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Minutes for OGF DFDL Working Group Call, October-28-2009
by Alan Powell 28 Oct '09

28 Oct '09

Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, October-28-2009 Attendees Alan Powell (IBM) Steve Marting (Progeny) Stephanie Fetzer(IBM) Apologies Mike Beckerle (Oco) Suman Kalia (IBM) Steve Hanson (IBM) Peter Lambros (IBM) 1. 051 Scoping Rules Reviewed latest draft v7. "It is a schema definition error if more that one format annotation occurs at the same annotation point, except when selectors are used, or if the same property is defined in long and short form." Agreed thaht multiple annotations should not be allowed. Wording on selectors is not clear. Will remove from this sentence ad add sentence to say that selectors have been applied already. Need better definition of 'applicable' and 'required' properties. Refer to property precedence section 2. Resolving points of uncertainty and parsing rules Discussed Alan's proposal for describing variable arrays. "An alternative might be to consider an array as two points of uncertainty. On point is for the array and the other, which is nested inside the first, for the element. We can then have the rule that the discriminator resolves the element uncertainty only which always exists so doesn't need to be 'potential'. The array uncertainty is resolved when minOccurs have been found." Needs further discussion 3. UTC timezone 'Z' There is a conflict between the ZZZU calendar pattern and the calendarUseZForUTC property ZU time zone (RFC 822) (Number) Z with output "Z" if the time zone is +00:00) calendarUseZForUTC Enum Valid values ?always?, ?never?, ?onInput?, ?onOutput? Applies when a time zone appears in the data with pattern ZZZ (that is, +hh:mm) and the time zone is UTC (that is, GMT+00:00). Specifies whether ?Z? or ?+00:00? should be used. Annotation: dfdl:calendarFormat I suggest we drop the property and have the following ZZZ (strict) => accept +00:00 only on input, use +00:00 on output ZZZU (strict) => accept Z only on input, use Z on output ZZZ (lax) => accept +00:00 & Z on input, use +00:00 on output ZZZU (lax) => accept +00:00 & Z on input, use Z on output Agreed to drop calendarUseZForUTC but need to add symbols IU and TU 4. Go through remaining actions Actions updated below 5. Plan to finish DFDL v1 Next call 04 November 13:00 UK (8:00 ET) Meeting closed, 14:15 Next action: 063 Actions raised at this meeting No Action 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 28/10: Discussed ICU farctional seconds behaviour. SF to send latest understanding. 033 MB: Need for scope indicator on discriminator 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 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: no progress 28/10: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: 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 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 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 30/09: no progress 07/10: no progress 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 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 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 28/10: no progress 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 28/10: no progress 062 SH investigate technical writer support. 28/10: SH had contacted S Gao to understand the W3 process and support. Closed actions: Work items: No Item target version status 005 Improvements on property descriptions not started 011 How speculative parsing works (combining choice and variable-occurence - currently these are separate) (from action 045) awaiting completion of actions 045 012 Reordering the properties discussion: move representation earlier, improve flow of topics not started 033 Numeric data - what physical reps are allowed for what logical types (from action 020) 037 ensure all behaviour documented 036 Update dfdl schema with change properties ongoing 038 Improve length section including bit handling some improvement in 036 042 Mapping of the DFDL infoset to XDM none not required for V1 specification 051 Revised scoping rules (from action 051) 037 awaiting completion of action 051 058 textPadCharacter %#rxx limitation and split to textxxxxPadCharacter 037 059 limit terminatorCanBeMissing to last element in schema. Ignore elsewhere. 037 060 New empty string semantic for dfdl:binaryBooleanTrueRep 037 061 Change maxOccurs violations from processing error to validation error (if not 'fixed') 037 062 Drop calendarUseZForUTC. describe zU, IU and TU symbols 037 ã Copyright IBM Corp. 1998, 2007 All Rights Reserved Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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

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DFDL scoping v7
by Alan Powell 28 Oct '09

28 Oct '09

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

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Resolving points of Uncertainty (potentially uncertainty)
by Alan Powell 28 Oct '09

28 Oct '09

Minutes of Oct 14th 5. Resolving points of uncertainty and parsing rules Alan & Steve H spent some time discussing the uncertainty document and Alan has sent out a revision for review. Comments welcome, especially on the listed rules for resolving uncertainty. Steve H wants to ensure that the rules for resolving uncertainty do not preclude the use of 'on-demand' parsing as this is a valuable performance and memory technique for implementations. Steve thinks that the current rules should be ok. And there will always be some formats to which on-demand parsing can't be applied well. A problem was spotted with uncertainty and arrays. If an element has minOccurs not equal to maxOccurs, but greater than zero (say x), then the point of uncertainty does not actually start until index x+1. What does it mean to place a discriminator on that element (or one of its children if complex) ? The rules as worded mean that for indices less than x+1, the discriminator might actually be used to resolve a higher point of uncertainty. Which is clearly wrong. Mike agreed that the full solution to this is part of existing action 033 which is looking at the need to scope indicators on discriminators. All agreed that scope indicators should be avoided if at all possible. A proposal was put forward for handling this specific array scenario. As well as states 'certain' and 'uncertain' add the concept of a 'possibly uncertain' state (better name welcome). This state is entered for the array element described above when processing indices 1 through x. Any discriminator evaluated in this state can result in false and cause backtracking, but if it evaluates to true it does not resolve anything. That can only happen in the 'uncertain' state. --------------------------------------------------------------------------------------------------------------------------------------------- I am wary of the 'potentially uncertain' state as I think it adds unnecessary complication. I wasn't on the call but I assume it was introduced as a way of tying the discriminator to resolving whether the element exists and not some previous uncertainty. An alternative might be to consider an array as two points of uncertainty. On point is for the array and the other, which is nested inside the first, for the element. We can then have the rule that the discriminator resolves the element uncertainty only which always exists so doesn't need to be 'potential'. The array uncertainty is resolved when minOccurs have been found. Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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

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Agenda for OGF DFDL WG call 21 Octobert 2009 - 13:00 UK (9:00 ET)
by Alan Powell 28 Oct '09

28 Oct '09

NOTE: Call starts at 9:00 am EDT as UK has already switched from summer time. 1. 051 Scoping Rules Check latest draft v7. Confirm agreement to "It is a schema definition error if more that one format annotation occurs at the same annotation point, except when selectors are used, or if the same property is defined in long and short form." 2. 045 Resolving points of uncertainty and parsing rules Confirm wording for 'potentially point of uncertainty" Confirm parsing rule 1. The length of a dfdl:representation 'text' component which has a terminator, separator or parent terminator or separator does not match the required length. 3. UTC timezone 'Z' There is a conflict between the ZZZU calendar pattern and the calendarUseZForUTC property ZU time zone (RFC 822) (Number) Z with output "Z" if the time zone is +00:00) calendarUseZForUTC Enum Valid values ?always?, ?never?, ?onInput?, ?onOutput? Applies when a time zone appears in the data with pattern ZZZ (that is, +hh:mm) and the time zone is UTC (that is, GMT+00:00). Specifies whether ?Z? or ?+00:00? should be used. Annotation: dfdl:calendarFormat I suggest we drop the property and have the following ZZZ (strict) => accept +00:00 only on input, use +00:00 on output ZZZU (strict) => accept Z only on input, use Z on output ZZZ (lax) => accept +00:00 & Z on input, use +00:00 on output ZZZU (lax) => accept +00:00 & Z on input, use Z on output 4. Go through remaining actions 5. Plan to finish DFDL v1 Status 10 Actions ( issues to be resolved ) 10 Work items (features to be documented, areas to be improved) Strawman Schedule Activity Schedule Who Resolve Action items 23 Oct - 30 Oct 2009 WG Write up work items 23 Oct - 2 Nov 2009 AP Restructure and complete specification 23 Oct - 13 Nov 2009 AP WG review 16 Nov - 27 Nov 2009 WG Incorporate review comments 30 Nov - 7 Dec 2009 AP OGF Editor Review 7 Dec - 19 Dec 2009 OGF OGF Public Comment period (60 days) 4 Jan - 5 Mar 2010 OGF OGF 28 Munich 15-19 March 2010 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 033 MB: Need for scope indicator on discriminator 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 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: 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 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 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 30/09: no progress 07/10: no progress 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. 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 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 062 SH investigate technical writer support. Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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

