- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Fri, 8 Apr 2011 15:00:57 +0100
- To: antoine.zimmermann@insa-lyon.fr
- Cc: public-rdf-wg@w3.org, Ian Davis <me@iandavis.com>
On 8 Apr 2011, at 14:29, Antoine Zimmermann wrote: > 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)? <my-gbox> dc:hasVersion <my-gbox/2011-04-08> . <my-gbox/2011-04-08> dc:date "2011-04-08"^xsd:date . (Or use another vocabulary with stronger versioning semantics instead of DC) > 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? Make a new g-box containing these two triples, and use some vocabulary to say that A=B+C > As other people suggested, I have the impression that there are use cases for identifying g-boxes and use cases for identifying g-snaps. I assert that all these use cases can be addressed by declaring some g-boxes immutable. One can have use case specific vocabularies that state which g-boxes are mutable and which not. Note that there is an isomorphism between g-snaps and immutable g-boxes. > 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) How do I say that a certain unnamed literal g-snap contains 123 triples? > and we name g-boxes. That is, in TriG: > > :G1 { :a :b :c . :x :y "{:u :v :w.}"^^rdf:gsnap } I don't understand what this is supposed to mean. You cannot write down a g-box. You can only write down a g-snap. The best you can do is saying that a g-box of a certain name has a certain g-snap as its content right now. Having two different syntactic constructs for writing down g-boxes and g-snaps is a confusing mess that solves no problem. Best, Richard > > :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 . > ] > > > ----Footnote---- > {1} I leave the relationship between :G1 and the content inside the curly brackets to a later email. > > > AZ. > > 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 > France > 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 > France > antoine.zimmermann@insa-lyon.fr > http://zimmer.aprilfoolsreview.com/ >
Received on Friday, 8 April 2011 14:01:31 UTC