title: How to trigger autocomplete on character - Ace Editor
body: <p>How can I do the following with the Ace Editor.</p>
  
  <ol>
  <li>User types the '@' character</li>
  <li>Autocomplete pops up</li>
  <li>User makes a selection from the dropdown</li>
  <li>The '@' gets removed now that the selection has been made</li>
  </ol>
  
  <p>I basically want the @ as a trigger for the autocomplete, but I don't want it hanging around after.</p>
  
  <p>Thank you</p>