Hi, l...@gnu.org (Ludovic Courtès) skribis:
> Andy Wingo <wi...@pobox.com> skribis: > >> On Thu 30 Jun 2011 12:44, Andy Wingo <wi...@pobox.com> writes: >> >>> I think we should add `when' and `unless' to the default environment. >>> >>> They go like this: >>> >>> (define-syntax when >>> (syntax-rules () >>> ((_ test then then* ...) >>> (if test (begin then then* ... (if #f #f)))))) >>> >>> (define-syntax unless >>> (syntax-rules () >>> ((_ test else else* ...) >>> (if (not test) (begin else else* ... (if #f #f)))))) >> >> WDYT? `unless' is nice for assertions, `when' is its converse, and most >> Schemes have them. I would like to add them to Guile too. > > Yes, feel free. Like Marijn, it seems more natural for me to return the values of the body’s last expression, rather than *unspecified*. Thanks, Ludo’.
