From: Matthew Johnson <musical.matthew@...>
Date: 2006-08-29T05:34:24+09:00
Subject: Re: Partial append_features?

> I'm looking for a way to copy methods from a Module, or specify  
> more directly which methods get included in a class. More or less,  
> I would like to be able to do something like this:
>
> module Foo
>   def do_one_thing
>   end
>   def do_second
>   end
>   def do_third
>   end
> end
>
> class Bar
>   append_from Foo, :do_second, :do_third
> end
>
> or
> module Baz
>   append_from Foo, :do_second, :do_third
> end
>
> and I would have a module Baz which could be included, without  
> having do_one_thing included.
>
> Is this possible in Ruby right now? My first approach was to get  
> the UnboundMethod instance_method from the Module, but I couldn't  
> find a way to attach these to an unrelated class since  
> UnboundMethod must have a is_a?-relationship with the binding object.

The closest I have seen to this is generating a module on the fly  
(with Module.new) that includes the  Module and then undefs all the  
methods you don't want.  That gives you a custom module to include  
that will have only the methods you are after.

Matthew