Two Standards ?

A random thought before the week end:

Can this WG (please!) produce two separate standards?

1) An RDF vocabulary similar to the original LDOM proposal
2) The ShEx Compact Syntax aiming at the data reuse scenarios

We already have RDF Schema. We already have OWL. We would already have a 
third language (LDOM or whatever). Why not have a forth language?

The situation in very similar to XML Schema vs. DTD. vs RELAX-NG. They 
all solve similar problems, but from different perspectives.

We are currently trying to mix different paradigms together and risk 
producing something that nobody will be happy with. People with OO 
background will wonder what the fuzz is about this parallel structure 
called "Shapes", raising the implementation costs and creating a mix of 
parallel semantic webs. And ShEx people don't want to worry about the 
interactions of the various triple models at all - instead have the 
ShExC files live outside of the triple store. And that makes sense 
because even if you introduce ldom:instanceShape to separate shapes from 
classes, you'd still run into conflicts with other ShEx models that also 
happen to use ldom:instanceShape. The only proper solution here is to 
not have triples in the first place.

Another constant source of conflict will be the role of SPARQL. The ShEx 
camp seems to be more concerned about the balance of expressivity and 
complexity, while the SPIN camp has plenty of use cases where 
expressivity is the main concern. Furthermore, a SPIN-like LDOM can more 
easily be combined with existing RDFS and OWL ontologies, filling gaps 
in that space.

We have a handful of ShEx supporters in the WG. I am sure they could 
turn their Member Submission into a formal spec quite rapidly. From an 
LDOM point of view we have plenty of stuff already implemented, and I'd 
be happy to wrestle and collaborate with anyone to flesh out the open 
details. The Requirements document is already being split into "Property 
constraints" and "Complex constraints", so both camps can harvest from 
the same catalog of requirements. We can also share test cases and 
produce a small document explaining how to map from one language to 
another. But the aforementioned reasons and the endless discussions over 
the last half a year provide plenty of arguments that justify why the WG 
chose to create two languages.

Why would this separation of deliverables not work?

Thanks,
Holger

Received on Friday, 13 February 2015 03:25:54 UTC