Re: Proposal c)

* Holger Knublauch <holger@topquadrant.com> [2015-05-07 11:19+1000]
> On 5/6/2015 19:55, Eric Prud'hommeaux wrote:
> >I grouped them and struck Jose's (I think he's fine with that but
> >I'll check). now: [[ three documents: primer, core semantics,
> >SPARQL functions SHACL (Shapes Constraint Language) Primer ericP
> >and Holger A Primer for SHACL, concentrating on the high-level
> >language, but also giving examples of constraints directly using
> >SPARQL syntax. Largely compatible with all the other proposals.
> >Core SHACL Semantics ericP SPARQL/SHACL Semantics ericP ]]
> 
> Thanks for updating the home page. I believe Primers are usually
> non-normative and therefore cannot be part of the formal
> deliverables. Furthermore, the Primer is orthogonal and could be
> added to the other proposals too.

Non-normative documents are deliverables, but aside from that, the
proposal is to separate the formal semantics from the primer and to
have a document that describes SPIN templates.

The only change I've made to the primer is to add some introductory
material in response to Karen and Arthur's assertions that it was not
a gentle enough introduction.


> Regarding the SPARQL/SHACL draft, it is a step in the right
> direction to acknowledge that the SPARQL dimension to SHACL also
> exists. You have basically just copied an outdated snapshot of my
> chapters 7 onwards into a new document, inserted a misleading
> introduction ("SPIN"?) and put your name on it. The result is

It's got SPIN templates, SPIN calling conventions (embedding arguments
in lists) and SPIN variable conventions (?this). None of these things
exist in SPARQL. To call them SPARQL is quite misleading. We could
invent a new name for SPARQL templates but SPIN seems pretty accurate.


> unfortunately a completely inconsistent and incomplete set of
> unrelated documents. Where did the content of chapters 1 - 6 end up?
> Does your Core Semantics document even have the same semantics? How

Not yet. The core semantics is more complex and will require some work
to express in templates. Note that the ShEx semantics started out
quite simple (basically Resource Shapes) and grew in response to user
feedback (e.g. multi-occurance). David Booth's proposal is to profile
out the intersection but I think we may be able to offer a more useful
language if we extend the templates to meet more of these use cases.


> does the RDF vocabulary of the core look like and where is its
> Turtle file? Where did the consistent reading experience for users
> go to? As expected, this splitting of documents is only leading to
> confusion. If we absolutely have to make such a split, we should do
> this once the language has stabilized. Meanwhile I have added code
> that injects Part 1 and Part 2 sub-headers into the TOC:
> 
>     http://w3c.github.io/data-shapes/shacl/#h-toc
> 
> Having said this, I am always trying to explore possible ways
> forward that everyone could live with. I observe that my draft could
> be renamed to
> 
>             "SHACL RDF Vocabulary and SPARQL-based Semantics"
> 
> This is self-contained, covers all requirements and doesn't need
> anything else. The core language elements are defined via templates
> and their SPARQL queries. IMHO elegant, consistent and easy to
> implement. With its many examples it could even serve as a Primer
> for now.
> 
> If enough people believe there is value in the WG publishing the
> alternative semantics document then your draft could be renamed to
> 
>             "SHACL Core Abstract Syntax and Declarative (?) Semantics"
> 
> and it should be made clear that this is about a small sub-set of
> SHACL only, similar to Part 1 of my draft. (FWIW I still believe
> something like "SHACL Lite" would be a better name.) We would then
> have two semantics documents for the core language. As long as they
> both define the same meaning, I see no problems with that. I
> personally do not see value in the Abstract Syntax document - it
> neither helps implementers nor is it easy to read by users nor is
> the language properly extensible - but I accept that other people
> may find this interesting from an academic point of view, so I would
> not vote against its publication as long as it doesn't mess up the
> consistency of the other spec.
> 
> On the general question of authorship, I guess we can reshuffle
> editors at any time - I am certainly open to adding other people as
> editors to "my" draft.
> 
> Cheers,
> Holger
> 
> 

-- 
-ericP

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Received on Thursday, 7 May 2015 11:47:01 UTC