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OGF DFDL WG Call Agenda 2012-07-31
by Steve Hanson 30 Jul '12

30 Jul '12

Please find agenda for the above call on GridForge at https://forge.ogf.org/sf/docman/do/downloadDocument/projects.dfdl-wg/docman… Regards Steve Hanson Architect, 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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Repeating groups in DFDL with continuation indicators - action 146
by Steve Hanson 30 Jul '12

30 Jul '12

Here's the proposal for discussion on tomorrow's call. Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 30/07/2012 18:30 ----- From: Steve Hanson/UK/IBM To: "Mike Beckerle" <mbeckerle.dfdl(a)gmail.com> Cc: dfdl-wg(a)ogf.org, "'Ryan Farrell'" <ryan.farrell.ctr(a)nrl.navy.mil> Date: 27/07/2011 09:29 Subject: RE: [DFDL-WG] [wg-all] Repeating groups in DFDL Hi Mike That looks pretty good. A couple of minor changes in bold red (I don't think there's a length() function). Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 From: "Mike Beckerle" <mbeckerle.dfdl(a)gmail.com> To: Steve Hanson/UK/IBM@IBMGB, "'Ryan Farrell'" <ryan.farrell.ctr(a)nrl.navy.mil> Cc: <dfdl-wg(a)ogf.org> Date: 26/07/2011 18:04 Subject: RE: [DFDL-WG] [wg-all] Repeating groups in DFDL From our call today, I suggest this schema, based on the assertion suggestion from steve/tim, and adding in the unparser/output direction calculations, and putting this together to match Ryan’s example schema. I’m not certain on the xpath expressions syntax. I may have number of “..” moves wrong (at least). I added outputValueCalc properties to the flag bits, I added occursCountKind=’parsed’ to the array, and the assertion to the repeatBit element. I put in the check so that a zero length array is possible based on the presentBit as well. <xs:element name="example"> <xs:complexType> <xs:sequence> <xs:element name="presentBit" type="xs:unsignedByte" dfdl:representation="binary" dfdl:alignment="1" dfdl:alignmentUnits="bits" dfdl:byteOrder="bigEndian" dfdl:lengthKind="explicit" dfdl:length="1" dfdl:outputValueCalc='{ if count(../A1) eq 0 then 0 else 1 }'/> <xs:element name="A1" minOccurs="0" maxOccurs="10" dfdl:occursCountKind='parsed'> <xs:complexType> <xs:sequence> <xs:element name="repeatBit" type="xs:unsignedByte" dfdl:representation="binary" dfdl:alignment="1" dfdl:alignmentUnits="bits" dfdl:byteOrder="bigEndian" dfdl:lengthKind="explicit" dfdl:length="1" dfdl:outputValueCalc='{ if exists( ../../A1[position()+1]) then 1 else 0 }'> <xs:annotation><xs:appinfo source="...dfdl url..."> <dfdl:assert>{ if ../../presentBit eq 0 then false else if dfdl:position() eq 1 then true else if ../[dfdl:position()-1]/repeatBit eq 0 then false else true } </dfdl:assert> </xs:appinfo></xs:annotation> </xs:element> <xs:element name="someField" type="xs:unsignedByte" dfdl:representation="binary" dfdl:alignment="1" dfdl:alignmentUnits="bits" dfdl:byteOrder="bigEndian" dfdl:lengthKind="explicit" dfdl:length="2"/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="aFieldAfterA1" type="xs:unsignedByte" dfdl:representation="binary" dfdl:alignment="1" dfdl:alignmentUnits="bits" dfdl:byteOrder="bigEndian" dfdl:lengthKind="explicit" dfdl:length="2"/> </xs:sequence> </xs:complexType> </xs:element> From: Steve Hanson [mailto:smh@uk.ibm.com] Sent: Tuesday, July 26, 2011 6:40 AM To: Mike Beckerle Cc: dfdl-wg(a)ogf.org; 'Ryan Farrell' Subject: Re: [DFDL-WG] [wg-all] Repeating groups in DFDL Yes we need a friendly way of saying 'I am the last item' when using occursCountKind is 'parsed'. But with what we have today, could we