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clarification on choice unparsing and empty sequences
by Mike Beckerle 11 Aug '15

11 Aug '15

The spec language around how choice branches are resolved when unparsing suggests that each branch must have an element in it somewhere. On unparsing there is the question of how one identifies the appropriate schema choice branch corresponding to the data in the infoset. This is complicated by the fact that the children may not be elements. They may themselves be sequences or choices.The selection of the choice branch is as follows: The element in the infoset is used to search the choice branches in the schema, in schema definition order, but without looking inside any complex elements. If the element occurs in a branch, then that branch is selected and if subsequently a processing error occurs, this selection is not revisited (that is, there is no backtracking). To avoid any unintended behavior, all the children of a choice can be modeled as elements. However, that passage of the spec seems incomplete now to me. Though at the time it was written and reviewed it seemed to be the solution to the issue. It does imply that each model group in a choice branch has to have an element somewhere, but I couldn't find that statement explicitly in the spec, and the spec does say empty model groups are specifically allowed. 14.1 Empty Sequences A sequence having no children is syntactically legal in DFDL. In the data stream, such a sequence can have non-zero length *LeftFraming* and *RightFraming* regions, but the SequenceContent region in between must be empty. It is a processing error if the SequenceContent region of an empty sequence has non-zero length when parsing. This leaves open the issue of hidden groups e.g., <sequence dfdl:hiddenGroupRef="mygroup"/> is an empty sequence? Or does the hidden group count as if there really are children of this sequence? I suspect the latter, but need to see how others have interpreted this. XML schema does not define an empty sequence that is the content model of a complex type definition as effective content so any DFDL annotations on such a construct would be ignored. It is a schema definition error if the empty sequence is the content model of a complex type, or if a complex type has nothing in its content model at all. That makes clear that both these are SDE: <complexType><sequence/></complexType> <complexType></complexType> But it leaves many scenarios unclear still. Consider this schema fragment: .... <choice> <sequence dfdl:terminator=";"/> <element name="foo"/> </choice> <element name="bar"/> .... If we are unparsing and the infoset is just <bar> then we can compute that finding <bar> in the infoset means the first branch is selected. So we would unparse that and output a ";". However, if there is true ambiguity like: <choice> <sequence dfdl:terminator=";"/> <sequence dfdl:terminator="/"/> <element name="foo"/> </choice> <element name="bar"/> That's effectively saying on parse either a ";" or a "/" may be found. On unparse, there is nothing to guide which choice branch other than telling us if <bar> is found, that the <foo> element branch is NOT selected. However, it is ok to just output the first always (;) if the infoset has a <bar> element. However, I wanted to check and see what others interpretation of the spec is for this issue. Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com Please note: Contributions to the DFDL Workgroup's email discussions are subject to the OGF Intellectual Property Policy <http://www.ogf.org/About/abt_policies.php>

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Re: [DFDL-WG] OGF DFDL WG Call Agenda 2015-08-11 - agenda item on ICU 'S' symbol
by Steve Hanson 11 Aug '15

