Re: DOW vs DOU

[cmassoglia@xxxxxxxxxxx (Charlie Massoglia)]

>
>Not wanting to miss a debate,   :-)
>
> I personally would write the following ONLY at gun point.  
>
>Message text written by "Kahn, David"
>>    KEY  SETLLF1234
>     KEY  READEF1234                 90
>     *IN90     DOWEQ*OFF
> (now processing something based on something that happened  BELOW this
>statement)
>     <.... whatever process ....>
 
If you insert the following code inside the loop, the DOW still works.
       KEY2 CHAINFILE2             90 
   
>     KEY  READEF1234                 90
>          ENDDO   >
>
>My father when he was a boy writing RPG,  taught me to write it this way. 
>
>     KEY  SETLLF1234
>     *IN90     DOUEQ*ON
>     KEY  READEF1234                 90
>     *IN90     IFEQ *ON
>                    LEAVE
>                    ENDIF
> (now processing something based on something directly ABOVE this statement)
 
If you insert the following code inside the loop, the DOU fails.
       KEY2 CHAINFILE2             90    

>     <.... whatever process ....>
>     
>          ENDDO
>
Primed read loops are a much better programming technique because the
indicator used on the DOW is always reset immediately prior to the ENDDO.
If you use the DOUEQ/IFEQ technique and someone reuses the indicator, the
loop will fail.


Charlie Massoglia, Massoglia Technical Consulting, Inc.
PO Box 1065, Okemos, MI 48854, USA
517-676-9700  Fax: 517-676-1006  EMAIL: cmassoglia@voyager.net


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