- From: Polleres, Axel <axel.polleres@siemens.com>
- Date: Thu, 10 May 2012 11:44:08 +0200
- To: Andy Seaborne <andy.seaborne@epimorphics.com>, "public-rdf-dawg@w3.org" <public-rdf-dawg@w3.org>
> Do you have suggestions? (I note the definition is based on your
> suggestions)
Right, but that pre-dated BIND, AFAIR... Anyways, I will think of something.
In principle, I ask myself, why we have to restrict the use of variables assigned to
in BIND *at all* except for not using variables within the expression on the LHS of the "AS".
> Maybe something needed for across a group?
Hmm, it seems to me that the current clause 12. in the grammar restrcitions
tries to prohibit something like this:
{
BIND ( ?X1 AS ?Y)
BIND ( ?X2 AS ?Y)
}
right? But I am not sure about whether we also want to prohibit this one:
{
BIND ( ?X1 AS ?Y)
}
{
BIND ( ?X2 AS ?Y)
}
Anyways, I'll try to check through the "history" again and re-think.
Best,
Axel
> -----Original Message-----
> From: Andy Seaborne [mailto:andy.seaborne@epimorphics.com]
> Sent: Thursday, 10 May 2012 11:07 AM
> To: public-rdf-dawg@w3.org
> Subject: Re: "in-scope" and BIND question
>
>
>
> On 09/05/12 15:27, Polleres, Axel wrote:
> > I havea a question on in-scope variables and BIND, particularly, on
> > item 12. in
> > http://www.w3.org/2009/sparql/docs/query-1.1/rq25.xml#sparqlGrammar
> > # " The variable assigned in a |BIND| clause must not be already
> > in-scope <http://www.w3.org/TR/sparql11-query/#variableScope>.
> > "
> > I am not sure here, what "already" in-scope means. Can we
> clarify that?
>
> Do you have suggestions? (I note the definition is based on your
> suggestions)
>
> > Particularly, when reading the in-scope definition, I am a
> bit unsure
> > of what happens with regards to e.g. UNION queries, i.e. my
> feeling is
> > that SELECT * { { BIND (1 AS ?Y) } UNION { <s> <p> ?Y } }
> shouldn't be
> > different from SELECT * { { <s><p> ?Y } UNION { BIND (1 AS
> ?Y) } } and
> > both should be allowed (returning 1 on the empty graph), is that
> > correct?
>
> This is legal. Scope as defined works bottom-up.
>
> Maybe something needed for across a group?
>
> Andy
>
> > thanks,
> > Axel
> > --
> > Dr. Axel Polleres
> > Siemens AG Österreich
> > Corporate Technology Central Eastern Europe Research &
> Technologies CT
> > T CEE
> > Tel.: +43 (0) 51707-36983
> > Mobile: +43 (0) 664 88550859
> > Fax: +43 (0) 51707-56682 mailto:axel.polleres@siemens.com
>
>
Received on Thursday, 10 May 2012 09:44:43 UTC