- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 7 Aug 2002 10:59:04 +0300
- To: <connolly@w3.org>
- Cc: <melnik@db.stanford.edu>, <guha@guha.com>, <w3c-rdfcore-wg@w3.org>
> > And it requires no changes to RDF whatsoever. Just use a > URI to denote > > the typed literal which denotes the value in question. Done. > > ... It's critical that these expressions > act like literals in the model theory. EH? They're URI denoted resources. Not literals. > i.e. you can tell, > from the model > theory, that > > val:(http://www.w3.org/2001/XMLSchema%23integer)15 > is not equal to > val:(http://www.w3.org/2001/XMLSchema%23integer)16 No, you can't. Since two different URIs can denote the same resource, you can't know at the RDF level whether the above do *not* equate to the same value. Of course, you can't know that anyway, even if you just had literals with an associated datatype. It may very well be the case that the datatype xsd:integer maps both 15 and 16 to the very same datatype value. So even some complex, structured/typed literal in the graph syntax such as (xsd:integer)10 is not really a "literal" but is as globally unambiguous as a URI, since that pairing of datatype and lexical form identifies one and only one datatype value! And because it incorporates a URI as part of its structure, either implicitly or explicitly. In fact, what is being proposed is a fourth atomic graph component, in addition to URIrefs, bnodes, and literals -- which is a TDL!!! a Typed Data Literal -- and which unambiguously denotes a datatype value. Kriminy! You simply can't treat literals as global constants. They are contextual. How may times do we have to go round this issue before we get past it?! Patrick
Received on Wednesday, 7 August 2002 03:59:11 UTC