li>
<li>
<code>.w</code> a mapper or a function evaluated when a warning occurs</li>
<li>
<code>.f</code> a mapper or an expression which is always evaluated before returning or exiting</li>
</ul>
<p>In <code>.e</code> and <code>.f</code>, the <code>.x</code> refers to the error / warning object.</p>
<div id="with-mappers" class="section level3">
<h3 class="hasAnchor">
<a href="#with-mappers" class="anchor"></a>With mappers</h3>
<div class="sourceCode" id="cb10"><pre class="sourceCode r"><code class="source