Re: Recursion in RDF Data Shape Languages

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On 05/21/2015 01:38 PM, Arthur Ryman wrote:
> Peter,

[...]

>> This document provides a particularly bad support for recursive
>> definitions because the running example can be easily handled without
>> recourse to recursive definitions,
> Agreed. The recursion is only apparent. The shape appears to have 
> circular references, but the actually meaning is obtained by labelling 
> nodes with the names of the node constraints they must satisfy.

The running example can easily be handled using SPIN, for example, without
any definitions, shapes, or constraints that reference back to themselves.

>> The exposition of the running example permits graphs where the contact
>> is the associate.
> I don't think so. The contact is not known by any person so it violates
> the associate constraint.

Not if the contact knows itself.

>> The document uses "unique name" where it could be misread to mean that
>> name is a key.
> Agreed, wrong wording. I meant that the names are distinct.

Huh?  The constraint indicates different, saying that there is one name per
x, not that the name is distinct in any way.

>> SPARQL 1.1 path expressions are much more general than path
>> expressions, which appear to be just properties and inverses.  A
>> different name should be chosen.
> Agreed. I was going to call them "simple path expressions". I should do
> that to avoid confusion with abritray SPARQL 1.1 path expression.
> 
> -- Arthur
> 
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Received on Thursday, 21 May 2015 22:12:58 UTC