Re: How do you read this code ?

["Charles Wilt" <charles.wilt@xxxxxxxxx>]

Now see, I think they meant to code:

if NOT ( (TTBAST = 'D' and ( TTA9CD = '001'
                                       or TTA9CD = '002'
                                       or TTA9CD = '003'
                                       or TTA9CD = '012'
                                       or TTA9CD = '013'
                                        )

             or ( TTBAST = 'H' and  TTA9CD = ' ')
           )

So not only did they screw up DeMorgan, they screwed up the RPG precedence.


Charles




On Fri, Nov 7, 2008 at 10:44 PM, Barbara Morris <bmorris@xxxxxxxxxx> wrote:

> Joe Pluta wrote:
> > This code is a big, huge, IF 1 = 1.
>
> I bet they meant to code the equivalent of this
>
>     IF NOT
>        (    (TTBAST = 'D' and TTA9CD = '001')
>           or TTA9CD = '002'
>          or TTA9CD = '003'
>          or TTA9CD = '012'
>          or TTA9CD = '013'
>           or (TTBAST = 'H' and  TTA9CD = *blanks)
>        )
>
> but they didn't understand DeMorgan's Law, so they just changed all the
> EQ's to NE's.
>
> I think the best way of coding NOT(complex expression) in fixed form RPG
> is to code it as an IF, and then use the ELSE to get the equivalent of NOT.
>      C     TTBAST        IFEQ      'D'
>      C     TTA9CD        ANDEQ     '001'
>      C     TTA9CD        OREQ      '002'
>      C     TTA9CD        OREQ      '003'
>      C     TTA9CD        OREQ      '012'
>      C     TTA9CD        OREQ      '013'
>      C     TTBAST        OREQ      'H'
>      C     TTA9CD        ANDEQ     '   '
>       * Empty "IF" section.  We want the opposite of this IF
>      C                   ELSE
>       C                   MOVE      TTOFCD               OFCD      2
>       C                   ENDIF
>
> But since that code is so old, I'm sure Joe's replacement is the correct
> one, since that's how it's been working.
>
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