- From: Arnaud Le Hors <lehors@us.ibm.com>
- Date: Tue, 22 Jul 2014 16:28:59 +0200
- To: public-rdf-shapes@w3.org
- Message-ID: <OFD0511F65.F3C57CFA-ONC1257D1D.004C839F-C1257D1D.004F8E90@us.ibm.com>
Hi all, I've been on vacation and haven't had a chance to follow the discussion in details but I'm a bit surprised by the way the discussion is going. We seem to have lost sight of the fact that the proposed charter was drafted based on the outcome of the workshop that took place last year and provided for a direction to follow. With that in mind, on behalf of the chairs of the workshop, I'd like to remind everyone that: TopQuadrant was invited to present at the workshop. During the workshop, Guoqian Jiang (Mayo) presented SPIN (with SPARQL queries, as it was in the Member Submission): http://www.w3.org/2001/sw/wiki/images/d/d6/RDF-Validation-Workshop-GJiang-v1.0.pdf 14-17 The workshop participants found this good for enforcement but not high-enough level for definition, like SPARQL. SPIN apparently has a more declarative representation, but that makes it basically like Application Profiles and Resource Shapes http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/0018.html ShEx is an extension of Resource Shapes to provide disjunction, grouping and semantic actions. ShExC is a human-facing schema language (like RNG Compact Syntax) capturing the ShEx expressivity in a much smaller syntax. Compare the ~20 lines of ShExC to the hundreds in < http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/att-0002/sotaspin-text.spin.ttl >. Independently of the shortcomings one may find in ShEx which I would expect a WG to discuss and address as necessary, I would like to point out that although the crux of the discussion has focused on validation, the workshop made it very clear that the need wasn't simply about validation but also about definition/description - as in describing the data a specific service can receive. Solutions that may be perfectly suitable for validation aren't necessarily as suitable for description. The workshop concluded with: The participants agreed that the W3C should launch an activity to develop a human and machine-readable description of the "shape" of the RDF graphs that a service produces or consumes. This description should be usable for validation, form-generation, as well as human-readable documentation. The participants further agreed that the solution must provide a declarative way of describing simple integrity constraints along with an extension mechanism that allows using technologies such as SPARQL to specify more complex constraints. Participants had the opportunity to agree to standardize SPIN or CIV. That's not what they thought the W3C should do. Note that this isn't to say that ShEx is necessary the perfect answer but I don't think it is very productive to ignore past discussions and agreements. Any counter proposal should be positioned with regard to the outcome of the workshop. Best regards. -- Arnaud Le Hors - Software Standards Architect - IBM Software Group
Received on Tuesday, 22 July 2014 14:29:37 UTC