title: How do I make part of my route optional?
body: <p>I have this route, which overrides a resource-generated route:</p>
  
  <pre><code>match "make_tiles(/:tile_type,(:finish))" =&gt; "tiles#new", :as =&gt; :make_tiles
  </code></pre>
  
  <p>This allows for nice URLs like <code>/make_tiles/two_two,matte</code></p>
  
  <p>But I'd like the option to use: <code>/make_tiles/two_two</code> also. Currently only <code>/make_tiles/two_two,</code> works.</p>
  
  <p>How can I get rid of the trailing comma requirement?</p>