James

It's a balance. One of the design goals for DFDL was to keep the simple cases simple.  So forcing all users to understand and specify a host of properties that only exist to handle esoteric use cases when they have a straightforward use case is counter to that.  For example, in many years of modeling data I have only encountered one format where the encoding for an element value was different to the encoding of its initiator, and until your case below I had not encountered a use case where the case sensitivity of an element's initiator and terminator were different. Such cases clearly exist, but are not common place. Hence why the WG adopted the design it did, with encoding related properties on a per object basis.  

Another example is that DFDL has a single separator property, and not a separator for sequences and a separator for arrays. This often forces you to wrap an array element in a sequence in order to carry the separator, but it reduces the overall number of properties, behaviours and interactions that need to be understood.

For common use cases, we have allowed extra properties. For example, there are separate justification and padCharacter properties for each simple type category, because it is very common to have a mix of such types in data and the justification and pad for different types is invariably different for each type.

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848



From:        "Garriss Jr., James P." <jgarriss@mitre.org>
To:        "dfdl-wg@ogf.org" <dfdl-wg@ogf.org>,
Date:        20/06/2013 12:50
Subject:        Re: [DFDL-WG] how to do mix of case sensitive        and        insensitive        delimiters
Sent by:        dfdl-wg-bounces@ogf.org



So which is worse, Steve, a bunch of extra properties in GeneralPurposeFormat, or making your schema designers resort to workarounds like this:
 
        <xs:sequence dfdl:separator="" dfdl:terminator="end" dfdl:ignoreCase="no">
                <xs:element name="weird" type="xs:string" dfdl:initiator="start" dfdl:ignoreCase="yes" dfdl:lengthKind="delimited"/>
        </xs:sequence>
 
Or this:
 
- wrap the element in a group
- set dfdl:ignoreCase to 'no' on the group.
- set dfdl:ignoreCase to 'yes' on the element.
- put the terminator on the group and the initiator on the element.
 
Do you really want your schema designers to have to do things like this?   It seems to me that a good design principle is to make life simpler for your users, not harder.
 
 
From: Steve Hanson [mailto:smh@uk.ibm.com]
Sent: Thursday, June 20, 2013 7:33 AM
To: Garriss Jr., James P.
Cc: dfdl-wg@ogf.org; dfdl-wg-bounces@ogf.org; Tim Kimber
Subject: Re: [DFDL-WG] how to do mix of case sensitive and insensitive delimiters
 
If we adopt that approach we end up with an explosion of properties. It's not just ignoreCase. There's encoding and its related properties too. We decided that encoding related properties applied per object, not per delimiter.

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848



From:        "Garriss Jr., James P." <jgarriss@mitre.org>
To:        Tim Kimber/UK/IBM@IBMGB, "dfdl-wg@ogf.org" <dfdl-wg@ogf.org>,
Date:        20/06/2013 12:21
Subject:        Re: [DFDL-WG] how to do mix of case sensitive and        insensitive        delimiters
Sent by:        dfdl-wg-bounces@ogf.org




All the various solutions proposed seem so convoluted.  Why not do the simple and obvious?  Something like:
 
dfdl:ignoreInitiatorCase=”yes”  dfdl:ignoreTerminatorCase=”no” dfdl:ignoreSeparatorCase=”no”  dfdl:ignoreElementCase=”yes”
 
From: dfdl-wg-bounces@ogf.org [mailto:dfdl-wg-bounces@ogf.org] On Behalf Of Tim Kimber
Sent: Thursday, June 20, 2013 5:34 AM
To: dfdl-wg@ogf.org
Subject: Re: [DFDL-WG] how to do mix of case sensitive and insensitive delimiters
 
The other way to do this is
- wrap the element in a group
- set dfdl:ignoreCase to 'no' on the group.
- set dfdl:ignoreCase to 'yes' on the element.
- put the terminator on the group and the initiator on the element.

Or the other way round if it works better that way.

regards,

Tim Kimber, DFDL Team,
Hursley, UK
Internet:  kimbert@uk.ibm.com
Tel. 01962-816742  
Internal tel. 37246742




From:        Mike Beckerle <mbeckerle.dfdl@gmail.com>
To:        dfdl-wg@ogf.org,
Date:        19/06/2013 23:42
Subject:        [DFDL-WG] how to do mix of case sensitive and insensitive delimiters
Sent by:        dfdl-wg-bounces@ogf.org






I have a wierd case where the initiator wants to be case insensitive matching, but the terminator wants to be case sensitive.

The only way I can think of dealing with this is to use the initiator, but handle the length via lengthKind='pattern' to grab the value, doing lookahead so it will stop before the terminator.
Then an empty sequence with a case sensitive terminator to pick off that part of the data stream.

--
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com
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Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU