On 29/09/13 19:13, Michael Brunnbauer wrote:
Hello Andy,
On Sat, Sep 28, 2013 at 09:02:04PM +0100, Andy Seaborne wrote:
?ep a void:sparqlEndpoint
SERVICE SILENT ?ep { ...
then ?ep is not bound if the federation fails. That a failure causes a
match
with unbound variables is expected but that ?ep is also unbound in this
case
surprised me. This is intended ?
Is it? In the latest version? Assuming ?ep a void:sparqlEndpoint
matches something in the local dataset
SERVICE SILENT ?ep --> failure
evaluates to the join identity (one row, no columns) and ?ep is unbound
in that. This joins with the eval of "?ep a void:sparqlEndpoint".
If not, please submit a JIRA with complete minimal example.
Thank you very much for your help so far!
I really should get into SPARQL algebra. Meanwhile I guess that ?ep should
stay bound if ?ep is bound in the first part of the query and is joined with
the join identity.
I upgraded to Fuseki 1.0.0 without success regarding this. So here is my JIRA:
https://issues.apache.org/jira/browse/JENA-552
Thanks - and (hopefully!) fixed.
Completely different topic: Has a "REPEAT WHILE" keyword/feature ever been
discussed for SPARQL UPDATE in the working group ? See:
http://www.brunni.de/sparql_turing_machine.txt
http://www.brunni.de/searchsparqlendpoints.txt
No. This gets into the whole area of a SPARQL syntax for something
rules-ish - obviously a good thing to have but beyond the remit of the
SPARQL-WG that has just finished.
Andy
Regards,
Michael Brunnbauer
