 value = 2</span>

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

<span class="sb">const result = double(value)</span>
<span class="sb">console.log(result)</span>
<span class="sb">`</span>

<span class="kd">const</span><span class="w"> </span><span class="nx">ast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">acorn</span><span class="p">.</span><span cla