I like this. The Stepper becomes available as an aid to help you answer questions about how things came to be. It is indeed often the case that I "lose the plot" when stepping forward and hence go to the end and work backward; this could put you there right away.
Yes, left-to-right scrolling makes much more sense, especially since screens are generally wider than taller, and have become more so in the HD era. Sort of like the file selector on an Apple, right? (I forget the name for that style of columnar presentation.) Is this a fair, operational restatement of your cautionary note: "It will be much less complicated to add just a `how did I get here?' button to the REPL and have the rest of the stepper reside in its own window, than trying to embed the whole stepper in the REPL"? Shriram _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
