- From: Jan Grant <Jan.Grant@bristol.ac.uk>
- Date: Tue, 21 Aug 2001 16:51:06 +0100 (BST)
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- cc: RDFCore Working Group <w3c-rdfcore-wg@w3.org>
Whoops, wrong thing, sorry. I'll try again. (Had a different AP in mind, or at least one that I recalled differently - namely, to demonstrate how to do strong typing and subclassing of collections; the conversation encompassed multiple things at the same time.) To answer the original AP... This action point is referring to a workaround for people using disjunctive range and/or domain. I've mentioned this before, but here goes for posterity: I've seen some people say that they were using a disjunctive range/domain interpretation in their applications. Opponents of this pointed out that it doesn't give you much (ie, you can't do any type inference) unless you accept a closed-world notion of your schema. The users responded that that's exactly what they _were_ doing, and that they were prepared to do so because of the wins that it gave them in their application domain. Given the same assumptions, there is a construction available that uses "standard" conjunctive semantics for domain (resp, range). To say "the domain of foo:bar can be foo:Baz or foo:Shmoo": <foo:Baz> <rdfs:subClassOf> _:c1 . <foo:Shmoo> <rdfs:subClassOf> _:c1 . <foo:bar> <rdfs:domain> _:c1 . (you can give a URI to _:c1 if it makes you feel better, it's not vital.) I've heard two objections to this: 1. It doesn't let you infer anything. This is the same complaint as was originally levelled at the disjunctive interpretation, and the response is the same: "I'm prepared to make some assumptions in this application domain"*. 2. Some stylistic objections from OO programmers who're unused to building a class hierarchy from the bottom up. This is a trick that'll appeal more to mathmos than Java hackers; otherwise it's a non-issue I think. Hopefully that completes the requirements of the AP 2001-08-02#10. jan * I don't use this; it's a workaround for people who do. -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287088 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk Usenet: The separation of content AND presentation - simultaneously.
Received on Tuesday, 21 August 2001 12:00:54 UTC