RE: Use of DTDs for typing

Dear James:

This note is in response to your mail to the XML Query WG on June 13
asking about DTD support in XML Schema. This is an official response,
and has been reviewed and approved by the Working Group.

Some of the WG members read your note as asking whether type information
in the DTD could be used in creating the data model and for static
typing.
They asked that we remind you that XQuery issue 54 addresses this:

" Issue 54 : Defining Behavior for Well Formed, DTD, and Schema
Documents
 xquery-define-schema-variants) 
Description:  We should specify the behavior of XQuery for well formed
XML, 
XML validated by a schema, and XML validated by a DTD"

Others, however, read your mail as asking whether a DTD can be used to
define a collection of types whose names could be used in treat and cast
operations and do specify function arguments.  That is, we need to be 
able to refer to a DTD in the context similar to the production below 
for a schema.

ContextDecl ::= ("namespace" NCNAME "=" StringLiteral) |
                 ("default" "namespace" "=" StringLiteral) |
                   ("schema" StringLiteral StringLiteral) 


On this issue there has been insufficient discussion and currently there
is no firm position.


Ashok Malhotra

On behalf of the XML Query Working Group

===========================================================
Ashok Malhotra              <mailto: ashokma@microsoft.com> 
Microsoft Corporation
212 Hessian Hills Road
Croton-On-Hudson, NY 10520 USA 
Redmond: 425-703-9462                New York: 914-271-6477

Received on Thursday, 28 June 2001 16:34:31 UTC