Open Grid Forum: Data Format Description Language Working Group

OGF DFDL Working Group Call, March-11-2009


Attendees
Alan Powell (IBM)
Steve Hanson (IBM)
Dave Glick (drac)
Suman Kalia (IBM)

Apologies
Mike Beckerle(Oco)
Tim Kimber (IBM)

1.  Specialized Annotations

Discussed SH proposal for using specialized annotations. Generally thought to be reasonable if details can be worked out. Additional suggestion for dfdl:format and dfdl:complextype to allow specialized annotaions as children rather than them being the union of all properties. Led to perhaps allowing scoped properties to be tied to specialized annotation. eg dfdl:sequence lengthKind and dfdl:element: lengthKind. Identified problem with short form properties on complexType, which specialized annotation should they apply to?
SH to update proposal.

2. Escape Schemes

IBM have done work to complete the current proposal (006) to provide a general mechanism that covers all cases and have concluded that it ends up to be much to complicated. They have suggested a simplified version  that covers that major cases only.
Summary. : allow a single reference on field to an escape scheme.
The escapeScheme defines one of 3 different escape alternatives
-  escapeCharacter and escapeforescapeCharacter
-  escape surround/bracket with escapeforescapeCharacter
-  escape surround/bracket with alternate escape surround/bracket
Also suggested adding  property to list 'Other characters that need to be escaped' as a catchall mechanism

AP document simplified proposal

3. Validation ranges and exclusion lists.

General agreement that validation outside that provided by schema validation should be avoided. Discussed SH emailed proposal to use unions to define validation ranges. Need to decide if benefit of validation ranges has enough value to justify the complication of allowing limited union support.  Be prepared to decide on the next call.


4. AOB
To be discussed
 - Consuming extraneous data after schema has be used.
-  'Floating' definitions
-  Actions

Next call 18 March 14:00

Meeting closed, 15:00 GMT

Actions raised at this meeting
No
Action

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.
020
SH: Resolve packedDecimalSignCodes behaviour depends on NumberCheckPolicy
22/10: No progress
10/12: added how to decide to overpunch and sign position
11/02: proposal largely agreed. SH to make minor changes
18/02: AP to document unsigned type behaviour
25/02: no progress
023
MB: Review Schema 1.1
29/1: AP and SH to talk to Sandy Gao
04/02 Call arranged for Friday
11/02: Call took place. Identified useful changes. Consolidate with previous list.
04/03: decided to stay on Schema 1.0.
024
String XML type
025
Escape schemes
21/1: discussed requirements
04/02: AP/SH to describe behaviour for known length text fields. Need to discuss if comment escapes should be supported.
11/02 new draft distributed:
18/02: SH up document concerns
25/02: SH and AP have refined proposal ready for approval.
04/03: SH and AP have further refined proposal.
11/03: discussed. suggested a simplified proposal be evaluated.
026
SH: Envelopes and Payloads
027
Property precedence tables
028
Variable markup
029
 valueCalc (output length calculation)
031
DG: Review dfdl v033
11/02:  Initial comments received
18/02: Will include work items 5 and 12.
11/03: complete
032
DG: Investigate compatibility between DFDL infoset and XDM
033
04/03: Assert/Discriminator semantics. AP to document. TK to check uses of discriminator besides choice.
034
04/03: AP remove redundant properties

Closed actions:

034 Work items:
No
Item
001
String XML type (Ian P) - Apr 30, 2008
002
Escape schemes (Ian P) - Apr 30, 2008
003
Variables - ??, 2008 (Mike)
005
Improvements on property descriptions - ??, 2008 (All - split TBD)
006
Envelopes and Payloads (Steve) - Apr 30, 2008
007
(from draft 32) valueCalc (Mike) - ??, 2008   mostly
complete
008
(from draft 32) Property precedence for writing (Steve) - under review
009
(from draft 32) Variable markup (Steve) - Mar 31, 2008   proposal needs writing up
010
(from draft 32) Assertions, discriminators and choice, including discussion of timing option (Suman) - Mar 31, 2008 * in progress *
011
(from draft 32) How speculative parsing works (combining choice and variable-occurence - currently these are separate) ??, 2008 (IBM)  in progress
012
(from draft 32) Reordering the properties discussion: move representation earlier, improve flow of topics ??, 2008 (Alan) * not started *
025
Augmented infoset and unparsing (Alan)   added but needs work
026  Remove duration

complete - specification updated



Alan Powell

MP 211, IBM UK Labs, Hursley,  Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM     email: alan_powell@uk.ibm.com  
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