Re: Indicators

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hi Tim,

> As such, if I want to do something when a condition IS VALID, I end having
> to use a double-negative, such as "Not Prt#Invld".
> For readability I would much rather use "Prt#Valid", but my output screen
> indicators would then have to be a series of 'N##'s.

One simple solution is to simply avoid the use of "negatives" in your
variable names.  In other words, never have an "invalid" variable, only a
"valid" variable.  For example:

     if ( Not Part#Valid );
         // do whatever you planned to do
     endif;

Another way to deal with it is to take the "valid" or "invalid" out of the
name altogether.  Remember, the purpose of variables is to store something
that can be changed...  the part of this particular variable that can be
changed is whether or not the part number is valid. :)   So, either
putting "valid" or "invalid" in the name doesn't make sense, that's the
part that changes.

Instead, make names for the VALUES of the variable, and use a more generic
name for the variable itself.  For example:

     D INVALID         c                   '0'
     D VALID           c                   '1'

     D Part#Status     s              1N   inz(VALID)

      /free

           chain (Part#) PARTMASTER;
           if %found();
              Part#Status = VALID;
           else;
              Part#Status = INVALID;
           endif;

      ... and later ...

           if ( Part#Status = INVALID );
           endif;

        ... or ...

           if ( Part#Status = VALID );
           endif;

      /end-free

Personally, I don't like your idea of having separate "Part#Valid" and
"Part#Invalid" variables and then having to figure out how to keep them in
sync all the time.  I don't think that's as intuitive.

That's just my opinion, of course.