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Agenda for OGF DFDL WG call 12 August 2009
by Alan Powell 12 Aug '09

12 Aug '09

1. Go though actions 2. Make dfdl:initiated disciminating Currently dfdl:initiatedContent is used purely as a check that all the content of a sequence or choice have an initiator specified. It would help implementations decide more quickly if optional complex elements are present, and therefore have to save state less often, if initiatedContent was also made discriminating. I would expect that in most uses cases the initiator is the discriminator so this change would make that simpler to specify. The same effect can be achieved by adding a dfdl:discriminator to each element but that is having to specify the same intent twice. If the initiator is not the discriminator then initiatedContent can be set to 'false'. You lose the schema checking but this is a less common case. 3. New occursCountKind for when number of occurrences can be resolved by parsing. 4. Scoping element and group reference (Suman) 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 026 SH: Envelopes and Payloads 08/04: Not discussed explicity, but recursive use of DFDL is tied up with this 22/04: Two aspects. Firstly compositional - do sufficient mechanisms exist to model an envelope with a payload that varies. Secondly markup syntax - this might be defined in the envelope. The second of these is very much tied up with the variable markup action 028, so will be considered there. SH to verify the composition aspect. 29/04: SH and AP working on proposal. related to Action 028 06/05: No progress 06/05: No progress 20/05: No Progress 27/05: Still a number of aspects to be decided. - Compostion - Does the envelope and payload need to be defined in the same schema or should they be dynamically bound at runtime? - Compostion- How is a variable payload specified. Choice or xs:any; New action raised to discuss xs:any - extracting dymanic syntax from data. Covered by action 029 valuecalc. 03/06: Dynamic runtime binding will not be supported. SH investigating use of variables to enable standalone and use in envelope of global element. 09/06: Payload should be specified using a choice rather than xs:any 17/06: SH still working on example using variables 24/06: SH to document how property list satisfies uses cases. 01/07: SH to document how property list satisfies uses cases. PL looking at variable also. MB suggested modelling first separator as data for use case 3. 15/07: Action 042 on variables now includes examples of enevlopes and payloads. SH will also circulate what he has agreed with WTX team. 29/07: no progress 05/08: see action 042 033 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) 03/06: No Progress (lower priority) 09/06: No Progress (lower priority) 24/06: No Progress (lower priority) 01/07: No Progress (lower priority) 15/07: No Progress (lower priority) 29/07: no progress (lower priority) 05/08: No Progress (lower priority) 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) 042 MB: Complete variable specification. To include how properties such as encoding can be set externally. Must be a known variable name. 06/05: No progress 20/05: AP to make proposal 27/05: MB proposed differentiating between input and output variables to avoid unnecessary evaluations during parse and unparse. Need to complete rest of variable specification. 03/06: Pointed out problem of declaring variables input or output when used to define syntax which is used both times. MB to update proposal to include how variables are set externally and how specific properties such as encoding are set. 09/06: SKK to use example to dicument his proposal 17/06: SKK to refine proposal. Other aspects need progress. 24/06: SKK proposal discussed but not accepted. PL to document simpler proposal. 07/01: PL working on proposal 15/07: PL has distributed his proposal. SH, MB and SKK have commented. Broad agreement in principle. Need to agree on better name for dfdl:variable to reflect the annotation's purpose. PL to update proposal. 15/07: No Progress (lower priority) 29/07: No Progress 05/08: SH and others had commented on Variables [Draft proposal - 20090715].doc. SH stated that fixOnMatch is not needed in dfdl v1.0 MB will document how to implement fixOnMatch behaviour with existing function. PL to update proposal 044 13/05: Bidi 20/05: AP: will check what IBM products support. 27/05: Bidi is supported so will be needed in dfdl v1 03/06: No Progress 09/06: No Progress 24/06: No Progress 01/07: AP started investigation and documented issues. Suggest do whatever XML does. 15/07: No further progress 29/07: No Progress 05/08: AP has been in touch with IBM bidi experts. 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. 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. 29/07: No Progress (lower priority) 05/08: No Progress (lower priority) 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 (lower priority) 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. 055 Document which properties can take an expression 056 resolve lenghtKind=bits including fillbytes 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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Minutes for OGF DFDL Working Group Call, Aug-05-2009
by Alan Powell 12 Aug '09

12 Aug '09

Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, Aug-05-2009 Attendees Mike Beckerle (Oco) Alan Powell (IBM) Apologies Peter Lambros (IBM) Suman Kalia (IBM) Steve Hanson (IBM) Actions discussed and updated below. Discussed 1) Properties that can take expressions - identification of all such properties - wording to use when describing them Agreed to be conservative and limit number of properties that can take expressions AP to document. 2) WSP entity - spec does not match WTX equivalent, is this intentional? - if yes then needs WSP+OWSP to handle 'at least one white space char' - if no then don't have an entity for 'any single white space char' Agreed to add new entity for 'one or more white space characters' 3) Spec says the format 'ref' and selector attributes must be expressed as an attribute since the are not a representation property. - should this be also applicable for properties that are not representation but related to name and reference (QName types): name, baseFormat, selector, escapeSchemeRef, textNumberFormatRef, textCalendarFormatRef, binaryCalendarFormatRef? Agreed these properties should be attributes only 4) dfdl:fillByte and what it means when bits are involved - part of the wider bit discussion Next call 12 August 14:00 UK Meeting closed, 15:00 Actions raised at this meeting No Action 055 Document which properties can take an expression 056 resolve lenghtKind=bits including fillbytes 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 026 SH: Envelopes and Payloads 08/04: Not discussed explicity, but recursive use of DFDL is tied up with this 22/04: Two aspects. Firstly compositional - do sufficient mechanisms exist to model an envelope with a payload that varies. Secondly markup syntax - this might be defined in the envelope. The second of these is very much tied up with the variable markup action 028, so will be considered there. SH to verify the composition aspect. 29/04: SH and AP working on proposal. related to Action 028 06/05: No progress 06/05: No progress 20/05: No Progress 27/05: Still a number of aspects to be decided. - Compostion - Does the envelope and payload need to be defined in the same schema or should they be dynamically bound at runtime? - Compostion- How is a variable payload specified. Choice or xs:any; New action raised to discuss xs:any - extracting dymanic syntax from data. Covered by action 029 valuecalc. 03/06: Dynamic runtime binding will not be supported. SH investigating use of variables to enable standalone and use in envelope of global element. 09/06: Payload should be specified using a choice rather than xs:any 17/06: SH still working on example using variables 24/06: SH to document how property list satisfies uses cases. 01/07: SH to document how property list satisfies uses cases. PL looking at variable also. MB suggested modelling first separator as data for use case 3. 15/07: Action 042 on variables now includes examples of enevlopes and payloads. SH will also circulate what he has agreed with WTX team. 29/07: no progress 05/08: see action 042 033 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) 03/06: No Progress (lower priority) 09/06: No Progress (lower priority) 24/06: No Progress (lower priority) 01/07: No Progress (lower priority) 15/07: No Progress (lower priority) 29/07: no progress (lower priority) 05/08: No Progress (lower priority) 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) 042 MB: Complete variable specification. To include how properties such as encoding can be set externally. Must be a known variable name. 06/05: No progress 20/05: AP to make proposal 27/05: MB proposed differentiating between input and output variables to avoid unnecessary evaluations during parse and unparse. Need to complete rest of variable specification. 03/06: Pointed out problem of declaring variables input or output when used to define syntax which is used both times. MB to update proposal to include how variables are set externally and how specific properties such as encoding are set. 09/06: SKK to use example to dicument his proposal 17/06: SKK to refine proposal. Other aspects need progress. 24/06: SKK proposal discussed but not accepted. PL to document simpler proposal. 07/01: PL working on proposal 15/07: PL has distributed his proposal. SH, MB and SKK have commented. Broad agreement in principle. Need to agree on better name for dfdl:variable to reflect the annotation's purpose. PL to update proposal. 15/07: No Progress (lower priority) 29/07: No Progress 05/08: SH and others had commented on Variables [Draft proposal - 20090715].doc. SH stated that fixOnMatch is not needed in dfdl v1.0 MB will document how to implement fixOnMatch behaviour with existing function. PL to update proposal 044 13/05: Bidi 20/05: AP: will check what IBM products support. 27/05: Bidi is supported so will be needed in dfdl v1 03/06: No Progress 09/06: No Progress 24/06: No Progress 01/07: AP started investigation and documented issues. Suggest do whatever XML does. 15/07: No further progress 29/07: No Progress 05/08: AP has been in touch with IBM bidi experts. 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. 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. 29/07: No Progress (lower priority) 05/08: No Progress (lower priority) 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 (lower priority) 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. 055 Document which properties can take an expression 056 resolve lenghtKind=bits including fillbytes Closed actions: Work items: No Item target version status 003 Variables (from action 042) 036 awaiting completion of action 042 005 Improvements on property descriptions not started 006 Envelopes and Payloads (from action 026) 036 awaiting completion of actions 026 and 042 007 valueCalc (from action 029) 036 ensure all aspects documented 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) 036 ensure all behaviour documented 036 Update dfdl schema with change properties 038 Improve length section including bit handling not started 042 Mapping of the DFDL infoset to XDM not required for V1 specification 051 Revised scoping rules (from action 051) 036 awaiting completion of action 051 052 add entity for 'one or more white space characters' 036 053 name, baseFormat, selector, escapeSchemeRef, textNumberFormatRef, textCalendarFormatRef, binaryCalendarFormatRef attributes only 036 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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Re: [DFDL-WG] Missing OccursCountKind
by Tim Kimber 11 Aug '09

