[BLACKBOX] Polymorphism

From: [at]} <Aubrey.McIntosh{>
Date: Thu, 20 Nov 2008 21:23:13 -0600

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In writing my List module, I have a method DoEach that walks the list,
and applies method Do to each element.

                        (this: List) Do (VAR params: ANYREC), NEW, EMPTY;
                        (root: List) DoEach (VAR params: ANYREC), NEW;

In moving some existing software to the new library module, it turns
out that I wish to apply a few different procedures to the list. In
trying to avoid procedure variables, I find I am drawing a blank.
Making several lateral extensions to the base record may be an
approach, particularly if there is a pointer to a record with that
particular implementation as one of the fields in params. I will
alternate between envisioning some structure to do this and Goggling
for the next while. A brief search of "Component Pascal Polymorphism"
seems more or less on target and enough reading to fill a night.

I thought I saw some message about this under the general heading of
polymorphism on this list some years ago. If anyone remembers this,
or can point to a file either in the distribution or online I'd focus
my thoughts there fairly early on.

-- 
-- 
Aubrey McIntosh, Ph.D.
1502 Devon Circle
Austin TX 78723-1814
http://home.grandecom.net/~amcintosh/aubrey/Search/
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Received on Fri Nov 21 2008 - 04:23:13 UTC