Notes from DFDL call 2007-05-09
Mike Beckerle
Simon Parker
Martin Westhead
Suman Kalia
Geoff Judd
Steve Hanson
Alan Powell
Notes:
Simon Parker of PolarLake was introduced. Welcome Simon!
Report from OGF 20
approximately 12 attendees at session
Notes from session are posted/sent by email.
We discussed the notes:
pointers - not core for v1.0, . A supplement would be ok.
multi-dim arrays - pointed out that we can do these via nesting, though
there are some drawbacks about storage order variation.
support for versioning - we agreed that we want to be compatible with
versioning approaches of DFDL schemas by users, but not address the
problem in the standard. It's not different for DFDL from XML Schema.
we need to revisit "selectors" topic since these could be used to mix
versions of a format into the same DFDL schema.
ISO CGM - common graphics metafile - suggested as a use case.
New floating point number formats, e..g., small ones like 14 bit ones used
in graphics and such.
We discussed whether there should be special DFDL-based annotations that
DFDL processors would provide visibility to for applications.
Alternative is "just look for the annotation on the schema", i.e., leave
it up to the applications to reach into the schema themselves. DFDL stays
out of this.
2nd point was that spec. needs to specify how various supported floating
point formats are approximated when converted to the XML types float and
double.
We decided that advanced floating point could be a supplement.
Validation: decided to mention in spec that streaming validation is an
allowed behavior for DFDL processors, and that if XML-schema or schematron
validation is performed by a DFDL processor that it must be consistent
with an XML Schema validator operating on an XML document as described by
the implied XML schema for the DFDL schema.
Issue raised - need "arbitrary whitespace" as delmiter. How to specify.
Issue raised - need arbitrary sized binary integer (or even decimal),
Bignums. Financial communities use these.
Selectors - need to revisit in a future call.
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(a)us.ibm.com
508-599-7046
