scope of bnodes in SPARQL vs N3

I gather DAWG is talking about reducing the scope of bnodes
from whole queries to just basic graph patterns; maybe the
current SPARQL spec is already this way; I don't track
SPARQL as closely as I used to... but it just crossed my radar again:

> Extending the scope of bnode labels across OPTIONAL/UNION has not
come 
> up as a application need.
>
> Fred - Your case of writing queries, with bnodes in the _:a form,
does 
> not meet my experience.  Use of _:a, as opposed to [], by application 
> writers appears quite rare in practice.
>
> As BGP's has proven natural extension point, it suggestes to me that 
> we have it right to scope bNodes to BGPs and not handle them in the 
> algebra.
  -- http://www.w3.org/mid/456C3E7A.1020609@hp.com

I suppose that doesn't affect the turtle/SPARQL relationship,
since turtle doesn't have {}s.
  http://www.dajobe.org/2004/01/turtle/#sec-diff-sparql

But it makes me wonder about the relationship between N3 and
SPARQL. I guess any N3 that uses {} can't be embedded in SPARQL
straightforwardly anyway.

I wonder if there are tests for the scope of bnodes in N3...
ah yes... in http://www.w3.org/2000/10/swap/test/regression.n3 :

:t1030 a test:CwmTest, test:CwmProofTest;
    test:referenceOutput <ref/underbarscope-out.n3>;
    test:description   "The scope of _:me should be the formula";
    test:arguments     """underbarscope.n3 --think""".

hm... that uses the funky log:notEqualTo; I wonder if there's
a more straightforward way to test it.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E

Received on Tuesday, 28 November 2006 19:25:10 UTC