[DFDL-WG] Agenda for OGF DFDL WG call 09 Decemberer 2009 - 13:00 UK (8:00 ET)

Tue Dec 8 12:06:05 CST 2009

1.      045  - Disciminators
Continued discussion of semantics of discriminators and arrays. 

2.      Clarification of postfix separators, 
terminators,finalTerminatorCanBeMissing
Agree semantics 

3.      Arrays

 occursCountKind="useAvailableSpace".  On unparsing, unused space should 
be padded with dfdl:fillByte (added below).  But if the number in the 
infoset is a lot less
than the box can hold, how do you know when re-parsing how many are in the 
box?  Also, if we are trying to fit things into a box, does it matter if 
items are left over? I          suggested this was an error below.  Need 
Mike's input as he has seen the use cases for this. 

Additional thoughts on occursCountKind="useAvailableSpace". 

I had been thinking that occursCountKind="useAvailableSpace" was for all 
'box' use cases but during discussions with Steve I realised that it does 
not cover the 2 use
cases I had in mind. 

1. COBOL occurs dependingOn with maximum occurrences allocated. 
 Array complex element   dfdl:lengthKind='explicit' dfdl:length='{MaxOccur 
* Length(row)}' 
   Sequence   dfdl:occursCountKind = 'expression' dfdl:occursCount = 
'{./NoOfOccurs}' 
      Row dfdl:lengthKind='...........' 

2. StopValue 

 Array complex element   dfdl:lengthKind='explicit' dfdl:length='{MaxOccur 
* Length(Row)}' 
   Sequence   dfdl:occursCountKind = 'StopValue' 
      Row  dfdl:lengthKind='...........' 

We need to articulate the use case for 
occursCountKind="useAvailableSpace". 

4.      Does the parser/serializer have to start on a global element?
-  Should the root global elements be designated in DFDL?
-  Is the SCD syntax usable to indicate 'starting' element to dfdl 
processor
-  Does the 'starting' element need to be a global element

5.       Semantics of  dfdl:lengthKind 'delimited'
Current definition: 'delimited' means the item is delimited by the item?s 
terminator (if specified) or an enclosing construct?s separator or 
terminator.
Does it need to be extended to cover 'infix' separators where last item 
can also be delimited by the end of the bitstream or the end of a 
fixed-length parent elemen

6.       UPA checks
Discuss Steve H email

7.       Go through remaining actions 

8.      Plan to finish DFDL v1
Agree terminology

Reworked plan

Activity

Schedule
Who
Complete Action items 

             - 18 Dec 2009 
 WG 
Complete Spec 
Write up work items
            ? 23 Dec 2009 
AP 
Restructure and complete specification
              - 23 Dec 2009 
AP 
Issue Draft 038
23 Dec 2009

WG review 
WG review
7 Dec ? 08 Jan 2010 
WG 
Incorporate review comments
4 Jan - 29 Jan 2010 
AP + 
Issue Draft 039
15 Jan 2010

Incorporate review comments
4 Jan - 29 Jan 2010 
AP + 
Issue Draft 040
29 Jan 2010

Initial OGF Editor Review 
Initial Editor review
1 Feb - 1 Mar 2010 
OGF 
Initial GFSG review
1 Feb - 1 Mar 2010

Issue Draft 041
1 Mar 2010

OGF Public Comment period (60 days) 

1 Mar - 30 Apr 2010 
OGF 
OGF 28 Munich 

15-19 March 2010 

Incorporate comments
Incorporate comments
28 May 2010

Issue Draft 042
28 May 2010

Final OGF Editor Review 
Final  Editor review
June  2010 
OGF 
final GFSG review
June  2010

Issue Final specification
30 June 2010

Publish proposed recommendation

1 July 2010

Grid recommendation process

1 Jan - 1 April 2011

Current Actions:
No
Action 
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
27/05: No Progress
03/06: The concern is that some dfdl schemas will fail UPA check when 
validation is turned on or when editted using tooling that enforces UPA 
checks. Renaming fields will resolve some/most issues. Need documentation 
that  describes issue and best practice.
17/06: no change
24/06: no change
01/07: no progress
...
12/08: No Progress (lower priority)
19/08: Clarify that this action is to go through the XML UPA checks to 
assess impact on dfdl schemas and advice best practice. Name clashes is 
just one example. SH or SKK
26/08: No Progress (lower priority)
09/09: no progress
...
04/11: no progress
11/11: Steve has started to look at this. He has requested a 'consumable' 
definition of the UPA rules from the XSD WG members. Even non-normative 
Appendix H in the XSD 1.0 spec is hard to consume.
18/11: no update
25/11: Steve H has not found simpler definition so may just go through 
them.
04/12: Steve has received a simpler description from S Gao and will go 
though each check.
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.
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
056
MB Resolve lengthUnits=bits including fillbytes
12/08: No Progress
...
28/10: no progress
04/11: MB to look at lengthUnits = bits
11/11: no update
18/11: no update
25/11: no update
04/12: no update. ALan will set up a separate call to progress this 
action.
064
MB/SH Request WG presentation at OGF 28
25/11: Session requested
04/12: no update
065
Resolve parsing rules for various lengthKinds
25/11: Agreed dfdl:lengthKind define how to extract the data. Didn'r
t discuss if this changes escaping.
04/12: Closed
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
068
Should the roots of messages be designated.?
069
Is the SCD syntax usable as a DFDL external.
070
Clarification of postfix separators, 
terminators,finalTerminatorCanBeMissing

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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IBM United Kingdom Limited - Registered in England and Wales with number 
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