11 Aug '15

Hi Andy Your internal ticket #630 gave rise to external ticket http://bugs.icu-project.org/trac/ticket/10962, which claims to have fixed the API docs to clarify the behaviour. S fractional second - truncates (like other time fields) to the count of letters when formatting. Appends zeros if more than 3 letters specified. Truncates at three significant digits when parsing. S SS SSS SSSS 2 23 235 2350 I can't see anywhere that addresses your point about about abutting versus non-abutting numeric symbols though? As far as DFDL spec is concerned, this is what we say today: S fractional second (see note 1) Number S SS SSS 2 24 235 There is no 'note 1', I think the note was made into a normal paragraph, which reads: Any number of fractional seconds "S" may by specified in the pattern and accepted by implementations, but an implementation is free to represent a limited number of fractional seconds internally. Excess fractional seconds are truncated, not rounded up. At least millisecond accuracy must be implemented. Unlike other fields, fractional seconds are padded on the right with zero. Regards Steve Hanson Architect, IBM DFDL Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 From: Andrew Edwards/UK/IBM To: Steve Hanson/UK/IBM@IBMGB Date: 11/08/2015 11:56 Subject: Re: [DFDL-WG] OGF DFDL WG Call Agenda 2015-08-11 Hi Steve Re agenda item 2 and calendar patterns with 'S', this ICU ticket from last year might be relevant - https://icu.sanjose.ibm.com/gcoctrac/ticket/630. It seems that the error reporting may also depend on whether the pattern has 'S' on it's own or next to other numeric pattern entities. i.e. 'HHmmssS' is subject to length checking, but 'HHmmss S' is not, due to the space before the 'S'. HTH, Andy Andy Edwards - IBM Integration Bus - DFDL Email: andy.edwards(a)uk.ibm.com Snail Mail: MP211, Hursley park, Hursley, WINCHESTER, Hants, SO21 2JN Tel int: 247222 Tel ext: +44 (0)1962 817222 Desk: DE3 V17 The Feynman problem solving Algorithm 1) Write down the problem 2) Think real hard 3) Write down the answer -- Murray Gell-mann in the NY Times From: Steve Hanson/UK/IBM@IBMGB To: dfdl-wg(a)ogf.org Cc: Mike Beckerle <mbeckerle(a)tresys.com>, jorge.marizan(a)gmail.com Date: 10/08/2015 18:29 Subject: [DFDL-WG] OGF DFDL WG Call Agenda 2015-08-11 Sent by: dfdl-wg-bounces(a)ogf.org Please find agenda for call on Redmine at https://redmine.ogf.org/dmsf_files/13489?download= Regards Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 -- dfdl-wg mailing list dfdl-wg(a)ogf.org https://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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OGF DFDL WG Call Agenda 2015-08-11
by Steve Hanson 10 Aug '15

10 Aug '15

Please find agenda for call on Redmine at https://redmine.ogf.org/dmsf_files/13489?download= Regards Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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Confirmed: DFDL Working Group Call (11 Aug 16:00 GDT in IBM Hursley DE3S09)
by Steve Hanson 10 Aug '15

10 Aug '15

Confirmed: DFDL Working Group Call 11/08/2015 - (Repeats) Location: IBM Hursley DE3S09 Steve Hanson has confirmed this meeting Repeats This entry repeats Required: mbeckerle(a)tresys.com, mbeckerle.dfdl(a)gmail.com Optional: Alex Wood1/UK/IBM@IBMGB, Andrew Edwards/UK/IBM@IBMGB, dfdl-wg(a)ogf.org, jorge.marizan(a)gmail.com, Mark Frost/UK/IBM FYI: OGF DFDL WG weekly call dial-in details. Passcode for Participants: 5381214 Canada Toll-Free 888-426-6840 China Toll-Free 10-800-711-1071 CHINA NETCOM GROUP USERS China Toll-Free 10-800-110-0996 CHINA TELECOM SOUTH USERS France Toll-Free 0800-94-0558 Germany Toll-Free 0800-000-1018 India Toll-Free 000-800-100-1176 Ireland Toll-Free 1-800-943-427 Israel Toll-Free 1-809-417-783 United Kingdom Caller Paid 0-20-30596451 United Kingdom Toll-Free 0800-368-0638 USA Caller Paid 215-861-6239 USA Toll-Free 888-426-6840 Other international numbers available - e-mail smh(a)uk.ibm.com. OGF DFDL Home: http://www.ogf.org/dfdl Redmine DFDL: http://redmine.ogf.org/projects/dfdl-wg DFDL Getting Started: http://www.ibm.com/developerworks/library/se-dfdl/ DFDL 1.0 Spec: http://www.ogf.org/documents/GFD.207.pdf

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OGF DFDL WG Call 2015-07-21 - cancelled
by Steve Hanson 21 Jul '15

21 Jul '15

Sorry for late cancellation, but something has come up which means I am no longer available. Next meeting is August 11th. Regards Steve Hanson Architect, IBM DFDL Co-Chair, OGF DFDL Working Group Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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Cancelled: DFDL Working Group Call
by Steve Hanson 21 Jul '15

21 Jul '15

Sorry for late cancellation but something has come up which means I am no longer available.

