Re: bang ! in turtle

On Mar 1, 2011, at 18:46 , Antoine Zimmermann wrote:
>> 
>> Afaik, there is no restriction for subjects as literals in SPARQL (which explains why "abc" bif:contains "b" works, for example) - that's my biggest concern about the whole issue. Two W3C recommendations (SPARQL and RDF) are effectively contradicting each other. For example, you could generate an invalid RDF document with a perfectly valid SPARQL query (e.g. CONSTRUCT { ?name bif:contains "foo" } WHERE { ?a a foaf:Person ; foaf:name ?name . ?name bif:contains "foo" })
> 
> Well, actually more or less all sem web standards other than RDF do use more general notions of triples (OWL 2 in the OWL 2 RL specification, RIF and SPARQL). That's not new.

Let us not go there. We are defining a serialization for RDF. If there are restrictions in RDF, they apply for the syntax.


> 
> But:
> 
> "Antoine"  ^foaf:names  az#me .
> 
> does not contain a literal in the subject position. In that triple, "Antoine" is really the object and az#me is the subject. The goal is simply to introduce syntactic sugar for ease of writing (just like the keyword "a" does not mean that there is a predicate "a" defined anywhere).
> 

Correct.

Ivan

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Ivan Herman, W3C Semantic Web Activity Lead
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