title: How to tell what functions are called by a function? Like traceback() with no error needed?
body: <p>Is there a function or debugger in R to show what functions were called by a function? i.e., it would function a bit like <code>traceback</code> but triggered by a call to function instead of an error, and showing not just the stack but the tree of function calls. Like:</p>
  
  <pre><code>A-&gt; B -&gt; C -&gt; D
      E -&gt; F
      G -&gt; C -&gt; D
  </code></pre>