Re: Looping over a tagged record?

["Samuel T. Harris" <u61783@gsde.hou.us.ray.com>]

Pascal Obry wrote:
> 
> "M R Goodwin" <mgoodwinSPAMMY@redrocketconsortium.com> writes:
> 
> > Hi!
> >
> > This is a part practical, and a part 'I wonder' type problem.
> > I have a tagged record that is pretty big.  Most, but not all of
> > the elements in it are a bounded string type.  Because I don't feel
> > like the typing and all I would need to do to assign and later change
> > values, I was wondering if there is anyway to loop over all elements in
> > the record, checking their type and then taking the right action...
> 
> And now to answer your question: No there is no way to iterate through record's
> fields.
> 
> Pascal.

I'm missing the original posting so here are my thoughts
bases on this snippet.

Given that Mr. Goodwin know what to do which each field type
and given the every way to get a record object implies the
code knows which record to expect, then I don't see why
Mr. Goodwin needs to "iterate" on each field since the code
will know which fields to expect and should not necessarily
need to query the type of each field.

It seems to me that given the operation in question being
define for scalar types, then one can easily define the
operation for each composite type as one defines them.
In other words, the type declaration should define
how said operation will be perform on the components.

The problem statement appears dubious to me as well.

Now, if Mr. Goodwin is simply trying to avoid lots of
boilerplate typing when applying this operation to 
composite types, especially records type which are
by definition heterogenous, then he can either use
generics such as I use to implement general width/image/value
function for all types OR he can use an ASIS based
tool to find his composite types and "generate" the
operation body specific to the contents of the composite
type.

-- 
Samuel T. Harris, Senior Software Engineer II
Raytheon, Aerospace Engineering Services
"If you can make it, We can fake it!"