RE: Namespaces, schemas, Simon's filters.

[Tim Bray <tbray@textuality.com>]

At 11:12 AM 29/08/01 -0700, Fuchs, Matthew wrote:
>One doesn't really need any new syntax.  If we consider complexTypes as
>introducing a new namespace (which we're perfectly free to do - the NS rec
>doesn't say anything about how you create or name a namespace, nor much
>about what a namespace is) then xsi:type is an attribute that says "the
>default namespace within this element is the namespace created by the
>complexType with this name".  That's it.

Suppose I believe that it's crucially important to be able to map 1-1 
from labels to schema definitions (I don't, although Rick & Matt have 
argued convincingly that it's good practice).  Suppose I believe that 
the way to accomplish this mapping is via the labels themselves (I 
don't; I think decorating the instance with definition-pointer 
attributes - from a different namespace, natch - is the way to go).

If I believed those things, I'd be violently against tying namespace 
creation to any particular schema language.  Matt is correct that the 
NS rec says nothing about how you "create" a namespace, it just tells 
you how to put elements and attributes in them.  If what is required is
a new way to put markup in namespaces, we'd need a generalized 
interface for doing this that an XSDL processor or any other software
has access to.  I also think that it's pretty important that in general, 
applications of different classes, upon reading a document, all agree 
what namespaces pieces of markup are in.  At the moment, the only
way I can see to accomplish this is by putting the namespace syntax 
right there in the instance. -Tim