From: SonOfLilit <sonoflilit@...>
Date: 2007-02-18T21:11:56+09:00
Subject: Re: More flexible inheritance

Hey, how about a new #include variant that does alias magic whenever a
method exists in both the class and the mixin module?

Aur Saraf

On 2/18/07, SonOfLilit <sonoflilit@gmail.com> wrote:
> Wouldn't this hurt performance a lot? For each and every message
> passed, one more step in lookup.
>
> I don't know.
>
> Aur Saraf
>
> On 2/18/07, Trans <transfire@gmail.com> wrote:
> > A notion came to me yesterday with regards to how we extend classes.
> > On the one hand we can create a module and include it into a class,
> > but this will not allow us to override a preexisting method -- for
> > that we must reopen the class and play the alias and/ or binding game.
> > Various ideas have been put forth for simplifying and improving the
> > robustness of this, from #wrap_method, alias_method_chain, as well
> > as :pre, :post methods and my own cuts (albeit they go a bit further
> > than just method wrapping). But occurs to me that these add
> > complexities onto something that is already straightforward if we are
> > willing to separate out all class concerns into modules. In other
> > words instead of writing:
> >
> >   class X
> >     def a; "a";  end
> >   end
> >
> > write:
> >
> >   module Xa
> >     def a; "a";  end
> >   end
> >
> >   class X
> >     include Xa
> >   end
> >
> >   X.new.a  #=> "a"
> >
> > Then it's easy enough to overlay new behaviors:
> >
> >   module Xb
> >     def a; "{"+super+"}";  end
> >   end
> >
> >   class X
> >     include Xb
> >   end
> >
> >   X.new.a  #=> "{a}"
> >
> > Since that works so well, it occurs to me, why not make this the
> > fundamental behavior of defining a class? In other words defining a
> > class:
> >
> >   class X
> >     def a; "a"; end
> >   end
> >
> > could be equivalent to writing:
> >
> >   class X
> >     include( Module.new{
> >         def a; "a";  end
> >     } )
> >   end
> >
> > So there would always be a module involved in the definition of a
> > class. And classes become simply containers of modules.
> >
> > T.
> >
> >
> >
>