[DFDL-WG] choiceBranchKey - suggest change to List of DFDL String Literals ?

[Steve Hanson]

Hi Mike

If I recall, choiceBranchKey was a single DFDL String Literal because the 
value to be matched against it is computed by a DFDL expression (from 
choiceDispatchKey), which can do things like lower casing strings or other 
manipulations.  Are you seeing use cases where multiple keys per branch 
are making the expression too complex?

Regards
 
Steve Hanson
IBM Hybrid Integration, Hursley, UK
Architect, IBM DFDL
Co-Chair, OGF DFDL Working Group
smh at uk.ibm.com
tel:+44-1962-815848
mob:+44-7717-378890



From:   Mike Beckerle <mbeckerle.dfdl at gmail.com>
To:     "dfdl-wg at ogf.org" <dfdl-wg at ogf.org>
Date:   12/12/2016 19:48
Subject:        [DFDL-WG] choiceBranchKey - suggest change to List of DFDL 
String  Literals ?
Sent by:        "dfdl-wg" <dfdl-wg-bounces at ogf.org>




Our first experience with requiring and implementing choiceBranchKey in 
Daffodil and we're already dealing with the fact that many times the same 
branch has multiple different keys all of which indicate that it should be 
selected.

Right now, dfdl:choiceBranchKey is a DFDL String Literal, so values like 
dfdl:choiceBranchKey="  " (that's two spaces) are legal and will work. If 
it was to be a whitespace separated value, then those would have to use 
DFDL Entities to express the whitespace.

I know I have seen COBOL data where there were multiple tags that denote 
the same structure.

I am curious what others experience with choiceBranchKey is, and how this 
issue was handled.  

I believe from prior emails that IBM has already implemented this in its 
DFDL implementation.

There is an erratum specifying that choiceBranchKey comparison is supposed 
to be case-sensitive (for performance reasons), but nothing heretofore 
about it using DFDL Entities to represent whitespace.


Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | 
www.tresys.com
Please note: Contributions to the DFDL Workgroup's email discussions are 
subject to the OGF Intellectual Property Policy
--
  dfdl-wg mailing list
  dfdl-wg at ogf.org
  https://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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.ogf.org/pipermail/dfdl-wg/attachments/20161213/d80887f0/attachment.html>