">method</span><span class="p">.</span><span class="nx">apply</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">,</span> <span class="nx">arguments</span><span class="p">),</span> <span class="k">this</span><span class="p">.</span><span class="nx">_chain</span><span class="p">);</span>
<span class="p">};</span>
<span class="p">});</span></pre></div> </td> </tr> <tr id="section-129"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-129">¶</a> </div> <p>Start chaining a wrapped Underscore object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">.</span><span class="nx">chain</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">this</span><span class="p">.</span><span class="nx">_chain</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">return</span> <span class="k">this</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-130"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-130">¶</a> </div> <p>Extracts the result from a wrapped and chained object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">wrapper</span><span class="p">.</span><span class="nx">prototype</span><span class="p">.</span><span class="nx">value</span> <span class="o">=</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
<span class="k">return</span> <span class="k">this</span><span class="p">.</span><span class="nx">_wrapped</span><span class="p">;</span>
<span class="p">};</span>
<span class="p">})();</span>
</pre></div> </td> </tr> </tbody> </table> </div> </body> </html>