Re: ILE RPG:Is the use of ITER & LEAVE Structured Programming?

>Of course, if you haven't seen COBOL's ALTER GOTO, you don't know what you are
>missing. The ALTER GOTO branches to different locations based on the value
>of a
>variable. The more obscure the variable, the higher your Obfuscation Factor.
>
>Of course, COBOL is a much superior language to RPG (<vbg>).
>Ducking before the incoming arrive,
>Bob Larkin



Then there was the ALTER verb on the old IBM/1130:

                ALTER paragraph-name-1 TO PROCEED TO paragraph-name-2
                ...
        PARAGRAPH-NAME-1.
                GOTO    PARAGRAPH-NAME-7.
        PARAGRAPH-NAME-4.
                ...
        PARAGRAPH-NAME-2.
                ...
        PARAGRAPH-NAME-7.
                ...

It was self-modifying code.  The target of the ALTER statement was a
paragraph that contained a single statement:  the GOTO.  Paragraph-name-2
was any other paragraph name in the program.

No matter what the compile listing looked like, the  code could change
itself to branch all over the place!  Quick, efficient (I think it
translated into a direct branch in the executable code), and a bear to
debug!

I only used it in one program (just to prove I could do it).

--Paul E Musselman
PaulMmn@ix.netcom.com


+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---