querying RDF lists

Hi all,

Here is my one comment on the Sparql query language last call [1]:

I have a specific requirement for being able to represent and access the contents of ordered lists within RDF [2].  I would very much like to see at least...

(a) a standard function (or some other mechanism) for querying whether some node is an element of some RDF list (i.e. something like isElementOfList(A, B))

... and preferably also ...

(b)  a standard function (or some other mechanism) for returning the numerical position of a node in an RDF list (i.e. something like listPosition(A, B))

... as part of the SPARQL query language WD as soon as possible.  I am concerned that the corresponding DAWG issue 'accessingCollections' has been marked as 'postponed', and it is not specified at what point this postponed issue is to be addressed.  

Speaking more generally from my own implementation experience, this functionality is required by almost any semantic web application, and I expect it to be a key part of any serious SPARQL implementation.  It would be a pain if every SPARQL implementation had a different custom function for doing this.

I'm very happy with everything else :)



[1] http://www.w3.org/TR/2005/WD-rdf-sparql-query-20050721/
[2] http://www.w3.org/TR/2005/WD-swbp-skos-core-guide-20050510/#secorderedcollections

Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Oxfordshire OX11 0QX
United Kingdom
Email:        a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440

Received on Monday, 3 October 2005 18:52:03 UTC