Re: [xml-dev] Can we treat XML elements and attributes as sets

[richard@inf.ed.ac.uk (Richard Tobin)]

In article <20050820141202.49219.qmail@web32901.mail.mud.yahoo.com>,
Mukul Gandhi <mukul_gandhi@yahoo.com> wrote:

>Elliotte mentions in the chapter about XML Namespaces,
>that "The URIs partitions the elements and attributes
>into disjoint sets".

Presumably he means that any element or attribute is in the set of
elements or attributes for some namespace (including "no namespace").
These sets are disjoint in the sense that no element in, say, the XSL
namespace is also in the XML Schema namespace.  If I'm interpreting it
correctly, the staement is certainly true.

The idea of elements and attributes being "in" namespaces, and of
namespaces being objects, has not been widely reflected in languages
and APIs.  Instead, namespaces are usually applied more directly to
*names*, with a name being considered a compound object with a
namespace part and a local part.  So in XSLT for example you don't
ask whether an element is in a namespace, but whether the namespace
uri part of its name has some value.

-- Richard