11 Aug '09

We already use lengthKind='implicit' to mean 'parse this structure normally, and its length will become apparent'. I think it would be consistent to use occursKind='implicit' to mean 'parse this array normally, and the number of occurrences will become apparent'. Similarly, I think it would be consistent to allow dfdl:initiatedContent ( with the new discriminating behaviour ) on an array, because we allow it on all other points of uncertainty ( or do we? ). regards, Tim Kimber, Common Transformation Team, Hursley, UK Internet: kimbert(a)uk.ibm.com Tel. 01962-816742 Internal tel. 246742 From: dfdl-wg-request(a)ogf.org To: dfdl-wg(a)ogf.org Date: 11/08/2009 18:00 Subject: dfdl-wg Digest, Vol 36, Issue 6 Send dfdl-wg mailing list submissions to dfdl-wg(a)ogf.org To subscribe or unsubscribe via the World Wide Web, visit http://www.ogf.org/mailman/listinfo/dfdl-wg or, via email, send a message with subject or body 'help' to dfdl-wg-request(a)ogf.org You can reach the person managing the list at dfdl-wg-owner(a)ogf.org When replying, please edit your Subject line so it is more specific than "Re: Contents of dfdl-wg digest..." Today's Topics: 1. Missing OccursCountKind (Alan Powell) ---------------------------------------------------------------------- Message: 1 Date: Tue, 11 Aug 2009 16:18:16 +0100 From: Alan Powell <alan_powell(a)uk.ibm.com> Subject: [DFDL-WG] Missing OccursCountKind To: dfdl-wg(a)ogf.org Message-ID: <OFD7E1715D.30B1C83D-ON8025760F.005278A0-8025760F.005410AB(a)uk.ibm.com> Content-Type: text/plain; charset="iso-8859-1" Tim has pointed out that as currently defined it is not possible to define an array where the number of occurrences is determined by the initiator. For example Scalar1: xxxxx Array: xxxx Array: xxxx Scalar2: xxx It is inconsistent that dfdl can identify optional elements using speculative parsing but not a variable number of occurrences. occursCountKind Enum Specifies how the actual number of occurrences is to be established. Valid values ?stopValue?, ?explicit?, 'implicit'? or ?useAvailableSpace? ?explicit? means use the value of the dfdl:occursCount property. ?implicit? means use the value of the maxOccurs on the declaration. It is a schema definition error if the value for minOccurs is not equal to maxOccurs. ?useAvailableSpace? means the occurrences fill the available space which is limited by a containing construct. ?stopValue? means look for a logical stop value which signifies the end of the occurrences. Annotation: dfdl:element Suggestions for new enumeration: 'parsed' , The number of occurrences is determined by parsing until a non-matching element is encountered. change 'implicit' to mean between minOccurs and maxOccurs As an addition should we allow the dfdl:initiatedContent property on arrays if we agree to make it discriminating? initiatedContent Booloean When 'true' indicates that all the children of the sequence are initiated. It is a schema definition error if any children have their dfdl:initiator property set to the empty string. When 'false', the children of the sequence may have their dfdl:initiator property set to the empty string. Annotation: dfdl:sequence, dfdl:choice, dfdl:group 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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Missing OccursCountKind
by Alan Powell 11 Aug '09

