Maybe macros John Cowan (26 Jun 2020 17:16 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (26 Jun 2020 17:43 UTC)
Re: Maybe macros John Cowan (26 Jun 2020 18:48 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (26 Jun 2020 18:57 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 04:29 UTC)
Re: Maybe macros Arthur A. Gleckler (26 Jun 2020 19:50 UTC)
Re: Maybe macros John Cowan (26 Jun 2020 19:52 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 03:44 UTC)
Re: Maybe macros Arthur A. Gleckler (27 Jun 2020 03:59 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 04:15 UTC)
Re: Maybe macros Arthur A. Gleckler (27 Jun 2020 04:29 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (27 Jun 2020 14:09 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 18:55 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (27 Jun 2020 20:46 UTC)
Re: Maybe macros John Cowan (27 Jun 2020 21:34 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 17:26 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 17:43 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 18:52 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 20:24 UTC)
Re: Maybe macros John Cowan (28 Jun 2020 18:54 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (28 Jun 2020 20:21 UTC)
Re: Maybe macros Alex Shinn (29 Jun 2020 00:02 UTC)
Re: Maybe macros Marc Nieper-Wißkirchen (29 Jun 2020 06:23 UTC)
Re: Maybe macros Wolfgang Corcoran-Mathe (28 Jun 2020 16:54 UTC)

Re: Maybe macros Marc Nieper-Wißkirchen 28 Jun 2020 20:20 UTC

>> If you want to leave the payload unspecified, you should also leave
>> the number of unspecified values unspecified. That certainly makes
>> sense.
>
>
> That is what R6RS permits in all such situations, but doing so was not only rejected by all R6RS implementers (except that in Racket "(if #f #f)" in a value context is a syntax error), but by the R7RS committee as well.  It's a theoretical nicety that no one actually wants.

We shouldn't mix two different things here. One is the number of
return values for expression that - theoretically - shouldn't yield
any value but which is already prescribed by history, and the other
one is number values in a Just/Left/Right that should be left opaque.

PS Is there a real-life bugfree example of a program that would break
if forms like `set!' evaluated to no value?