Re: implementing today's resolution

Hi Peter,

thanks for starting to bring structure into the suggested refactorings 
(also in your later email). I do believe we need to tackle them one by 
one, and break them into separate ISSUEs. So below are some references 
to tickets (I raised a few of them recently):

On 5/29/2015 6:39, Peter F. Patel-Schneider wrote:
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> Here is my list of some differences between
> https://w3c.github.io/data-shapes/shacl/ (SHACL) and
> https://www.w3.org/2014/data-shapes/wiki/Shacl-sparql (SHACL-SPARQL) and my
> proposals on how to make improvements as per the resolution of today.
>
> peter
>
>
>
>
> The Language
>
> Top-Level Constructs: The top-level construct in SHACL-SPARQL is uniformly
> the combination of a scope and a shape, with other information permissible.
> Shapes are uniformly local.  Global constraints are different from shapes.
> Proposal: Use the uniform SHACL-SPARQL construct.  There are naming issues
> that then would need to be resolved.

On this one I would suggest that you create an ISSUE in which you 
explain a problem with the current draft and why you believe your own 
proposal would be better. To me this feels almost like a matter of 
taste, but I think we need to get to the bottom of this difference. I 
cannot really speak on your behalf on this topic.


>
> Scopes: SHACL-SPARQL has more ways of providing scope (although SHACL may
> have recently incorporated most of them).
> Proposal:  Use SHACL-SPARQL scope mechanism.

Raised: http://www.w3.org/2014/data-shapes/track/issues/62

>
> Classes: SHACL-SPARQL does not do anything special for any SHACL construct
> that is also an instance of rdfs:Class.
>
> Recursion: SHACL permits certain kinds of recursion, but does not correctly
> specify  how recursion works.  SHACL-SPARQL forbids recursion.
> Proposal: Forbid recursion, waiting for a proposal on how it can be done
> correctly and effectively.

Already open: http://www.w3.org/2014/data-shapes/track/issues/22

>
> Templates: SHACL has a template mechanism.
> Proposal: Keep the template mechanism.
>
> Functions: SHACL has a function mechanism.
>
> Non-SPARQL: SHACL permits other execution mechanisms.
>
>
> The Interface
>
> Invoking SHACL: SHACL has a set of supported operations.  SHACL-SPARQL has
> one call, with a control graph and a data graph.  Note: There is a proposal
> for a more flexible design.
>
>
> The Semantics
>
> Access to control graph: SHACL uses access to the control graph from
> constraint to define constructs.  SHACL permits access to the control graph
> when determining constraint violations.
> Proposal;  Define the semantics without accessing the control graph.

Already open: http://www.w3.org/2014/data-shapes/track/issues/47

>
> Extensions to SPARQL: SHACL requires certain extra functions; SHACL-SPARQL
> does not.
> Proposal:  Define the semantics of SHACL without using extra functions.
>
> Mapping to SPARQL: SHACL and SHACL-SPARQL have different mappings to SPARQL,
> mostly because SHACL uses the extra functions.
> Approach:  If the extra functions are not used, then a mapping more like the
> SHACL-SPARQL one is probably needed.

Both raised with: https://www.w3.org/2014/data-shapes/track/issues/63


>
> RDFS Inference:  SHACL does not use RDFS inference.  SHACL-SPARQL does.

Open: http://www.w3.org/2014/data-shapes/track/issues/1

Holger

Received on Monday, 1 June 2015 06:02:52 UTC