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

[Mike Beckerle]

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
<http://www.ogf.org/About/abt_policies.php>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.ogf.org/pipermail/dfdl-wg/attachments/20161212/6293c1ba/attachment.html>