11 Aug '09

Tim has pointed out that as currently defined it is not possible to define an array where the number of occurrences is determined by the initiator. For example Scalar1: xxxxx Array: xxxx Array: xxxx Scalar2: xxx It is inconsistent that dfdl can identify optional elements using speculative parsing but not a variable number of occurrences. occursCountKind Enum Specifies how the actual number of occurrences is to be established. Valid values ?stopValue?, ?explicit?, 'implicit'? or ?useAvailableSpace? ?explicit? means use the value of the dfdl:occursCount property. ?implicit? means use the value of the maxOccurs on the declaration. It is a schema definition error if the value for minOccurs is not equal to maxOccurs. ?useAvailableSpace? means the occurrences fill the available space which is limited by a containing construct. ?stopValue? means look for a logical stop value which signifies the end of the occurrences. Annotation: dfdl:element Suggestions for new enumeration: 'parsed' , The number of occurrences is determined by parsing until a non-matching element is encountered. change 'implicit' to mean between minOccurs and maxOccurs As an addition should we allow the dfdl:initiatedContent property on arrays if we agree to make it discriminating? initiatedContent Booloean When 'true' indicates that all the children of the sequence are initiated. It is a schema definition error if any children have their dfdl:initiator property set to the empty string. When 'false', the children of the sequence may have their dfdl:initiator property set to the empty string. Annotation: dfdl:sequence, dfdl:choice, dfdl:group 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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hard case example - delimiter is whatever found after first field
by Mike Beckerle 05 Aug '09

05 Aug '09

We've been worrying about a supposed hard case that I think is not very hard. Consider a DFDL schema that is for a file like this: field1;field2;field3 field1;fie./ld2;fi./eld3 field1.fi/;eld2.fi;/eld3 field1/fi.;eld2/fie;.ld3 field1;fi/.eld2;field./3 Each record contains three fields, all strings. Delimiter is either ".", ";", or "/" depending on what is in the data. The first field can be unambiguously parsed. It ends in one of ".", ";", or "/" and cannot contain any of those 3. The second and third field are separated by whatever was used to terminate the first field. The subsequent fields need to use the actual delimiter that was found after field one because they are allowed to contain the other two delimiters as content, as illustrated in the example above where field2 and field3 are broken up with those characters. To handle this I suggest a schema something like this: <element name="delim" type="string" dfdl:lengthKind="pattern" dfdl:lengthPattern="[\.|\;|\/]"/> <element name="record"> <complexType> <sequence> <element name="f1" type="string" dfdl:lengthKind="pattern" dfdl:lengthPattern="(^[\.|\;|\/])*"/>  <sequence> <annotation><appinfo> <dfdl:hidden ref="delim"/> </appinfo></annotation> </sequence> <sequence dfdl:separator="{ ../delim }" dfdl:terminator="\n"> <element name="f2" type="string" dfdl:lengthKind="delimited"/> <element name="f3" type="string" dfdl:lengthKind="delimited"/> </sequence> </sequence> </complexType> </element> The above record uses a regexp to pick off the first field excluding all possible delimiters. Then a hidden field picks off the actual delimiter that is found. Subsequently there is a sequence, whose separator is specified by referencing the hidden field. This works exactly the way any computed delimiter works. The "delim" field is, in essence, a header field specifying the delimiter. The cost of this in complexity is that that we have to specify the potential set of delimiters in two regular expression patterns. For a case like this I have no problem with this minor complexity. I think this can be made to work for parsing. Some details (properties) are missing of course, but the concept should be clear. For an obscure case like this, I think this is very preferable to yet another keyword in DFDL. For output, I think an output value calc would be needed to figure out the value for the delim field. We would need functions in the expression library to examine the strings in the infoset of field2 and field3 for the possible delimiter characters so that on output we could figure out whether to use ".", ";", or "/" as the delim element's value. I don't know if our proposed function library includes the necessary functions. Do we need to concern ourselves with unparsing/writing out this kind of format for DFDL v1.0, or is parsing enough? ...mike

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Minutes for OGF DFDL Working Group Call, July-29-2009
by Alan Powell 05 Aug '09

