[r6rs-discuss] Library version numbers
sperber at informatik.uni-tuebingen.de
Tue Oct 31 12:24:48 EST 2006
[I'm not speaking for the R6RS editors.]
Marcin 'Qrczak' Kowalczyk <qrczak at knm.org.pl> writes:
> For example it's not possible to say "version (3 n) for n>=2 or
> version (m n) for m>=4" (i.e. "3.2 or newer"), nor even "(3 2 . m)
> for any tail m".
> Perhaps I misunderstood how version numbers would typically be used in
> practice. But wouldn't it be better if "and" and "or" were applicable
> to version conditions as a whole, rather than individual subversion
While the above disclaimer applies, I wrote the original versioning
spec, and this seems like a clear omission.
Here's how I'd like to fix it:
<version reference> -> <empty>
| <version spec> ; new
<version spec> -> (<subversion reference> ...)
| (and <version spec> ...)
| (or <version spec> ...)
| (not <version spec> ...)
This would allow saying:
(or (3 (>= 2))
which would match:
3.2, 3.3, 3.2.1, 3.5.2, etc., 4, 4.0, 4.1.1, etc.
I believe the dual occurrence of `and', `or', and `not' is
unambiguous, as crossing from <version spec> to <subversion reference>
always involves an additional open paren, and there's no way back up.
Would that address your concern?
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla
More information about the r6rs-discuss