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Proposals for textPadCharacter
by Tim Kimber 23 Oct '09

23 Oct '09

I'm in general agreement with the proposals, apart from the suggestion that we have separate properties for each simple data type. I understand that strings are generally right-padded with spaces, and numbers left-padded with zeros. However, I don't know of any common convention for padding booleans or calendar types. If a user wants to specify a padding character for all integers, they already have several options: - set textPadCharacter explicitly on each simple element that requires padding - put textPadCharacter into a format block, and use that format block ( or more likely, another derived from it ) for all integers - create a restriction of xs:int ( or whatever ) , add the required dfdl:textPadCharacter to it, and ensure that all other padded integers types are restrictions of it. Exactly the same applies to textStringJustification, textBooleanJustification, so whatever the outcome of this, we should adopt a consistent approach for both properties. regards, Tim Kimber, Common Transformation Team, Hursley, UK Internet: kimbert(a)uk.ibm.com Tel. 01962-816742 Internal tel. 246742 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

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Re: [DFDL-WG] Fw: DFDL Scoping v6
by Steve Hanson 23 Oct '09

23 Oct '09

Alan I've re-read the spec and you are quite right. That just leaves b), a use case for which personally I have no need. I therefore have no objection to the removal of multiple non-selector annotations. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Alan Powell/UK/IBM To: Steve Hanson/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org, dfdl-wg-bounces(a)ogf.org Date: 23/10/2009 08:59 Subject: Re: [DFDL-WG] Fw: DFDL Scoping v6 Steve The semantics of selectors are the you select the dfd:format block with the matching selector OR the dfdl:format block with no selector at an annotation point. I don't think that case 1a was supported anyway. Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 From: Steve Hanson/UK/IBM@IBMGB To: dfdl-wg(a)ogf.org Date: 22/10/2009 18:41 Subject: [DFDL-WG] Fw: DFDL Scoping v6 A couple of things about the new scoping rules: 1) As Alan said in the minutes, there was one thing we didn't discuss on the call, namely a proposal that multiple DFDL format annotations on the same XSDL component be disallowed. This simplifies things, as we currently have rules that govern how properties on multiple annotations combine. Whilst agreeing that this a simplification is desirable, if I recall correctly, there were a couple of motivating use cases, which we should bear in mind when deciding this: a) I am using selectors to model two different format variations, and some properties are common to both. I code the common properties in one dfdl:selector-free annotation, and the ones that differ in two annotations that have a dfdl:selector. b) I am simulating multiple inheritance by using two annotations each with a different dfdl:ref. 2) One other thing was discussed on the call. Relates to rule 3 below. When a component's set of 'explicit' properties are combined with the working set of 'explicit' properties, it is a schema definition error if same property appears in each set. It was questioned whether it should be an error if the properties have the same value. We agreed to leave the rule as-is, but revisit it if it proved to be a restriction when creating DFDL xsds. