January 2022 - dfdl-wg - lists.ogf.org

revisit: nillable complex types and %ES restriction
by Mike Beckerle 25 Jan '22

25 Jan '22

The Daffodil user community is complaining about the DFDL v1.0 restriction that nillable complex types can only have %ES; (empty data) as their nilled representation. Multiple important data standards find this restriction quite awkward. It has significant negative impact on usability because it eliminates polymorphism of paths. The path needed to refer to an element value has different ending element path steps depending on whether it is nilled or not. The value of having DFDL create an XML infoset is lost if something as basic as this cannot be done in such a way that path expressions work alike to how they would work in regular XML/XSD. Is there a significant reason why this restriction cannot be lifted? If not we would probably plan to define a dfdlx namespace property that can be used to enable this alternate behavior, and then we could prototype this new fuctionality in Daffodil and propose this for DFDL 2.0 revision.

2 1

clarification: lengthKind 'delimited' but no terminating delimiter in scope
by Mike Beckerle 25 Jan '22

25 Jan '22

Is this an SDE? Or allowed? Daffodil currently implements this as allowed, and it ends up behaving much like "endOfParent", i.e., a scan for delimiters, when none are specified, scans as far as it can. However, given that we have endOfParent to express this behavior, seems to me that delimited with no delimiter should be an SDE. Thoughts?

2 1

OGF DFDL WG Calls for 2022
by Steve Hanson 19 Jan '22

19 Jan '22

Due to an imminent change in my mail technology, I am deferring sending out calendar invites for our 2022 calls until February. I anticipate the first call will be 10th February. In 2021 we only had 7 calls, so for 2022 a call every 4 weeks would make sense. Regards Steve Hanson IBM Hybrid Integration, Hursley, UK Architect, IBM DFDL Co-Chair, OGF DFDL Working Group smh(a)uk.ibm.com tel:+44-1962-815848 mob:+44-7717-378890 Note: I work Tuesday to Friday

1 0