Action 286 closed.
286
Create table that compares Daffodil features to IBM DFDL features (Steve/Mike)
16/2: Take table from section 22 of DFDL 1.0 spec and add columns showing implementations.
1/3: No progress
10/5: No progress. Work on this for next call.
...
7/6: No further progress
5/7: Steve has added column for IBM DFDL and emailed to WG. Mike will add column for Daffodil.
2/8: Closed. Mike has added column and discussion for Daffodil and emailed to WG. Steve to convert to an experience document and add to Redmine @ https://redmine.ogf.org/dmsf_files/13539?download=. Document can be updated as required.


Regards
 
Steve Hanson
IBM Integration Bus, Hursley, UK
Architect, IBM DFDL
Co-Chair, OGF DFDL Working Group
smh@uk.ibm.com
tel:+44-1962-815848
mob:+44-7717-378890



From:        Mike Beckerle <mbeckerle.dfdl@gmail.com>
To:        Steve Hanson/UK/IBM@IBMGB
Cc:        DFDL-WG <dfdl-wg@ogf.org>
Date:        19/07/2016 20:13
Subject:        Re: [DFDL-WG] Action 286 - Daffodil v IBM DFDL feature comparison




Table with Daffodil column added, and additional details below.
Feature Detection IBM DFDL Daffodil v2.0
Validation External switch Yes partial. Parsing only.
Named Formats dfdl:defineFormat or dfdl:ref Yes Yes
Choices xs:choice in xsd Yes Partial - choiceDispatchKey and choiceBranchKey not supported.
Arrays where size not known in advance dfdl:occursCountKind 'implicit', 'parsed', 'stopValue' Partial - not 'stopValue' Partial – not ‘stopValue’
Expressions Use of a DFDL expression in any property value Yes Yes. Limitation - query-style expressions not supported. These are expressions which require iteration over children of an element rather than constant-time access.  For example fn:count(/a/b) where element 'a' has multiple element 'b' children separated by other element declarations. Hence, gathering all the b children requires iterating.
End of parent dfdl:lengthKind "endOfParent" No No
Simple type restrictions xs:simpleType in xsd Partial - not unions Partial – not unions
Text representation for types other than String dfdl:representation "text" for Number, Calendar or Boolean types Yes Partial – type Boolean not implemented
Delimiters dfdl:separator <> "" or dfdl:initiator <> "" or dfdl:terminator <> "" or dfdl:lengthKind "delimited" Yes Yes
Nils XSDL nillable 'true' in xsd Yes Partial - nilKind 'logicalValue' not supported
Defaults XSDL default or fixed in xsd Partial - unparsing only Partial
Simple types - ?? (Some support in parsing and in unparsing)
Complex types – No
Bi-Directional text. dfdl:textBiDi 'yes' No No
Lengths in Bits dfdl:alignmentUnits 'bits' or dfdl:lengthUnits 'bits' Yes Yes
Delimited lengths and representation binary element dfdl:representation 'binary' (or implied binary) and dfdl:lengthKind 'delimited' Yes Partial – delimiters must not use character class entities like %NL or %WSP*.
Regular expressions dfdl:lengthKind 'pattern',
dfdl:assert with dfdl:testkind 'pattern' ,
dfdl:discriminator with dfdl:testkind 'pattern' 		Partial - only for dfdl:lengthKind Yes
Zoned numbers dfdl:textNumberRep 'zoned' Yes No
IBM 390 packed numbers dfdl:binaryNumberRep 'packed'   Yes No
IBM 390 packed calendars dfdl:binaryCalendarRep 'packed' No No
IBM 390 floats dfdl:binaryFloatRep 'ibm390Hex' Yes No
Unordered sequences dfdl:sequenceKind 'unordered' Yes No
Floating elements dfdl:floating 'yes' No No
dfdl functions in expression language dfdl:functions in expression No Yes
Hidden groups dfdl:hiddenGroupRef <> '' No Yes
Calculated values dfdl:inputValueCalc <> '' or dfdl:outputValueCalc <> '' No Yes
Escape schemes dfd:defineEscapeScheme in xsd Yes Yes
Extended encodings Any dfdl:encoding value beyond the core list Yes Partial - iso-8859-1 works. Others - TBD.
Asserts dfdl:assert in xsd Partial - not on global elements or simple types Yes
Discriminators dfdl:discriminator in xsd Partial - not on global elements or simple types Yes
Prefixed lengths dfdl:lengthKind 'prefixed' Partial - not nested prefixed lengths No
Variables dfdl:defineVariable,
dfdl:newVariableInstances,
dfdl:setVariable
Variables in DFDL expression language
Note that variables as a feature is dependent on the Expressions feature. 		Partial - not newVariableinstance or external variables Partial – not newVariableInstance
BCD calendars dfdl:binaryCalendarRep "bcd"   Yes No
BCD numbers dfdl:binaryNumberRep "bcd" Yes No
Multiple schemas xs:include or xs:import in xsd Yes Yes
IBM 4690 packed numbers dfdl:binaryNumberRep "ibm4690Packed" Yes No
IBM 4690 packed calendars dfdl:binaryCalendarRep "ibm4690Packed" Yes No
DFDL Byte Value Entities Use of %#r syntax in a DFDL String Literal other than the dfdl:fillByte property Yes No
DFDL Standard Character Set Encodings dfdl:encoding name begins with "X-DFDL-". No Partial: X-DFDL-US-ASCII-7-BIT-PACKED, but not the 6-bit variant.
Bit Order - Least Significant Bit First dfdl:bitOrder with value 'leastSignificantBitFirst' No Yes



