Mike

I have been reviewing ch 6 Sequence Groups, Initiators and Separators  of  proposal-to-simplify-null-default-optional-handling-v4.doc and I am uneasy about the approach of transforming the DFDL. This is because
  1. They are examples rather than rules so do not fully explain the syntax.
  2. The results are often so convoluted that they do not, at least to me, provide any clarification. So much so that  I believe most of the examples are actually wrong.

I think that we should either provide proper transformation rules or just stick to explaining original DFDL syntax.

Comments added to Ch 6 examples.



Alan Powell

MP 211, IBM UK Labs, Hursley,  Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM     email: alan_powell@uk.ibm.com  
Tel: +44 (0)1962 815073                  Fax: +44 (0)1962 816898


Mike Beckerle <beckerle@us.ibm.com>
Sent by: dfdl-wg-bounces@ogf.org

23/10/2007 23:03

To
dfdl-wg@ogf.org
cc
Subject
[DFDL-WG] Material for Call on 2007-10-24






We had been reviewing the facets and default/null/optional a few weeks back.

I said I would make revisions as a number of people had objections.

Here are documents based on these comments.


Main things I did: (1) strict adherence to minOccurs and maxOccurs. No more notion that these are only for validity checking.
(2) simple rule for default values: if it's required and there's a default value, then use the default value. This is for both input and output.

I put a bunch of work into illustrating the semantics of things like dfdl:separatorPolicy="suppress" and so forth. I had been trying to simplify this, but gave up. We're back to 3 policies here: keep, suppress, suppressAtEnd. I did figure out a way to express these via DFDL rewriting.

...mikeb

Mike Beckerle
STSM, Architect, Scalable Computing
IBM Software Group
Information Platform and Solutions
Westborough, MA 01581
direct: voice and FAX 508-599-7148
assistant: Pam Riordan  
                priordan@us.ibm.com
                508-599-7046
[attachment "proposal-on-facets.doc" deleted by Alan Powell/UK/IBM] [attachment "proposal-to-simplify-null-default-optional-handling-v4.doc" deleted by Alan Powell/UK/IBM] --
 dfdl-wg mailing list
 dfdl-wg@ogf.org
 http://www.ogf.org/mailman/listinfo/dfdl-wg





Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU