title: Optimal UUID RegEx with optional delimeters
body: <p>I have already found a question for UUID regular expressions <a href="https://stackoverflow.com/questions/136505/searching-for-uuids-in-text-with-regex">here</a>, but these expressions do not account missing delimeters.</p>
  
  <p>I have come up with the <a href="http://regexpal.com/?flags=gi&amp;regex=%5Cb(%5B0-9a-f%5D%7B8%7D-%3F(%5B0-9a-f%5D%7B4%7D-%3F)%7B3%7D%5B0-9a-f%5D%7B12%7D)%5Cb&amp;input=foo%7Cbar%3Af81d4fae-7dec-11d0-a765-00a0c91e6bf6%7Cbaz" rel="nofollow noreferrer">following expression</a>, but is there a more optimal RegEx?</p>
  
  <p><code>/\b([0-9a-f]{8}-?([0-9a-f]{4}-?){3}[0-9a-f]{12})\b/i</code></p>