W3C home > Mailing lists > Public > public-rdf-shapes@w3.org > April 2015

Re: vote for supporting "closed shapes"

From: Erik Wilde <dret@berkeley.edu>
Date: Fri, 24 Apr 2015 08:21:39 -0700
Message-ID: <553A5F83.2060401@berkeley.edu>
To: public-rdf-shapes@w3.org
CC: Iovka Boneva <iovka.boneva@univ-lille1.fr>
hello iovka.

On 2015-04-22 23:34, Iovka Boneva wrote:
> What do you mean by "to constrain additional triples to certain
> vocabularies" ?

i think i mean what your explaining down below. only that it may sound a 
bit odd, because RDF does not have this concept of a vocabulary which 
can be identified when you see terms from it, so it sounds a bit odd for 
RDF. but that's what people often want to do in practice: allow 
something specific, some extensions, and nothing else.

> By 'additional triples', do you mean those that do not match anything
> mentioned in the constraint ? That is, if the constraint is something like
> :name String | (:firstName String, :lastName String)
> then is it the case that the additional triples are all those whose
> property is different from :name, :firstName and :lastName ?

it would be those that also use the name as a subject, but are not 
firstName or lastName. for example something like middleName that is not 
part of the core name vocabulary.

> By vocabulary, do you mean a set of IRIs allowed as properties for the
> triples ?

that's the problem: ideally, you would want to have a vocabulary 
identified, so that terms from it can be identified as belonging to it. 
in XML, namespaces do that for you, and because that's a very usefu 
scoping mechanism, that's how a lot of vocabularies are defined and used.

in RDF there is no such identification, and frankly i am not quite sure 
how to best deal with that. URI prefixes or patterns would be one way, 
but that would of course be a hack.

> If my guesses are right, then all this can be easily handled by shape
> expressions (and their bag semantics). Note that closed shapes are also
> handled.

if all of this is already part of the requirements, then i think that's 
excellent. i started this thread because arnaud told me that this 
feature was not yet part of the requirements.

cheers,

dret.

-- 
erik wilde | mailto:dret@berkeley.edu  -  tel:+1-510-2061079 |
            | UC Berkeley  -  School of Information (ISchool) |
            | http://dret.net/netdret http://twitter.com/dret |
Received on Friday, 24 April 2015 15:22:08 UTC

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