Re: What we voted on at the f2f

Karen,

+1.

Most of the semantics of SHACL core/lite/high-level/part-1 can be
expressed by providing a normative translation to ANY precisely
defined language. We are simply picking SPARQL for this purpose
because it is a W3C spec, is familiar to the WG, and happens to be
efficiently executable by mature engines. This choice in no way
implies that SPARQL is the only possible implementation or extension
language.

That being said, SPARQL can only do part of the job. There are
"control" aspects of SHACL that cannot be expressed in SPARQL. These
other aspects should also be formally defined, but we can defer that
to Part 3 which is intended for people who want to implement SHACL
engines.

-- Arthur

On Tue, Mar 24, 2015 at 1:04 PM, Karen Coyle <kcoyle@kcoyle.net> wrote:
> We clearly have different interpretations of the meaning of our vote at the
> face-to-face, which was:
>
> RESOLUTION: Define semantics using SPARQL as much as possible
>
> My view may be naive, but I took this to mean that the specification would
> use SPARQL as the "abstract language" to define the meaning of the SHACL
> vocabulary. The minutes of the f2f show that the vote was taken in the
> context of a discussion of the "normative expression" for SHACL, and a
> "formalism." Others suggested included the use of Z as a formalism, but that
> didn't get much traction.
>
> There is another view, which is that the SHACL specification describes a
> SPARQL implementation, although other implementations are not excluded. This
> view treats the specification as a description of the SPARQL implementation,
> referring to it as a "built-in" language for SHACL. In this view, there is
> no "abstract language" formally defining SHACL.
>
> I see a rather large gap between using SPARQL as a formalism in the
> specification, and assuming that the SHACL standard is a SPARQL
> implementation. In fact, I don't think that we made a decision as to the
> implementation of SHACL or to any stated relationship between SHACL as a
> specification and any particular implementations of SHACL.
>
> However, as I said, my view may be naive, but I wonder if we can't clarify
> at least what we voted on at the f2f, since we seem to be intoning that vote
> in our discussion here with at least two different meanings.
>
> kc
> --
> Karen Coyle
> kcoyle@kcoyle.net http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
>

Received on Wednesday, 25 March 2015 13:11:33 UTC