Re: Cobol Question

[Jim Essinger <esinger@xxxxxxxx>]

Greetings all,

>I was reading some code and I came across this line in the
>Initialization Module of the Procedure Division.
>CALL PROCEDURE 'CHKAPPAUT'
>USING WS-APP.
>I never heard of Call Procedure. What is it?
>Diane

Call (program) is to another executable program (ILE or OPM) - which has
overhead and multiple calls are slow.
Call (procedure) is to a module (ILE only) that is bound at compile or call
time, therefore a faster call.

??Integrated Language Environment?? (ILE) allows you to write more object
like programs (like java or c++) and not pay a heavy price each time you
call a program.  The Old Program Model (OPM) has a high overhead when you
call a program multiple times.  ILE allows you to create a module (mini
program or procedure) that can be bound into the  program at program
creation time or at call time.  Once the module has been called and is part
of the run group,  the rest of the calls to that module are just as fast as
calls to a paragraph within the program.

ILE allows you to be VERY granular when you write a program.  Create a set
of modules that will do all I/O (add new, change, read, update, delete,
etc)  for a file.  Test the heck out of the modules, make the modules into
a service program, then make all other programs use that set of modules to
access the file.  This is the closest we can come to encapsulating the data
in OS/400 Cobol.

Any ILE module can be included in the program run group.  A CALL PROCEDURE
can call an ILE RPG, ILE CL, ILE C, or ILE COBOL module and make it just
about as fast as the PERFORM statement call, but using the strength of each
of the languages.

There is a lot more about ILE to be said, and it is not really that
complex, it just seems like it.


----------------------------------------------------------

Jim Essinger
Senior Programmer/Analyst
Student Loan Fund of Idaho
PO Box 730
Fruitland, ID 83619
208-452-4058
esinger@fmtc.com

------------------------------------------------------------