05 Aug '09

Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, July-29-2009 Attendees Steve Hanson (IBM) Alan Powell (IBM) Apologies Peter Lambros (IBM) Suman Kalia (IBM) Mike Beckerle (Oco) Actions discussed and updated below. Discussed 1) Properties that can take expressions - identification of all such properties - wording to use when describing them 2) WSP entity - spec does not match WTX equivalent, is this intentional? - if yes then needs WSP+OWSP to handle 'at least one white space char' - if no then don't have an entity for 'any single white space char' 3) Spec says the format 'ref' and selector attributes must be expressed as an attribute since the are not a representation property. - should this be also applicable for properties that are not representation but related to name and reference (QName types): name, baseFormat, selector, escapeSchemeRef, textNumberFormatRef, textCalendarFormatRef, binaryCalendarFormatRef? 4) dfdl:fillByte and what it means when bits are involved - part of the wider bit discussion Next call 5 August 14:00 UK Meeting closed, 14:40 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 026 SH: Envelopes and Payloads 08/04: Not discussed explicity, but recursive use of DFDL is tied up with this 22/04: Two aspects. Firstly compositional - do sufficient mechanisms exist to model an envelope with a payload that varies. Secondly markup syntax - this might be defined in the envelope. The second of these is very much tied up with the variable markup action 028, so will be considered there. SH to verify the composition aspect. 29/04: SH and AP working on proposal. related to Action 028 06/05: No progress 06/05: No progress 20/05: No Progress 27/05: Still a number of aspects to be decided. - Compostion - Does the envelope and payload need to be defined in the same schema or should they be dynamically bound at runtime? - Compostion- How is a variable payload specified. Choice or xs:any; New action raised to discuss xs:any - extracting dymanic syntax from data. Covered by action 029 valuecalc. 03/06: Dynamic runtime binding will not be supported. SH investigating use of variables to enable standalone and use in envelope of global element. 09/06: Payload should be specified using a choice rather than xs:any 17/06: SH still working on example using variables 24/06: SH to document how property list satisfies uses cases. 01/07: SH to document how property list satisfies uses cases. PL looking at variable also. MB suggested modelling first separator as data for use case 3. 15/07: Action 042 on variables now includes examples of enevlopes and payloads. SH will also circulate what he has agreed with WTX team. 29/07: 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) 03/06: No Progress (lower priority) 09/06: No Progress (lower priority) 24/06: No Progress (lower priority) 01/07: No Progress (lower priority) 15/07: No Progress (lower priority) 29/07: no progress (lower priority) 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) 042 MB: Complete variable specification. To include how properties such as encoding can be set externally. Must be a known variable name. 06/05: No progress 20/05: AP to make proposal 27/05: MB proposed differentiating between input and output variables to avoid unnecessary evaluations during parse and unparse. Need to complete rest of variable specification. 03/06: Pointed out problem of declaring variables input or output when used to define syntax which is used both times. MB to update proposal to include how variables are set externally and how specific properties such as encoding are set. 09/06: SKK to use example to dicument his proposal 17/06: SKK to refine proposal. Other aspects need progress. 24/06: SKK proposal discussed but not accepted. PL to document simpler proposal. 07/01: PL working on proposal 15/07: PL has distributed his proposal. SH, MB and SKK have commented. Broad agreement in principle. Need to agree on better name for dfdl:variable to reflect the annotation's purpose. PL to update proposal. 15/07: No Progress (lower priority) 29/07: No Progress 044 13/05: Bidi 20/05: AP: will check what IBM products support. 27/05: Bidi is supported so will be needed in dfdl v1 03/06: No Progress 09/06: No Progress 24/06: No Progress 01/07: AP started investigation and documented issues. Suggest do whatever XML does. 15/07: No further progress 29/07: 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 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. 29/07: No Progress (lower priority) 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 054 ICU DecimalNumber behaviour 15/07: No progress 29/07: No Progress. Closed actions: Work items: No Item target version status 003 Variables (from action 042) 036 awaiting completion of action 042 005 Improvements on property descriptions not started 006 Envelopes and Payloads (from action 026) 036 awaiting completion of actions 026 and 042 007 valueCalc (from action 029) 036 ensure all aspects documented 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) 036 ensure all behaviour documented 036 Update dfdl schema with change properties 038 Improve length section including bit handling not started 042 Mapping of the DFDL infoset to XDM not required for V1 specification 051 Revised scoping rules (from action 051) 036 awaiting completion of action 051 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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Invitation: Invitation: OGF DFDL Working Group weekly call (Aug 12 14:00 GDT in DE2K09) (12 Aug 14:00 GDT in DE2K09)
by Alan Powell/UK/IBM 04 Aug '09

