[DFDL-WG] Minutes for OGF DFDL Working Group Call, February 17-2010

Thu Feb 18 08:44:22 CST 2010

Open Grid Forum: Data Format Description Language Working Group

OGF DFDL Working Group Call, February 17-2010

Attendees
Steve Hanson (IBM) 
Alan Powell (IBM) 
Steve Marting (Progeny) 
Peter Lambros (IBM) 
Stephanie Fetzer (IBM)

Apologies
Mike Beckerle (Oco) 
Suman Kalia (IBM) 
Tim Kimber(IBM) 

1. Comments of latest discriminators doc v5. 

Steve questioned:   It is a processing error if none of the choice 
branches are known to exist
Steve: I know we agreed on this but I?m concerned that I am now unable to 
model the situation where I have a header, a footer, and in between either 
nothing or exactly 1 of a choice of n records 

It was agreed that the body could be an optional complex element with the 
choice as its content.

Also confirmed

dfdl:discriminator can be an annotation on 
·        a local xs:element declaration 
·        an xs:element reference 
·        an xs:group reference (when the top level of a choice branch)
·        an xs:sequence (when the top level of a choice branch) 
·        an xs:choice (when the top level of a choice branch) 

Action 045 will be closed.

2. Remaining 037 review issues 

16.2 scannablility with lengthKind pattern:   
Confirm that this is what we agreed 
In summary, you can use a data pattern on any element (complex, simple 
text, simple binary) as long as the bytes are legal in the stated 
encoding, which where binary data is involved in practice means an 8-bit 
ASCII encoding. 

By 8-bit ASCII we really mean an encoding where all the codepoints from 
0-255 map to the equivalent value. Subsequent investigation indicates that 
'all' 8-bit ASCII encodings have gaps so there isn't a valid character. 
Mike has suggested 
1) for all ascii-based character sets, we say that bytes 0x00 to 0xFF all 
map to exactly those codepoints in ISO 10646 for the infoset, and vice 
versa. 

2) define dfdl:encoding="bytes" as a special character set name which has 
the above property. 

Briefly discussed but no conclusion.

3. Go through Actions 
Updated below 

4. Biztalk comparison 
Short discussion which noted that DFDL could match Biztalk representation 
properties but was missing support for attributes and some simple types. 
Decided that we don't need to do anything in DFDL v1.

5 DFDL v1 Specification completion.
It was agreed that the spec should be in the OGF review process by OGF 28 
in March.
Alan stated it needed 2 more drafts. 
Draft 39 with all the updates completed for a final WG review - available 
24 Feb
Comments by 3 March
Draft 40 with updates for OGF submission - available 5 March

Meeting closed, 14:00

Next call  Wednesday 24 February January 2010  13:00 UK 

Next action: 083
Actions raised at this meeting

No
Action 

Current Actions:
No
Action 
049
20/05 AP Built-in specification description and schemas
03/06: not discussed
24/06: No Progress
24/06: No Progress (hope to get these from test cases)
15/07: No progress. Once available, the examples in the spec should use 
the dfdl:defineFormat annotations they provide.
...
14/10: no progress
21/10: Discussed the real need for this being in the specification. It 
seemed that the main value is it define a schema location for downloading 
'known' defaults from the web. 
28/10: no progress
04/11: no progress
11/11: no update
18/11: no update
25/11: Agreed to try to produce for CSV and fixed formats
04/12: no update
09/12: no update
16/12: no update
23/12: no update
06/01: no progress. If there is no resource to complete this action it can 
be deferred
13/01:no progress
20/01: no progress
27/01: no progress
29/01: No progress.  The predefined formats do not need to be available 
when the spec is published.
Suman said that he had been mapping COBOL structures to DFDL and it didn't 
look as though the way text numbers are define is very usable. He will 
document for next call 
03/02: No progress
10/02: No progress
17/03: No progress
066
Investigate format for defining test cases
25/11:IBM to see if it is possible to publish its test case format.
04/12: no update
09/12: no update
16/12: reminded dent to project manager
23/12: SH will send another reminder.
06/01: Another reminder will be sent
13/01: no update
20/01: no update
27/01: no progress
29/01: no progress
03/02: IBM is still investigating
10/02: IBM is still investigating
17/02: IBM is willing in principle to publish the test case format and 
some of the test cases. May need some time to build a 'compliance suite'
079
MB:Encoding for binary fields when lenghtkind is pattern
17/02: Discussed but no conclusion
080
AP:Clarify semantics of fn:poisition and fn:count
17/02: no progress
081
AP: Inf and Nan
The description is the way ICU behaves but need clarification. It isn't 
clear how inf and Nan are represented in the infoset. Need to investigate 
if XML allows these values
17/02: XML allows Nan and inf for float and double Dfdl will do the same. 
Requires more investigation of ICU. 