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 22/10/2009 18:12 ----- From: Steve Hanson/UK/IBM To: Alan Powell/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org Date: 21/10/2009 10:39 Subject: Re: [DFDL-WG] DFDL Scoping v6 Alan 1) There's a rule that got absorbed into the end of rule 2 of the combining rules. The rules are also specific to element ref -> global element -> simple type. They need to be generalised to handle the four combination cases you cite. Here's an amended set: Rules 1. Create an empty working set of "explicit" properties. Create an empty working set of "default" properties. 2. Move to the innermost schema component in the chain of references. 3. Assemble its directly relevant "explicit" properties from its local dfdl:ref (if present) and its local properties (if present), the latter overriding the former (that is, local wins). Combine these with the current working set of "explicit" properties. It is a schema definition error if there is the same property appears twice. Result is a new working set of "explicit" properties. Obtain directly relevant "default" properties from in-scope unnamed dfdl:format block (if present). Combine these with the current working set of "default" properties, the latter overriding the former (ie, inner wins). Result is a new working set of "default" properties. 4. Move to the schema component that references the current component, and repeat step 3. If there is no referencing component, move to step 5. 5. Validate the resultant set of properties. The "explicit" properties take priority, "defaults" only used when no "explicit" is present. It is a schema definition error if a required property is in neither the "explicit" nor the "default" working sets. 2) I think we should also define the property term "required". I think "directly relevant" could be replaced by "applicable" (I know "directly relevant" was my term :) 3) In Fig 5 you have dfdl:lengthKind on a xs:sequence - that is no longer allowed. 4) In Fig 5 I think you should add an extra applicable property to the dfdl:format in schema 1, to show how it gets picked up. Otherwise you are not showing how all the rules are being applied, and the statement " Nothing from the default dfdl:format block in SCHEMA1" will be mis-interpreted. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Suman Kalia <kalia(a)ca.ibm.com> To: Alan Powell/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org, dfdl-wg-bounces(a)ogf.org Date: 21/10/2009 03:53 Subject: Re: [DFDL-WG] DFDL Scoping v6 Sent by: dfdl-wg-bounces(a)ogf.org Some comments added in the document Suman Kalia IBM Toronto Lab WMB Toolkit Architect and Development Lead WebSphere Business Integration Application Connectivity Tools http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.h… Tel : 905-413-3923 T/L 969-3923 Fax : 905-413-4850 T/L 969-4850 Internet ID : kalia(a)ca.ibm.com From: Alan Powell <alan_powell(a)uk.ibm.com> To: dfdl-wg(a)ogf.org Date: 10/20/2009 10:20 AM Subject: [DFDL-WG] DFDL Scoping v6 Sent by: dfdl-wg-bounces(a)ogf.org I have updated the scoping proposal with the help of Steve and Stephanie. The main changes are to clarify the wording, define new terms, add more examples and propose disallowing multiple annotation at the same point (other than for selectors) Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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 -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg [attachment "ogf-dfdl-new-scoping-rules-with-default-V6.doc" deleted by Steve Hanson/UK/IBM] [attachment "ogf-dfdl-new-scoping-rules-with-default-V6_SKK.doc" deleted by Steve Hanson/UK/IBM] -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg 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 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 -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg 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

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Fw: DFDL Scoping v6
by Steve Hanson 23 Oct '09

23 Oct '09

A couple of things about the new scoping rules: 1) As Alan said in the minutes, there was one thing we didn't discuss on the call, namely a proposal that multiple DFDL format annotations on the same XSDL component be disallowed. This simplifies things, as we currently have rules that govern how properties on multiple annotations combine. Whilst agreeing that this a simplification is desirable, if I recall correctly, there were a couple of motivating use cases, which we should bear in mind when deciding this: a) I am using selectors to model two different format variations, and some properties are common to both. I code the common properties in one dfdl:selector-free annotation, and the ones that differ in two annotations that have a dfdl:selector. b) I am simulating multiple inheritance by using two annotations each with a different dfdl:ref. 2) One other thing was discussed on the call. Relates to rule 3 below. When a component's set of 'explicit' properties are combined with the working set of 'explicit' properties, it is a schema definition error if same property appears in each set. It was questioned whether it should be an error if the properties have the same value. We agreed to leave the rule as-is, but revisit it if it proved to be a restriction when creating DFDL xsds. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 22/10/2009 18:12 ----- From: Steve Hanson/UK/IBM To: Alan Powell/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org Date: 21/10/2009 10:39 Subject: Re: [DFDL-WG] DFDL Scoping v6 Alan 1) There's a rule that got absorbed into the end of rule 2 of the combining rules. The rules are also specific to element ref -> global element -> simple type. They need to be generalised to handle the four combination cases you cite. Here's an amended set: Rules 1. Create an empty working set of "explicit" properties. Create an empty working set of "default" properties. 2. Move to the innermost schema component in the chain of references. 3. Assemble its directly relevant "explicit" properties from its local dfdl:ref (if present) and its local properties (if present), the latter overriding the former (that is, local wins). Combine these with the current working set of "explicit" properties. It is a schema definition error if there is the same property appears twice. Result is a new working set of "explicit" properties. Obtain directly relevant "default" properties from in-scope unnamed dfdl:format block (if present). Combine these with the current working set of "default" properties, the latter overriding the former (ie, inner wins). Result is a new working set of "default" properties. 4. Move to the schema component that references the current component, and repeat step 3. If there is no referencing component, move to step 5. 5. Validate the resultant set of properties. The "explicit" properties take priority, "defaults" only used when no "explicit" is present. It is a schema definition error if a required property is in neither the "explicit" nor the "default" working sets. 2) I think we should also define the property term "required". I think "directly relevant" could be replaced by "applicable" (I know "directly relevant" was my term :) 3) In Fig 5 you have dfdl:lengthKind on a xs:sequence - that is no longer allowed. 4) In Fig 5 I think you should add an extra applicable property to the dfdl:format in schema 1, to show how it gets picked up. Otherwise you are not showing how all the rules are being applied, and the statement " Nothing from the default dfdl:format block in SCHEMA1" will be mis-interpreted. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Suman Kalia <kalia(a)ca.ibm.com> To: Alan Powell/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org, dfdl-wg-bounces(a)ogf.org Date: 21/10/2009 03:53 Subject: Re: [DFDL-WG] DFDL Scoping v6 Sent by: dfdl-wg-bounces(a)ogf.org Some comments added in the document Suman Kalia IBM Toronto Lab WMB Toolkit Architect and Development Lead WebSphere Business Integration Application Connectivity Tools http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.h… Tel : 905-413-3923 T/L 969-3923 Fax : 905-413-4850 T/L 969-4850 Internet ID : kalia(a)ca.ibm.com From: Alan Powell <alan_powell(a)uk.ibm.com> To: dfdl-wg(a)ogf.org Date: 10/20/2009 10:20 AM Subject: [DFDL-WG] DFDL Scoping v6 Sent by: dfdl-wg-bounces(a)ogf.org I have updated the scoping proposal with the help of Steve and Stephanie. The main changes are to clarify the wording, define new terms, add more examples and propose disallowing multiple annotation at the same point (other than for selectors) Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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 -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg [attachment "ogf-dfdl-new-scoping-rules-with-default-V6.doc" deleted by Steve Hanson/UK/IBM] [attachment "ogf-dfdl-new-scoping-rules-with-default-V6_SKK.doc" deleted by Steve Hanson/UK/IBM] -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg 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 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

2 1

Fw: Minutes for OGF DFDL Working Group Call, October-21-2009 - next week's call time
by Steve Hanson 22 Oct '09

