[DFDL-WG] Action 174: Making DFDL implementations easier

[Mike Beckerle]

I would also like to suggest that utf16Width='variable' should be optional.

On Wed, May 23, 2012 at 1:25 PM, Steve Hanson <smh at uk.ibm.com> wrote:

> Agreed on list, just need to answer questions 1) and 3) below.
>
> Regards
>
> Steve Hanson
> Architect, Data Format Description Language (DFDL)
> Co-Chair, *OGF DFDL Working Group* <http://www.ogf.org/dfdl/>
> IBM SWG, Hursley, UK*
> **smh at uk.ibm.com* <smh at uk.ibm.com>
> tel:+44-1962-815848
> ----- Forwarded by Steve Hanson/UK/IBM on 23/05/2012 18:21 -----
>
> From:        Steve Hanson/UK/IBM
> To:        dfdl-wg at ogf.org
> Date:        15/05/2012 09:55
> Subject:        Making DFDL implementations easier
> ------------------------------
>
>
> Please see below for a proposal to make an additional set of DFDL features
> optional.  The goal is to make it considerably easier to create a minimal
> conforming DFDL processor for binary data.
>
> Regards
>
> Steve Hanson
> Architect, Data Format Description Language (DFDL)
> Co-Chair, *OGF DFDL Working Group* <http://www.ogf.org/dfdl/>
> IBM SWG, Hursley, UK*
> **smh at uk.ibm.com* <smh at uk.ibm.com>
> tel:+44-1962-815848
> ----- Forwarded by Steve Hanson/UK/IBM on 11/05/2012 12:50 -----
>
>  *Feature* *Detection*  Text representation for types other than String dfdl:representation="text"
> for Number, Calendar or Boolean types  Delimiters dfdl:separator <> "" or
> dfdl:initiator <> "" or dfdl:terminator <> "" or dfdl:lengthKind="delimited"  BCD
> calendars dfdl:binaryCalendarRep="bcd"    Multiple schemas xs:include or
> xs:import in xsd  Named Formats dfdl:defineFormat or dfdl:ref  Choices xs:choice
> in xsd **  Arrays where size not known in advance dfdl:occursCountKind
> 'implicit', 'parsed', 'stopValue' **  Advanced expressions Advanced
> features of the DFDL expression language (tbd)
> *** Including one of these features mean that speculative parsing is
> needed.*
>
> Remaining questions:
>
> 1) What about lengthKind 'endOfParent' ?
> 2) Is leaving out choices too restrictive?
> 3) Expression language subset
>
> The result is that a minimal conformant DFDL implementation just needs to
> support the following annotations and properties, and does not need
> speculative parsing.
>
> dfdl:element
> dfdl:sequence
> dfdl:format
>
> byteOrder
> encoding
> utf16width
> alignment
> alignmentUnits (bytes)
> fillByte
> leadingSkip
> trailingSkip
> lengthKind (explicit, implicit)
> length
> lengthUnits (bytes, characters)
> representation (binary)
> textPadKind
> textTrimKind
> textStringJustification
> textStringPadCharacter
> truncateSpecifiedLengthString
> decimalSigned
> binaryNumberRep
> binaryVirtualDecimalPoint
> binaryFloatRep (ieee)
> binaryBooleanTrueRep
> binaryBooleanFalseRep
> binaryCalendarRep (binarySeconds, binaryMilliseconds)
> binaryCalendarEpoch
> sequenceKind (ordered)
> occursCountKind (fixed, expression)
> occursCount
>
> Regards
>
> Steve Hanson
> Architect, Data Format Description Language (DFDL)
> Co-Chair, *OGF DFDL Working Group* <http://www.ogf.org/dfdl/>
> IBM SWG, Hursley, UK*
> **smh at uk.ibm.com* <smh at uk.ibm.com>
> tel:*+44-1962-815848* <%2B44-1962-815848>
>
>
> 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
>
> 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 at ogf.org
>  https://www.ogf.org/mailman/listinfo/dfdl-wg
>



-- 
Mike Beckerle | OGF DFDL WG Co-Chair
Tel:  781-330-0412
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