- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 14 Nov 2001 12:17:27 +0200
- To: phayes@ai.uwf.edu, bwm@hplb.hpl.hp.com
- Cc: w3c-rdfcore-wg@w3.org
> >Similarly, in the S proposal, would not xsd:byte be a subProperty of > >xsd:short which is a subProperty of ... > > Sure. But only insofar as the value spaces are concerned. The lexical space of a data type subclass is not necessarily a subset of the lexical space of its data type superclasses. Though in the case of xsd:byte and xsd:short, I think they are. > > > >>They can all be straightforwardly handled in RDF/XML. > >> > >> > >>The S and CD proposals require that users conform to a given > >>'idiom', and are often incompatible with current common usage in > >>which literals are used to refer to things other than strings; > > > > > >I know what you mean here, but I object to the term incompatible. > >Current RDF does not do anything about datatypes. > > I said current USAGE, and I was going on what others have said about > people writing things like > > Pat shoeSize "10" . > > I know we don't currently have an official position on this, but I > thought it was a common observation that people do these wicked > things whether we say it is OK or not. But if we had the definition shoeSize rdfs:range xsd:integer . and the user making the above statement knows about that range definition, then it's not really "wicked". Granted, the statement re-expressed as Pat shoeSize [ rdf:value "10"; rdf:type xsd:integer ] . or Pat shoeSize <xsd:integer:10> . is more explicit and safe. > >In one interpretation all literals denote strings, and if I have a > >property with value "10", then that's just fine. An application can > >'know' that it should interpret that as an integer. With for > >example, the X and S and DC proposals they can continue to do so. > >The datatype information is simply not represented in the RDF model; > >its encoded in the definition of the property. I think that relying on property range constraints in this manner is not going to address all cases and as my recent examples show, in cases where non-locally typed literals are bound by inference to superordinate properties, things blow up. > ? That is what the P(++) proposals do; seems to me that is exactly > what the others fail to do. (??) The X proposal doesn't fail to do this, and in fact could be viewed almost as an extension of the P++ proposal, adding to it a statement-centric model but agreeing that all components of a statement (including literal objects) are nodes which may serve as subjects of other statements. > Well, see my response to Sergey on that example. That would only work > in that form if there was a datatype mapping from numerals to > kilogram weights, which is unlikely. See my URV re-expression of Sergey's examples for how that might be done in a generic manner. Patrick
Received on Wednesday, 14 November 2001 05:17:34 UTC