22 Oct '09

Please note that for next week only the time difference between UK and US is 1 hour less than normal, due to DST changes not occuring in sync. Next week's call is therefore from 9-11 Eastern. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 22/10/2009 17:38 ----- From: Alan Powell/UK/IBM@IBMGB To: dfdl-wg(a)ogf.org Date: 22/10/2009 16:06 Subject: [DFDL-WG] Minutes for OGF DFDL Working Group Call, October-21-2009 Sent by: dfdl-wg-bounces(a)ogf.org Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, October-21-2009 Attendees Suman Kalia (IBM) Steve Hanson (IBM) Alan Powell (IBM) Peter Lambros (IBM) Steve Marting (Progeny) Stephanie Fetzer(IBM) Apologies Mike Beckerle (Oco) 1. Scoping Rules Continued the discussion on scoping rules. Alan's had distributed a new scoping document draft(v6) with input from Steve H and Stephanie. Suman and Steve H had made comments which we went through on the call. Suman was concerned that the wording implied that the dfdl:format on the xs:schema didn't need to provide defaults for all the dfdl:properties which he thought was a departure from previously. Others pointed out that that had never been the case and that it was not possible to validation dfdl:format blocks in isolation only at the point of use. Discussed whether the dfdl:defineFormat annotations should be in the table of annotation points. Alan pointed out there were other similar annotations, defineNumberFormat, etc. Decided to remove from the table but mention them below as they are only brought in scope when referenced. Discussed the need for more examples and Alan pointed out that in general we had agreed that the spec would not contain many examples as the should also be a primer. Agreed to change one example to element->element ref -> simpleType. Steve H suggested that following update to the rules Rules 1. Create an empty working set of "explicit" properties. Create an empty working set of "default" properties. 2. Move to the innermost schema component in the chain of references. 3. Assemble its directly relevant "explicit" properties from its local dfdl:ref (if present) and its local properties (if present), the latter overriding the former (that is, local wins). Combine these with the current working set of "explicit" properties. It is a schema definition error if there is the same property appears twice. Result is a new working set of "explicit" properties. Obtain directly relevant "default" properties from in-scope unnamed dfdl:format block (if present). Combine these with the current working set of "default" properties, the latter overriding the former (ie, inner wins). Result is a new working set of "default" properties. 4. Move to the schema component that references the current component, and repeat step 3. If there is no referencing component, move to step 5. 5. Validate the resultant set of properties. The "explicit" properties take priority, "defaults" only used when no "explicit" is present. It is a schema definition error if a required property is in neither the "explicit" nor the "default" working sets. Note: we didn't discuss the suggested change of disallowing multiple annotations at the same point (other than for selectors) or the same property in short and long form. Please review this change. 2. Resolving points of uncertainty and parsing rules Reviewed the latest draft (v5) that Alan had distributed. The only change was the introduction of the 'potentially uncertain' state discussed on the call last week. Alan was not overly happy with the new concept and will try some other way of describing the problem. 3. Comments on Draft 036 No comments received. It is now available on gridforge. 4. Go through remaining actions Actions updated below 5. Plan to finish DFDL v1 Alan pointed out that in order to meet the target of having the document ready for approval at the next OGF meeting we need to have all the action items resolve in the next month or so. Alan will produce an outline schedule for completing the spec. Also discussed if there is any technical writer support available within IBM to edit the specification. Steve H will contact Sandy Gao to see who edits the XML schema specification Next call 28 October 13:00 UK Meeting closed, 14:30 Actions raised at this meeting No Action 062 SH investigate technical writer support. 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 033 MB: Need for scope indicator on discriminator 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 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: 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 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 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 30/09: no progress 07/10: no progress 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. 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 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 062 SH investigate technical writer support. Closed actions: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Decided to list the know issues and combine with action 012 .Closed Work items: No Item target version status 005 Improvements on property descriptions not started 011 How speculative parsing works (combining choice and variable-occurence - currently these are separate) (from action 045) awaiting completion of actions 045 012 Reordering the properties discussion: move representation earlier, improve flow of topics not started 033 Numeric data - what physical reps are allowed for what logical types (from action 020) 037 ensure all behaviour documented 036 Update dfdl schema with change properties ongoing 038 Improve length section including bit handling some improvement in 036 042 Mapping of the DFDL infoset to XDM none not required for V1 specification 051 Revised scoping rules (from action 051) 037 awaiting completion of action 051 058 textPadCharacter %#rxx limitation and split to textxxxxPadCharacter 037 059 limit terminatorCanBeMissing to last element in schema. Ignore elsewhere. 037 060 New empty string semantic for dfdl:binaryBooleanTrueRep 037 061 Change maxOccurs violations from processing error to validation error (if not 'fixed') 037 ã Copyright IBM Corp. 1998, 2007 All Rights Reserved Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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 -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg 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

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Minutes for OGF DFDL Working Group Call, October-21-2009
by Alan Powell 22 Oct '09

