Re: Improving EXISTS

good afternoon;

> On 2016-06-25, at 17:58, Andy Seaborne <andy@apache.org> wrote:
> 
> The tests contributed by Peter and the discussions around them show that there are bugs in the spec.
> 
> The RDF Shapes working group uses EXISTS and also uses "pre-binding" which is a form of parameterized query(*) in SHACL [1] and the EXISTS mechanism is related to parametrization.
> 
> W3C process for corrections to recognized generally to be inflexible. It is normally to wait for the next WG to run and end which is a multiyear cycle - that does not fit with the RDF Shapes WG timescale.
> 
> A suggestion (from Arnaud Le Hors / RDF Shapes chair, as well as other people) is to use the Community Group mechanism to build consensus in the SPARQL community, including implementers and users.
> 
> Community Groups can publish reports. These are not W3C standards. They do provide a way to record consensus or alternatives. This could be used to supplement the SPARQL errata process [2].
> 
> Whether that is a specific CG for this one task, or using "RDF Tests" is a matter of refinement - for me, I prefer which ever one looks like it creates the better community.
> 
> Thoughts and comments?

- request parameters are a de facto requirement, as they were established by sesame and now users expect them.
if there is to be an effort to ratify a standard behaviour, that deserves a group of its own, independent of any concern for shapes and/or exists.

- as to exists itself, its semantics is underspecified and a working group tasked with its definition would be worth while.
the charter should include any possible changes in the clause syntax and the run-time semantics, but should avoid any suppositions as to implementation. 

- once the semantics is defined, the rdf test group should proceed to define and ratify tests.

best regards, from berlin,


---
james anderson | james@dydra.com | http://dydra.com