Re: Question about prototyping

["Charles Wilt" <charles.wilt@xxxxxxxxx>]

I didn't even think about "private" procedures.....

If the procedure is "private" and thus only used within the module,
then I leave the prototype in the module as well.

It doesn't make sense to me to put the prototype in a copy book when
the procedure can't be used by anybody else.

Most of my private procedures exist to provide modularity with defined
interfaces to the code.  Not for reusability.

Charles

On Mon, Dec 22, 2008 at 9:59 AM, Adam Glauser <adamglauser@xxxxxxxxx> wrote:
> Yes.  If you are familiar with Java or other OO languages, this is like
> a "private" method.  You essentially get a subroutine that can avoid
> using global variables and has a well defined interface.  One benefit is
> that if you later realize that this is something that could be used in
> multiple programs after all, it is a lot easier to move it to a service
> program than if it was originally written as a subroutine.
>
> The fact that procedures can be (and should be, where possible) written
> so they have no side effects leads to IMO the biggest benefit of
> procedures over subroutines.  Maintenance is a lot simpler if you can
> just look at the CALLP line and determine whether the variables you are
> interested in are used or changed by the procedure.  With subroutines,
> you have look at the subroutine code and determine which variables are
> updated and which key lists are used before you can confidently change
> any of the code surrounding the EXSR.
>
> Also, just to be clear, it would be the prototype in the copybook, not
> the procedure.  Your instinct is right however.  If the code is reusable
> within a single program, there is a good chance it can be reused in
> other programs as well.
>
> HTH,
> Adam