title: regex for "mentions"
body: <p>I'm struggling to come up with a regex that would find the ampersat in the beginning of words only. For example: </p>
  
  <p>Here: <code>The @dog went to the park.</code></p>
  
  <p>But not here: <code>The d@og went to the park.</code></p>
  
  <p>Or here: <code>The@dog went to the park.</code></p>
  
  <p>Essentially, I just want to capture normal "mention" behavior, while omitting weird edge cases. I feel that this is common enough that there must be some well-established regex for this. </p>
  
  <p>Edit: </p>
  
  <p>I tried with this:</p>
  
  <pre><code>/(@\w+)/gi
  </code></pre>
  
  <p>But, it captures cases that I do not wish to obtain. </p>