- From: Jan Hidders <jan.hidders@ua.ac.be>
- Date: Wed, 24 Sep 2003 17:08:12 +0200
- To: www-ql@w3.org
Hello Mary,
Mary Fernandez wrote:
>
> In the [XQuery 1.0 and XPath 2.0 Data Model], Section 4.3,
> there is a set of constraints on element nodes. #3 is
> the one that you are looking for:
>
> "Element nodes must satisfy the following constraints.
>
> [....]
>
> 3. The sequence of nodes in the children property is ordered and
> must be in document order. ... etc..."
Indeed, that was exactly what I had overlooked and only realized afterwards.
> In the [XQuery 1.0 and XPath 2.0 Formal Semantics], Section 2.2 gives
> a formal notation for the XQuery Data Model, but it _does not_ repeat
> the constraints specified in the data model document. The editors
> are working right now to make the relationship between documents
> more clear and to identify normative vs. informative text. I will
> make a note to refer to the data model constraints explicitly in
> Section 2.2.
That certainly would have helped. In all modesty I think that if I'm
having trouble understanding the formal semantics, then some other
people are probably also having a hard time getting their head around
it. That's actually one of the reasons why we are trying at the moment
to come up with a formal semantics for a small but relevant subset of
XQuery that can be used to do (database or other) theory.
Having said that, I still think that the problem with the content
construction for new elements *is* a real problem (although easy to fix)
but I refer for that to my reaction to Peter's mail.
--
Jan Hidders
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Received on Wednesday, 24 September 2003 11:09:54 UTC