- From: pat hayes <phayes@ihmc.us>
- Date: Thu, 21 Aug 2003 00:50:23 -0700
- To: Jan Grant <Jan.Grant@bristol.ac.uk>, w3c-rdfcore-wg@w3.org
>On Mon, 18 Aug 2003, Eric Miller wrote: > >> > I'm waiting on one thing. As I understand it, the value spaces of >> > xsd:integer and xsd:decimal no longer intersect. If that is correct >> > then >> > one datatype test case needs changing, since it currently suggests >> > otherwise. >> > >> > The test case is >> > http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/ >> > Manifest.rdf#semantic-equivalence-between-datatypes >> > >> > which says that >> > >> > [[ >> > eg:foo eg:bar "10"^^<xsd:integer> . >> > ]] >> > rdfs+dt(xsd:integer, xsd:decimal)-entails >> > [[ >> > eg:foo eg:bar "10.0"^^<xsd:decimal> . >> > ]] >> > >> > I'm waiting on a confirmation that this is, or is not, actually the >> > case, in light of recent xsd clarifications. >> >> Are you waiting on a particular answer from the RDFCore group to >> repond? The XML Schema group? A particular individual? > >Hopefully for Pat to just confirm that I didn't imagine it when I >thought I heard him say that this is now the treatment of XSD types: ie, >that their denotation is a pair of (typename, value). What you probably heard me say was a report of an email discussion with members of the XSD WG a while ago, trying to reconcile apparently inconsistent assertions in the XSD specs, which seem to define some value spaces in the same way, but also state categorically that all simple XSD datatypes have disjoint value spaces. The upshot of this discussion was (1) the current state of the XSD specs is confused (2) the XML schema WG is aware of this and plans to fix it (in 1.1) in the near future, probably (3) by formally defining value spaces to be pairs of (type, value). However, that (3) was just one person's report, and from more recent email discussions with other members of the WG I have the sense that they will be using a different technique altogether, one which relies on making a distinction between values being 'equal' and values being 'identical'. I have sent them some rather critical remarks on this approach, but it seems clear that they are about as tired of this issue as we are of the datatyped literal issue. I would strongly suggest that what we do at this stage is simply to not get into this tar-pit. Questions of what XSD values are identical/equal to what others should be left to XSD to sort out. If we have ANY test cases which presume ANY issues of identity or non-identity between xsd: datatypes, please let us simply remove them without further comment. We have agreed that RDF plain literals are the same as xsd:string literals: that is all we need to do; all the other questions are up to other people to decide. The semantics has been carefully worded so as to refer all such issues to the defining authority of the datatype, which in this case is XML schema WG, not us. If we try to second-guess what they are really saying, we will still be arguing about this stuff in 2010. Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Friday, 22 August 2003 17:45:05 UTC