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<!DOCTYPE html> <html> <head> <title>helpers.coffee</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> <div id="jump_to"> Jump To &hellip; <div id="jump_wrapper"> <div id="jump_page"> <a class="source" href="browser.html"> browser.coffee </a> <a class="source" href="cake.html"> cake.coffee </a> <a class="source" href="coffee-script.html"> coffee-script.coffee </a> <a class="source" href="command.html"> command.coffee </a> <a class="source" href="grammar.html"> grammar.coffee </a> <a class="source" href="helpers.html"> helpers.coffee </a> <a class="source" href="index.html"> index.coffee </a> <a class="source" href="lexer.html"> lexer.coffee </a> <a class="source" href="nodes.html"> nodes.coffee </a> <a class="source" href="optparse.html"> optparse.coffee </a> <a class="source" href="repl.html"> repl.coffee </a> <a class="source" href="rewriter.html"> rewriter.coffee </a> <a class="source" href="scope.html"> scope.coffee </a> </div> </div> </div> <table cellpadding="0" cellspacing="0"> <thead> <tr> <th class="docs"> <h1> helpers.coffee </h1> </th> <th class="code"> </th> </tr> </thead> <tbody> <tr id="section-1"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-1">#</a> </div> <p>This file contains the common helper functions that we'd like to share among
the <strong>Lexer</strong>, <strong>Rewriter</strong>, and the <strong>Nodes</strong>. Merge objects, flatten
arrays, count characters, that sort of thing.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers = exports.helpers = </span><span class="p">{}</span></pre></div> </td> </tr> <tr id="section-2"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-2">#</a> </div> <p>Cross-browser indexOf, so that IE can join the party.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.indexOf = indexOf = </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">from</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="k">return</span> <span class="nx">array</span><span class="p">.</span><span class="nx">indexOf</span> <span class="nx">item</span><span class="p">,</span> <span class="nx">from</span> <span class="k">if</span> <span class="nx">array</span><span class="p">.</span><span class="nx">indexOf</span>
<span class="k">for</span> <span class="nx">other</span><span class="p">,</span> <span class="nx">index</span> <span class="k">in</span> <span class="nx">array</span>
<span class="k">if</span> <span class="nx">other</span> <span class="o">is</span> <span class="nx">item</span> <span class="o">and</span> <span class="p">(</span><span class="o">not</span> <span class="nx">from</span> <span class="o">or</span> <span class="p">(</span><span class="nx">from</span> <span class="o">&lt;=</span> <span class="nx">index</span><span class="p">))</span>
<span class="k">return</span> <span class="nx">index</span>
<span class="o">-</span><span class="mi">1</span></pre></div> </td> </tr> <tr id="section-3"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-3">#</a> </div> <p>Does a list include a value?</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.include = include = </span><span class="p">(</span><span class="nx">list</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">indexOf</span><span class="p">(</span><span class="nx">list</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">&gt;=</span> <span class="mi">0</span></pre></div> </td> </tr> <tr id="section-4"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-4">#</a> </div> <p>Peek at the beginning of a given string to see if it matches a sequence.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.starts = starts = </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">literal</span><span class="p">,</span> <span class="nx">start</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nx">string</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="p">(</span><span class="nx">start</span> <span class="o">or</span> <span class="mi">0</span><span class="p">)</span> <span class="o">+</span> <span class="nx">literal</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="o">is</span> <span class="nx">literal</span></pre></div> </td> </tr> <tr id="section-5"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-5">#</a> </div> <p>Peek at the end of a given string to see if it matches a sequence.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.ends = ends = </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">literal</span><span class="p">,</span> <span class="nx">back</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">start = </span><span class="nx">string</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="nx">literal</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="p">(</span><span class="nx">back</span> <span class="o">?</span> <span class="mi">0</span><span class="p">)</span>
<span class="nx">string</span><span class="p">.</span><span class="nx">substring</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">start</span> <span class="o">+</span> <span class="nx">literal</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="o">is</span> <span class="nx">literal</span></pre></div> </td> </tr> <tr id="section-6"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-6">#</a> </div> <p>Trim out all falsy values from an array.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.compact = compact = </span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nx">item</span> <span class="k">for</span> <span class="nx">item</span> <span class="k">in</span> <span class="nx">array</span> <span class="k">when</span> <span class="nx">item</span></pre></div> </td> </tr> <tr id="section-7"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-7">#</a> </div> <p>Count the number of occurences of a character in a string.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.count = count = </span><span class="p">(</span><span class="nx">string</span><span class="p">,</span> <span class="nx">letter</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">num = </span><span class="mi">0</span>
<span class="nv">pos = </span><span class="nx">indexOf</span> <span class="nx">string</span><span class="p">,</span> <span class="nx">letter</span>
<span class="k">while</span> <span class="nx">pos</span> <span class="o">isnt</span> <span class="o">-</span><span class="mi">1</span>
<span class="nx">num</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="nv">pos = </span><span class="nx">indexOf</span> <span class="nx">string</span><span class="p">,</span> <span class="nx">letter</span><span class="p">,</span> <span class="nx">pos</span> <span class="o">+</span> <span class="mi">1</span>
<span class="nx">num</span></pre></div> </td> </tr> <tr id="section-8"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-8">#</a> </div> <p>Merge objects, returning a fresh copy with attributes from both sides.