There is a list of implementation specific things not implemented for Daffodil also. The list needs updating, but includes at least:

* xs:boolean - not supported
* dfdl:ignoreCase - not supported
* binary form for xs:date, xs:time, and xs:dateTime are not supported.
* dfdl:utf16Width='variable' not supported
* extended ICU symbols 'u' and 'I' in calendarPattern - not supported
* dfdl:textStandardBase - not supported (behaves as 10)

W.r.t, the additional you listed for IBM: Daffodil has fn:count(), fn:exactlyOne(), but not the other 3. Daffodil does not yet support BOMs No known limitation here - I would be curious as to a test that illustrates this limitation so we could try it on Daffodil Daffodil supports prefixed QNames in path steps. However, Daffodil's interpretation of NCNames in path steps does NOT currently take any default namespace into account. This makes Daffodil incompatible with IBM DFDL, which does not allow QNames, and so depends on those names being made meaningful by way of default namespace. Making Daffodil compatible with IBM's behavior here is Daffodil JIRA ticket https://opensource.ncsa.illinois.edu/jira/browse/DFDL-1446 Daffodil supports this property value.


Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com
Please note: Contributions to the DFDL Workgroup's email discussions are subject to the OGF Intellectual Property Policy


On Mon, Jul 4, 2016 at 11:49 AM, Steve Hanson <smh@uk.ibm.com> wrote:
286
Create table that compares Daffodil features to IBM DFDL features (Steve/Mike)
16/2: Take table from section 22 of DFDL 1.0 spec and add columns showing implementations.
1/3: No progress
10/5: No progress. Work on this for next call.
...
7/6: No further progress
5/7:

To kick this off here is the optional features table from spec section 21 with a column added for IBM DFDL

Feature Detection IBM DFDL
Validation External switch Yes
Named Formats dfdl:defineFormat or dfdl:ref Yes
Choices xs:choice in xsd Yes
Arrays where size not known in advance dfdl:occursCountKind 'implicit', 'parsed', 'stopValue' Partial - not 'stopValue'
Expressions Use of a DFDL expression in any property value Yes
End of parent dfdl:lengthKind "endOfParent" No
Simple type restrictions xs:simpleType in xsd Partial - not unions
Text representation for types other than String dfdl:representation "text" for Number, Calendar or Boolean types Yes
Delimiters dfdl:separator <> "" or dfdl:initiator <> "" or dfdl:terminator <> "" or dfdl:lengthKind "delimited" Yes
Nils XSDL nillable 'true' in xsd Yes
Defaults XSDL default or fixed in xsd Partial - unparsing only
Bi-Directional text. dfdl:textBiDi 'yes' No
Lengths in Bits dfdl:alignmentUnits 'bits' or dfdl:lengthUnits 'bits' Yes
Delimited lengths and representation binary element dfdl:representation 'binary' (or implied binary) and dfdl:lengthKind 'delimited' Yes
Regular expressions dfdl:lengthKind 'pattern',
dfdl:assert with dfdl:testkind 'pattern' ,
dfdl:discriminator with dfdl:testkind 'pattern' 		Partial - only for dfdl:lengthKind
Zoned numbers dfdl:textNumberRep 'zoned' Yes
IBM 390 packed numbers dfdl:binaryNumberRep 'packed'   Yes
IBM 390 packed calendars dfdl:binaryCalendarRep 'packed' No
IBM 390 floats dfdl:binaryFloatRep 'ibm390Hex' Yes
Unordered sequences dfdl:sequenceKind 'unordered' Yes
Floating elements dfdl:floating 'yes' No
dfdl functions in expression language dfdl:functions in expression No
Hidden groups dfdl:hiddenGroupRef <> '' No
Calculated values dfdl:inputValueCalc <> '' or dfdl:outputValueCalc <> '' No
Escape schemes dfd:defineEscapeScheme in xsd Yes
Extended encodings Any dfdl:encoding value beyond the core list Yes
Asserts dfdl:assert in xsd Partial - not on global elements or simple types
Discriminators dfdl:discriminator in xsd Partial - not on global elements or simple types
Prefixed lengths dfdl:lengthKind 'prefixed' Partial - not nested prefixed lengths
Variables dfdl:defineVariable,
dfdl:newVariableInstances,
dfdl:setVariable
Variables in DFDL expression language
Note that variables as a feature is dependent on the Expressions feature. 		Partial - not newVariableinstance or external variables
BCD calendars dfdl:binaryCalendarRep "bcd"   Yes
BCD numbers dfdl:binaryNumberRep "bcd" Yes
Multiple schemas xs:include or xs:import in xsd Yes
IBM 4690 packed numbers dfdl:binaryNumberRep "ibm4690Packed" Yes
IBM 4690 packed calendars dfdl:binaryCalendarRep "ibm4690Packed" Yes
DFDL Byte Value Entities Use of %#r syntax in a DFDL String Literal other than the dfdl:fillByte property Yes
DFDL Standard Character Set Encodings dfdl:encoding name begins with "X-DFDL-". No
Bit Order - Least Significant Bit First dfdl:bitOrder with value 'leastSignificantBitFirst' No




Some IBM DFDL restrictions are not captured in the table, mainly due to non-implementation of many of the later errata. Full details here https://www.ibm.com/support/knowledgecenter/SSMKHH_10.0.0/com.ibm.etools.mft.doc/df00150_.htm but the key omissions are:



Regards
 
Steve Hanson
IBM Integration Bus, Hursley, UK
Architect, IBM DFDL
Co-Chair, OGF DFDL Working Group
smh@uk.ibm.com
tel:+44-1962-815848
mob:+44-7717-378890
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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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