Refinements worry me too. They make it a lot harder to read and understand code, or track down where strange behavior is coming from. I wish I could just ignore

Refinements worry me too. They make it a lot harder to read and understand code, or track down where strange behavior is coming from. I wish I could just ignore them, but unfortunately libraries like ActiveRecord probably won't. And then there are the performance problems. Since so many people dislike them, I wonder what the community response will be? Will JRuby just leave them unimplemented? That seems bad, but I'm not sure I'd mind too much. But that's not viable if it means Rails and other things won't work on JRuby.