Alan Powell
MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM email: alan_powell@uk.ibm.com
Tel: +44 (0)1962 815073
Fax: +44 (0)1962 816898
----- Forwarded by Alan
Powell/UK/IBM on 23/01/2008 17:18 -----
| Alan Powell/UK/IBM
23/01/2008 12:08
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| DFDL
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Subject
| OGF DFDL WG call today 23-01-2008 -
agenda |
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Review items from previous calls.
- OGF22
- Specification drafts
- Expression language
- Property precedence
- UML for DFDL schema
Discussion for this call
- Review entity proposal
- Steve's suggestions
1) This is related to the
white space discussion around entities. One way to handle the situation
where the terminator can vary is to allow the DFDL markup properties (dfdl:terminator,
dfdl:separator, etc) to be lists, just like we already do for dfdl:nullValues.
(IBM's WTX has this capability).
2) We've allowed the prefix of a prefixed length to be explicitly described
as a non-event field using dfdl:lengthPrefixType. Should we permit this
for markup properties? Instead of supplying a list of possible values,
you supply a simple type with enums for the values. This could be viewed
as an alternative/complementary to 1). There is a limitations - because
we are using XSDL enumeration facet, we are constrained by its syntax so
I don't see how we could use our own entity scheme or expressions. Also,
I suspect that enums are inherently unordered so we'd need a way of saying
which to use on output (use an element of simple type and use XSDL default
attribute?). Lastly, we should not force a user to model an initiator
as an element/type - most users just see it as a piece of text so just
entering the value must still be allowed.
3) Let's say my delimiter is dynamically defined at the start of the data,
like EDI allows. We would handle that in DFDL using an expression or variable.
However, EDI also allows random white space to appear after the delimiter.
Can our expression/entity syntaxes handle this? Does this preclude
use of 1) or 2)?
Alan Powell
MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM email: alan_powell@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
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