Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, May 26-2010 Attendees Steve Hanson (IBM) Alan Powell (IBM) Suman Kalia (IBM) Stephanie Fetzer (IBM) Mike Beckerle (Oco) Apologies Tim Kimber(IBM) 1 Nils, defaults The whole call was spent discussing the proposed changes to the nils and defaults sections including Stephanie's comments. Definition of 'has default value' Minor clarifications to simple element. For complex element it is an 'effective' default value. Clarified default for choices. Definition:'required' Clarified that required is in terms of the infoset. Didn't like the used of 'index' in the definition of variable occurrence elements. Agreed that ASSERTs do not make an element required. Stephanie to consider examples to confirm this is correct. Suggest introducing 'required context' to explain defaulting in complex elements. Discussed the restriction that choice branches may noy have minOccurs = 0 and whether that was sufficient. The was introduced to prevent the empty string being implicitly a valid choice but Mike pointed out that making all the children of a choice branch optional has the same effect. Not resolved. Discussed whether anonymous sequences and choices were required. Concluded that it wasn't a valid question when required is in terms of the infoset. Thus if anonymous sequences and choices have an initiator or terminator they will always be present in the data stream. If they need to be optional then the seq/choice has to be wrapped in an element. Suggest removing the definition of success. Largely agreed on the definition of missing. 2 OGF 29 Chicago, June 20-22 Not discussed 3 Current Actions Not discussed 4 Trailing alignment with lengthKind delimited or endOfParent Is it sensible to allow Trailing skip bytes with LK delimited The grammar says that trailing alignment is applied before the separator So the parser must search for the separator then remove the trailing bytes from the value and length. @Data1 *Data2*# - Test1 value=Data1 length=5 @Data1*Data2*# - Test1 value=Da length=2 (do we require that the trailing data must be the fillByte?) But bear in mind that the grammar effectively says: RightFraming = Terminator TrailingSkipBytes So the combination of dfdl:lengthKind="delimited" & dfdl:trailingSkipBytes would work when the delimiter is a terminator. Not discussed Meeting closed, 16:30 Next call Wednesday 02 June 2010 15:00 UK (10:00 ET) Next action: 092 Actions raised at this meeting No Action Current Actions: No Action 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 ... 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' 24/03: No progress 03/03: Discussions have been taking place on the subset of tests that will be provided. 10/03: work is progressing 17/03: work is progressing 31/03: work is progressing 14/04: And XML test case format has been defined and is being tested. 21/04. Schema for TDML defined. Need to define how this and the test cases will be made public 05/05: Work still progressing 12/05: Work still progressing 084 Check behaviour of dfdl:inputValueCalc and outputValueCalc. 14/04: no prorgess 21/04: no progress 05/05: no progress 26/05: Alan has looked at the precedence tables and the look OK. Suggest closing. 085 ALL: publicize Public comments phase to ensure a good review.. 14/04: see minutes 21/04: Press release, OMG and other standards bodies. 05/05: Alan and Steve H have contacted other standards bodies. Will ask them to add comments on spec 15/05: still no public comments 086 AP: Nils and Defaults during unparsing - update table 31/03: TK to documetn use cases for parsing 14/04: Investigate new property to control empty string behaviour. 21/04: After investigation a new property is not required. New rules developed and tables updated. Need examples of complexTypes to confirm tables apply. Review Nils, defaulting spec section. 05/05: Discussed defaulting complex elements. Tables updated but need to add terminator. SH; to confirm WMD behaviour when infoset item has no value on unparsing Need to describe defaulting choices. 15/05: More discussion. Alan updating sections 26/05: Discussed draft updates. Stephanie to confirm asserts do not make an element required. Alan will update draft.. All: review rest of draft. 088 define semantics of choiceKind 'fixedLength' 31/03: TK to provide definition of calculable length. Investigate PL/I varchars and Cobol occurs dependingon. 14/04Tim had distributed a document starting the definition of calculable length for the longest choice member. Alan had done some investigation of COBOL occurs depending on and when used in the working section of a program then the maximum storage was reserved but when used in the linkage section the dependent number was uses. We need to understand how the WMB COBOL importer deals with ODO. 21/04: Need to define 'calculable length' and WMB importer ODO behaviour. 05/05: TK: Still need definition of calculable length. SKK: WMB COBOL imported behaviour with ODO 15/05: Suman sent an expmle of an imported Cobol ODo which suggested that the maximum space was reserved. He will extend the example. 091 The IBM team had questioned whether timezones should be just UTC+/- offset or should GMT and other short time zones be allowed. Alan to investigate 15/05: Alan to talk to Ruth. 26/05: Ruth confirmed that it was only the offset from UTC or GMT. For DFDL purposes thates are the same. Suggest closing. Closed actions No Action 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 070 Write DFDL primer 071 Write test cases. 083 Implement RFC2116 097 Remove functions that returns duration 098 occursCountKind="expression" is parsing only 099 nilValue and OccuresStopValue cannot have an expression. On unparsing only outputValueCalc can have a forward reference. 100 Need to state in 4.1.2 Infoset that value is optional. 101 When dfdl:textNumberRep is ?zoned? only the pattern for positive numbers is used. Only the following pattern characters may be used: '+' MUST BE present at the beginning or end of the pattern to indicate whether the leading or trailing digit carries the overpunched sign, if the logical type is signed '+' MAY BE present at the beginning or end of the pattern to indicate whether the leading or trailing digit carries the overpunched sign, if the logical type is unsigned 'V' MAY BE used to indicate the location of an implied decimal point '0' indicates the number of required digits (including overpunched). '#' indicates the number optional digits. 102 Also textNumberPolicy implies it applies to zoned, but doesn't state what zoned behaviour it covers. I think it should be consistent with binaryNumberCheckPolicy for packed, and control whether positive punched data is accepted or rejected when parsing an unsigned type, and whether unpunched data is accepted or rejected when parsing a signed type. 103 - textStandardBase - textStandardGroupSeparator - textStandardExponentCharacter - textStandardInfinityRep - textStandardNanRep - textStandardZeroRep - textZonedSignStyle 104 4 Unsigned decimal Proposed solution: - Allow xs:nonNegativeInteger which enables unsigned unbounded integers to be modelled. The problem to solve is then just for xs:decimal. - Call the new property dfdl:decimalSigned. It only applies to xs:decimal or user defined restrictions thereof. It applies to all physical decimals, as its name implies (not just zoned or packed). Regards Alan Powell Development - MQSeries, Message Broker, ESB IBM Software Group, Application and Integration Middleware Software ------------------------------------------------------------------------------------------------------------------------------------------- IBM MP211, Hursley Park Hursley, SO21 2JN United Kingdom Phone: +44-1962-815073 e-mail: alan_powell@uk.ibm.com Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU