- From: Dan Connolly <connolly@w3.org>
- Date: Sun, 24 Jun 2001 23:58:03 -0500
- To: Dan Brickley <Daniel.Brickley@bristol.ac.uk>, Jonathan Borden <jborden@mediaone.net>
- CC: w3c-rdfcore-wg@w3.org
Dan Brickley wrote: > ---------- Forwarded message ---------- > Date: Thu, 21 Jun 2001 21:17:27 -0400 > From: Jonathan Borden <jborden@mediaone.net> > To: www-rdf-comments <www-rdf-comments@w3.org> > Cc: www-rdf-interest <www-rdf-interest@w3.org> > Subject: forest grammar/tree regular expression for RDF > Resent-Date: Thu, 21 Jun 2001 21:19:34 -0400 (EDT) > Resent-From: www-rdf-comments@w3.org > > I hope the RDFCore WG will consider the forest grammar/tree regular > expression as a specification of the formal RDF XML syntax. The unordered > nature of RDF is best described as a forest grammar and this presents > difficulties for traditional XML schema languages such as DTDs. > > I have specified this as a RELAXNG schema for RDF > http://www.openhealth.org/RDF/RDF1.rng in terms of solidifying the RDF XML > syntax under the issue: > http://www.w3.org/2000/03/rdf-tracking/#rdfms-formal-grammar Very nice! It has a few special cases that I don't think are necessary (e.g. rdf:value is just another propertyElement/propertyAttribute, and rdf:Description is just a typedNode) but other than that, it seems to be quite a compact and precise description of the RDF syntax. Is there an online service ala XSV that checks documents w.r.t. this sort of schema? let's see if I can find one by following my nose from the namespace name... sigh... 404 at http://relaxng.org/ns/structure/0.9 > > An advantage of specifying the grammar in this language is that it has a > good formal semantics which is based on the formal semantics of XDuce. > http://www.cis.upenn.edu/~hahosoya/xduce/ . Note that the XML Schema > formalism in http://www.w3.org/TR/xmlschema-formal appears to be based on > XDuce as well which is referenced. > > Because I realize the politics around RELAXNG, I have converted this to the > language used by XDuce and by the XML Schema Formalism: > http://www.openhealth.org/RDF/RDFSyntaxFormal. Ah.. that's even easier to read. Production 4 is ambiguous, no? 4.type description = rdf:Description[ idAboutAttr?, bagIdAttr?, propAttr?, propertyElt* ] | typedNode <rdf:Description/> matches both alternatives, no? As I say, I don't see any need to special-case rdf:Description in the grammar. And I must have been mis-reading the other syntax; I don't see the rdf:value special case here. Where is the definition of the literal type? I don't see any use of the 'any' type. > It is really quite simple. > > Jonathan Borden > The Open Healthcare Group > http://www.openhealth.org -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 25 June 2001 00:58:08 UTC