use a discriminator on the repeating element that fails when the indicator of the previous repeat was 0 ? So speculation starts to parse the thing after the last repeat on the assumption it is another repeat and then fails and backtracks. <dfdl:assert>{if dfdl:position() eq 1 then true else if './present[dfdl:position()-1]' eq 0 then false else true}</dfdl:assert> Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 From: "Mike Beckerle" <mbeckerle.dfdl(a)gmail.com> To: "'Ryan Farrell'" <ryan.farrell.ctr(a)nrl.navy.mil>, <dfdl-wg(a)ogf.org> Date: 22/07/2011 23:44 Subject: Re: [DFDL-WG] [wg-all] Repeating groups in DFDL Sent by: dfdl-wg-bounces(a)ogf.org Great example Ryan, We've spent quite a bit of time over the last several months on textual formats with these kinds of characteristics, which I would describe as "occurrances determined by parsing" - that is, you look at the data to determine "is there another element or not" one by one as they are parsed. We need to make sure the properties are there to make this work for the binary case as well. I actually believe we cannot handle this format right now. We don't have a property which says to look at the current element to determine whether to expect a subsequent element, as a way of determining occurrence counts. Next week we'll add resolving this example to the workgroup actions list. ...mikeb Mike Beckerle Senior Technology Leader/Manager Deloitte Managed Analytics 100 Fifth Avenue, Waltham, MA 02451 Tel/Direct: +1 781 330 0412 | Fax: +1 866 253 3006 www.deloitte.com -----Original Message----- From: dfdl-wg-bounces(a)ogf.org [mailto:dfdl-wg-bounces@ogf.org] On Behalf Of Ryan Farrell Sent: Tuesday, July 19, 2011 2:12 PM To: dfdl-wg(a)ogf.org Subject: [DFDL-WG] [wg-all] Repeating groups in DFDL For anyone that was at the 19/07 phone meeting, this is what Adam Fox and I were trying to find a solution to. If anyone knows of a solution, please contact me or adam.fox(a)nrl.navy.mil. ---------------------------------------------------------------------------- ------------------------ Please see the attached xml schema while reading this message. The problem we want to solve is how to represent a structure that can have a variable amount of occurences (even zero), and the amount of repeats is controlled by a one bit field, which we will call"repeatBit". The repeating structure in this case is "A1". The element before it, "presentBit", determines if there is at least one occurence of A1. If presentBit is zero, then A1 has zero occurences. If presentBit is one, then A1 has AT LEAST one occurence. The first element in A1 is "repeatBit". What repeatBit does is tells us if there will be another occurence of A1 after the current occurence. When repeatBit is zero, then that means we will read through the rest of A1, then that is the last occurence of A1. As long as repeatBit continues to be one however, we will read through the rest of A1, then start a new occurence. I have included all the known required DFDL notation. Please let me know what is missing. EXAMPLE INPUT (results are in base 10): NOTE: Not all bits are used in these examples. Unused bits should be ignored for the purpose of the examples. 1) 0111 0101 presentBit = 0 aFieldAfterA1 = 3 2) 1011 1010 presentBit = 1 A1 -repeatBit = 0 -someField = 3 aFieldAfterA1 = 2 3) 1101 0110 0000 0000 presentBit = 1 A1 -repeatBit = 1 -someField = 1 A1 -repeatBit = 0 -someField = 3 aFieldAfterA1 = 0 -- 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 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 Minutes 2012-07-25
by Steve Hanson 27 Jul '12

