Re: ILE Questions

[boldt@xxxxxxxxxx]

Rajeev wrote:
>Please pardon me if these sound too trivial but they
>have really puzzled me.
>
>1. Can a RPGLE program call another RPGLE program
>through the use of CALLP? They both run in the
>different Activation Group.

Yes.  In fact, CALLP is the preferred approach.

>2. What's difference between CALLB and CALLP? Can they
>be used in place of one another?

CALLB is used for "bound calls".  CALLP can be used
for both dynamic and bound calls.  Again, forget
about CALLB.  CALLP is the preferred approach.

>3. Are ExtPgm and ExtProc used for "just" the renaming
>purpose or there is some other very useful features
>associated with them?

EXTPGM and EXTPROC are keywords used on prototype
definitions.  When using EXTPGM, the procedure is
called dynamically.  Using EXTPROC gives you a
bound call.

>4. Why can't I have "Value" parameters for main
>procedure? Any logic behind that?

Value parameters are not supported for main procedures
since there is always the possibility that they might
be called using a dynamic call.  Value parameters are
supported only for bound calls.

>5. And lastly(scoped to this mail only) why there is
>no F-Spec in Subprocedures?

To make the implementation of procedures easier.
It would have taken a heck of a lot of work to add
that kind of functionality to the language.

>
>Thanks a lot for bearing with me.

Cheers!  Hans

Hans Boldt, ILE RPG Development, IBM Toronto Lab, boldt@ca.ibm.com


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