title: Exclude results from List Comprehensions in Elixir
body: <p>I have a simple list comprehension:</p>
  
  <pre class="lang-ex prettyprint-override"><code>for x &lt;- [some_list] do
    case _compute(x) do
      nil -&gt; nil # directly exclude this value from output
      val -&gt; val # add this value to output as usual
    end
  end
  </code></pre>
  
  <p>Short of running the whole comprehension, and then filtering out <code>nil</code> values, is there a better was to do this?</p>