- From: Graham Klyne <GK@NineByNine.org>
- Date: Fri, 17 Jan 2003 12:29:32 +0000
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- Cc: rdf Core <w3c-rdfcore-wg@w3.org>, pat hayes <phayes@ai.uwf.edu>
At 11:32 AM 1/17/03 +0000, Brian McBride wrote: > From PFPS: > >>In trying to make the OWL semantics correspond to the RDF semantics I came >>up with the following problems in RDF datatyping: >> >>1/ A datatype is an element of IR, because the RDF MT says that datatypes are >>denoted by URI references. However, rdf:XMLLiteral is said to be a >>datatype, but rdf:XMLLiteral is a URI reference. Something is wrong here. I think we should say something like "rdf:XMLLiteral denotes a datatype". >>2/ XSD-interpretations include in their datatypes the XML Schema datatypes >>that are problematic when removed from XML documents or have other >>problems. XSD-interpretations also include, for example, the datatype >>named FOO, which is not defined as an XML datatype. Hmmm... I think we've understood in discussion that we don't expect *all* XSD datatypes to be recognized, but I'm not sure if the limitation here is adequately expressed anywhere. >>3/ A datatype has to be more than is specified in the RDF MT. Except for >>XSD-interpretations, which explicitly mention the URI-reference to datatype >>relationship, there is no way of tying the intended URI-reference for a >>datatype to that datatype. For example, if I have D containing a datatype >>for integers and a datatype for strings, there is no way to require that a >>particular URI reference, say ex:int, denotes the integer datatype. >> >> >>It probably makes more sense to say that a datatype is a four-tuple, >>consisting of a URI reference, a lexical space, a value space, and a >>lexical-to-value mapping. I'm not sure I fully understand this, but the final suggestion seems reasonable to me. #g ------------------- Graham Klyne <GK@NineByNine.org>
Received on Friday, 17 January 2003 07:22:21 UTC