- From: Olivier Corby <Olivier.Corby@sophia.inria.fr>
- Date: Wed, 14 Mar 2012 14:44:48 +0100
- To: public-rdf-dawg@w3.org
Received on Wednesday, 14 March 2012 13:45:25 UTC
I fear that the design is becoming over complex.
We used to have two kinds of repetitions:
+ * without loop in the path (except first step of + ...)
{n,m} with loop in the path
Now we would have three kinds of repetitions:
+ * without loop, without duplicate
{+} {*} without loop, with duplicate
{n,m} with loop with duplicate
In addition, {} notation is (in general) used for set but {+} enables
duplicates so it is misleading
In addition {n,m} and {+} do not behave the same with loops, so it is
not uniform
(By the way, our experience in my team is that loops in {n,m} are not
welcome because very often {1,n} is used to limit the length of paths
wrt +, but unfortunately paths are then trapped into loops (use case
with symmetric relation, e.g. foaf:knows{1,5}))
Concerning distinct, I am able to prototype distinct as a global
operator on path expression:
?x distinct(path) ?y
I would support this design.
Olivier
Received on Wednesday, 14 March 2012 13:45:25 UTC