RE: Recommendations for Modular Coding HOWTO

My general observation is that there are a lot of RPG programmers (not
even a majority, just a good number) who don't want to learn anything
new and it doesn't matter one way or the other. For those who are
willing to learn new concepts, it would probably be better to start with
fixed format RPG IV since it's very similar to RPG III.

I know one thing that drives me crazy when learning new concepts are
dumb examples. I really don't need to write another "Hello World"
program but on the other hand, I don't want to start off with an example
of sending a probe to Mars either. I also like it when the examples
build on themselves.

If I were going to teach this, I think I'd do something like the
following:
- Find a straight forward RPG III program (or write one but it has to
actually do something that can be applied in day to day programming)
that uses some common routines
- Demonstrate the CVTRPGSRC command with that program and how little it
does to the source (I know this is easy but you need to show it's easy),
spend a little time going over what this command changed.
- Pick one of the common routines and convert it to a procedure with a
meaningful name
- Move that procedure to a module
- Pick another common routine, convent it to a procedure in another
module, point out how this can get messy with lots of modules compiled
together
- Show a service programs using the two modules demonstrated above and
how it can make life easier
- Show how binding directories can be helpful when multiple service
programs are involved (or when you have a bunch of modules going into a
service program)
- Show how to use DSPPGM to determine what the various objects that make
up a particular program are

I would not introduce free format code in this class unless you want to
leave it as an exercise for the student.

Matt

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Wilt, Charles
Sent: Wednesday, April 26, 2006 7:30 AM
To: RPG programming on the AS400 / iSeries
Subject: RE: Recommendations for Modular Coding HOWTO

Mike,

Good point.  I also started working with RPG after knowing Pascal, C,
C++, and Java.

However, I think the reverse would also be true.  If a monolithic RPG
III programmer learned how to code modules and subprocedures, then
he/she would have an easier time learning a new language like Java or
C++.

The question is which would be easier, learning modern modular
programming in RPG or an entirely new language?

It would seem logical that learning a new technique in a language whose
syntax you basically already know would be easier than learning a new
technique along with a new syntax at the same time.  But perhaps that's
not the case.  Maybe it's easier to learn a new "alien" technique in an
"alien" environment.

Does anyone else have any observations?

Charles Wilt
--
iSeries Systems Administrator / Developer
Mitsubishi Electric Automotive America
ph: 513-573-4343
fax: 513-398-1121
  

> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx 
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Mike Eovino
> Sent: Tuesday, April 25, 2006 8:49 PM
> To: RPG programming on the AS400 / iSeries
> Subject: Re: Recommendations for Modular Coding HOWTO
> 
> Is teaching them a new language (not RPG IV) an option?  I came to RPG
> from VB, and it made ILE concepts (modules, service programs,
> subprocedures) pretty easy to understand.  I've heard other RPG
> programmers say that once they learned a little Java, they could
> equate modules to classes and subprocedures to methods, and then they
> made sense.  They never really saw the benefit of ILE concepts until
> they learned another language that forced them to think that way.
> 
> I realize this may well not be an option, but if you have the time, it
> might be worth it.
> 
> Mike E.
> 
> On 4/25/06, Wilt, Charles <CWilt@xxxxxxxxxxxx> wrote:
> > All,
> >
> > I'm trying to locate some reference materials to help my RPG III
> > programmers get a better picture of how to code in a more modular
> > fashion.
> >
> > Materials with RPG IV examples would be great, but it seems 
> most RPG IV
> > reference material is geared toward syntax instead of application
> > design.
> >
> > Anybody have any favorites or know of training that focuses 
> on the usage
> > of RPG IV instead of the syntax.
> >
> > Thanks,
> >
> > Charles Wilt
> > --
> > iSeries Systems Administrator / Developer
> > Mitsubishi Electric Automotive America
> > ph: 513-573-4343
> > fax: 513-398-1121