title: Emacs tab auto-complete for R data.table?
body: <p>Anyone know how to get auto-complete working in Emacs for R data.tables (ess-mode)?</p>
  
  <p>For example when I type tab below I'd like autocomplete to add "alpha"</p>
  
  <pre><code>DT &lt;- data.table(alpha = 1:5)
  DT[&lt;type tab here&gt;
  </code></pre>
  
  <p>thanks, jason</p>