From: "Jonathan Robie" <jonathan.robie@d...>
> The complex types of DTDs are not named types in the Data Model, and that
> means that you can't match them with SequenceType in XQuery - there is no
> type annotation to match.

Hi Jonathan,

Thanks for the answer.

Maybe you're answering a different question. My (limited) understanding of
the Data Model spec is that the complex types of DTDs would be mapped to
anonymous types. It seems they must be validated, in order to get at simple
types like NMTOKENS?

I must be wrong, if there is no type annotation at all.

> If RELAX NG wants to define a mapping into our Data Model, that mapping
> could produce named types. The XQuery and XSLT Working Groups have not
> produced a mapping for RELAX NG.

I'm not sure, for complex types, that the named types a mapping could
produce would be any more useful than anonymous types. Names are not
typically used in that way in RELAX NG.

There are other, more fundamental issues. RELAX NG validation is
multi-level, e.g., the contents of elements may need to be examined to
determine which pattern is valid, and more than one might be. XQuery seems
to deal with non-determinism using a "first match" rule for both complex and
simple types. There is not even, in RELAX NG, a well-defined notion of
"first", as in that language choice represents the commutative union
operation.

Bob