I personally am much more excited by “sliders” than the structure-aware diffs. Marking additions between [], it is the difference between e.g.

  handle_case [some new
    case over multiple lines
  handle_case] some existing case
  
  [  check_invariant();
  }
  
  function newFunc(){
    ...
  ]  check_invariant();
  }

And

  [handle_case some
    new case]
  handle_case old case

  [function newFunc(){
    ...
    check_invariant();
  }]