- From: Steve Harris <steve.harris@garlik.com>
- Date: Wed, 3 Nov 2010 17:13:31 +0000
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: SPARQL Working Group <public-rdf-dawg@w3.org>
On 2010-11-03, at 16:22, Andy Seaborne wrote:
>
> On 03/11/10 15:42, Steve Harris wrote:
>>> ex:agg(?y, ?z)+1 is an expression - it needs a solution to calculate the "+".
>> Yeah, makes sense in Projection, but that doesn't apply to grouping, does it? "Naming" expressions is compulsory in SELECT already, as they have to be associated with some variable name in the result format.
>>
>
> And before the projection step?
>
> If we have
>
> SELECT (ex:agg1(?y, ?z)+ex:agg2(?y, ?z)+1 AS ?A)
> {
> ...
> }
> GROUP BY ?x
>
> then in each row, each ex:agg?(?y, ?z) needs to turn into a value. Operator + evaluates each argument, then calls op:numeric-add.
>
> How, in expression evaluation, does ex:agg1(?y, ?z) get mapped to a value? I would like to avoid wholesale changes to expression evaluation unless there is no other way.
Yep, that's fair enough.
- Steve
--
Steve Harris, CTO, Garlik Limited
1-3 Halford Road, Richmond, TW10 6AW, UK
+44 20 8439 8203 http://www.garlik.com/
Registered in England and Wales 535 7233 VAT # 849 0517 11
Registered office: Thames House, Portsmouth Road, Esher, Surrey, KT10 9AD
Received on Wednesday, 3 November 2010 17:14:08 UTC