- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Thu, 12 Feb 2009 18:10:44 -0800
- To: Bijan Parsia <bparsia@cs.manchester.ac.uk>
- Cc: W3C OWL Working Group <public-owl-wg@w3.org>
On Thu, Feb 12, 2009 at 3:05 PM, Bijan Parsia <bparsia@cs.manchester.ac.uk> wrote: > > On 12 Feb 2009, at 22:43, Alan Ruttenberg wrote: > >> To where can I point Jos to in our spec that defines this behavior? > > ? We don't define the behavior I described. We say that implementations must > support at least 16 digits. If they don't support more we are silent on what > they should do. I described two possibilities. This worries me. The problem is that http://www.w3.org/TR/xpath-functions/ says: For xs:decimal values the number of digits of precision returned by the numeric operators is ·implementation-defined·. If the number of digits in the result exceeds the number of digits that the implementation supports, the result is truncated or rounded in an ·implementation-defined· manner If our spec allowed that it might be the case that an ontology was inconsistent in some implementations and consistent in others. If we don't already disallow this then I think we should. If we do, then I'd appreciate if someone could point out to me what prevents this. Regards, Alan > >> The reason I ask is that in some cases the XML docs say operations >> involving such literals are implementation specific. > > Well we don't say what non-conforming implementation should do. If an > implementation supports on 16 digits that doesn't license it to do what it > wants with 17 digit numbers. It can, of course, do what it wants, but that > behavior wouldn't be conforming. > >> I contended that >> that would not be the case for OWL but didn't find a place that said >> this explicitly. > > I don't know that there is. We're nowhere nearly as rigid about conformance > as I would, ideally, like. But that's probably poltico-socially wise. > > I think at the moment the advice I'd give users is that if an implementation > doesn't do static and dynamic analysis to determine if it's overflowed and > throw *at least* a warning, that they complain about the implementation > saying, "You claim to handle only 16 digits, but you really handle more, > just not in conformance with the spec, loser" > > Cheers, > Bijan. > >
Received on Friday, 13 February 2009 02:11:20 UTC