title: Where did the argument go in this example?
body: <p>I am currently reading the <a href="https://github.com/MostlyAdequate/mostly-adequate-guide/blob/master/ch2.md" rel="noreferrer">Mostly Adequate Guide on functional programming, chapter 2</a>.</p>
  
  <p>There, the following example is given</p>
  
  <pre><code>var getServerStuff = function(callback) {
    return ajaxCall(function(json) {
      return callback(json);
    });
  };
  </code></pre>
  
  <p>which is then refactored into:</p>
  
  <pre><code>var getServerStuff = ajaxCall;
  </code></pre>
  
  <p>While explaining the refactoring, the author argues that</p>
  
  <pre><code>return ajaxCall(function(json) {
    return callback(json);
  });
  </code></pre>
  
  <p>is the same as</p>
  
  <pre><code>return ajaxCall(callback);
  </code></pre>
  
  <p>While I understand that <code>ajaxCall</code> is called with the return value of the anonymous function (which is just the return value of <code>callback</code>), I don't get how the refactored version is supposed to work - where did the <code>json</code> argument go? What am I missing?</p>