- From: Pat Hayes <phayes@ihmc.us>
- Date: Tue, 1 Mar 2011 23:31:01 -0600
- To: nathan@webr3.org
- Cc: RDF WG <public-rdf-wg@w3.org>
On Mar 1, 2011, at 6:14 PM, Nathan wrote: > Pat, can you clarify for me, in your original mail, when you said "graph token" did you mean g-text (representation), or g-box (resource). Um. At the time I hadn't made this distinction clearly. Sandro came along later and made it. I guess I ought to be honest and say that they are both 'tokens', and that at first I was thinking of something more like a text, and then thought that once we had tokens, they could also be things like boxes, which is a lot more use. > I'm asking because I'm trying to establish whether you're saying blank node identifiers would/could be scoped to the g-box (consistent over time) or per g-text (a property of the serialization, as currently). I'd say both, but not to both a text and a box. That is, each text and maybe each box specifies a unique scope for any bnode. It can't be in two scopes at once. So when you take a snapshot of a box, you get a graph which is the 'state' of the box, but it has new bnodes in it. And each separate text, or even a copy of the text, contains its own unique bnodes. Pat > > Best, > > Nathan > > Pat Hayes wrote: >> On Feb 28, 2011, at 1:42 PM, David Wood wrote: >>> On Feb 24, 2011, at 13:12, Pat Hayes wrote: >>> >>>> It is much simpler: it is just wanting the WG to acknowledge that "an RDF graph" can either be a mathematical set, or it can be some kind of document or data structure or file than can be transmitted over a computer network. But it can't be both. >>> What is the difference between an "RDF graph" and a RESTful "resource"? >> (Following definitions in existing specifications and discussions...) An RDF graph is a set, in the mathematical sense. This is a pure-mathematical abstraction, AKA a Platonic abstraction. A RESTful resource, as I understand it, is something that can be 'poked' with an HTTP (or other XXTP) request and when so poked will emit a "representation" of itself. I use scare quotes because exactly what this word means here has been the topic of much, um, discussion. But whatever it means, it is quite certain that emitting a representation of any kind is not something that a set could do, because sets can't DO anything. (And even if they could, they would do the same thing every time, whereas a REST resource is a thing with state, which can do different things every time, eg a clock.) >>> What is the difference between an "RDF graph token" and a RESTful "representation"? >> Well, a graph can have all kinds of tokens, to be strict, eg you can draw a picture of one on a piece of paper. But the kind I was talking about could be a RESTful resource, which was the main point. So whats the difference between a RESTful resource and a RESTful representation? Again, as I understand it, the key difference is that the first has a state - its like a g-box - whereas the second doesn't - its like a g-text (of the g-snap which is the abstraction defining the state of the g-box, if I have Sandro's terminology right.) Now, I admit that it would be perfectly correct to call a g-text a graph token as well. Sandro has made a further distinction that I wasn't trying to tackle, between the instantaneous 'graph state' of a g-box and the serialization of this graph that gets sent when you poke it with a transfer protocol prompt. Speaking purely from an abstract conceptual model point of view there isn't much to choose between these, but when we get into Web architecture it is a rather important distinction. Pat >>> Regards, >>> Dave >>> >>> >>> >>> >> ------------------------------------------------------------ >> IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office >> Pensacola (850)202 4440 fax >> FL 32502 (850)291 0667 mobile >> phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > ------------------------------------------------------------ IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 mobile phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Wednesday, 2 March 2011 05:32:53 UTC