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From: "Kai Schuelke" <kai.schuelke@gmx.net>
Newsgroups: comp.lang.ada
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Subject: Re: Function pointer in Ada?
Date: Thu, 16 May 2002 21:06:32 +0200
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Date: 2002-05-16T21:06:32+02:00
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I took the String a watched for the least significant Operation (binary
operations only at first), which is the root of my tree. I put the left side
of the String onto the left branch, same on the right side, until I get a
remaining number or a variable name.

y = 5*x + 3     becomes

Op:              +
                /        \
Op:        *          3    Num
            /    \
Num:   5    x       Var

Therefore I need a record to describe a leaf that consists of
- 2 pointers to the next leafs
- A storage, that indicates what the leaf is: a operation, a constant or a
variable

I  used:
type LEAF is record
    Left,
    Right : operation_pointer := null    -- thats why I started to post in
this thread
    Con  : FLOAT;
    Var   : BOOLEAN;
end record;

Does anybody see a more ada-like way to do it? Somebody wrote that this is C
style.

Thanks

Kai Schuelke   looking forward to learn something new.

PS: This program works just fine right know, but it is intended to learn
something about Ada. So please don't mind my asking for better ways.