Re: AW: Thoughts on validation requirements

On Jul 28, 2014 12:08 AM, "Peter F. Patel-Schneider" <pfpschneider@gmail.com> 
wrote:
>
> On 07/27/2014 02:36 AM, Bosch, Thomas wrote:
>>
>> Hi Dimitris
>>
> [...]
>
>> Regarding ShEx:
>>
>> - I am also unconfortable with the un-typed validation but I also see 
the need
>> to support it. Unless of course RDF somewhere specifies that every 
resource
>> MUST have a rdf:type. This however should not be the primary focus of 
ShEx
>> since it is not the common case.
>
>
> [...]
>
>
> I'm still trying to figure out how ShEx is supposed to be used for 
validation.  I could make some guesses, but I think that it would be better 
for someone how was involved with ShEx to tell me.

I'm guessing here from your exploration of ShEx that you see how one
can verify a node in an instance graph against a start rule in a
schema but you are unclear on why and when one would want to. My
guess might be wrong so I'll just describe a use case at a high level
and ask wait for you to ask specific questions.

The XML world topically uses XML Schema and RelaxNG to communicate
structural constraints which apply at a particular point in a
process. A good example is WSDL which associates a service with a
particular schema. This is used to generate code and validate the
exchanged messages. LDP is a good analog of this in RDF-land. Resource
Shapes uses oslc:resourceShape to tie an LDP service to a schema
describing what graph shapes that service works with.
<http://www.w3.org/Submission/2014/SUBM-shapes-20140211/#resourceShape>
The ShEx semantics are an attempt to formalize the apparent behavior
of Resource Shapes to clarify, e.g. verification WRT a value set
<http://www.w3.org/mid/53C917E6.7020701@gmail.com>.

I may not have answered your question, but perhaps we can work from here.


> peter
>