From: MenTaLguY <mental@...>
Date: 2007-10-07T06:51:19+09:00
Subject: Re: The Case for Multiple-Inheritance

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On Sun, 2007-10-07 at 04:34 +0900, Sylvain Joyeux wrote:
> > [1] i.e. the inheritance graph is made linear by ensuring that each
> > module only appears once in a class' ancestry

> You don't control *where* your module ends up in the inheritance
> chain, something class inheritance partially does (i.e. you have a
> tree or a graph, therefore a partial ordering). With modules, you
> trade one problem with another.

Linearization has nothing to do with modules per se.  It's one
well-known technique for addressing ambiguity in the presence of
multiple inheritance.  See for instance:

 http://www.webcom.com/haahr/dylan/linearizations.html

The reason linearization is used is that partial ordering is not a
strong enough constraint to avoid ambiguity in method dispatching.
While linearization can be avoided, you would need to make other
trade-offs to compensate (i.e. you can't have your multiply inherited
cake and eat it too).

-mental

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