title: Vim positive lookahead regex
body: <p>I am still not so used to the vim regex syntax. I have this code:</p>
  
  <pre><code>rename_column :keywords, :textline_two_id_4, :textline_two_id_4
  </code></pre>
  
  <p>I would like to match the last id with a positive lookahead in VIMs regex syntax.</p>
  
  <p>How would you do this?</p>
  
  <pre><code>\id@=_\d$
  </code></pre>
  
  <p>This does not work.</p>
  
  <p>This perl syntax works:</p>
  
  <pre><code>id(?=_\d$)
  </code></pre>
  
  <p>Edit - the answer:</p>
  
  <pre><code>/id\(_\d$\)\@=
  </code></pre>
  
  <p>Can someone explain the syntax?</p>