27 Jul '12

Please find minutes from the above call on GridForge at https://forge.ogf.org/sf/docman/do/downloadDocument/projects.dfdl-wg/docman… Errata document is now at v010 here: http://forge.gridforum.org/sf/go/doc16280?nav=1 Regards Steve Hanson Architect, DFDL, IBM SWG Co-Chair, OGF DFDL Working Group Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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OGF DFDL WG Call Agenda 2012-07-25
by Steve Hanson 25 Jul '12

25 Jul '12

Please find agenda for the above call on GridForge at https://forge.ogf.org/sf/docman/do/downloadDocument/projects.dfdl-wg/docman… Regards Steve Hanson Architect, 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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initiatedContent property question
by Mike Beckerle 25 Jul '12

25 Jul '12

The initiatedContent flag seems intended to serve as a discriminator using initiators as string-literal tags. My question: I see no language prohibiting this, but ... can/should one use this in conjunction with an initiator expression (evaluated at runtime from data), or do we restrict and say that initiatedContent="yes" requires a static string literal for the initiator for all the children? ...mikeb -- Mike Beckerle | OGF DFDL WG Co-Chair Tel: 781-330-0412

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Rescheduled: OGF DFDL Working Group weekly call (25 Jul 15:00 GDT in IBM Hursley DE2K09)
by Steve Hanson 20 Jul '12

20 Jul '12

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 GridForge DFDL: http://forge.ogf.org/projects/dfdl-wg/ Moving next call to Wednesday as Steve is on leave on Tuesday

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OGF DFDL WG Call Minutes 2012-07-17
by Steve Hanson 17 Jul '12

17 Jul '12

Please find minutes from the above call on GridForge at https://forge.ogf.org/sf/docman/do/downloadDocument/projects.dfdl-wg/docman… Errata document is now at v010 here: http://forge.gridforum.org/sf/go/doc16280?nav=1 Regards Steve Hanson Architect, DFDL, IBM SWG Co-Chair, OGF DFDL Working Group Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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can an initiator be terminating markup?
by Mike Beckerle 17 Jul '12

17 Jul '12

Did we do a clarification about this? That is, when parsing for delimiters, do you scan for a subsequent fields initiator? I.e., can a subsequent field's initiator behave as terminating markup for a prior field? I somehow think we decide the answer to this is no, but didn't find discussion of it or rationale. -- Mike Beckerle | OGF DFDL WG Co-Chair Tel: 781-330-0412

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OGF DFDL WG Call Agenda 2012-07-17
by Steve Hanson 16 Jul '12

16 Jul '12

Please find agenda for the above call on GridForge at https://forge.ogf.org/sf/docman/do/downloadDocument/projects.dfdl-wg/docman… Regards Steve Hanson Architect, 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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ICU and maximum integer digits
by Steve Hanson 11 Jul '12

11 Jul '12

The ICU web documentation says the following about formatting (unparsing) numbers, which has been copied into the DFDL specification: If the number of actual integer digits exceeds the maximum integer digits, then only the least significant digits are shown. For example, 1997 is formatted as "97" if the maximum integer digits is set to 2. If the number of actual integer digits is less than the minimum integer digits, then leading zeros are added. For example, 1997 is formatted as "01997" if the minimum integer digits is set to 5. If the number of actual fraction digits exceeds the maximum fraction digits, then rounding is performed to the maximum fraction digits. For example, 0.125 is formatted as "0.12" if the maximum fraction digits is 2. This behavior can be changed by specifying a rounding increment and/or a rounding mode. If the number of actual fraction digits is less than the minimum fraction digits, then trailing zeros are added. For example, 0.125 is formatted as "0.1250" if the mimimum fraction digits is set to 4. The latest draft of the spec has incorporated errata 2.29 which now defines the terms maximum integer digits, etc, and does so in terms of the pattern. · The term maximum fraction digits is the total number of ‘0’ and ‘#’ characters in the fraction sub-pattern above. · The term minimum fraction digits is the total number of ‘0’ characters (only) in the fraction sub-pattern above. · The term maximum integer digits is the total number of ‘0’ and ‘#’ characters in the integer sub-pattern above. · The term minimum integer digits is the total number of ‘0’ characters (only) in the integer sub-pattern above. That all looks to make sense, but on close reading the ICU behaviour of maximum integer digits appears to be undesirable, in that it will silently truncate oversize integer portions. From above "For example, 1997 is formatted as "97" if the maximum integer digits is set to 2." Interestingly, while ICU derives minimum integer digits, minimum fraction digits and maximum fraction digits from the pattern, ICU does not derive maximum integer digits from the pattern and instead uses a default of 309. There is an explicit ICU API call that you have to make to set it. Because of this inconsistent ICU behaviour, the IBM DFDL implementation has omitted to use this ICU API today, and so allows up to 309 digits to be formatted regardless of pattern. Eg, "#0" works for infoset values"1", "12", "123456789" without any loss. As well as avoiding the silent truncation, this is convenient for variable length text numbers, as a single textNumberPattern value such as "#0" can be set in scope and widely used, but means variable length text numbers do not have their integer digit length policed (fixed length text numbers are policed by length of element). I think it is worth ratifying that the spec words above are the true intended behaviour, and if so noting that an implementation should a) not set the ICU API, b) let the maximum integer digits default to 309, and c) implement maximum integer digits processing itself. Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848 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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