I favour dropping nullTerminated. If we have null terminated, then why don't we have a lengthKind called CRLFTerminated - it is far, far more common in actual message data.  I suspect nullTerminated would be used very little. Most data emitted from C programs will be mapped by a struct, where character 'strings' are fixed length padded with nulls, not variable length and terminated by one. Also, minimising the number of lengthKind enums is important - lengthKind is the critical property which controls parsing and the less cases the user has to understand the better.
 
Regards

Steve Hanson
Programming Model Architect
WebSphere Message Brokers
Hursley, UK
Internet: smh@uk.ibm.com
Phone (+44)/(0) 1962-815848


Suman Kalia <kalia@ca.ibm.com>
Sent by: dfdl-wg-bounces@ogf.org

26/02/2009 19:01

To
Alan Powell/UK/IBM@IBMGB
cc
dfdl-wg@ogf.org
Subject
[DFDL-WG] Fw:  Reducing the number of DFDL properties.






nullTerminated  is a very familiar paradigm which the users understand.  We need to keep usability in mind; keep simple tasks simple. Yes it is redundant and you can do the same with 2 properties ( lengthKind=delimited and terminator=NULL) but it is well worth to keep it..  Same argument can be made for trimKind..

I am ok if we drop typeSubstitution although it is a convenient way to specify whole bunch properties grouped together for a type and reuse it.

Suman Kalia
IBM Toronto Lab
WMB Toolkit Architect and Development Lead
WebSphere Business Integration Application Connectivity Tools

http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.html

Tel : 905-413-3923  T/L  969-3923
Fax : 905-413-4850 T/L  969-4850
Internet ID : kalia@ca.ibm.com
----- Forwarded by Suman Kalia/Toronto/IBM on 02/26/2009 01:52 PM -----
From: Alan Powell <alan_powell@uk.ibm.com>
To: mbeckerle.dfdl@gmail.com
Cc: dfdl-wg@ogf.org
Date: 02/26/2009 12:27 PM
Subject: [DFDL-WG] Reducing the number of DFDL properties.




Mike

A number of people at IBM have become concerned at the number of properties in DFDL and have identified a number of 'usability' properties that could be dropped. They feel that we should be simplifying the properties wherever possible and not introducing multiple ways of doing the same function without very good reason.

The following are offered for consideration.
1.        lengthKind='nullterminated'
This is just shorthand for lengthKind=delimited and terminator='%Null'.  It was felt this this is not even the most common terminator so why have a special case?
2.        trimKind
It is felt that there aren't any cases when you would want to pad but not trim and vice versa so make padKind control both.
3.        typeSubstitution.
Is this needed in DFDL v1?

Can you consider these before the call next week

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

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





--
dfdl-wg mailing list
dfdl-wg@ogf.org
http://www.ogf.org/mailman/listinfo/dfdl-wg --
 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