Re: SPARQL-friendly alternative to rdf:Lists?

Hi Axel,

The problem is that SPARQL property paths do not allow the *ordering* of 
the elements to be easily retained in the result set.  For example, a 
property path like this obtains all elements, but does not guaranteed 
their order in the result set:

   { :list rdf:rest*/rdf:first ?element }


On 10/11/2013 11:45 PM, Axel Polleres wrote:
> FWIW, just to mention that property paths in SPARQL1.1 should have
> made it a lot easier to query lists in SPARQL. Cf. examples at:
> (also
> contains an example to query the elements of a list) Would that cover
> your use case? If not, what'd be missing?
> best, Axel
> -- Prof. Dr. Axel Polleres Institute for Information Business, WU
> Vienna url:  twitter: @AxelPolleres
> On Oct 11, 2013, at 4:02 PM, David Booth <> wrote:
>> rdf:Lists are notoriously difficult to use in SPARQL if one wishes
>> to retain the *order* of the items in the list.  James Leigh and
>> David Wood made a nice proposal a few years ago to address this
>> problem directly at the RDF level,
>> but for whatever
>> reasons, that work was not included in the charter of the current
>> RDF working group.  As a result people often use some other means
>> of representing ordered lists in RDF, such as by [item, index]
>> pairs.
>> For those who use an alternate way to represent an *ordered* list
>> of items in RDF (instead of rdf:List), I am wondering:
>> 1. What *ordered* list representation do you prefer, and why?
>> 2. Have there been any efforts toward standardizing alternative
>> *ordered* list representations in RDF?  E.g., has anyone written up
>> a spec on how they prefer to do it?
>> Thanks, David

Received on Saturday, 12 October 2013 03:57:55 UTC