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Re: Fwd: SPARQL: graph syntax should be N3 subset

From: <jos.deroo@agfa.com>
Date: Mon, 6 Dec 2004 10:48:59 +0100
To: andy.seaborne@hp.com
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>, public-rdf-dawg-request@w3.org
Message-ID: <OF8E2E7B9A.8FCF47AF-ONC1256F62.002F9B99-C1256F62.0036113C@agfa.com>

Andy wrote:
> After these areas, Jos has should how optionals can map to N3 but I find 
> idioms necessary opaque and don't think there is sufficient value in a 
> syntax when the user has to use some unnatural way of writing queries.

I now think that

SELECT ?name ?mbox
    (?person foaf:name ?name)
  [ (?person foaf:mbox ?mbox) ]

should have been written as

q:select {(?name ?mbox) a q:Answer};
q:where  {?person foaf:name ?name.
          ?person foaf:mbox ?mbox}.

q:select {(?name q:unknown) a q:Answer};
q:where  {?person foaf:name ?name;
          ?person @not foaf:mbox ?mbox}.

but that @not is not yet existing and is
better to avoid as it assumes closed world

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Monday, 6 December 2004 09:49:38 UTC

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