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Re: Shapes are Classes, even if you don't use rdf:type

From: Holger Knublauch <holger@topquadrant.com>
Date: Mon, 26 Jan 2015 11:27:20 +1000
Message-ID: <54C597F8.4080503@topquadrant.com>
To: public-data-shapes-wg@w3.org
On 1/26/2015 11:21, Peter F. Patel-Schneider wrote:
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> If shapes cannot be the object of rdf:type triples, then they probably
> should not be considered to be classes.

Yes, the updated LDOM design has

     rdfs:Class rdfs:subClassOf ldom:Shape

which makes the term "Shape" more general than "Class". All classes can 
play the role of a shape, which means that wherever a function needs a 
Shape as an argument, a Class can be used too. Which in turn means that 
nobody really has to instantiate "Shape" unless they want to make clear 
that this is just meant to be an abstract description of constraints 
that should never be instantiated. And I can see that this distinction 
can make sense sometimes, e.g. in ldom:ShapeConstraint.

(Classes of course have other characteristics not covered by Shape, 
which makes the conceptual hierarchy between the two terms less clear - 
the above is just a pragmatic definition in the context of LDOM execution).

Overall I think this whole discussion is just a foretaste of the 
difficulties that we will have in explaining the difference between 
those concepts to the user community.

Holger
Received on Monday, 26 January 2015 01:30:50 UTC

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