title: Sequence-like function which reports all the errors
body: <p>I'm looking for a function in the standard library with a signature similar to this one:</p>
  <pre><code>Traversable f =&gt; f (Either e a) -&gt; Either [e] (f a)
  </code></pre>
  <p>Or maybe something like this:</p>
  <pre><code>(Traversable f, Monoid e) =&gt; f (Either e a) -&gt; Either e (f a)
  </code></pre>
  <p>The idea is to collect the errors instead of failing when the first error is encountered.</p>
  <p>I saw that my function looked very much like <code>sequence</code> and I was hoping that there was already a typeclass that modelled this pattern.</p>