This is not true! We have a ``ScalaClassFileEditor``, hence I think it should be very possible to 

1) no-op the call to ``installSemanticHighlighting``, and
2) hooking the semantic highlighting engine on sources attached to classfiles

If you guys are ok, I'll only fix the comment for the moment (and maybe I'll see tonight if I can push a new PR to add 1 and 2).