- From: Patrick Stickler <patrick.stickler@nokia.com>
- Date: Thu, 21 Feb 2002 11:55:48 +0200
- To: Pat Hayes <phayes@ai.uwf.edu>, RDF Core <w3c-rdfcore-wg@w3.org>
- CC: Brian McBride <brian_mcbride@hp.com>
On 2002-02-21 11:13, "ext Patrick Stickler" <patrick.stickler@nokia.com> wrote: > On 2002-02-21 0:29, "ext Pat Hayes" <phayes@ai.uwf.edu> wrote: > >> Ok, guys. Another version now at >> http://www.coginst.uwf.edu/users/phayes/simpledatatype1.html >> This changes the previous one as follows. Pat, Your latest treatment of inline literals seems to embrace the outside-the-graph interpretation view that I've been suggesting for the union-based minimal proposal (and which in fact I've been suggesting for several months now). What the rdfs:drange is really saying is that the property value can be *either* a value bNode or a literal -- i.e the datatype class contains the members of both spaces, i.e the datatype class is the union of the value space and lexical space of the datatype. And the interpretation is that, if the property value is a literal, it is treated as a lexical form (how else can you equate it to the value triple idiom?) and if its a bNode it is a value. This is my union-based proposal exactly. Why not then, for the sake of the users (and us too ;-) toss out all the extra d* vocabulary, and both the value triple and doublet idioms (which were desparate measures before considering datatype classes as unions) and say exactly the same thing using the present RDF/S vocabulary using a treatment of datatype classes as unions of lexical and value spaces? I.e. That both of the following have the same datatyping above-the-graph interpretation ppp rdfs:range xsd:integer . xxx ppp "34" . xxx ppp _:1 . _:1 xsd:integer "34" . and in both cases, we're talking about the integer 34. And that the statement xxx ppp "34" . in isolation of any datatyping knowledge has no datatyping interpretation. It might get some later, but that's the risk of the inline, implicit idiom. But, insofar as the graph syntax and MT is concerned: The literal "34" in all cases above, in the graph itself, denotes the literal "34". It *never* denotes 34, ever. The URI xsd:integer denotes the RDF datatype class, which contains both values and lexical forms of the xsd:integer datatype (is the union of the value and lexical spaces). The bNode _:1 denotes the value but *NOT* 34 (you need an application that knows about xsd:integer to *know* that the value is 34! Apart from the actual extra-RDF interpretation you can *never* know what value the bNode actually denotes! only that it denotes a single determinable value obtainable from the datatyping interpretation) Simple. Clear. Unambiguous. Easy. And with the additional assertions that: Everything denoted by a literal node has an rdf:type of rdfs:Literal. Everything denoted by a URIref node or bNode has an rdf:type of rdfs:Resource. rdfs:Literal is not a subclass of rdfs:Resource Then using range intersection, folks can constrain property values to either the inline idiom (lexical forms only) or the datatype triple idiom (values only) using one of ppp rdfs:range ddd . ppp rdfs:range rdfs:Literal . (lexical forms only) or ppp rdfs:range ddd . ppp rdfs:range rdfs:Resource . (values only) Again, simple, clear, explicit, intuitive, easy. Surely if you can make the MT work for your latest treatment of the inline idiom, which really does assume a union treatment of datatype classes, it can be made to work for the above minimalist solution and we can achieve a solution that users will *enjoy* using and not flail about over with moaning and gnashing of teeth. Eh? Regards, Patrick -- Patrick Stickler Phone: +358 50 483 9453 Senior Research Scientist Fax: +358 7180 35409 Nokia Research Center Email: patrick.stickler@nokia.com
Received on Thursday, 21 February 2002 04:54:17 UTC