From: Brian Buckley <briankbuckley@...>
Date: 2005-11-08T01:35:23+09:00
Subject: Re: memoize and yaml

> module Memoize
>    def memoize(name)
>      name = name.to_sym
>      old_method = instance_method(name)
>      remove_method(name)
>
>      define_method(name) do |*args|
>        @cache ||= {}
>        signature = [name] + args
>
>        if @cache.include?(signature) then
>          @cache[signature]
>        else
>          @cache[signature] = old_method.bind(self).call(*args)
>        end
>      end
>    end
> end

Two questions of this solution.  (It works and is what I need now so
I'm just looking to round out Ruby skills.)

1 Why is  the 'remove_method(name)' line necessary?  Does not the next
define_method call get rid of the method anyway by overriding?

2 The module requires use of 'extend' instead of 'include'.  Is there
a comparable 'include' solution, and (if there is) would it be
preferred because, for example, one could not use this solution on a
class that already extends something else?

Thanks!

Brian Buckley