A number of changes in rdf:text

Hello,

I've just done some work on the rdf:text specification. (BTW, it would be good
to add the URL http://www.w3.org/2007/OWL/wiki/InternationalizedStringSpec to
the sidebar of the Wiki; otherwise, one always has to hunt for it around.) Here
is the summary of the changes:


- I've changed the definition of characters to be exactly as in XML Schema,
which is exactly as in XML 1.1. Indeed, Unicode provides for 1,114,112 different
code points. Furthermore, XML 1.1 disallows the use of some of them, which
leaves us with exactly 1,112,061 code points. I've updated the example in the
document to this extent.

I was not aware of this -- sorry for the confusion!


- I've changed slightly the definition of language tags. In the previous version
of the spec, it was unclear whether the language tags need to be validated
against the IANA registry. The current solution is to make our definitions
independent of the IANA registry. (Otherwise, the semantics of OWL 2 ontologies
and the consequences one can draw from them might change each time the IANA
registry is updated -- clearly a bad situation.)


- In response to numerous comments (e.g., by Addison Phillips), I've changed the
definition of the facet for language matching. We are currently using RFC 4647
instead of arbitrary regular expressions. In order to reflect this change, I've
renamed the facet to rdf:langRange. This is because we now use the so-called
language ranges from RFC 4647, and I thought it would be good to make a clear
distinction with the xs:pattern facet (which is a regular expression). We are
using now the so-called basic language range matching. RFC 4647 defines also a
more expressive extended language range matching; however, I am really not sure
how to implement this in OWL 2. (Note that we don't just need to match a
language range against a language tag; instead, we need to be able to test
emptiness and/or finiteness of such ranges, and we need to be able to intersect
the language ranges with regular languages; for extended language ranges this
seems quite complex.)


- In response to a comment by Jos de Bruijn, I've promoted two subsections to
sections.


- I've done some general editorial work on the spec. I've moved the discussion
of compatibility with RDF into the introduction, and I've tried to keep the
definitions crisp and clear.


There are still two editorial comments left in the document, but these are in
the functions part; I believe that these need to be resolved by RIF. Please let
me know should you have any comments.

Regards,

	Boris

Received on Thursday, 26 March 2009 14:48:14 UTC