Suppose that I have the following Turtle declaration:

@prefix : <http://example.org#> .

:ls :list (:a :b :c)

Is there a way to get the positions of the elements in the collection?

For example, with this query:

PREFIX :     <http://example.org#>
PREFIX rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#> 

SELECT ?elem WHERE {
 ?x :list ?ls .
 ?ls rdf:rest*/rdf:first ?elem .
}

I get:

--------
| elem |
========
| :a   |
| :b   |
| :c   |
--------

But I would like a query to obtain:

--------------
| elem | pos |
==============
| :a   |  0  |
| :b   |  1  |
| :c   |  2  |
--------------

Is it possible?

rdf sparql
Edit
Report