22 Oct '09

Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, October-21-2009 Attendees Suman Kalia (IBM) Steve Hanson (IBM) Alan Powell (IBM) Peter Lambros (IBM) Steve Marting (Progeny) Stephanie Fetzer(IBM) Apologies Mike Beckerle (Oco) 1. Scoping Rules Continued the discussion on scoping rules. Alan's had distributed a new scoping document draft(v6) with input from Steve H and Stephanie. Suman and Steve H had made comments which we went through on the call. Suman was concerned that the wording implied that the dfdl:format on the xs:schema didn't need to provide defaults for all the dfdl:properties which he thought was a departure from previously. Others pointed out that that had never been the case and that it was not possible to validation dfdl:format blocks in isolation only at the point of use. Discussed whether the dfdl:defineFormat annotations should be in the table of annotation points. Alan pointed out there were other similar annotations, defineNumberFormat, etc. Decided to remove from the table but mention them below as they are only brought in scope when referenced. Discussed the need for more examples and Alan pointed out that in general we had agreed that the spec would not contain many examples as the should also be a primer. Agreed to change one example to element->element ref -> simpleType. Steve H suggested that following update to the rules Rules 1. Create an empty working set of "explicit" properties. Create an empty working set of "default" properties. 2. Move to the innermost schema component in the chain of references. 3. Assemble its directly relevant "explicit" properties from its local dfdl:ref (if present) and its local properties (if present), the latter overriding the former (that is, local wins). Combine these with the current working set of "explicit" properties. It is a schema definition error if there is the same property appears twice. Result is a new working set of "explicit" properties. Obtain directly relevant "default" properties from in-scope unnamed dfdl:format block (if present). Combine these with the current working set of "default" properties, the latter overriding the former (ie, inner wins). Result is a new working set of "default" properties. 4. Move to the schema component that references the current component, and repeat step 3. If there is no referencing component, move to step 5. 5. Validate the resultant set of properties. The "explicit" properties take priority, "defaults" only used when no "explicit" is present. It is a schema definition error if a required property is in neither the "explicit" nor the "default" working sets. Note: we didn't discuss the suggested change of disallowing multiple annotations at the same point (other than for selectors) or the same property in short and long form. Please review this change. 2. Resolving points of uncertainty and parsing rules Reviewed the latest draft (v5) that Alan had distributed. The only change was the introduction of the 'potentially uncertain' state discussed on the call last week. Alan was not overly happy with the new concept and will try some other way of describing the problem. 3. Comments on Draft 036 No comments received. It is now available on gridforge. 4. Go through remaining actions Actions updated below 5. Plan to finish DFDL v1 Alan pointed out that in order to meet the target of having the document ready for approval at the next OGF meeting we need to have all the action items resolve in the next month or so. Alan will produce an outline schedule for completing the spec. Also discussed if there is any technical writer support available within IBM to edit the specification. Steve H will contact Sandy Gao to see who edits the XML schema specification Next call 28 October 13:00 UK Meeting closed, 14:30 Actions raised at this meeting No Action 062 SH investigate technical writer support. 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 033 MB: Need for scope indicator on discriminator 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 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: 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 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 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 30/09: no progress 07/10: no progress 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. 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 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 062 SH investigate technical writer support. Closed actions: 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 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Decided to list the know issues and combine with action 012 .Closed Work items: No Item target version status 005 Improvements on property descriptions not started 011 How speculative parsing works (combining choice and variable-occurence - currently these are separate) (from action 045) awaiting completion of actions 045 012 Reordering the properties discussion: move representation earlier, improve flow of topics not started 033 Numeric data - what physical reps are allowed for what logical types (from action 020) 037 ensure all behaviour documented 036 Update dfdl schema with change properties ongoing 038 Improve length section including bit handling some improvement in 036 042 Mapping of the DFDL infoset to XDM none not required for V1 specification 051 Revised scoping rules (from action 051) 037 awaiting completion of action 051 058 textPadCharacter %#rxx limitation and split to textxxxxPadCharacter 037 059 limit terminatorCanBeMissing to last element in schema. Ignore elsewhere. 037 060 New empty string semantic for dfdl:binaryBooleanTrueRep 037 061 Change maxOccurs violations from processing error to validation error (if not 'fixed') 037 ã Copyright IBM Corp. 1998, 2007 All Rights Reserved Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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

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DFDL Scoping v6
by Alan Powell 21 Oct '09

21 Oct '09

I have updated the scoping proposal with the help of Steve and Stephanie. The main changes are to clarify the wording, define new terms, add more examples and propose disallowing multiple annotation at the same point (other than for selectors) Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 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

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