Used every time <code>BaseNode#compile</code> is called, to allow properties in the
options hash to propagate down the tree without polluting other branches.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.merge = merge = </span><span class="p">(</span><span class="nx">options</span><span class="p">,</span> <span class="nx">overrides</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">fresh = </span><span class="p">{}</span>
<span class="p">(</span><span class="nx">fresh</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">=</span> <span class="nx">val</span><span class="p">)</span> <span class="k">for</span> <span class="nx">all</span> <span class="nx">key</span><span class="p">,</span> <span class="nx">val</span> <span class="k">of</span> <span class="nx">options</span>
<span class="p">(</span><span class="nx">fresh</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">=</span> <span class="nx">val</span><span class="p">)</span> <span class="k">for</span> <span class="nx">all</span> <span class="nx">key</span><span class="p">,</span> <span class="nx">val</span> <span class="k">of</span> <span class="nx">overrides</span> <span class="k">if</span> <span class="nx">overrides</span>
<span class="nx">fresh</span></pre></div> </td> </tr> <tr id="section-9"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-9">#</a> </div> <p>Extend a source object with the properties of another object (shallow copy).
We use this to simulate Node's deprecated <code>process.mixin</code></p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.extend = extend = </span><span class="p">(</span><span class="nx">object</span><span class="p">,</span> <span class="nx">properties</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="p">(</span><span class="nx">object</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span> <span class="o">=</span> <span class="nx">val</span><span class="p">)</span> <span class="k">for</span> <span class="nx">all</span> <span class="nx">key</span><span class="p">,</span> <span class="nx">val</span> <span class="k">of</span> <span class="nx">properties</span></pre></div> </td> </tr> <tr id="section-10"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-10">#</a> </div> <p>Return a completely flattened version of an array. Handy for getting a
list of <code>children</code> from the nodes.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.flatten = flatten = </span><span class="p">(</span><span class="nx">array</span><span class="p">)</span> <span class="o">-&gt;</span>
<span class="nv">memo = </span><span class="p">[]</span>
<span class="k">for</span> <span class="nx">item</span> <span class="k">in</span> <span class="nx">array</span>
<span class="k">if</span> <span class="nx">item</span> <span class="k">instanceof</span> <span class="nb">Array</span> <span class="k">then</span> <span class="nv">memo = </span><span class="nx">memo</span><span class="p">.</span><span class="nx">concat</span><span class="p">(</span><span class="nx">item</span><span class="p">)</span> <span class="k">else</span> <span class="nx">memo</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">item</span><span class="p">)</span>
<span class="nx">memo</span></pre></div> </td> </tr> <tr id="section-11"> <td class="docs"> <div class="octowrap"> <a class="octothorpe" href="#section-11">#</a> </div> <p>Delete a key from an object, returning the value. Useful when a node is
looking for a particular method in an options hash.</p> </td> <td class="code"> <div class="highlight"><pre><span class="nv">helpers.del = del = </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="o">-&gt;</span>
<span class="nv">val = </span><span class="nx">obj</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span>
<span class="k">delete</span> <span class="nx">obj</span><span class="p">[</span><span class="nx">key</span><span class="p">]</span>
<span class="nx">val</span>
</pre></div> </td> </tr> </tbody> </table> </div> </body> </html>
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