title: Metrics for Change Size when using diff tools
body: <p>Does anybody know any diff tool which counts some metrics for "Change Size". I'm searching for a diff tool that uses the diff output and reports something like:</p>
  
  <ol>
  <li><p>The number of changed/added/removed attributes;</p></li>
  <li><p>The number of changed/added/removed operations;</p></li>
  <li><p>The nunmber of changed class' "extends/implements";</p></li>
  <li><p>The nunmber of changed class' name/package</p>
  
  <p>...</p></li>
  </ol>
  
  <p>It should be, of course, an AST diff tool. A simple text-based diff tool won't be able to do that.</p>
  
  <p>This report would be interesting to give the designer the dimension of a change between two versions of the code.</p>