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Newsgroups: comp.lang.ada
Subject: Re: How come Ada isn't more popular?
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From: Markus E Leypold
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Date: Wed, 07 Feb 2007 10:42:01 +0100
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Maciej Sobczak <no.spam@no.spam.com> writes:

> Dmitry A. Kazakov wrote:

>
>> For handling cycles there are weak pointers.
>
> Not only. 

Not at all you wanted to say.

> If you have cycles, then you'd better rethink the design.

let rec fac n = if n = 0 then 1 else n * (fac (n-1));;

a) closure
b) cycle

:-). 

A lot of OO models with callback also require cycles. E.g. A knows B
and B registers a callback with A in certain situations.

> The difference is between a) graph treated as a mesh (or mess) of
> nodes which "own" each other and b) graph treated as a collection of
> nodes.

> The former might have ownership cycles between nodes, but not the
> latter, where ownership is an acyclic relation between graph and nodes.

> I agree that this kind of restructuring is not always possible, but
                                            ^^^^^^^^^^^^^^^^^^^^^

!!.

Regards -- Markus