Re: Why you shouldn't be afraid to use VARCHAR in RPGLE

Vern,
I believe I saw this once already posted, not sure, but if necessary, I
will put it in as an IBM Ideas item.
On the side of IBM, this could be something rather obvious, and probably
not wait to have it submitted, WADR.
JS

El jue, 11 dic 2025 a las 9:04, Vern Hamberg via RPG400-L (<
[email protected]>) escribió:

> Javier
>
> Have you submitted this as an Idea? IBM do listen to us, and I'm very
> impressed about that.
>
> *Regards*
>
> *Vern Hamberg*
>
> IBM Champion 2025 <cid:[email protected]> CAAC
> (COMMON Americas Advisory Council) IBM Influencer 2023
>
>
> On 12/11/2025 8:14 AM, Javier Sanchez wrote:
> > Thanks Barbara.  Nothing better than explanations coming from the
> creators
> > of the compiler.  Of course you guys know what all that means and your
> > contributions will always be appreciated.
> >
> > BTW, I have wondered a lot why you guys have not yet implemented the
> C-like
> > expression as:
> > boolVal = (a = b ? 0: 1);
> > This is not only necessary for modern RPG but it should have been
> provided
> > long time ago! :-)
> > JS
> >
> > El mié, 10 dic 2025 a las 22:04, Barbara Morris (<[email protected]>)
> > escribió:
> >
> >> On 2025-12-10 12:25 p.m., James H. H. Lampert via RPG400-L wrote:
> >>> On 12/10/25 4:06 AM, Infodorado InfoDorado via RPG400-L wrote:
> >>>> The RPG compiler is a single-pass compiler
> >>> No, it can't be pure single-pass. If it were, then a program in which a
> >>> variable is NOT defined in a D-spec, nor in the first C-spec in which
> it
> >>> appears, would not compile, much less run. And it's trivially simple to
> >>> construct an example of this (it took me about 2 minutes), and it
> >>> compiles and runs just fine. I'd quote the source here, but it would
> >>> likely be mangled beyond recognition.
> >>>
> >> It's a single pass through the source but it gathers information that it
> >> can use multiple times.
> >>
> >> The compiler usually allows forward-referencing, so you can code LIKE(x)
> >> where x is defined later.
> >>
> >> But for free-form definitions, the compiler requires the parameter for
> >> the data-type keywords to be defined before the keyword is seen.
> >>
> >>      dcl-s x char(con1);  // bad, con1 not defined yet
> >>      dcl-c con1 5;
> >>      dcl-s y char(con1);  // ok, con1 is defined
> >>
> >> Where it becomes extra fun is when you have a data structure that LOOKS
> >> defined.
> >>
> >>      dcl-ds ds1;
> >>         subf char(10);
> >>      end-ds;
> >>      dcl-s x char(%size(ds1));  // %size(ds1) is not defined. WHAT???
> >>
> >> RPG allows you to define the length of a data structure later, either
> >> due to being on an I spec, possible an externally-described I spec, or
> >> on a C spec.
> >>
> >>        C            MOVE    *blanks       ds1        50
> >>
> >> Almost certainly wrong columns, but you get what I mean. I'm defining
> >> DS1 to have a length of 50 here, not the length of 10 that it looked
> >> like it should have. Shenanigans? Yep, but upward-compatible R Us.
> >>
> >> We have a H-spec/CTL-OPT keyword for that: DLCOPT(*NOCHGDSLEN). With
> >> that keyword, the compiler doesn't allow you to change the length of the
> >> data structure like that, so it's considered defined as soon as all the
> >> subfields are defined.
> >>
> >> --
> >> Barbara
> >>
> >> --
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