RE: 'in the result of'



> -----Original Message-----
> From: Sandro Hawke [mailto:sandro@w3.org]
> Sent: 26 May 2009 16:51
> To: Seaborne, Andy
> Cc: public-rdf-text@w3.org
> Subject: 'in the result of'
> 
> 
> You wrote:
> 
> > Maybe (intro):
> >
> > """ ...typed rdf:text literals MUST NOT occur in
> > published RDF content or in the results of SPARQL basic graph pattern
> > matching [SPARQL] using extended SPARQL Basic Graph Matching"""
> >
> > *in the result of* is the key here.
> 
> which doesn't seem right to me.  Don't you instead want to rule out the
> SPARQL queries being against a graph using rdf:PlainLiteral?
> 
> Are you really okay with this:
> 
> graph:
>      <a> <b> "Hello@en"^^rdf:PlainLiteral.
> query:
>      SELECT ?x WHERE { ?x <b> "Hello@en"^^rdf:PlainLiteral }
> }

Fairly OK - I'm not so worried about this situation - others might be.

It would take an app writer who has knowledge of rdf:PlainLiteral to do it hence OK to me.  I do care about data exchange and don't like the two representations of the same thing that existing systems will see as different.

The case that need addressing is in what happens to results of BGP matching, you plug a SPARQL/OWL BGP extension into an existing engine and ^^rdf:PlainLiteral come out (in SPARQL Query Results in XML) and queries that did work may not.  This, to my reading, is not covered by "published RDF content" (it's not 'publishing' to me) so I suggest explicit text to deal with it.

> 
> I thought this was part of what you were trying to rule out.
> 
> It seems to me the text you've proposed allows that, but happens to
> (oddly) rule out stuff like this:
> 
> graph:
>     <a> <b> "Hello"@en.
> query:
>     CONSTRUCT { ?x ?y "Hello@en"^^rdf:PlainLiteral }
>     WHERE     { ?x ?y "Hello"@en }

I believe that is already covered by the "published RDF content" text.  It is "MUST NOT".

> 
> which doesnt seem like something we need to worry about.

We do.  It creates a graph with "Hello@en"^^rdf:PlainLiteral which wil not be understood as "Hello"@en by deployed systems.

> 
>      -- Sandro

 Andy

Received on Tuesday, 26 May 2009 16:09:18 UTC