ISSUE-105: Updated proposal with sh:prefixes

Following the (once again lively) discussion about the SPARQL prefixes 
topic, I have updated the spec with my proposal. See section 10.2 Prefix 
Declarations for SPARQL Queries:

     http://w3c.github.io/data-shapes/shacl/#sparql-prefixes

This document already included an earlier proposal with the simpler 
sh:prefix syntax that was rejected by the group, so what is in the 
document now is probably more acceptable. The section is easy to take 
out if it's not acceptable to the WG.

Note that I have further simplified the approach to make it more 
predictable and less verbose. In this proposal, we recommend users to 
attach their prefix declarations to the graph resources (usually 
instances of owl:Ontology). This makes it possible to freeload on 
owl:imports to transitively reuse other prefix declarations. The 
sh:sparql definitions within a given graph would basically always just 
point to their own owl:Ontology, very similar to how rdfs:isDefinedBy is 
used. Note this is just a recommendation, and people may still create an 
independent object to hold their prefixes.

I have not yet gone through the other parts of the document to clarify 
that the values of sh:select (and similar properties) are SPARQL 
fragments only, not necessarily complete queries. But that would be a 
simple next step.

Since Arnaud has announced that he does not want to spend much further 
meeting time on this topic, please send any feedback via email so that I 
can adjust my proposal if needed.

Thanks,
Holger

Received on Thursday, 15 September 2016 05:55:10 UTC