RE: Can an RPG module call another RPG module?

[Ken Sims <mr2087@xxxxxxxxx>]

Hi Don -

> Well, I've learned something new today.  I was always told RPG did not
> support recursion.  Of course, I've never had a need for it, or at least,
> never thought of a need.
RPG III does not support recursion.  ILE supports recursion.  I'm not sure
if ILE RPG program calls allow recursion, but procedure call definitely do.

Just this morning I wrote a program with a procedure which calls itself
recursively to walk a tree of records (like a bill-of-materials but not
actually that).  Since the operating system makes sure that there are
separate copies of the local variables, all I have to do is reposition the
file back to where it needs to be after returning from a callp.  This saves
needing to have a MODS or arrays to save data.

The only limitation is that procedures calls are limited in depth.  It was
255.  It could have been raised in the newer releases.  With the data I'm
working with, the depth should never be more than about three, so I'm not
checking for the limit.  If I hit the recursion limit I want the program to
crash.

If you need a greater depth than whatever the recursion limit is, you would
need to fall back to the old methods.

Ken
Opinions expressed are my own and do not necessarily represent the views of
my employer or anyone in their right mind.