- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Mon, 18 Aug 2003 14:50:40 -0400 (EDT)
- To: dave.beckett@bristol.ac.uk
- Cc: www-rdf-comments@w3.org
From: Dave Beckett <dave.beckett@bristol.ac.uk> Subject: Re: RDF model theory is now underspecified Date: Mon, 18 Aug 2003 19:26:08 +0100 > Since this is a question on the syntax draft, and not RDF Semantics > at all, I'll reply. > > On Mon, 18 Aug 2003 12:24:31 -0400 (EDT) "Peter F. Patel-Schneider" > <pfps@research.bell-labs.com> wrote: > > > > The current editor's draft of RDF Syntax > > (http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-syntax-grammar-20030117/ > > dated 18 August 2003) contains the following new wording in a > > normative note within Section 6.1.9 > > > > During input processing of XML Schema Datatypes within RDF, > > software MAY apply the appropriate whitespace normalization > > immediately before the lexical to value mapping, and MAY produce a > > warning if any whitespace is changed in this normalization. > > Read the document and the references to find out what MAY means. > > This is also pretty much what the editor's draft of RDF concepts says > on the matter, reworded to apply to the syntax data model mapping. > > > Although ``input processing ... immediately before the lexical to > > value mapping'' is not particularly well defined, I take this to mean > > that the RDF Graph corresponding to > > You give no specific problem with that phrase. When and where does this input processing happen? It seems strange that ``input processing'' happens ``immediately'' before some semantic processing. These two can happen at quite different times, even perhaps in different programs. > > > > <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" > > xmlns:eg="http://example.org/"> > > > > <rdf:Description rdf:about="http://www.example.org/a"> > > <eg:prop rdf:datatype="http://www.w3.org/2001/XMLSchema#int"> 3 > > </eg:prop> > > </rdf:Description> > > > > </rdf:RDF> > > > > remains unchanged as > > > > <http://www.example.org/a> <http://example.org/prop> " 3 > > "^^<http://www.w3.org/2001/XMLSchema#int> . > > It MAY. Huh? Does this mean that even the RDF graph that corresponds to a RDF/XML document is underspecified? > > However, it appears to me that this note means that the RDF model > > theory is now underspecified, as RDF software, including software that > > computes entailments, may choose to treat > > " 3 "^^<http://www.w3.org/2001/XMLSchema#int> > > as denoting the integer three instead of some non-literal. > > > > I view this change as undesirable. > > We had several implementor feedback reports on this point and made > this change to reflect the reality of running code for XML schema > datatypes. Implementors now MAY make that entailment above. This is then a serious source of incompatability between different RDF implementations. > The RDF Semantics document is not underspecified here, particularly > since the running code we have had feedback on, implements it. > > Dave So, does <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:eg="http://example.org/"> <rdf:Description rdf:about="http://www.example.org/a"> <eg:prop rdf:datatype="http://www.w3.org/2001/XMLSchema#int"> 3 </eg:prop> </rdf:Description> </rdf:RDF> xsd-entail <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:eg="http://example.org/"> <rdf:Description rdf:about="http://www.example.org/a"> <eg:prop rdf:datatype="http://www.w3.org/2001/XMLSchema#int">3</eg:prop> </rdf:Description> </rdf:RDF> or not? In the last-call specification it did not. Now it appears that the answer is that ``It depends.'' Thus my claim of underspecification. Peter F. Patel-Schneider
Received on Monday, 18 August 2003 14:50:51 UTC