-------- Original Message -------- Subject: Re: Any Prolog language lawyer out there? Date: Wed, 20 Oct 2004 14:09:14 +0200 From: Bart Demoen bmd@cs.kuleuven.ac.be Organization: KULeuvenNet Newsgroups: comp.lang.prolog References: 41750912.8040102@cs.unipr.it 1098196164.417498@seven.kulnet.kuleuven.ac.be slrncnaat8.jkn.jan@ct.xs4all.nl 87acuijutl.fsf@gondolin.bb.bawue.de 1098259920.942884@seven.kulnet.kuleuven.ac.be
I wrote:
Goal : integer(- 4) Specification result : Must fail
Goal : integer(-4) Specification result : Must succeed
So it seems that the space between the - and the 4 is important.
I do not have the final copy of the standard, and although I do remember that there has been discussion about it, I do not remember the final outcome, so can anybody check that's indeed what the standard says ?
I got hold of a standard ...
It says at the end of section that Jens was quoting from:
"A term which is the name - followed directly by a numeric constant, denotes the cirresponding negative constant"
In the standard "directly" means something like "with no space in between".
That decides the issue I think: - 4 should not be read as a negative integer; and -4 should be read as a negative integer.
Cheers
Bart Demoen