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Re: Looking at the current proposals for SHACL

From: Holger Knublauch <holger@topquadrant.com>
Date: Mon, 23 Mar 2015 08:59:23 +1000
Message-ID: <550F494B.8010709@topquadrant.com>
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, public-data-shapes-wg@w3.org
On 3/20/2015 21:47, Peter F. Patel-Schneider wrote:
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> Thinking further on
>
> An alternative design would be to hard-code the sh:valueShape property into
> the engine, and do the recursion in the outer layer, outside of SPARQL.
>
> I don't see how it would work.

I believe I had explained this before, although these things can easily 
get lost in the many emails. It would basically be a new bullet item in

http://w3c.github.io/data-shapes/shacl/#operation-validateConstraint

that would hard-code the sh:valueShape template by recursively calling 
validateNodeAgainstShape for each value of the property. This solution 
does have the same limitations as the approach based on sh:hasShape.

Holger


>
>
> peter
>
>
> On 03/19/2015 09:46 PM, Holger Knublauch wrote:
>>
>> On 3/20/15 1:30 PM, Peter F. Patel-Schneider wrote:
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>>> So you are saying that you can either do recursive shapes inside
>>> SPARQL, which requires an extension to SPARQL, or outside of SPARQL,
>>> which requires something more than SPARQL.  OK, I'll change the wording
>>> to "It provides a formal specification for SHACL in terms of SPARQL
>>> plus something extra to handle recursive shapes."
>> Yes the critical difference is that option 2 could still be executed
>> with off-the-shelf SPARQL processors.
>>
>> I would also be fine with the same solution that you have, and simply
>> disallow recursion at sh:valueShape.
>>
>> Thanks, Holger
>>
>>
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Received on Sunday, 22 March 2015 23:00:38 UTC

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