04 Aug '09

Invitation: Invitation: OGF DFDL Working Group weekly call (Aug 12 14:00 GDT in DE2K09) 12/08/2009 14:00 - 15:00 Chair: Alan Powell/UK/IBM@IBMGB Sent By: "Alan Powell/UK/IBM" <alan_powell(a)uk.ibm.com> Location: DE2K09 has invited you to a meeting. Required: mbeckerle(a)oco-inc.com, Steve Hanson/UK/IBM, Suman Kalia/Toronto/IBM@IBMCA Optional: dfdl-wg(a)ogf.org, Tim Kimber/UK/IBM Normal call deleted by mistake by Steve Participant Passcode: 8190865 Country Toll Numbers Freephone/Toll Free Number AUSTRIA 43-1-928-9652 BELGIUM 32-2-400-6791 0800-4-9612 DENMARK 45-7014-0237 FRANCE LYON: 33-4-26-69-12-74 080-511-3725 FRANCE MARSEILLE: 33-4-86-06-00-74 080-511-3725 FRANCE PARIS: 33-1-70-70-81-58 080-511-3725 GERMANY 49-69-2222-20363 0800-100-6504 IRELAND 353-1-247-7768 ITALY 39-02-3600-3648 800-985-679 LUXEMBOURG 352-27-000-1312 NETHERLANDS 31-20-713-2741 0800-020-3237 SPAIN 34-91-414-1542 800-099-667 SWEDEN 46-8-566-10-780 SWITZERLAND 41-44-580-3334 0800-000-516 UNITED KINGDOM BIRMINGHAM: 44-121-210-9014 0800-279-9193 UNITED KINGDOM GLASGOW: 44-141-202-3214 0800-279-9193 UNITED KINGDOM LEEDS: 44-113-301-2114 0800-279-9193 UNITED KINGDOM LONDON: 44-20-7019-0808 0800-279-9193 UNITED KINGDOM MANCHESTER: 44-161-601-1414 0800-279-9193 USA 866-505-4412

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Invitation: OGF DFDL Working Group weekly call (12 Aug 14:00 GDT in DE2K09)
by Alan Powell 03 Aug '09

03 Aug '09

Normal call deleted by mistake by Steve Participant Passcode: 8190865 Country Toll Numbers Freephone/Toll Free Number AUSTRIA 43-1-928-9652 BELGIUM 32-2-400-6791 0800-4-9612 DENMARK 45-7014-0237 FRANCE LYON: 33-4-26-69-12-74 080-511-3725 FRANCE MARSEILLE: 33-4-86-06-00-74 080-511-3725 FRANCE PARIS: 33-1-70-70-81-58 080-511-3725 GERMANY 49-69-2222-20363 0800-100-6504 IRELAND 353-1-247-7768 ITALY 39-02-3600-3648 800-985-679 LUXEMBOURG 352-27-000-1312 NETHERLANDS 31-20-713-2741 0800-020-3237 SPAIN 34-91-414-1542 800-099-667 SWEDEN 46-8-566-10-780 SWITZERLAND 41-44-580-3334 0800-000-516 UNITED KINGDOM BIRMINGHAM: 44-121-210-9014 0800-279-9193 UNITED KINGDOM GLASGOW: 44-141-202-3214 0800-279-9193 UNITED KINGDOM LEEDS: 44-113-301-2114 0800-279-9193 UNITED KINGDOM LONDON: 44-20-7019-0808 0800-279-9193 UNITED KINGDOM MANCHESTER: 44-161-601-1414 0800-279-9193 USA 866-505-4412

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Cancelled: OGF DFDL Working Group weekly call
by Steve Hanson 27 Jul '09

27 Jul '09

holiday

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Cancelled: OGF DFDL Working Group weekly call
by Steve Hanson 22 Jul '09

22 Jul '09

Mike & Alan both on vacation.

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