- From: pat hayes <phayes@ai.uwf.edu>
- Date: Wed, 7 Aug 2002 12:08:45 -0400
- To: Jan Grant <Jan.Grant@bristol.ac.uk>
- Cc: w3c-rdfcore-wg@w3.org
>On Wed, 7 Aug 2002, Dave Beckett wrote: > >> >> >>>"Patrick.Stickler" said: >> > [lots] >> >> Don't read into a proposed N-Triples syntax change more than I wrote. >> I could have put it has datatype(decimal, "2.0") or somesuch. >> Specifically don't read that as qnames but evocative of how XSD is >> used in XML; similar how the xsi:type is being used in this RDF/XML - >> a special attribute. >> >> But I'm still waiting for the triples for these RDF/XML + xsi:type >> examples. Which is hard to do if they have no n-triples syntax. >> I'll create a better N-triples if needed when I'm clear what (if >> anything) has changed in the graph. Catch 22. > >What's changed in the graph is that the space of "literals" has >expanded; that is that > > jenny age "10" . > >and > > jenny age number(10) . > >are distinct triples, but that > > jenny age number(10) . > bob age number(10) . > >indicates that jenny and bob really do have the same age. > >As to how much it has expanded: this proposal seems to be capable of >going two ways: > >1. the space of literals is expanded by a small set of other literal >types to provide a sufficient foundation for datatyping to be built >upon. That a small set can be sufficient is indicated by the success >people have in using RDBM systems, I suppose. This proposal would then >need guidelines as to what to do with other "datatypes": eg: factor out >units in property values; use uri-labelled resources for enumerations >and taxons; use graph-structure to express compound types. > >This reading means that the RDF parser must have a transform from some >serialised form to the appropriate value, but that the values are what >are present in the graph. In this case, the "hook" for that transorf is >the xsi:type attribute. The space of literals is not extnsible by third >parties. > >Presumably for datatyping and range constraints, etc, rdf:Literal >(rdfs:Literal? I forget) is subclassed into numbers (or ints and reals), >strings, langstrings, whatever. > >That literals are essentially self-denoting entities is obvious in this >setup. Well, no; in fact, they can't be self-denoting in this setup. If (int)10 is supposed to denote an integer, then if it were self-denoting it would have to be an integer, which it isn't. In fact, you can't put integers into syntax, so *anything* that denotes integers isn't self-denoting. Pat -- --------------------------------------------------------------------- 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 Wednesday, 7 August 2002 12:08:36 UTC