Idiomatic elixir to execute if params is not nil? : <p>How to go about filtering out invalid params like nil or empty list before proceed to process the params?</p>

<p>The <code>case</code> use below seems to be common but it's not clear code -- I am pretty sure there is a simpler and idiomatic way to do this.</p>

<pre><code> def load(token) do

   case token do
     nil -&gt; nil
     [] -&gt; nil
     token -&gt; process(token)
   end

 end
</code></pre>
