Re: Boeing XRI Use Cases

John Bradley writes:

> I think I understand what you are getting at with the 
> definition of "anyURI"  in XSD 1.1 being a superset of  valid 
> namespace declarations in Namespace Recommendations.

Great, thank you.  I do apologize that, on 2nd reading, the note I sent 
had lots of typos including some that made it inaccurate.  I think you got 
the sense anyway, but for the record, here's a cleaned up version of the 
text to which you responded (changes marked >>>like this<<):

I wrote: 
----
No, that's not the case.  The XML Namespaces Recommendations continue to 
be the normative >>sources<< on what is and is not a legal namespace in an 
XML document.  XML Schema does define an anyURI type that is intended to 
be useful >>as a signal that<< a given datum is intended to be a >>URI<< 
and/or IRI.

>>We<< realized early that >> the Schema Datatypes Recommendation<< could 
>>not!<< provide practical validation rules that would in fact reject all 
illegal IRIs while accepting all correct ones.  As a trivial example, the 
URI specifications delegate to the specifications for particular schemes 
for syntax details, and we knew there was no way we wanted to put in 
separate rules for http, mailto, tel, etc.  XSD 1.0 >>therefore<< broadly 
>>indicated<< that the strings >>are<< to be validated as URIs, but 
realizing that this was a fuzzy and ultimately impractical burden to put 
on processors, the rules are loosened in XSD 1.1, which now accepts any 
string of legal XML characters. 
----

Please accept my apologies for any confusion.

Noah

--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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Received on Thursday, 7 August 2008 14:10:10 UTC