[DFDL-WG] Fw: Minutes from DFDL session at OGF 28

[Steve Hanson]

Overall OGF registered attendees thought to be around 250.

Number at DFDL session: 7.  Apart from Erwin (Data AD), DFDL was new to 
everyone.

Notes from session (from minutes taken by Erwin Laure based on questions 
asked): 

Validation on input and output? Means conforming to the schema defined 
(e.g. integer between 0 and 100). dfdl assert could be used for asserting 
correctness of the data. Further complex validation would be via an 
external step (eg, Schematron invocation).
Using DFDL to model data structures generated by OO code, particularly use 
of inheritance? Could be a use case for allowing complex type inheritance 
in DFDL in the future. 
Data often comes with units, infoset would want to reflect this? Could be 
achieved using expressions, dfdl:inputValueCalc and dfdl:hidden to apply a 
scaling factor based on units. 
What's the efficiency of DFDL? Particularly, can tests be turned off for 
fast read/write? The spec defines the behavior of the parser but not how 
to implement it. For instance, validation is not mandatory.
Open source reference implementation would be good to have. (Lots of 
nodding).
Scientific floating point data compresses badly. Knowing data structure 
can allow a more intelligent compression. DFDL is not intending to do 
transformations but that could be done on top. 
Encryption/compression could also be a use case for multi-layers, or for 
additional functions in the expression language.
Need to reach out to DAIS-WG and DR-WG for (public) comments and to see 
whether DFDL will be actively used by those groups. Open source 
implementation would obviously help here.
Comment on the spec: Should be a proposed recommendation (GFD-P-R) not 
informational (GFD-I).






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