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Re: SPARQL Grammar updated

From: Steve Harris <steve.harris@garlik.com>
Date: Mon, 26 Apr 2010 10:45:57 +0100
Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
Message-Id: <59733EDA-BC8A-4985-BCB3-BD11305E4501@garlik.com>
To: Andy Seaborne <andy.seaborne@talis.com>
On 2010-04-25, at 18:11, Andy Seaborne wrote:
> * GROUP_CONCAT(?x,?y ; SEPARATOR=";")
> 
> At F2F3, we converged on this named parameters form of GROUP_CONCAT.  I suggested a uniform treatment with params available in custom aggregates. However, having tried this, I found it leads to complexity without obvious benefit.
> 
> Question:
> Is this legal:
>  GROUP_CONCAT(?x,?y ; SEPARATOR=?sep)
> where ?sep is some in-scope variable?  For now, I've made the separator a fixed string depending clarification.

I think constants only is a good idea. As I mentioned at the F2F, it otherwise raises a host of issues around grouped v's non-grouped values.

As everything after the ; is passed directly to the set function, that expression must either be GROUP BY ?sep, or it would have to be SAMPLE(?sep), or similar, and I don't really want to go there.

- Steve

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Received on Monday, 26 April 2010 09:46:29 GMT

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