- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Wed, 31 Dec 1969 17:21:06 -0700
- To: Dan Connolly <connolly@w3.org>
- Cc: w3c-rdfcore-wg@w3.org
>XML Schema has not only the 9 or so >primitive types, but also bunch of facets >for user-defined types ala "integers >between 5 and 10". > >I don't think any of the recent datatyping >proposals allows me to express that datatype. > >Is that a problem[ftf]? > >I suggest, tentatively, that it is. I suggest it isn't. Heres why: we shouldn't expect to be able to *express* a datatype in RDF. The actual definitions of the datatypes is done outside RDF, and RDF then *uses* the datatypes so defined (assuming they have somehow been given a special URI which can be used by an RDF engine to retrieve the relevant machinery). So if someone defines a datatype like, say xsdd:integersBetweenFiveAndTen, then the RDF datatyping should work with that as well as with any other datatype. What that URI needs to 'supply' is well-defined: 1. A recognizer for members of the lexical space of the datatype. 2. A computable mapping from members of the lexical space to (some canonical representation of) members of the value space. and that's all, in principle, though it wouldn't hurt to have a few others as well, eg an identity recognizer for lexical forms if (2) is expensive to compute. >[crud; I was gonna write a bit more, but >I've got another meeting. I think I better >send this now, though, before I put it >off for another three weeks...] > >[ftf] http://www.w3.org/2001/sw/RDFCore/20020225-f2f/#d-2002-02-26-3 > > >-- >Dan Connolly, W3C http://www.w3.org/People/Connolly/ -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Thursday, 2 May 2002 15:19:41 UTC