> On Jan 28, 2016, at 9:31 AM, Alex Knauth <alexan...@knauth.org> wrote: > > Would there be a way to support check-syntax arrows automatically in the > stepper, so that we could see that they are really two different y's, because > the arrows point to different places? Would that be possible?
That’s a fascinating idea. I think it wouldn’t work “out of the box” because in the case of recursive functions, you could have multiple bindings present for the same binding location. It might be possible to build something that worked by using both the syntactic information and a runtime tag, though. Any interest in coming to California to work on it? John Clements > >> On Jan 28, 2016, at 12:04 PM, Matthias Felleisen <matth...@ccs.neu.edu> >> wrote: >> >> >> Thanks for the bug report and the reminder that 2e omits a discussion of >> name capture in beta-value. >> >> The stepper works semantically correctly precisely because it reuses the >> underlying evaluation machinery. It inserts machinery that can reconstruct >> (reify) the internal state of execution as real programs at the correct >> place. >> >> The stepper works syntactically incorrectly because the >> reification/reconstruction fails to check for variable name conflicts. It >> simply reuses existing variables. The alternative might be to gensym >> variable names but doing so for all variable names will be equally >> confusing. >> >> Pragmatically, this has not been a problem in the past. People tend to use >> the stepper for programs that don't pose these problems or on the occasion >> they do, they overlook (and perhaps don't see) the problem. >> >> I am sure John Clements will think about this and come up with an idea. >> >> -- Matthias > > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
