- From: Francis McCabe <frankmccabe@mac.com>
- Date: Fri, 19 Oct 2007 08:59:56 -0700
- To: public-rdf-dawg-comments@w3.org
Referring to
http://www.w3.org/TR/2007/CR-rdf-sparql-query-20070614/
The treatment of the ORDER BY solution processing is less than clear.
The text states:
[16] OrderClause ::= 'ORDER' 'BY' OrderCondition+
[17] OrderCondition ::= ( 'ASC' | 'DESC' ) BrackettedExpression )
| ( Constraint | Var )
This grammar permits *any* expression or constraint to be an order
condition. But the text fails to give clear semantics for this.
For example, what does
.... order by ?x < 34
mean?
Perhaps the intention is something like:
eval(Q order by Exp) = sort({ (S,Exp) .. S satisfies Q })
where
(S1,Exp1) o< (S2,Exp2) iff Exp1 < Exp2
However, that would not permit a reasonable interpretation for
order by ?x < 34
(which would seem to be a weird case anyway)
Looking forward to a response
Frank McCabe
P.S. It would have been helpful if the committee adopted an OASIS-
style policy of putting line numbers on the specification. Then I
could quote line numbers at you.
Received on Friday, 19 October 2007 16:00:15 UTC