support XML Literals in RDF (was Re: Test cases: XML Literal value space and exclusive canonicalization)

> Date: Thu, 7 Aug 2003 11:08:44 +0100
> From: Dave Beckett <dave.beckett@bristol.ac.uk>
> To: Martin Duerst <duerst@w3.org>
> Cc: www-rdf-comments@w3.org, pat hayes <phayes@ihmc.us>, Benja Fallenstein <b.fallenstein@gmx.de>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org, w3c-i18n-ig@w3.org, msm@w3.org

> On Mon, 04 Aug 2003 13:55:25 -0400
> Martin Duerst <duerst@w3.org> wrote:
> 
> <snip/>
>> So it seems to be true, for simple datatype literals, that
>> 
>> Abstract syntax == lexical value ~= representation in RDF/XML
>> 
>> (the ~= including generic issues such as character escaping,
>> but no datatype-specific issues).
> 
> Yeah, sort of.  And the Unicode characters in the lexical form that
> can't be written in XML.
> 
> <snip/>
>  
>> Is every RDF application required to support XML Literals?
>> Or only the syntactic parts, and the RDF/XML to Graph conversion
>> (including canonicalization) if appropriate?
> 
> Only those that deal with mapping between the abstract syntax and the
> XML syntax (either direction).  
> 
> The "pure" RDF applications work on graphs and need have no XML-specific
> code.  XML Literals just look like any other datatype to RDF graph
> applications and should need no extra support in the graph.
> 
> <snip/>

Although any RDF-only application, i.e., an application that *only* 
needs to determine the RDF implications of an RDF graph, does not need 
any special code to support XML Literals beyond the code needed to 
support sequences of octets, an RDF application that goes beyond these 
implications, for example to determine whether a literal is in LV, will 
need considerable code to support XML Literals.

Also, any application that needs to determine the RDFS implications of 
an RDF graph needs at least an oracle to determine whether a sequence of 
octets is in the value space of rdf:XMLLiteral.

Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies

Received on Thursday, 7 August 2003 06:57:59 UTC