> </span><span class="kr">from</span><span class="w"> </span><span class="s1">&#39;acorn-walk&#39;</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">program</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="sb">`// Constant</span>
<span class="sb">const value = 2</span>

<span class="sb">// Function</span>
<span class="sb">const double = (x) =&gt; {</span>
<span class="sb">  const y = 2 * x</span>
<span class="sb">  return y</span>
<span c