Inheritance and other buzzwords

[Tim Bray]

I think that altogether too much is being heaped up here on too narrow
a base.  What does XML do?  It allows documents to be subdivided into 
parts, and for those parts to be given names.  As an additional benefit, 
it allows the parts' names and contents, when they are textual, to 
contain characters from around the world.  The trade-off is that the parts 
have to be arranged in a hierarchically nested fashion.  XML does this in 
such a way that systems can agree on where the parts are, what they are 
named, and what their contents are, without having to share any software.  
That's all!  

The current namespace proposal adds one level of indirection to the names 
we give document components, and includes a technique for ensuring that 
the names are unique across the universe of the Internet.  That's all!  

It seems obvious to me that there are a variety of ways that DTDs could 
usefully be made namespace-aware; this does *not* mean that I think we 
know how to write down rules for automatic schema synthesis; I still
think humans should design documents.  I want such a designer to be able
to say "My namespace is ID'ed by URI1, and my X element has to start with 
an A element from the URI2 namespace, followed one of my own Z elements, 
followed by..." you get the idea.  Then the software can sort out the 
prefixes and do perfectly good validation. This could probably be done 
very nicely in front-end filters and allow the use of current 
8879-based technology.  

In fact, why doesn't someone on this list write such a preprocessor?  I 
think conventional DTD's, with the additional leverage of universal names, 
would be damn useful.

I think it's a base requirement that any document design language of the 
future deal with qualified (i.e. universal) names.  Any such facility that 
seriously gets in the way of using this kind of name just won't fly in the 
Web milieu.  The idea of trying to get serious mileage out of any kind of a 
name that can't be mapped to a URI is something that will work only in a 
closed inward-looking shop.  Which there are a lot of out there, but we're 
supposed to be designing technology for the Internet.

I do not understand architectural forms well enough to have an opinion
as to how well they co-exist with universal names.  But Eliot doesn't
seem too worried by it.

Cheers, Tim Bray
tbray at textuality.com http://www.textuality.com/ +1-604-708-9592


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