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Re: shapes-ISSUE-157 (constraint component support): the support for constraint components is incorrectly stated [SHACL Spec]

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Fri, 29 Apr 2016 00:28:06 -0700
To: Holger Knublauch <holger@topquadrant.com>, public-data-shapes-wg@w3.org
Message-ID: <57230D06.6090704@gmail.com>
There are still some glitches with contexts.

"For example, the context of the component defining the sh:closed property is
sh:NodeConstraint. This means that sh:closed can only be used with sh:constraint."

This seems to indicate that the meaning of contexts is to limit which
properties they can be used with.  This is not correct - the meaning of
contexts is to limit which constraint classes they can occur in.  These
limitations then limit which properties they can be used with, but limiting
the properties is not the meaning of contexts.

"The relationship between a constraint component and the constraint type that
it can be used with is called the context of the component."

Many components can be used with multiple constraint types.



peter




On 04/28/2016 04:09 PM, Holger Knublauch wrote:
> Ok, I have rolled back to the previous policy of listing the constraint classes:
> 
> https://github.com/w3c/data-shapes/commit/19ef548ffe19371d17c4fffb14086ef3064e2028
> 
> 
> I had thought it would be more readable with the properties only, but this was
> indeed less precise.
> 
> Please confirm we can close this.
> 
> Holger
> 
> 
> On 28/04/2016 22:44, RDF Data Shapes Working Group Issue Tracker wrote:
>> shapes-ISSUE-157 (constraint component support): the support for constraint
>> components is incorrectly stated [SHACL Spec]
>>
>> http://www.w3.org/2014/data-shapes/track/issues/157
>>
>> Raised by: Peter Patel-Schneider
>> On product: SHACL Spec
>>
>> The "support" for constraint components is stated in terms of sh:constraint,
>> sh:property, and sh:inverseProperty.  This does not work, because any
>> constraint can be used as the object of a sh:constraint triple.
>>
>> For example, the intent in the spec is that sh:datatype should not be used
>> in inverse property constraints, but the spec allows sh:datatype constraint
>> component properties to appear in inverse property constraints.
>>
>>
>> 3.1.3 sh:datatype
>>
>> The property sh:datatype can be used to restrict the datatype of all value
>> nodes. The values of sh:datatype must be resources representing datatypes,
>> such as xsd:string.
>>
>> Constraint Component: sh:DatatypeConstraintComponent
>>
>> Supported Context Properties: sh:constraint, sh:property
>>
>>
>>
> 
> 
Received on Friday, 29 April 2016 07:28:39 UTC

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