title: How can I get permutations of a list?
body: <p>How can I get permutations of a list in Elixir?</p>
  
  <p>Eg, for <code>["a", "b", "c"]</code>, I would expect:</p>
  
  <pre><code># [["a", "b", "c"], ["a", "c", "b"], 
  # ["b", "a", "c"], ["b", "c", "a"],
  # ["c", "a", "b"], ["c", "b", "a"]]
  </code></pre>