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Confirmed: DFDL Working Group Call (21 Jul 16:00 GDT in IBM Hursley DE3S09)
by Steve Hanson 20 Jul '15

20 Jul '15

OGF DFDL WG weekly call dial-in details. Passcode for Participants: 5381214 Canada Toll-Free 888-426-6840 China Toll-Free 10-800-711-1071 CHINA NETCOM GROUP USERS China Toll-Free 10-800-110-0996 CHINA TELECOM SOUTH USERS France Toll-Free 0800-94-0558 Germany Toll-Free 0800-000-1018 India Toll-Free 000-800-100-1176 Ireland Toll-Free 1-800-943-427 Israel Toll-Free 1-809-417-783 United Kingdom Caller Paid 0-20-30596451 United Kingdom Toll-Free 0800-368-0638 USA Caller Paid 215-861-6239 USA Toll-Free 888-426-6840 Other international numbers available - e-mail smh(a)uk.ibm.com. OGF DFDL Home: http://www.ogf.org/dfdl Redmine DFDL: http://redmine.ogf.org/projects/dfdl-wg DFDL Getting Started: http://www.ibm.com/developerworks/library/se-dfdl/ DFDL 1.0 Spec: http://www.ogf.org/documents/GFD.207.pdf Confirming call. Agenda to follow.

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OGF DFDL WG Call Minutes 2015-06-23
by Steve Hanson 23 Jun '15

23 Jun '15

Please find minutes from the above call at https://redmine.ogf.org/dmsf_files/13440?download= Next call is 21st July. Regards Steve Hanson Architect, IBM DFDL, Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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Rescheduled: DFDL Working Group Call (21 Jul 16:00 GDT in IBM Hursley DE3S09)
by Steve Hanson 23 Jun '15

23 Jun '15

Rescheduled: DFDL Working Group Call 21/07/2015 - (Repeats) Location: IBM Hursley DE3S09 Steve Hanson has rescheduled this meeting. You have not yet responded. Repeats This entry repeats Required: mbeckerle(a)tresys.com, mbeckerle.dfdl(a)gmail.com Optional: Alex Wood1/UK/IBM@IBMGB, Andrew Edwards/UK/IBM@IBMGB, dfdl-wg(a)ogf.org, jorge.marizan(a)gmail.com, Mark Frost/UK/IBM FYI: OGF DFDL WG weekly call dial-in details. Passcode for Participants: 5381214 Canada Toll-Free 888-426-6840 China Toll-Free 10-800-711-1071 CHINA NETCOM GROUP USERS China Toll-Free 10-800-110-0996 CHINA TELECOM SOUTH USERS France Toll-Free 0800-94-0558 Germany Toll-Free 0800-000-1018 India Toll-Free 000-800-100-1176 Ireland Toll-Free 1-800-943-427 Israel Toll-Free 1-809-417-783 United Kingdom Caller Paid 0-20-30596451 United Kingdom Toll-Free 0800-368-0638 USA Caller Paid 215-861-6239 USA Toll-Free 888-426-6840 Other international numbers available - e-mail smh(a)uk.ibm.com. OGF DFDL Home: http://www.ogf.org/dfdl Redmine DFDL: http://redmine.ogf.org/projects/dfdl-wg DFDL Getting Started: http://www.ibm.com/developerworks/library/se-dfdl/ DFDL 1.0 Spec: http://www.ogf.org/documents/GFD.207.pdf

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Cancelled: DFDL Working Group Call
by Steve Hanson 23 Jun '15

23 Jun '15

Cancelled: DFDL Working Group Call 30/06/2015 - (Repeats) Location: IBM Hursley DE3S09 Steve Hanson has cancelled this meeting. Your calendar will be updated to reflect this change. Repeats This entry repeats Required: mbeckerle(a)tresys.com, mbeckerle.dfdl(a)gmail.com Optional: Alex Wood1/UK/IBM@IBMGB, Andrew Edwards/UK/IBM@IBMGB, dfdl-wg(a)ogf.org, jorge.marizan(a)gmail.com, Mark Frost/UK/IBM FYI:

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