I would also like to suggest that utf16Width='variable' should be optional.
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
IBM SWG, Hursley, UK
smh@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@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
IBM SWG, Hursley, UK
smh@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
IBM SWG, Hursley, UK
smh@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
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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