n class="c1">// Walk to accumulate variable and parameter definitions.</span>
<span class="kd">class</span><span class="w"> </span><span class="nx">VariableWalker</span><span class="w"> </span><span class="k">extends</span><span class="w"> </span><span class="nx">Walker</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="nx">Identifier</span><span class="w"> </span><span class="p">(</span><span class="nx">node</span><span class="p">,</span><span class="w"> </span><sp