- From: Sean B. Palmer <sean@miscoranda.com>
- Date: Fri, 23 Nov 2007 10:32:03 +0000
- To: "Renato Golin" <renato@ebi.ac.uk>
- Cc: semantic-web@w3.org
On Nov 23, 2007 10:14 AM, Renato Golin <renato@ebi.ac.uk> wrote: > The only meaningful place I can see you could put magic numbers > for all kinds of RDF is in the RDF header itself. such as: > > <rdf:RDF (...) magic_constant_1="42" (...)> I'm not sure that that would ever be required, and it'd be an extension to RDF/XML anyway. In the case of RDF Stylesheets I'm quite sure you could get away with magic triples rather than using some kind of attribute, though as I say I'm not entirely sure what form it should take yet. It's mainly academic at this point, though I did try my hand at making a language with mergeable stylesheets that can be applied to streaming input. Cuts down on the network accesses. Incidentally I noticed the other day that the application/rdf+xml RFC is incorrect in its magic numbers section: [[[ Magic number(s): none Although no byte sequences can be counted on to consistently identify RDF, RDF documents will have the sequence "http://www.w3.org/1999/02/22-rdf-syntax-ns#" to identify the RDF namespace. This will usually be towards the top of the document. ]]] - http://www.ietf.org/rfc/rfc3870.txt Actually the following document is valid RDF/XML but doesn't use the RDF namespace anywhere: <SomeClass xmlns="http://example.org/#"> <prop>Hello</prop> </SomeClass> Of course RDF/XML documents served using one of the generic XML media types have to use <rdf:RDF>, or else there must be a hint given to the parser. > I always like to give the Mozilla/IE/Firefox history as an example to show > that conformity, when compulsory, makes anyone's life much easier. Heh, indeed. I don't mind walking on that thin blue line between description and prescription. > > that makes it hard when you want to merge mergeable stylesheets. > > You'll end up with a cascading rdf:type not necessarily compatible, I see... Yeah, so just to spell it out if you have the following three documents: <> a :Stylesheet . - one.rdf <> a :Stylesheet . - two.rdf <> a :Stylesheet . - three.rdf And then you do an RDF merge of them, in say cwm or whatever: cwm one.rdf two.rdf three.rdf > output.rdf Then output.rdf ends up being: <one.rdf> a :Stylesheet . <two.rdf> a :Stylesheet . <three.rdf> a :Stylesheet . Whereas of course you wanted <output.rdf> a :Stylesheet. For that reason you should probably dispatch on some required part of the stylesheet language, or there could literally be a magic triple property. > Maybe some easy-to-use-batteries-included programming > language will come for the semantic web I sorta dread that happening, really, because it's already been attempted over a span of years with N3Logic which fits exactly what you've said: it's not a very good programming language by itself. Part of what I'm doing with the work of which this thread is a spinoff is trying to engineer a better approach to the generic handling of RDF. > Anyway, standards are to be enforced or all of us will go crazy > figuring out every single possibility that might happen. Yup! Cf. TAG's TagSoupIntegration-54 issue: http://www.w3.org/2001/tag/issues.html#TagSoupIntegration-54 -- Sean B. Palmer, http://inamidst.com/sbp/
Received on Friday, 23 November 2007 10:32:11 UTC