[DFDL-WG] Agenda for OGF WG call 27 May 2009

Wed May 27 04:24:18 CDT 2009

Note: the call is scheduled for 1 hour 

Agenda: 

1. Go through actions. 

2. Completing DFDL V1

3. AOB

Current Actions:
No
Action 
012
AP/SH: Update decimalCalendarScheme
10/9: Not allocated yet
17/9: No update
24/9: Add calendar binary formats to actions
22/10: No progress
16/1: proposal distributed and discussed. Will be redistributed
21/1: add locale, 
04/02: changed from locale to specific properties
18/2: Need more investigation of ICU strict/lax behaviour.
08/04: Not discussed
22/04: AP to complete asap once the ICU strict/lax behaviour is 
understood. 
29/04: No progress
06/05: No progress
13/05: Calendar has been added to latest spec version v034 but still a few 
details to clarify.
20/05: No Progress
026
SH: Envelopes and Payloads
08/04: Not discussed explicity, but recursive use of DFDL is tied up with 
this
22/04: Two aspects. Firstly compositional - do sufficient mechanisms exist 
to model an envelope with a payload that varies. Secondly markup syntax - 
this might be defined in the envelope. 
The second of these is very much tied up with the variable markup action 
028, so will be considered there. SH to verify the composition aspect.
29/04: SH and AP working on proposal. related to Action 028
06/05: No progress
06/05: No progress
20/05: No Progress
027
SH: Property precedence tables
08/04: Not discussed
22/04: Two things missing from the existing precedence trees. Firstly, 
does not show alternates (eg, initiator v initiatorkind). Secondly, need a 
tree per concrete DFDL object (eg, element). SH to update.
29/04: No progress
06/05: SH is updating tables which will be ready for next call
13/05: SH emailed updated version. AP commented.. See minutes for issues 
and property changes.
20/05: Updated version circulated. Review before next call and be ready 
for vote.
028
SH: Variable markup 
08/04: Discussed briefly at end of call, IBM to see whether there any use 
cases that require recursive use of DFDL.
15/04: Use case was distributed and will be discussed on next call.
22/04: The use case in question is EDI where the terminating markup for 
the payload segments is defined in the ISA envelope segment. The markup is 
modelled as an element of simple type where the allowable markup values 
are defined as enums on the type. But we need to handle two cases - 
firstly where the envelope is present, so the value used by the payload is 
taken from the envelope. Secondly where only the payload is present. Here 
we need a way of scanning for all the enum values, and adopting the one we 
actually find, when parsing. And using a default when unparsing. SH to 
explore use of a DFDL variable, where the variable has a default, but also 
has a type that is the same as the markup element - that way we get to use 
the enums without defining everything twice.
29/04: SH and AP working on proposal.
06/05: No progress
13/05: No progress
20/05: No Progress
029
MB: valueCalc (output length calculation)
08/04: Not discussed
22/04: Action allocated to MB, this is to complete the work started at the 
Hursley WG F2F meeting.
29/04: No progress
06/05: MB will have update for next call
13/05: MB will have update for next call
20/05: Some progress. will be circulated this week
032
DG: Investigate compatibility between DFDL infoset and XDM
08/04: No update
22/04: No update
29/04: No update
06/05: DG indicates will have update next week
13/05: see minutes
20/05: No Progress
033
AP/TK: Assert/Discriminator semantics. AP to document. TK to check uses of 
discriminator besides choice.
08/04: In progress within IBM
22/04: Waiting for TK to return from leave to complete. 
29/04: TK has sent examples shown need for discriminators beyond choice. 
Agreed. MB to respond to TK 
06/05: Discussed suggestion of adding type indicator to discriminator. MB 
to provide examples.
15/03: Semantic documented in v034. MB to provide examples of need for 
scope indicator on discriminator
20/05: MB to provide examples of need for scope indicator on discriminator 
(but lower priority than action 029)
036
SH: Provide use case for floating component in a sequence
08/04: Raised
15/04: Use case sent and discussed. SH to do further investigation
22/04: IBM feedback from WTX team is that alternate suggested ways of 
modelling the EDI floating NTE segment have significant usability issues. 
The DFDL principle is that for a problem that can be expressed as 
two-layered, then two DFDL models are needed.  The EDI NTE segment does 
not fall into this though, as its use is on a per sequence basis. Ongoing. 

29/04: Agreed that need to be in V1. SH to make a proposal
06/05: No progress
20/05: SH has almost completed the proposal
037
All: Approach for XML Schema 1.0 UPA checks.
22/04: Several non-XML models, when expressed in their most obvious DFDL 
Schema form, would fail XML Schema 1.0 Unique Particle Attribution checks 
that police model ambiguity.  And even re-jigging the model sometimes 
fails to fix this. Note this is equally applicable to XMl Schema 1.1 and 
1.0. While the DFDL parser/unparser can happily resolve the ambiguities, 
the issue is one of definition. If an XSD editor that implements UPA 
checks is used to create DFDL Schema, then errors will be flagged. DFDL 
may have to adopt the position that: 
a)DFDL parser/unparser will not implement some/all UPA checks (exact 
checks tbd)
b) XML Schema editors that implement UPA checks will not be suitable for 
all DFDL models
c) If DFDL annotations are removed, the resulting pure XSD will not always 
be valid (ie, the equivalent XML is ambiguous and can't be modelled by XML 
Schema 1.0)
Ongoing in case another solution can be found.
29/04: Will ask DG and S Gao for opinion before closing
06/05: Discussed S Gao email and suggestions. Decided need to review all 
XML UPA rules and decide which apply to dfdl.
20/05: SH or SKK to investigate
038
MB: Submit response to OMG RFI for non-XML standardization
22/04: First step is for MB to mail the OGF Data Area chair to say that we 
want to submit
29/04: MB has been in contact with OMG and will sunbit dfdl.
06/05: MB has prepared response to OMG. Will send DFDL sepc v033
20/05: Response has been sent to OMG based on v034
039
SKK: Approach for creating Schema-For-DFDL xsds. 
22/04: Resolve issue around multiple declarations needed for DFDL 
properties, perhaps using MB's meta approach
29/04: Don't like qualified attributes in long form. SKK to check there 
are no code gen implications, eg EMF.
06/05: SKK will send update by Friday
20/05: SKK and MB have produced Schema for DFDL, XSD dfdl subset and 
examples.. Close
042
MB: Complete variable specification.
To include how properties such as encoding can be set externally. Must be 
a known variable name.
06/05: No progress
20/05: AP to make proposal
043
13/05:  Types in the infoset.  Currently infoset types have defined value 
space but that implies a parser would have to validate input. Is this 
correct?
20/05: SH No progress
044
13/05:  Bidi
20/05: AP: will check what IBM products support.
045
20/05: AP: Speculative parsing

No
Action 
045
20/05 AP: Speculative Parsing
046
20/05 AP: Document changes to simple type scoping
047
20/05 AP: Scoping for non-format annotations
048
20/05: AP investigate Restart
049
20/05 AP Built-in specification description and schemas

Alan Powell

 MP 211, IBM UK Labs, Hursley,  Winchester, SO21 2JN, England
 Notes Id: Alan Powell/UK/IBM     email: alan_powell at uk.ibm.com 
 Tel: +44 (0)1962 815073                  Fax: +44 (0)1962 816898

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