[DFDL-WG] Agenda for OGF DFDL WG call 23 Septembert 2009 - 13:00 UK (8:00 ET)

Alan Powell alan_powell at uk.ibm.com
Tue Sep 22 11:49:34 CDT 2009


NOTE: Start time is 13:00 uk (8:00 ET). Calendar entry has not been 
updated

1 Go through actions - 

In particular be ready to approve 

057 - semantics for occursCountKind ='parsed'   

Became a general discussions about arrays and optional elements.

dfdl:occursCountxxx  properties should apply to both arrays and optional 
elements so can be used to control the existence on optional elements.

dfdl:occursStopValue is always a logical value and applies to simple 
elements only. Literal values are specified as a terminator of the array. 
Spec needs updating

Enumerations for dfdl:occursCountKind should be:

'fixed'  - use xs:maxOccurs which must equal xs:minOccurs
'expression' - use dfdl:occursCount which must be an expression
'stopValue' - logical value to mark end of array
'parse' - use normal speculative parsing rules
'useAvailableSpace' - size deliniated by parent.

The semantics of dfdl:occursCountKind='parsed' are 
'parse as many as possible then validate against min/maxOccurs is 
validation is on. This is consistent with XML UPA checks as any other 
semantic would cause UPA failures.


051 - scoping rules  (email from AP)

2.  %#rxx in TextPadCharacter 
It has been proposed that use of the rew entity should be restricted in 
textPadCharacter

3. finalTerminatorCanBeMissing
It has been proposed to restrict the use of this propoerty to the last 
field in a definition as the only known used case is missing <LF> at end 
of file


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
27/05: No Progress
03/06: No Progress (low priority)
09/06: No Progress (low priority)
17/06: SH to check ICU code for lax calendar behaviour
24/06: no progress
01/07: no progress
15/07: no progress
29/07: no progress
05/08: no progress
12/08: no progress
19/08: Inconsistencies are being found in ICU behaviour so Calendars need 
reviewing again.
26/08: Specific three character short time zones may not be  maintained 
during round tripping when there is more than one short form for a time 
zone offset. Because dates and datetimes in the infoset only maintain a 
time zone offset so on unparsing it isn't possible to say which short form 
will be selected for a particular offset when there is more than one 
possible. Need to document.
09/09: no progress
16/09: 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)
27/05: No Progress (lower priority)
....
19/08: No Progress (lower priority)
26/08: No Progress (lower priority)
09/09: no progress
16/09: no progress
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 prgress
15/07: No Progress (lower priority)
29/07: No Progress (lower priority)
05/08: No Progress (lower priority)
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
16/09: no progress
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 
19/08: No Progress 
26/08: No Progress 
09/09: no progress
16/09: no progress
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.
.....
19/08: No Progress (lower priority)
26/08: No Progress (lower priority)
09/09: no progress
051
Scoping rules.
MB: to document change to scoping rules to satisfy implementation concerns
17/06: MB and SH proposals discussed. Needs further discussion
24/06: AP to update presentation with latest proosal
24/06: AP had updated presentation. MB to review
08/07: Discussed at length. Simple types will now take annotations. 
Variables will be used for parameters.
15/07: No further progress. Needs final write up.
29/07: No Progress
05/08: No Progress 
12/08: No Progress 
19/08: AP will document new syntax rules.
26/08: No Progress 
09/09: AP has documented new scoping rules. Not discussed
16/09: Not disussed. AP to update element reference examples
054
ICU DecimalNumber/ Calendar behaviour
15/07: No progress
29/07: No Progress.
05/08: No Progress. This action is to discover and document ICU behaviour. 
DFDL will do whatever ICU does.
12/08: No Progress 
19/09: More examples of inconsistent behaviour discovered
09/09: no progress
16/09: no progress


056
resolve lenghtUnit=bits including fillbytes
12/08: No Progress
19/08: No Progress
26/08: No Progress 
09/09: no progress
057
Decide semantics and enumeration for 'parsed'  occursCountKind 
26/08: Subsequent discussion agreed on 'parsed' Need to agree semantics
09/09: no progress
16/09: occursxxx applies to array and optional elements. occursCountKind 
enumeration agreed. Semantics of 'parsed' are 'parse as many as possible.
059
9/9: define how encoding,  byteorder and floating point format externally
16/09: no progress



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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