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Re: Fwd: A use case for graph literals: Schemapedia (ISSUE-5)

From: Antoine Zimmermann <antoine.zimmermann@insa-lyon.fr>
Date: Fri, 08 Apr 2011 15:29:44 +0200
Message-ID: <4D9F0DC8.5010401@insa-lyon.fr>
CC: RDF Working Group WG <public-rdf-wg@w3.org>, Ian Davis <me@iandavis.com>
Talking about graph literals: how one can say that the content of a 
g-box at a certain point in time is a certain g-snap? If named graphs 
are in fact named g-box, then how can one relate this name to the 
content at a certain point in time (for instance, to talk about a 
certain version of the g-box)?

Another question is, how can one specify the differences between two 
versions of a g-box? For instance, g-box@2011-04-01 extends 
g-box@2010-04-01 by adding the triples { :x :y :z . :a :b :c .}.
How can I explicit refer to these specific 2 triples if I can only talk 
about g-boxes?

As other people suggested, I have the impression that there are use 
cases for identifying g-boxes and use cases for identifying g-snaps.

My opinion at the moment is that we use graph literals for g-snaps (so 
we don't have to give them names, they are fully defined by their 
lexical value) and we name g-boxes. That is, in TriG:

:G1 { :a :b :c . :x :y "{:u :v :w.}"^^rdf:gsnap }

:G1 identifies a g-box which somehow is related^{1} to the g-snap:

:a :b :c .
:x :y "{:u :v :w.}"^^rdf:gsnap

and "{:u :v :w.}"^^rdf:gsnap is identifying exactly the g-snap:

:u :v :w.

I can also say:

:G1 :earlierVersion [
    :content "{:a :b :c .}"^^rdf:gsnap .
    :atTime "2010-04-01"^^xsd:date .

{1}  I leave the relationship between :G1 and the content inside the 
curly brackets to a later email.


Le 08/04/2011 14:30, Richard Cyganiak a écrit :
> Forwarding on behalf of Ian ...
> Begin forwarded message:
>> Thanks Richard,
>> A very slight clarification is that the example I gave was from
>> http://open.vocab.org/ but http://schemapedia.com/ uses the same style
>> of RDF.
>> An example of one of schemapedia's embedded examples is:
>> http://schemapedia.com/examples/68740744ab36d400d81a1d1af23701e7.rdf
>> Ian
>> On Fri, Apr 8, 2011 at 11:32 AM, Richard Cyganiak<richard@cyganiak.de>  wro=
>> te:
>>> I just had a conversation with Ian Davis on Twitter that yielded a use ca=
>> se for defining datatype IRIs for graph literals. I thought I'd share it as=
>>   input into ISSUE-5 [1].
>>> He uses Turtle snippets as literals in SchemaPedia [2]. SchemaPedia is a =
>> site that helps find RDF vocabularies, and it lists example usage snippets =
>> for the vocabularies. The site's back-end is RDF-based. Turtle literals are=
>>   used to store the examples, as well as change events when examples are mod=
>> ified. See [3] for a typical change event.
>>> Currently Ian uses plain literals, because no datatype was readily availa=
>> ble.
>>> The idea of abusing Ivan's format URIs from [4] came up.
>>> Best,
>>> Richard
>>> [1] http://www.w3.org/2011/rdf-wg/track/issues/5
>>> [2] http://schemapedia.com/
>>> [3] http://api.talis.com/stores/openvocab/meta?about=3Dhttp://open.vocab.=
>> org/changes/f07ca76699a536dd38b5cbbbe1ba181d&output=3Drdf
>>> [4] http://www.w3.org/ns/formats/

Antoine Zimmermann
Researcher at:
Laboratoire d'InfoRmatique en Image et Systèmes d'information
Database Group
7 Avenue Jean Capelle
69621 Villeurbanne Cedex
Tel: +33(0)4 72 43 61 74 - Fax: +33(0)4 72 43 87 13
Lecturer at:
Institut National des Sciences Appliquées de Lyon
20 Avenue Albert Einstein
69621 Villeurbanne Cedex
Received on Friday, 8 April 2011 13:30:13 UTC

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