-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sun, Aug 26, 2018 at 04:07:13PM -0400, Mark H Weaver wrote:
[...] > It's true that Guile historically has a special object distinct from all > other objects, which (if #f #f) and various other expressions return, > and which prints as "#<unspecified>". > > However, the fact that some existing code out there might depend on the > existence of this distinguished object, and that certain expressions in > Guile return it, is historical baggage which carries non-zero costs as > we move to native code generation. > > I would also argue that it carries a terrible conceptual cost, in that > it leads to confusion between the concept of a truly unspecified return > value (as in R5RS) and this distinguished value in Guile that is called > "the unspecified value", a non-sensical notion. > > I would also avoid Guile's #nil. That is a very special value, for one > purpose relating to Elisp compatibility, and ideally it should not be > used for anything else. I must admit that I'm... pretty confused about this very prescriptive tone. Sorry. Cheers - -- tomás -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAluDsH8ACgkQBcgs9XrR2kZCMwCfQpgyL+cC38ZHKqhV0rAG02sq +WIAnjXIVutY/p0Q3nrbZjfNuVzhcDgY =/B5d -----END PGP SIGNATURE-----
