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Re: Questions on grammar restrictions on Blank Node reuse across patterns and a more fundamental question on Update semantics for confirmation (was: Re:Draft response KK-15)

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Thu, 24 May 2012 18:19:54 +0100
Message-ID: <4FBE6DBA.3040008@epimorphics.com>
To: "Polleres, Axel" <axel.polleres@siemens.com>
CC: "public-rdf-dawg@w3.org" <public-rdf-dawg@w3.org>

>>> * Add the restriction on blank node label usages across BGPs
>>>     (and QuadPatterns? Depending on 1)) also to the grammar
>> restrictions
>>>     in query, i.e. at
>>> http://www.w3.org/2009/sparql/docs/query-1.1/rq25.xml#sparqlGrammar
>>
>> No.
>
> I assume the "No" is for the QuadPAtterns part...

"no" to add restriction.


>  May I still suggest
> as small editorial fix to explicitly add the restriction on blank node
> label usages across BGPs in the numbered list in Section 19.8, i.e.
> add something like:
>
>   <li>The same BLANK_NODE_LABEL must not appear in different GroupGraphPatterns
>    within the same query</li>
>
> just in order to have *all* grammar restrictions in one place?

This isn't quite right - a label can be used in one BGP (a stronger 
condition)

The text in 5.1.1 is

[[
A label can be used in only a
single basic graph pattern in any query.
]]
and that means no reuse across GroupGraphPatterns

Putting all the restrictions in one place is a good idea.  I'll do that.

	Andy


>
>
> Any other opinions on any of the points above?
>
> Cheers,
> Axel
>
Received on Thursday, 24 May 2012 17:20:35 GMT

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