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

This works in RPG... doesn't this do what you are asking for?
Where iResult is an indicator.
iResult will be either on or off based on whether x = y.

iresult = ( x = y);      

(Although it won’t set 'x' = to 'y'). 





-----Original Message-----
From: RPG400-L <[email protected]> On Behalf Of Infodorado InfoDorado via RPG400-L
Sent: Thursday, December 11, 2025 4:54 PM
To: RPG programming on IBM i <[email protected]>; Javier Sanchez <[email protected]>
Cc: Infodorado InfoDorado <[email protected]>
Subject: Re: Why you shouldn't be afraid to use VARCHAR in RPGLE

About that: "boolVal = (a = b ? 0: 1);"

Could that be implemented by "boolVal = (a = b)"? 
Am I missing something in the C-like syntax? It's been a long time since I looked at C. 

--Alan Cassidy


> On 12/11/2025 9:14 AM EST Javier Sanchez <[email protected]> wrote:
> 
> 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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