- From: Steve Harris <steve.harris@garlik.com>
- Date: Mon, 27 Sep 2010 13:20:54 +0100
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: Axel Polleres <axel.polleres@deri.org>, SPARQL Working Group <public-rdf-dawg@w3.org>
On 2010-09-23, at 08:36, Andy Seaborne wrote: > > > On 22/09/10 06:59, Axel Polleres wrote: >> I have a small question about the Definition of "Group" in the query draft: >> >> "Group((),Ω) = { 1 -> Ω }" >> >> ... shouldn't that be: >> >> "Group((),Ω) = { () -> Ω }" >> >> i.e., what is the 1 supposed to mean? > > The 1 is any key. When the set of groups keys is the empty, which happnes for > > SELECT (count(*) AS ?c) { ?s ?p ?o } > > then there needs to be a key value for the group. > > It could be said to be slightly more sense to be (1), not 1, as it's a list when then the key isn't empty. The key just needs to be unique, and here, there is only one key so it's arbitrary. Yeah, I went for a non-list value so there was no possibility of it being the same as a "real" key, but it's perhaps not as clear as it should be. - 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 Monday, 27 September 2010 12:21:29 UTC