Re: CAT bug in ILE RPG

>>Has anyone else run across bugs with the CAT operation code in RPG IV?
>>Using CAT in some situations gives us unpredictable results, such as
fields
>>being concatenated in the wrong order.  (However, if instead we use EVAL
>>and the plus sign on these same fields to concatenate them, the program
>>works fine!)
>>
>> field1  CAT  field2:0   resultfld
>>          CAT  field3:0   resultfld
>>             .
>>             .
>>             .
>>          CAT  field9:0   resultfld
>>
>>The above does not work!!
>>
>>But the following does work (we use %trimr because all 9 fields have
>>trailing blanks):
>>
>>         EVAL     resultfld=%trimr(field1)+%trimr(field2)+ ...
>>+%trimr(field9)
>>
>Each of the nine fields that I am concatenating is a 4-byte character
>string containing zero, one, or two numeric characters left-justified,
>and then padded on the right with blanks.  The result field is a
>16-character blank field.
>(It just so happens that the 3rd and 9th fields are always blanks.)
>In this example, in the interest of simplication, I have represented the
>numeric contents of the 9 fields with uppercase alphabetic characters,
>and represented the blanks with lowercase "b"s.
>
>Abbb  CDbb   bbbb   EFbb   GHbb   JKbb   LMbb   NPbb   bbbb
>
>Per this example, the result field will always contain the following:
>
>ACDbbGHJKLMNPEFG

I asked around here yesterday to see if any of
my colleagues was aware of any problem with CAT,
but no-one knew of any.  But today, Barbara came
back to me with a possible problem.  What release
are you running?  Could you clarify exactly how
the fields are declared?  Do any of the fields
overlap in any way with field RESULTFLD?  Are
some fields declared local to a procedure and
other declared global?  Are any fields defined
as varying length?

BTW, you may be better off anyways using the +
operator in an EVAL since it performs much better
than a sequence of CATs.

Cheers!  Hans

Hans Boldt, ILE RPG Development, IBM Toronto Lab, boldt@ca.ibm.com
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