Re: SPARQL syntax proposals

> On Tuesday, the DAWG f2f took up syntax issues. We came up with a
> syntax that was acceptable to all or most (don't know how SteveH would
> phrase his feelings) of the attendees. These are expressed as examples
> below. The principal change was in expressing the graph pattern in
> "turtle+variables". Afterwords, Andy, Steve and I worked out how to
> express regexps and not get an inscrutable grammar like perls.
> We also changed AND to FILTER to express some constraints that we had
> put on the effect of the value constraints section (namely that this
> section ONLY restrict results, never add results or even, I think,
> produce variables bindings).
> These examples give a pretty good idea of our ideas:
> simple query:
> SELECT * WHERE { ?p ?s ?o }
> which prefix:
> PREFIX foaf: <http://example/foaf#>
> SELECT ?me ?you
>  WHERE { ?me foaf:knows ?you. ?you foaf:knows <fred> }
> could also have either of these forms:
>  WHERE { ?me rdf:type foaf:Person.} # trailing thingy in lexer
>  WHERE { ?me rdf:type foaf:Person .} # parses same as above
> ex with GRAPH and '.' in (but not ending) a QName.
>  WHERE { GRAPH ?g  { ?g dc:source myPartOfUriSpace:foo.rdf } }
> this is like turtle but n3 does not currenlty allow '.'s in names.

True and this is actually under investigation

In meantime I got positive implementation experience with . in qnames
i.e. all my RDF, OWL and N3 tests are running again.

Jos De Roo, AGFA

Received on Sunday, 6 March 2005 15:10:05 UTC