Fw: [dfdl-wg] Transform examples

[Steve Hanson]

Here's a candidate list of words.

- Transform
- Map
- Converter
- Conversion
- Translation
- Render
- Representation
- Formatter
- Cast

We could also consider prefixing a word with 'Physical', eg,
'PhysicalRender'

Regards, Steve


----- Forwarded by Steve Hanson/UK/IBM on 24/11/2004 11:08 -----
                                                                           
             Martin Westhead                                               
             <martinwesthead at y                                             
             ahoo.co.uk>                                                To 
             Sent by:                  "Chappell, Alan R"                  
             owner-dfdl-wg at ggf         <chappella at BATTELLE.ORG>,           
             .org                      dfdl-wg at gridforum.org               
                                                                        cc 
                                                                           
             22/11/2004 17:31                                      Subject 
                                       Re: [dfdl-wg] Transform examples    
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Hi Alan,

Thanks for this. Some thoughts/questions/comments that occurred to me
looking at your example.

First a general point:

  - On one of the calls which I think was just me and the IBMers they
pointed out quite strongly that the ther "transformation" has other
connotations that make it very confusing here, Mike also agrees. I think
we need to choose a different name to avoid such confusion. Mike
suggested "converters"/"convertions" which is suitably general. I also
thought about "casting" but I think that's perhaps too specific. Either
way it would be nice to choose something or our discussions will be
rather difficult to follow.

(I'll continue to use transform for this email...)

On the example:
  - I was expecting the definition of the input and output types to the
transform should have equal status. Here it seems that the input is
specified implicitly in the parameter set it will accept.

  - Why does asciiToInt read byte[]? I would expect it to read at least
char[] (or probably xs:string, since there is no xs:char). The intent
would be that you could then compose it with a character converter of
your choice.

  - In general I think the typing and compositional properties of the
transformations are the nut that requires cracking here. My proposal is
that the types should be specified in XML data model at all levels so
instead of byte[] you would have:

<xs:sequence>
   <xs:element name="anon" type="xs:byte" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>

that's all for now...

Cheers,

Martin








Chappell, Alan R wrote:
> Third try... No zip, just the 3 files important to the simple transform
> example....
>
> ------------------------------------------------------------------------
> *From:* Chappell, Alan R
> *Sent:* Friday, November 19, 2004 1:39 PM
> *To:* dfdl-wg at gridforum.org
> *Subject:* *MJ-REJECTED* Transform examples
>
> Second try on sending these examples. I've cut the set down to the 3
> important files so hopefully it will get through this time.
>
> ------------------------------------------------------------------------
>  *From:* Chappell, Alan R
> *Sent:* Thursday, November 18, 2004 8:47 AM
> *To:* dfdl-wg at gridforum.org
> *Subject:* *MJ-REJECTED* Transform examples
>
> Here is the example I mentioned yesterday. Look particularly at
> dfdltransforms.xsd, BasicAsciiIntExp.xsd, and BasicBinIntExp.xsd. Note
> the "Exp" on those last two files indicate that they are expansions of
> the information in the original versions of those files. These make a
> first stab at giving a fully verbose description of the structure and
> the transforms, i.e., it’s working towards the canonical representation
> Martin talked about yesterday. The "dfdltransforms" gives the
> definitions of transforms and their components.
>
> There are lots of things that can be improved here.
> <<dfdl-examples.zip>>
> Alan R. Chappell
> chappella at battelle.org
>
> Pacific Northwest National Laboratory
> Battelle Seattle Research Center
> (206) 528-3228
>
>