Open Grid Forum: Data Format Description Language Working Group

Weekly Working Group Conference Call
13:00 GMT, 24 September 2008


Attendees
Mike Beckerle (Oco)
Alan Powell (IBM)

Apologies
Steve Hanson (IBM)

1. Physical to Logical type conversions.
Discussed table distributed by AP
Simple type text (+ xml) binary
String n/a
Float ?? FloatFormat:
IEEE, IBM390Hex
Double ?? FloatFormat:
IEEE, IBM390Hex
Decimal/Integer NumberFormat:
text, zoned 		NumberFormat:
packed, BCD
Long, Int, Short, Byte, NumberFormat:
text, zoned 		NumberFormat:
packed, BCD, twosComplement, binary
UnsignedLong, Unsignedint, Unsignedshort, Unsignedbyte NumberFormat:
text, zoned 		NumberFormat:
packed, BCD, binary
DateTime
Date
Time
Duration
Boolean
HexBinary


Agreed to keep FloatFormat rather than FloatBinaryFormat and not to have NumberTextFormat and NumberBinaryFormat. Reduces the number of properties.
No need to add text to floatFormat
Add NumberFormat Binary to do the 'normal' cases ie twoscomplement for signed types and unsigned binary for unsigned types. Remove twoscomplement. Can add other signed formats like onescomplement later when supported
Keep zoned for unsigned text even though it will produce the same output as text but it also limits the allowable NumberPattern.
Remove BCD from Long etc


Need to investigate calendar/date text and binary formats. Add to existing action


2. WTX unresolved items.

Last weeks decisions:

3,4 agreed to drop textCharacterSize and DBCSOnly from dfdl V1

7  Padding; deferred pending proposal from IBM (WTX)

9 Add zeroRequiredOnInput to meet WTX requirement - resolved

17 finalTerminatorCanBeMissing, finalPostFixSeparatorCanBeMissing.
Agreed to drop these properties and change the default syntax of terminator and postFixSeparator to be optional on parsing the last element of a sequence but always written on unparsing.

Continued this weeks:

20 unordered sequence does not necessarily need initiator, speculative parsing can work it out too.

Discussed relaxing initiator restriction and infoset order

Decided to add enum unorderedInitiated to sequenceKind for  unordered initiated item and change unordered to be  resolved by speculative parsing
sequenceKind Enum

Valid values are "ordered", "unordered" "unorderedInitiated"

This property cannot have an expression used to compute its value.

When "ordered", this property means that the contained items of the sequence will be encountered in the same order that they appear in the schema, which is called schema-definition-order.

When "unordered", this property means that the items of the sequence will be encountered in any order.

When "unorderedInitiated", this property means that the items of the sequence will be encountered in any order, but each item must have an initiator

Annotation: dfdl:sequence



The infoset order for unordered and unorderedInitiated is the order in the datastream.

25. ChoiceKind fixed or variable

These are still needed. Decided to leave choiceKind  as a single property but change fixed and variable longestLength and variableLength

27 OccursKind for delimited arrays.
  occurskind = delimited had been removed in error and will be put back.
  occurskind renamed to occursLenghtKind

7 padding
AP has done more investigation and main deficiency vs WTX is lack of support for pad to miminum length for variable length items. Agreed to add this. Will use minLength facet for strings and the number pattern for Text numbers.

4. AOB

Will discuss End of Data next week

Next call  1st Oct

Meeting closed, 14:05 GMT

Actions raised at this meeting
No
Action

Current Actions:
No
Action
003
AP: Update spec from WTX document
13/8:  All resolved issues have been added to spec. Remaining unresolved items need discussion
10/9: Alan will pull out the remaining unresolved items and circulate for discussion next week
17/9: Doc distributed and partially discussed
004
MB: Mike will also author a new section in response to comments from Sandy Gao and Suman Kalia, explicitly connecting syntax with DFDL semantics
16/7: no progress
10/9: Mike not convinced this is necessary. Steve to talk to Sandy to see if it is needed for any IBM implementation that extends the existing XML parsing framework
006
SH: Distribute hidden proposal
16/7: Done. MB to review
13/8: MB to review
10/9: Mike has located this and will review
17/9: Proposal agreed
007
AP: enum + expression wording
13/8: no progress
10/9: No update
17/9: No update
011
SH: Update decimal supplement
13/8: Editorial changes needed.
10/9: Alan to incorporate into main spec
17/9: No update
012
??: Update decimalCalendarScheme
10/9: Not allocated yet
17/9: No update
24/9: add calendar binary formats to actions
013
MB: Description and use cases for EndofData syntax
10/9: Steve didn't receive this mail, he now has and will review
014
SH: Use cases for lengthKind pattern on binary fields.
10/9: Not done
17/9: No update
015
AP: removed extended floats
10/9: No update
17/9: No update
016
AP: add hidden changes to spec
017
All: Review EndOfData changes

033 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)
004
Selectors (Suman) - Apr 30, 2008
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) - *complete but 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 *
013
(from F2F) New scoping rules
014
(from F2F) Occurs, OccurSeparator changes
015
(from F2F) choices and Output (Mike)
016
(from F2F) xpath forward references (Alan) *complete*
017
(IBM WTX review) Minor agreed updates (Alan) *complete*
018
(IBM WTX review) Review generateNewLine (Alan) *complete*
020
(IBM WTX review) Special value for zero seen eg 'zero'. (Steve)
021
(IBM WTX review) 'EndOfData' changes (Alan)
022
(IBM WTX review) Unresolvable choices - infoset changes *complete*
023
(IBM WTX review) separatorKind=’prefix’ ‘infix’ or ‘postfix’ (Alan)
024
(IBM WTX review)  StopValue clarification (Alan)  
025
Augmented infoset and unparsing (Alan)  



Alan Powell

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



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