Re: Benefits of Sub-procedures

[Ken Sims <mr3111@xxxxxxxxx>]

Hi Bob -

> I personally have been using RPGIV and sub-procedures, service programs,
> etc. since '96.  But I am running into an ever increasing number of
> programmers that ask the basic question "Why use a sub-procedure when it
> does the same thing as a program call?"
 <snip>
> p.s. And I have tried arguing easier maintenance - which they will
> always argue that pure ILE RPGIV is harder to maintain because of the
> increased number of objects and source members to keep track of!

Huh????  If they are writing API-type programs to encapsulate functions, 
service programs will REDUCE the number of objects.  One service program 
can perform the functions of many separate API-type programs.

Another major benefit of procedures (even non-exported procedures within 
the same program that calls them) is the use of const and the resulting 
ability to pass expressions as input parameters to the procedure.

And along with that, as you mentioned, the capability to receive a value 
back into an expression.

Then combine that to have an expression involving the output of multiple 
procedures as an input parameter to yet another procedure.  (Whose output 
could be the input to yet another procedure in the same overall expression.)

And how about the ability for a procedure to call itself recursively?  That 
can be nice for chasing chains as long as it doesn't go too deep.

Ken
http://www.ke9nr.net/
Opinions expressed are my own and do not necessarily represent the views of 
my employer or anyone in their right mind.