Closed actions
No
Action 
045
20/05 AP: Speculative Parsing
27/05: Psuedo code has been circulated. Review for next call
03/06: Comments received and will be incorporated
09/06: Progress but not discussed
17/06: Discussed briefly
24/06: No Progress
01/07: No Progress
15/07: No progress. MB not happy with the way the algorithm is documented, 
need to find a better way.
29/07: No Progress 
05/08: No Progress. Will document behaviour as a set of rules.
12/08: No Progress 
...
16/09: no progress
30/09: AP distributed proposal and others commented. Brief discussion AP 
to incorporate update and reissue
07/10: Updated proposal was discussed.Comments will be incorporated into 
the next version.
14/10: Alan to update proposal to include array scenario where minOccurs > 
0
21/10: Updated proposal reviewed
28/10: Updated proposal reviewed see minutes
04/11: Discussed semantics of disciminators on arrays. MB to produce 
examples
11/11: Absorbing action 033 into 045.  Maybe decorated discrminator kinds 
are needed after all. MB and SF to continue with examples. 
18/11: Went through WTX implementation of example. SF to gather more 
documentation about WTX discriminator rules.
25/11: Further discussion. Will get more WTX documentation. Need to 
confirm that no changes need to Resolving Uncertainty doc.
04/11: Further discussion about arrays.
09/12: Reviewed proposed discriminator semantic.
16/12: Reviewed discriminator examples and WTX semantic.
23/12: SF to provide better description of WTX behaviour and invite B 
Connolley to next call
06/01:B Connolly not available. SF to provide more complete description.
13/01: Stephaine took us through a description of WTX identifiers. Mike 
agreed to write up in DFDL terms.
20/01: Mike will write up
27/01: further discussion of discriminators
29/01: Alan had  emailed both proposals but not enough time to discuss
02/02: Agreed to adopt 'component exists' semantics for discriminators
10/02: 'component exists' proposal updated. comments by next call.
17/02: reviewed needs minor updates. 
Closed
082
MB: Should alignment be 0 or 1 based
17/02: Mike has reworded the section to be 1 based and Agreed this was OK
Closed

Work items:
No
Item
target version
status
005
Improvements on property descriptions 

not started
012
Reordering the properties discussion: move representation earlier, improve 
flow of topics 

not started 
036
Update dfdl schema with change properties 
ongoing

042
Mapping of the DFDL infoset to XDM 
none
not required for V1 specification
069
ICU fractional seconds
039

070
Write DFDL primer 

071
Write test cases.

072
it is a processing error if the number of occurrences in the data does not 
match the value of the expression or prefix
039

073
Rename dfdl:separatorPolicy="required" to "always". 
039
Defferred untilaction 071 agreed
078
document UPA checks
039

079
Semantics of length=0, nil handling and defaults. (A071)
039

080
Tlog: Allow LengthKind delimited for packed/bcd (A074)
039

081
Update empty sequence section (A075)
039

082
semantics of minOccurs= 0 on choice branches (A076)
039

083
Implement RFC2116

084
Length|Kind pattern scanability rules

085
Invalid character substitution

086
infoset round tripi: Rephrase sentence 'It is possible to define a schema 
so that when infoset unparsed and the datastream reparsed, the same 
infoset will be produced'

087
Clarify use of relative paths in global components.

088
'DFDL expression'

089
Ageed that dfdl:represetnation 'text' is implied for strings and 
dfdl:represetnation 'binary' is implied for hexbinary

091
textStringPadCharacter textNumberPadCharacter  must be a 1 byte character 
if the char set encoding is variable width?

092
 finalDocumentTerminatorCanBeMissing and  
finalDocumentSeparatorCanBeMissing allowed only in 'default' format 

093
 remove textNumberFormat and textCalendarFormat.

094
Alignment should be  1 based

Regards

Alan Powell

Development - MQSeries, Message Broker, ESB
IBM Software Group, Application and Integration Middleware Software
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