Matthew, Out of curiosity, could you explain why you'd prefer #:else everywhere instead of [else ...] ? Would such an #:else allow for multi-line bodies?
On Sat, May 4, 2013 at 5:06 PM, Matthew Flatt <mfl...@cs.utah.edu> wrote: > At Sat, 4 May 2013 09:15:22 -0500, Robby Findler wrote: > > On Sat, May 4, 2013 at 9:07 AM, Matthew Flatt <mfl...@cs.utah.edu> > wrote: > > > > > At Fri, 3 May 2013 17:29:52 -0400, Eli Barzilay wrote: > > > > A few minutes ago, Robby Findler wrote: > > > > > > > > > > FWIW, this was the bug in redex that prompted me to send this > > > > > message (it was there for some time since it wasn't a syntax error > > > > > .... it was similar in spirit to the code I posted; things broke > > > > > when #f was an argument) > > > > > > > > [I think that it's good to have a much more relaxed policy about > > > > breaking compatibility in cases like this: so far there was no real > > > > code found that uses the feature, but there is one instance of code > > > > that would get fixed by the change...] > > > > > > Well, Ian provided an example from real code, right? Ian is willing to > > > change his code, but the code sounds real. > > > > > > There's also the use in `unparse-pattern' in Redex. Maybe that's the > > > troublesome one that Robby has in mind changing (or he would be happy > > > to change it, obviously), but it's another real example. > > > > > > > > No, that was not the example. The code I sent at the beginning of the > > thread was an adjusted version of the bug that hid in Redex for, roughly, > > months. It was a real bug and caused real problems and we knew something > > was wrong but didn't find it for some time. > > > > In other words, this isn't some made-up, code cleanliness-based request. > > Yes, I understand that you faced a real bug. I hedged above on > `unparse-pattern' not to suggest that your actual bug was > uninteresting, but to suggest that I might misunderstand the > relationship between the bug and the current state of our repository. > > All else being equal, I'm definitely in favor of a change to a sensible > `else' for `match'. The "else" that isn't equal, however, is backward > compatibility, and I think we're at the right point in our development > cycle to defer backward incompatibilities to the next language --- > hence my vote to defer. > > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev >
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