[DFDL-WG] Unparsing dfdl:lenghtKind='pattern'
Alan Powell
alan_powell at uk.ibm.com
Thu Jan 14 09:22:40 CST 2010
The Specification currently says that on unparsing
dfdl:lengthKind='pattern' behaves like dfdl:lenghtKind='implict' but since
we limited 'implict' to certain logical/representation combinations this
is no longer correct.
Proposals
1. When unparsing complex elements with dfdl:lengthKind='pattern', the
length is the length of the children (same as 'implicit')
When unparsing simple elements with dfdl:lengthKind='pattern' the length
is the implicit length for those that have one and length of the data
supplied in the infoset converted to the representation with no
padding/filling for the rest.
For string/text and hexbinary/binary that is reasonable
For number/text/standard and zoned it is governed by the numberPattern
For number/binary/ binary use 'implicit' lengths
For number/binary/packed or bcd use minimum number of bytes
For Calendar/text it is governed by the calendarpattern
For Calendar/binary/packed or bcd use minimum number of bytes
For Calendar/binary/binarymilliseconds or binaryseconds use implicit
lengths
For Boolean/text use the length of the true/false rep.
For Boolean/binary use implicit length (32)
2. A new property dfdl:patternOutputLengthKind
3. We could limit dfdl:lenghtKind 'pattern' to complex elements so that
there is always a lengthKind for child simple elements but this would
introduce 'unnecessary' complex items in the infoset when there is only
one child.
Alan Powell
MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM email: alan_powell at uk.ibm.com
Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898
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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.ogf.org/pipermail/dfdl-wg/attachments/20100114/75421eab/attachment.html
More information about the dfdl-wg
mailing list