[Versa] Question about query

[Chimezie Ogbuji]

> see
> http://lists.fourthought.com/pipermail/versa/2005-August/000086.html
> and issue 1010 in the issue log.
> 
> Since I've received no objections to the proposal I've moved it to
> accepted so it is valid next gen versa.

Sweet..


> Well, if you read the new spec there is a concept of null/None kinda in
> there.  It is the results of casting a node --> literal or vice versa.
> 
> I don't like the idea of owl:Nothing because that itself is a resource
> and you would ask for "http://foo.com" and get back "owl:Nothing" and
> with out further checking you would not know you got back a different
> resource then you asked for.

For a model that *did* understand OWL, this would be prefered since
owl:Nothing is explicitely different from <http://foo.com> by
definition, but I agree that it would require that the Versa query
processor itself understands OWL constructs and we don't want that.

> So are we in agreement, the following queries return an empty set if
> the resource is not in the model:
> 
> <http://foo.com/res>
> @"http://foo.com/res"
> foo:res

Yes