-------- Original Message -------- Subject: Re: Any Prolog language lawyer out there? Date: 21 Oct 2004 10:19:55 GMT From: Jan Wielemaker jan@ct.xs4all.nl Reply-To: jan at nospam.swi.psy.uva.nl Organization: SWI, University of Amsterdam 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 1098274154.598785@seven.kulnet.kuleuven.ac.be 77bbf36a.0410210015.1db2726c@posting.google.com 1098349684.287109@seven.kulnet.kuleuven.ac.be

In article 1098349684.287109@seven.kulnet.kuleuven.ac.be, Bart Demoen wrote:

Mats Carlsson wrote:

...

...

In the standard "directly" means something like "with no space in between".

That must be wishful thinking on your part. There is no such definition of "directly" in the document.

I should indeed have been more careful.

In principle, everything in the standard has a well-agreed upon meaning. In an attempt to ensure that, page 2 of the standard says in the 3th paragraph of section 3:

# Words and phrases not defined in this glossary are assumed # to have the meaning given in ISO 2382-15; if they do not # appear in ISO 2382-15, then they are assumed to have # their usual meaning.

"directly" is not defined in the ISO Prolog glossary (rest of section 3)

So we should check ISO 2382-15 ... I couldn't get hold of ISO 2382-15 (it is too expensive to acquire just to set this dispute) and if anybody has access to it and can check whether it defines "directly", please let us know.

If it isn't in ISO 2382-15, we must take the usual meaning of "directly". I think (apparently together with GNU Prolog and the makers of http://www.sju.edu/~jhodgson/prolog_proj/framed_spec.html) that in the context as it is used in the explanation of negative numbers, it means

"no spaces [or other stuff] in between"

That was also my line of thinking, but Mats is formally right. Summarising and highlighting the LAYOUT Mats refers to.

<negative integer> ::= -, <integer> <integer> ::= <LAYOUT>, <integer token> <integer token> ::= <digit>+ The _immediately_ can only talk about the first rule above, so its meaning is formally irrelevant as the second rules allows for layout :-( Thats why I went for a weaker form of reasoning claiming directly, only used here, means something special. I'm inclined to reject - 4, until someone can, in addition to the standard, explain a rationale for these rules.

Cheers --- Jan