Hi Steve,
That is a good suggestion.
An important point that I can try to make, in the abstract is that both
cases you outline would have very similar annotations on the logical
model. That part of it would not need to change. The explicit
declarations are additional material that would (typically) be presented
to the compiler in advance.
I don't think its particularly important for us to get hung up on the
declaration of new conversions at this stage. After discussing this with
Mike, I think it makes sense to separate that section off into a new
document, that we could discuss separately.
At the heart of what I think is important in this conversions document
is the semantics for describing the conversions and how they are chosen.
In order for the standard to be comprehensible and comprehensive in its
description of DFDL I think we need to nail down these details. It is,
if you like a useful side effect, that doing so provides the hooks to
allow extensibility, but I think it is important in of itself to have a
clear description of how that all works. In principle we should be able
to hand this standards doc to two developers, lock them in separate
rooms and have them build two DFDL parsers that do the same thing for
all the many complex corner cases and I think we need a framework like
the one I have outlined to get that to work.
That said I think there are a lot of issues with what I laid out, Mike
identified many of them, which need attention and group discussion.
Talk to you tomorrow,
Martin
>-----Original Message-----
>From: owner-dfdl-wg(a)ggf.org [mailto:owner-dfdl-wg@ggf.org] On Behalf Of
>Steve Hanson
>Sent: Tuesday, January 31, 2006 1:41 AM
>To: dfdl-wg(a)ggf.org
>Subject: Re: [dfdl-wg] More documents
>
>I've read the Conversions document and to be honest I had a great deal
of
>trouble trying to work out what was going on. I'd like to see an
example of
>a DFDL schema that models a text stream that contains (say) a complex
type
>with string, integer and decimal children, with DFDL properties used to
>handle the implicit conversions from text to logical data type. Then
I'd
>like to see the same DFDL schema but with equivalent conversions
explicitly
>declared and used instead of the DFDL properties.
>
>Regards, Steve
>
>Steve Hanson
>WebSphere Message Brokers,
>IBM Hursley, England
>Internet: smh(a)uk.ibm.com
>Phone (+44)/(0) 1962-815848
>
>
>
> Mike Beckerle
> <beckerle(a)us.ibm.
> com>
To
> Sent by: Mike Beckerle
<beckerle(a)us.ibm.com>
> owner-dfdl-wg@ggf
cc
> .org dfdl-wg(a)ggf.org,
> owner-dfdl-wg(a)ggf.org,
"Westhead,
> Martin (Martin)"
> 28/01/2006 04:17 <westhead(a)avaya.com>
>
Subject
> Re: [dfdl-wg] More documents
>
>
>
>
>
>
>
>
>
>
>
>Oh yeah, forgot the attachment.
>Mike Beckerle
>STSM, Architect, Scalable Computing
>IBM Software Group
>Information Integration Solutions
>Westborough, MA 01581
>voice and FAX 508-599-7148
>home/mobile office 508-915-4767
>
>
>
>
> Mike
> Beckerle/Worcester/IBM@IBMUS
> Sent by: owner-dfdl-wg(a)ggf.org
>
To
> "Westhead, Martin
(Martin)"
> 01/27/2006 07:50 PM <westhead(a)avaya.com>
>
cc
> dfdl-wg(a)ggf.org,
> owner-dfdl-wg(a)ggf.org
>
Subject
> Re: [dfdl-wg] More
documents
>
>
>
>
>
>
>
>
>
>
>
>
>
>Sorry I missed the call this past week. Here are my comments and some
>in-line editing on the
>
>
>I actually think the primary reason to push this document forward is
NOT
>extensibility, but because it is needed to clarify the basic semantics
of
>DFDL. That is, it allows us to make very clear exactly what properties
in
>the annotations are guiding the selection of which conversion
functions.
>
>...mikeb
>
>Mike Beckerle
>STSM, Architect, Scalable Computing
>IBM Software Group
>Information Integration Solutions
>Westborough, MA 01581
>voice and FAX 508-599-7148
>home/mobile office 508-915-4767
>
>
>
> "Westhead, Martin (Martin)"
> <westhead(a)avaya.com>
> Sent by: owner-dfdl-wg(a)ggf.org
>
To
>
<dfdl-wg@ggf
> 01/23/2006 04:58 PM .org>
>
cc
>
>
Subject
> [dfdl-wg]
> More
> documents
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>These are documents 3 and 4 of a set of 3 :).
>
>The documents are:
>- bundles - a reusable block of DFDL statements
>- Conversions - a proposal for the semantic details as to how
>conversions are chosen during the operation of a DFDL parser. These
>semantics include a description as to how the conversions can be
extended.
>
>These documents round off the current set of proposals from the
>extensibility design team. The team has reasonable consensus on these
>documents, with the (relatively trivial) exception of bundles where
there
>may be some outstanding issues. We believe that with these two
documents
>there is enough material to support the necessary extensibility.
However,
>we have not yet worked through enough examples of round tripping to
>understand whether that is sufficiently well covered and we are
expecting
>that all the ideas in these documents will require refining by the
group as
>a whole.
>
>I would like to discuss these two documents on Wednesday (if possible).
>
>Thanks,
>
>Martin[attachment "DFDL_Conversions_4.doc" deleted by Mike
>Beckerle/Worcester/IBM] [attachment "DFDL_Bundles_2.doc" deleted by
Mike
>Beckerle/Worcester/IBM]
>
>(See attached file: DFDL_Conversions_4.doc)
