Re: Evaluate complex conditions

[stewart@xxxxxxxxxxx]

You can write a generalised routine to evaluate logical
expressions in any HLL.
The key to brackets is to call the parser recursively
which you can't do with RPG. However you can fake it by
using exsr and an array as a 'stack'.
Can provide an example if it would be useful.

Another mostly ignored technique is a truth table.
The RPG indicators can be set with the input logical values,
then do a movea into a char variable of required size,
and seek for matches in your truth table. This is only
useful if the logic is known beforehand, but is not a 
nightmare to maintain if you document it sensibly.


At 09:18 23/10/2000 -0500, you wrote:
>Has anyone ever written or seen an example of program code designed to
>evaluate complex conditions?  For example, if you wanted to evaluate a =
>b and (c = d or c = e or c = f).  I'm looking for something that can do
>multiple levels of parenthesis and all "and/or" combinations.
>
>--
>Terry Grider
>tgrider@arkansas.net
>
>
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