Re: IsNegative

[Gary Guthrie <GaryGuthrie@xxxxxxxx>]

Doug,

One use for IsNegative might be when a function returns 1 of several
possible return codes, where a negative number indicates an error
condition.

Though, I'd probably prefer to see a figurative constant *NEGATIVE of
type indicator so that in a D-spec you could have some field, say Error
initialized to *NEGATIVE. Then in C-specs you could code

   If   Error

after a procedure call. Then you could cycle through the individual
negative return codes if necessary. Obviously, this can be handled in a
number of ways, but to me, this is the clearest way.

Gary Guthrie



Douglas Handy wrote:
> 
> 
> OK, at least we know now where you were coming from.  I agree that in
> some cases having a function named IsXxxx() which returns a true/false
> indication can increase readability.  That's why you'll find things
> like IsNumeric() or IsNull() in VB.
> 
> Personally, I'm not sure IsNegative() has as much merit, but it sure
> wouldn't bother me in code either.  Just add something like the
> following to your program.  It will accept any numeric variable of any
> size up to 30 digits and 9 decimals; packed, zoned, binary, integer,
> etc.  I'm not positive about floating point, but I think it is OK too.
> 
>      D IsNegative      PR             1
>      D  Value                        30P 9 Const
> 
>      C                   If        IsNegative( My_Numeric_Var)
>      C                   ....
>      C                   Endif
> 
>      P IsNegative      B
>      D IsNegative      PI             1
>      D  Value                        30P 9 Const
>      C                   Return    ( Value < 0 )
>      P IsNegative      E
> 
> Personally, I'd put the IsNegative() function in a service program
> with other similar functions.
> 
> That's the beauty of user-defined procedures.  You don't have to
> petition Hans & Company to add this kind of stuff to RPG.  Just do it
> yourself!  And it works even on V3R2.  Now.
> 
> Doug
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