There is no explicit control over justification
and trimming for binary data. For a specific type of binary data, it is
what it is. Packed decimals for example are always right-justified.
I don't think interpreting x00x00x0F
as a nil value is a good idea. Typically this is unsigned zero, but it
is a valid number and not an out-of-type value. I can see that one might
want to use xFFFFFFF or x000000 as nil, as these values are often blatted
into storage by (eg COBOL) programs and both are out-of-type (although
you can handle the latter as zero using dfdl:binaryPackedSignCodes property).
The way you handle these as nil is using dfdl:nilLiteralCharacter,
set to "%#rFF" or "%#r00" respectively, which handles
the variable length. There is no way to provide a nil literal value
for a variable length binary element, because no trimming takes place.
Regards
Steve Hanson
IBM Hybrid Integration, Hursley, UK
Architect, IBM
DFDL
Co-Chair, OGF
DFDL Working Group
smh@uk.ibm.com
tel:+44-1962-815848
mob:+44-7717-378890
Note: I work Tuesday to Friday
From:
Mike Beckerle <mbeckerle.dfdl@gmail.com>
To:
Bradd Kadlecik <braddk@us.ibm.com>
Cc:
DFDL-WG <dfdl-wg@ogf.org>
Date:
14/04/2020 23:57
Subject:
[EXTERNAL] Re:
[DFDL-WG] Behavior of nilKind literalValue with respect to binaryNumberRep
of packed
Sent by:
"dfdl-wg"
<dfdl-wg-bounces@ogf.org>
Can you give what the bytes look like for typical values
of various sizes small and large, how their length is determined,
and what a nil value looks like in bytes?
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Owl Cyber
Defense | www.owlcyberdefense.com
Please note: Contributions to the DFDL Workgroup's email
discussions are subject to the OGF
Intellectual Property Policy
On Tue, Apr 14, 2020 at 4:54 PM Bradd Kadlecik <braddk@us.ibm.com>
wrote:
Yes that works for fixed length but not variable length
which is possible for packed decimal with bigEndian.
Regards,
Bradd Kadlecik
z/TPF Development |
|
Phone:
1-845-433-1573
E-mail: braddk@us.ibm.com
|
2455 South Rd
Poughkeepsie, NY 12601-5400
United States |
Mike
Beckerle ---04/14/2020 03:56:45 PM---Not sure I understand the mixture
of the concepts of justification and packed decimal here.
From: Mike Beckerle <mbeckerle.dfdl@gmail.com>
To: Bradd Kadlecik <braddk@us.ibm.com>,
DFDL-WG <dfdl-wg@ogf.org>
Date: 04/14/2020 03:56 PM
Subject: [EXTERNAL] Re: [DFDL-WG] Behavior of nilKind
literalValue with respect to binaryNumberRep of packed
Not sure I understand the mixture of the concepts of justification and
packed decimal here.
I usually think of packed decimal as fixed length and without padding.
Let me assume this example: 12345C is value 12345, 00000C is zero, and
00000F is the nil indicator.
So, bigEndian byte order, I think dfdl:nilvalue="%#r00;%#r00;%#r0F;"
is what I'd expect to see for a literalValue nilValue to match that.
I'm guessing some assumption in the above doesn't match your use case,
so please correct.
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Owl Cyber Defense | www.owlcyberdefense.com
Please note: Contributions to the DFDL Workgroup's email discussions are
subject to the OGF
Intellectual Property Policy
On Tue, Apr 14, 2020 at 2:59 PM Bradd Kadlecik <braddk@us.ibm.com>
wrote:
I think there is a problem when the literalValue is left-justified
for binary data such as packed decimals. This seems problematic because
a "0" value might be indicated by having the last byte be 0x0C
for a signed numeric while a nil value might be desired to be understood
by having the last byte be a 0x0F. In both cases, all preceding bytes are
0x00. In the case that the packed decimal is of variable length, there
seems no way to represent this nil value unless it is understood that the
fillByte is used for the area preceding the NilElementLiteralContent. Apologies
if I might of missed some clarification made regarding this.
Regards,
Bradd Kadlecik
z/TPF Development |
|
Phone:
1-845-433-1573
E-mail: braddk@us.ibm.com
|
2455 South Rd
Poughkeepsie, NY 12601-5400
United States |
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