- From: Antoine Zimmermann <antoine.zimmermann@insa-lyon.fr>
- Date: Fri, 08 Apr 2011 17:50:39 +0200
- To: Richard Cyganiak <richard@cyganiak.de>
- CC: public-rdf-wg@w3.org, Ian Davis <me@iandavis.com>
Right, I was expecting this. Then the question is, how do we define immutable g-boxes. There have been several emails saying that: <my-gbox/2011-04-08> { :a :b :c } means that <my-gbox/2011-04-08> contains *at least* ":a :b :c." Some saying that it contains *exactly* ":a :b :c." And some saying that it should mean <my-gbox/2011-04-08> *entails* { :a :b :c }. If the gbox is immutable, it should be "exactly", and maybe "at least" or "entails" otherwise. Perhaps we need a vocabulary for this: rdf:MutableGraph, rdf:ImmutableGraph. Then, what is a graph which is not declared as mutable/immutable? I don't find the answer "use immutable gbox" completely satisfying because it leads to several unanswered questions. Le 08/04/2011 17:34, Richard Cyganiak a écrit : > On 8 Apr 2011, at 15:13, Antoine Zimmermann wrote: >>> <my-gbox> dc:hasVersion<my-gbox/2011-04-08> . >>> <my-gbox/2011-04-08> dc:date "2011-04-08"^xsd:date >> >> This does not tell me what is in<my-gbox/2011-04-08>. > > Sorry, I thought that was clear: > > <my-gbox/2011-04-08> { ... content goes here ... } > >>>> 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 >> >> How do you make a gbox containing those two triples? > > <name-of-the-g-box> { ... two triples ... } > >>>> 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. >> >> Perhaps but you don't say how I define the content of an immutable gbox. > > <my-immutable-g-box> { ... content of the immutable g-box ...} > > <my-immutable-g-box> a ex:VersionedSnapshot; ex:timestamp "2011-04-08"^^xsd:date > > (where ex: is a use case specific vocabulary that we don't have to define in this WG) > >>>> :G1 { :a :b :c . :x :y "{:u :v :w.}"^^rdf:gsnap } >>> >>> I don't understand what this is supposed to mean. >> >> This is just a TriG document. At the moment, there is no well defined semantics for it, so I'm just using it at a syntax to somehow connect the URI of the g-box (G1) to a certain g-snap (between the outermost curly brackets). The literal inside that g-snap is just a typed literal, perfectly valid in RDF. A system does not necessarily need to understand that specific datatype, but the idea is to interpret this as a g-snap. >> >>> 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. >> >> At some point either you should be able to talk about specific triples in g-boxes or in g-snaps. It is fine for me to have immutable g-boxes to be able to talk about fixed g-snaps, but I still need a way to make explicit the triples inside. > > Right. For making explicit the triples inside a g-box (mutable or not), all you really need is the ability to write down<IRI, g-snap> pairs. > > Best, > Richard > > >> >>> >>> 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. >> >> -- >> 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/ > -- 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 15:51:08 UTC