- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Fri, 11 Jul 2014 14:51:27 -0700
- To: kcoyle@kcoyle.net, Jose Emilio Labra Gayo <jelabra@gmail.com>
- CC: "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
On 07/11/2014 02:32 PM, Karen Coyle wrote: > > > On 7/11/14, 12:56 PM, Peter F. Patel-Schneider wrote: >> I'm still trying to figure out how shape expressions can constrain the >> shape of RDF graphs. Yes, they can constrain the shape of a RDF graph >> flowing out of a single source, but that's only part of the problem. >> Another part, and one that I think is much more important, is >> constraining the "shape" of nodes that belong to a particular class. > > Classes are orthogonal to shapes -- classes are semantic, shapes are > syntactic. The Description Set Profile [1], which was an XML schema model for > creating shapes with RDF, tried to address that (and I think it's worth > looking at). That project was perhaps premature and never completed, but I am > still convinced that the need to define the shape of our data exists. Sure, but the first thing that I want to do is to check whether nodes that have rdf:type links to :Person also have :spouse links and that spouse has a type link to :Person. If you don't like rdf:type links then use some other link there, but the idea is still the same - I want to know whether the nodes that I care about (nodes with type :person, nodes with a :university) link, ...) have a particular "shape". Of course, I *also* want to have more complex conditions, like nodes that have an rdf:type link to :Person in the RDFS closure of the graph, but something that can't even do the first part of this don't seem very useful to me, except in one-to-one situations and maybe not even then. > And > shaping - as the DSP does - requires a big picture of your data. Much > validation looks at individual "bits" but there is also a need to formulate > and test large, complex structures, in addition to individual statements. If > this capability does not exist in ShEx then we need to add it. Agreed. > > kc > [1] http://dublincore.org/documents/dc-dsp/ peter
Received on Friday, 11 July 2014 21:51:58 UTC