- From: Dave Beckett <dave.beckett@bristol.ac.uk>
- Date: Wed, 21 Nov 2001 21:04:23 +0000
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- cc: w3c-rdfcore-wg@w3.org
>>>Brian McBride said: > I got the following example from Roland Schwaenzl > > Apparently, they use the fact that an RDF parser is required to turn of > parsing when it encounters a name in the RDF namespace it does > recognise. <snip/> The existing M&S is rather vague on this point IMHO: "The RDF element is a simple wrapper that marks the boundaries in an XML document between which the content is explicitly intended to be mappable into an RDF data model instance. The RDF element is optional if the content can be known to be RDF from the application context." -- 2.2.1. Basic Serialization Syntax http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/ since context is never defined. and in the grammar: [6.1] RDF ::= ['<rdf:RDF>'] obj* ['</rdf:RDF>'] -- http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/#RDF and thus rdf:RDF is actually entirely optional in the grammar. We could specify it clearer in several ways. I've currently got these words in my editors draft: If the content is known to be RDF/XML by context, such as when RDF/XML is embedded inside other XML content, then the grammar can either start at Element Node RDF (only when an element is legal at that point in the XML) or at production nodeElementList (only when element content is legal, since this is a list of elements). Note that if such embedding ocurrs, the grammar may be entered several times but no state is expected to be preserved. http://ilrt.org/discovery/2001/07/rdf-syntax-grammar/#section-Infoset-Grammar This gets around another issue - the XML infoset upon which this is based is not defined for namespaced XML elements / attributes, so we can't actually deal with them at all in the regular grammar: XML 1.0 documents that do not conform to [Namespaces], though technically well-formed, are not considered to have meaningful information sets. That is, this specification does not define an information set for documents that have element or attribute names containing colons that are used in other ways than as prescribed by [Namespaces]. -- http://www.w3.org/TR/2001/REC-xml-infoset-20011024/#intro so for Rolands example, the current wording allows his application to enter/leave RDF processing at the rdf:RDF element; and we don't and shouldn't define what is outside that. Dave
Received on Wednesday, 21 November 2001 16:07:36 UTC