Certainly having dummy empty sequence with leadingSkip before a repeating element having such requirement is another option model developer can use. Let's not handle this property differently and keep the spec the way it is right now.. Suman Kalia IBM Canada Lab WMB Toolkit Architect and Development Lead Tel: 905-413-3923 T/L 313-3923 Email: kalia@ca.ibm.com For info on Message broker http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.ht... From: Steve Hanson <smh@uk.ibm.com> To: Suman Kalia/Toronto/IBM@IBMCA, Cc: dfdl-wg@ogf.org Date: 10/17/2012 04:33 AM Subject: Re: [DFDL-WG] Spec: Leading skip applied to every repeat of a repeating element [s] It is certainly true that the DFDL philosophy is that you wrap a repeating element if you want to specify framing that applies to the array as a whole. Array separator, initiator, terminator, leadingSkip, alignment and trailingSkip are all consistent in this respect, so it does seem wrong to change leadingSkip to behave in a different way. For leadingSkip, there is an alternative to wrapping the repeating element in a sequence, you could instead insert an empty sequence immediately before the repeating element. Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh@uk.ibm.com tel:+44-1962-815848 From: Suman Kalia <kalia@ca.ibm.com> To: Steve Hanson/UK/IBM@IBMGB Cc: dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org Date: 16/10/2012 23:03 Subject: Re: [DFDL-WG] Spec: Leading skip applied to every repeat of a repeating element [s] The DFDL approach will work for COBOL case but it would require wrapping the repeating element having such alignment requirement in a dummy sequence. Not very good from a logical model point of view but certainly will be consistent with other DFDL properties.. Suman Kalia IBM Canada Lab WMB Toolkit Architect and Development Lead Tel: 905-413-3923 T/L 313-3923 Email: kalia@ca.ibm.com For info on Message broker http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.ht... From: Mike Beckerle <mbeckerle.dfdl@gmail.com> To: Steve Hanson/UK/IBM@IBMGB Cc: dfdl-wg@ogf.org Date: 16/10/2012 13:45 Subject: Re: [DFDL-WG] Spec: Leading skip applied to every repeat of a repeating element [s] Sent by: dfdl-wg-bounces@ogf.org I would assume that the skip properties are not array-oriented, as they don't have "occurs" in their name. Hence, they apply to each element instance in the same way as lengthKind and encoding and other non "occurs" properties. ....mike From: Steve Hanson <smh@uk.ibm.com> To: dfdl-wg@ogf.org, Date: 10/16/2012 04:18 AM Subject: [DFDL-WG] Spec: Leading skip applied to every repeat of a repeating element [s] Sent by: dfdl-wg-bounces@ogf.org Need confirmation from the DFDL WG as to the purpose of the leadingSkip property. The grammar says that leadingSkip applies to all occurrences of an array element. Suman has indicated (below) that his intent for the property was to apply to the array as a whole. The DFDL approach for 'array as a whole' properties is to carry them on a wrapper sequence, not the element itself. Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh@uk.ibm.com tel:+44-1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 16/10/2012 09:02 ----- From: Suman Kalia/Toronto/IBM@IBMCA To: Steve Hanson/UK/IBM@IBMGB Cc: Alex Wood1/UK/IBM@IBMGB Date: 15/10/2012 22:58 Subject: Re: [Work Item 9791] Spec: Leading skip applied to every repeat of a repeating element [s] I intended the behavior of leading and trailing skip counts for repeats to be same as in MRM. I can't say for sure if this would break anything in PL/1 as we have not implemented but certainly this behavior is required for COBOL.. We can discuss this in workgroup and if everyone agrees add it to Errata.. Suman Kalia IBM Canada Lab WMB Toolkit Architect and Development Lead Tel: 905-413-3923 T/L 313-3923 Email: kalia@ca.ibm.com For info on Message broker http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.ht... From: Steve Hanson/UK/IBM@IBMGB To: Suman Kalia/Toronto/IBM@IBMCA, Cc: Alex Wood1/UK/IBM@IBMGB Date: 10/15/2012 01:24 PM Subject: Re: [Work Item 9791] Spec: Leading skip applied to every repeat of a repeating element [s] Does that mean in MRM that we have asymmetric behaviour between leadingSkip and trailingSkip ? I'm reading that for MRM leading skip was just for first element, but trailing skip is for every repeat. That's not how the DFDL grammar says things work - it applies leading skip to every repeat. Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh@uk.ibm.com tel:+44-1962-815848 From: Suman Kalia/Toronto/IBM@IBMCA To: Steve Hanson/UK/IBM@IBMGB Date: 15/10/2012 15:18 Subject: Re: [Work Item 9791] Spec: Leading skip applied to every repeat of a repeating element [s] I am travelling and offsite and cannot access the RTC.. Yes trailing skip count get applied to every repeating element.. this is the same semantic we have in MRM.. In COBOL terms , these are slack bytes which are added at the end of the structure if required. Suman Kalia IBM Canada Lab WMB Toolkit Architect and Development Lead Tel: 905-413-3923 T/L 313-3923 Email: kalia@ca.ibm.com For info on Message broker http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.ht... 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@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