Hi everybody,
I tried a simple Factorial function and the two pgms can be found below.
I think a recursive function should not be access outside memory areas,
anyway every parm passed by reference can be accessed.
So, in my opinion, having different sources can be a good solution.
It's not a "masterpiece" :D even though it seems to run properly.
As you can see I used both BY REFERENCE and BY CONTENT parms to enforce a
kinf of program isolation.
Hope this helps.
Best regards.
Massimo
Main program.
IDENTIFICATION DIVISION.
PROGRAM-ID. "ZPFATMAI".
AUTHOR. TOTI.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 PGMNAME PIC X(08) VALUE 'ZPFATTOR'.
01 RISULTATO PIC 9(15) VALUE 0.
LINKAGE SECTION.
01 PARM-AREA.
05 PARM-LENGTH PIC S9(04) COMP.
05 NUMERO PIC 9(03).
05 FILLER PIC X(200).
PROCEDURE DIVISION USING PARM-AREA.
DISPLAY 'INIZIO PROGRAMMA - ZPFATMAI'.
CALL PGMNAME USING
BY REFERENCE RISULTATO
BY CONTENT NUMERO.
DISPLAY 'NUMERO=' NUMERO ' FATTORIALE=' RISULTATO.
FINE.
GOBACK.
Recursive routine.
IDENTIFICATION DIVISION.
PROGRAM-ID. "ZPFATTOR" RECURSIVE.
AUTHOR. TOTI.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 PGMNAME PIC X(08) VALUE 'ZPFATTOR'.
01 NUMERO-1 PIC 9(03).
LINKAGE SECTION.
01 RISULTATO PIC 9(15).
01 NUMERO PIC 9(03).
PROCEDURE DIVISION USING RISULTATO NUMERO.
DISPLAY 'INIZIO PROGRAMMA - ZPFATTOR'.
DISPLAY 'RISULTATO IN INPUT=' RISULTATO.
DISPLAY 'NUMERO IN INPUT=' NUMERO.
IF NUMERO > 1 THEN
COMPUTE NUMERO-1 = NUMERO - 1
CALL PGMNAME USING
BY REFERENCE RISULTATO
BY CONTENT NUMERO-1
COMPUTE RISULTATO = RISULTATO * NUMERO
ELSE
MOVE 1 TO RISULTATO
END-IF.
DISPLAY 'RISULTATO IN OUTPUT=' RISULTATO.
FINE.
2013/7/30 John McKown <[email protected]>
> Given our change control procedures, it would likely not be _allowed_ to
> have multiple COBOL programs in a single source member. But I'm not sure of
> that. This is a way to have RECURSIVE calls, but now we are getting very
> complicated because I'm certain that the programmer will want each separate
> program to have equal access to the WORKING-STORAGE of the "main" routine.
> Which means having all, or most, of the WORKING-STORAGE in a COPY book with
> the EXTERNAL attribute on all the 01 and 77 levels.
>
> And I just had another thought because this might be a CICS program, the
> programmer didn't say. In which case all of this is very moot.
>
>
> On Tue, Jul 30, 2013 at 9:31 AM, John Gilmore <[email protected]> wrote:
>
> > Peter Farley's point, which I took as a given, is correct. Such
> > programs need to be compiled independently, although they can of
> > course be batched together with others using process statements.
> >
> > John Gilmore, Ashland, MA 01721 - USA
> >
> > ----------------------------------------------------------------------
> > For IBM-MAIN subscribe / signoff / archive access instructions,
> > send email to [email protected] with the message: INFO IBM-MAIN
> >
>
>
>
> --
> This is a test of the Emergency Broadcast System. If this had been an
> actual emergency, do you really think we'd stick around to tell you?
>
> Maranatha! <><
> John McKown
>
> ----------------------------------------------------------------------
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> send email to [email protected] with the message: INFO IBM-MAIN
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