[DFDL-WG] DFDL Expressions and hex literal constants

[Steve Hanson]

Mike

I think there might be a wider problem in specifying any hex in XPath 
expressions.  Tim's been looking into this as part of an IBM DFDL defect.

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh at uk.ibm.com
tel:+44-1962-815848



From:   Mike Beckerle <mbeckerle.dfdl at gmail.com>
To:     dfdl-wg at ogf.org, 
Date:   13/06/2013 00:24
Subject:        [DFDL-WG] DFDL Expressions and hex literal constants
Sent by:        dfdl-wg-bounces at ogf.org




I haven't found a way in XPath to specify a hexadecimal integer number.

E.g., I want to write expressions like 
{ if (../magicNum eq 0xa1b2c3d4) then 'bigEndian' 
  else if (.../magicNum eq 0xd4c3b2a1) then 'littleEndian'
    else error()
}

But it rejects the 0x notation. Do I really have to write decimal 
everywhere? When dealing with binary data this is a bit of a nightmare.

I think the above code is clear to anyone, but if I convert those numbers 
to decimal it becomes completely obscure. 

...mike

-- 
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | 
www.tresys.com
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