Re: Additional RPGLE Enhancement Requests

["Hans Boldt" <hboldt@xxxxxxxxxxxx>]

Charlie Massoglia, Massoglia Technical Consulting, Inc.
> Thanks for your interest Hans!

Well, it won't be too long before we have to start thinking seriously
about the next release!


> >
> >For example, to take your example above (which I believe overlays
> >externally described fields consecutively over some subfield), this
> >could be achieved by something like the following enhancement:
> >
> >    D  Combined         30A
> >    D   Field1                 OVERLAY(Combined:1)
> >    D   Field2                 OVERLAY(Combined:*NEXT)
> >    D   Field3                 OVERLAY(Combined:*NEXT)
> >
> *NEXT is even better and accomplishes the goal, eliminating database
> dependencies.  Of course, the length of the field combined is still
> hardcoded.  What happens when the combined lengths of Field1, Field2, and
> Field3 change to something other than 30.  We still have to manually change
> the length of the field combined.  That still remains an unnecessary
> database dependency.
>
> Please do not misunderstand, if *NEXT is easy to do, please do it even if we
> still have to hardcode the length of Combined.  You can tackle that problem
> later.
>
> RPG IV should NEVER require you to code a database dependency.

> >So, unless we have more compelling reasons for full expressions in
> >D-Specs, it will probably have to wait a while.
> >
> >BTW, we also want to relax the rule that requires OVERLAY to overlay
> >a subfield.  We are thinking at least of allowing a subfield to overlay
> >the data structure name.
> >
> Please! Please! Please!  (John Carr will also like this one.)
> >

The reason I mentioned the idea of relaxed OVERLAY rules is that the
combination of relaxed OVERLAY rules and OVERLAY(x:*NEXT) should go a
long way in avoiding database dependencies.  Consider the following
data structure:

   D  Combined     DS
   D   Field1                 OVERLAY(Combined:1)
   D   Field2                 OVERLAY(Combined:*NEXT)
   D   Field3                 OVERLAY(Combined:*NEXT)

The data structure name COMBINED is implicitly defined with a length
that is the sum of the subfield lengths!

I just had another wild and crazy idea:  How about if we implicitly
define overlayed subfields with the appropriate length to contain all
overlaying subfields?  (I'm not sure if I can convince the rest of my
team on this one, though!)


> What about multi-dimensional arrays?

This one's been on the back burner for years now, as you know.
Considering the amount of work required, we've always considered other
items to be more "bang for the buck".  Who knows when this will filter
up the priority list!


Cheers!  Hans

Hans Boldt, ILE RPG Development, IBM Toronto Lab, hboldt@vnet.ibm.com


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