Re: text equation

Hmm... that looks like something Perl would be more
apt at doing.  Perl is great at parsing.

I can see that would be a big program in RPG if you are
looking for all possible cases.  You have to look for the
parenthesis, you have to look at the signs, most mathematical
formulas use sign hierarchy (* and / before + and -) most are
left to right, but some are right to left, etc...

That is, 12 * 10 + 3 / 2 can produce a number of answers,
depending on how you parse it.
61.5 = ((12 * 10) + 3) / 2 = Left to right
121.5 = (12 * 10) + (3 / 2) = Hierarchy
138 = 12 * (10 + (3 / 2)) = Right to left (APL uses this)

and then you get into combinations of hierarchy and left to right
or right to left.  Most interpreters doe them with hierarchy and
Left to Right (such as Visual Basic).  I'm not sure what the
Eval statement does, I would assume the same way.

It doesn't look like a quick program.

Regards,

Jim Langston

Eric Panissard wrote:

> Hi everybody,
>
> I am looking for an RPG sub-program who can recognize and calculate a text
> equation like :
>     (250*(12+45.5))-10
>
> the equation can contain : the 4 basic operation, decimal point, multiple
> parenthesis

<SNIP>

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