Data types (Was: Re: [Xpath-ng] Proposal for definition of values/lists)

[David Rosenborg]

> I think that we can ask implementers to specify the same things for
> this data type as we insist on for data types defined in modules, i.e.
> to define how it gets converted into and from strings, numbers,
> booleans and lists.

Sounds reasonable to me.

> 
> The other thing that I've been pondering is whether we should have a
> built-in expanded QName data type. I think that it might be really
> useful, particularly for defining nodes (which have names that are
> expanded QNames). I have a feeling that this will be contentious, and
> of course how exactly a QName is represented is very problematic...
> 

Just as an anecdot: I once implemented such a data type in my
XPath implementation. However, I can't remeber ever using it.
Of course this doesn't mean it's a bad idea, just that for *my*
uses of XPath to this date, the XPath 1.0 functionality has
been good enough.

But you've maybe found other benefits (such as notational,
as I read your post). How do you mean that the
representation is problematic? Isn't it just a pair of
two strings, the local part and the namespace URI?

Cheers,
David