:arglist=&gt;
  [{:left=&gt;{:int=&gt;"1"@5},
    :op=&gt;"+ "@7,
    :right=&gt;{:left=&gt;{:int=&gt;"2"@9}, :op=&gt;"+ "@11, :right=&gt;{:int=&gt;"3"@13}}},
   {:int=&gt;"45"@16}]}
</code></pre>
<p>Parslet calls this the <em>intermediary tree</em>. There are three types of nodes in
this tree:</p>
<ul>
	<li><strong>Hashes</strong>: a node that has named subtrees</li>
	<li><strong>Arrays</strong>: a node storing a collection of sub-nodes</li>
	<li><strong>Strings</strong> are the leaves, containing the <em>