Re: FOR loop limit

["M. Lazarus" <mlazarus@xxxxxxxx>]

Vern,

 The ironic thing is that the S/36 (and the 
36EE) RPGII compiler handled this without 
generating an error.  I don't recall if the target value rolled over to 0.

 -mark


At 1/30/09 08:39 AM, you wrote:
> Has anyone brought up the DO loop with start value and limit value?
> Seems the issue of too small an index variable has been with us for some
> time.
>
> Try this code in ILE RPG -
>
> *C     *1             DO        9             X                  1 0
> *C                   DSPLY     X
> C**      **             **ENDDO
>
> *
>
> *Compile with TRUNCATE(*YES) and you get an infinite loop - with
> TRUNCATE(*NO) you get the overflow error. (***CMA************
> disclaimer********** - ********
> *I may have the parameter name wrong - hope y'all understand the intent)*
> **
> This was the earliest from of a FOR kind of loop that I'm aware of in my
> time on the system. Others have more history than I.
>
> So IBM have never checked this kind of thing, it seems.
>
> David, if you want to do something about it, submit a PMR (problem
> report or software service request) - see if IBM say it is by design or
> not - you will get a better answer from the people that make the
> compiler than from us, who are just guessing. Or submit a design change
> request (DCR).
>
> Regards
> Vern
>
> David FOXWELL wrote:
> > Why don't we start at 0 like in other languages?
> >
> > Eg,
> >
> > For (int i=0 ; numberloops-1 ; i++)
> > Index= i + 1;
> >
> >
> > EndFor
> >
> > What is the value of Index when the loop ends?
> >
> >
> >
> >
> >
> > -----Message d'origine-----
> > De : rpg400-l-bounces@xxxxxxxxxxxx 
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] De la part de Rory Hewitt
> > Envoyé : jeudi 29 janvier 2009 18:44
> > À : RPG programming on the IBM i / System i
> > Objet : Re: FOR loop limit
> >
> > Jeff,
> >
> > It's always been a pain like this. I assume 
> there's some backwards-compatibility issue that made it work like this:
> >
> > for x = 1 to 3;
> >   ...do something
> > endfor;
> >
> > After the loop, x is 4, *not* 3.
> >
> > If you step through in debug, you can see how 
> it stops on the endfor after the 3rd time and 
> then stops again on the endfor before moving 
> on. It's documented in the RPG manual, but 
> still it seems screwy to me. Couldn't they have 
> added processing to not increment the counter 
> after the last one (or to decrement it back again)?
> >
> > Rory
> >
> > On Thu, Jan 29, 2009 at 9:32 AM, Jeff Crosby 
> <jlcrosby@xxxxxxxxxxxxxxxx>wrote:
> >
> >
> >> I learned something new today.
> >>
> >> Take the following program:
> >>
> >>     D x               S              3P 0
> >>     D y               S              3P 0
> >>
> >>      /free
> >>
> >>       *INLR = *On;
> >>       Y = 999;
> >>
> >>       For X = 1 To Y By 1;
> >>       EndFor;
> >>
> >>       Return;
> >>
> >>      /end-free
> >>
> >>
> >> The program bombs with the dreaded "Message . . . . :   The target for a
> >> numeric operation is too small to hold the result (C G D F)."
> >>
> >> I guess when the endfor is reached the last time through, it attempts
> >> to set the value of x to 1,000.
> >>
> >> Live and learn.
> >>
> > --
> > This is the RPG programming on the IBM i / 
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> >
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