title: Rails partials with single-table inheritance
body: <p>I want to use partials in rails along with single-table inheritance. I currently have this working:</p>
  
  <pre><code>render partial: @vehicle
  
  # which renders the relevant view, depending on object type, eg:
  #   views/trucks/_truck.haml
  #   views/car/_car.haml
  </code></pre>
  
  <p>I want to leave these default views in place, and create an additional compact view for each object, perhaps like this</p>
  
  <pre><code># example code only, I want to write something like:
  render partial: 'compact', locals: {vehicle: @vehicle}
  
  # and then have this render (for example) with
  #   views/trucks/_compact.haml
  #   views/car/_compact.haml
  </code></pre>
  
  <p>I can happily rename things or change the file names or locations, but what is the simplest way to support two kinds of views (compact and default)?</p>
  
  <p>There will be many more classes later, so looking for very clean, elegant code.</p>
  
  <p>(rails 3.0.5+ on ruby 1.9.2)</p>