From: matz@... (Yukihiro Matsumoto)
Date: 2000-09-13T00:46:14+09:00
Subject: [ruby-talk:4899] Re: Re-binding a block

Hi,

In message "[ruby-talk:4895] Re: Re-binding a block"
    on 00/09/12, Dave Thomas <Dave@thomases.com> writes:

|I'm trying to do something more generic, and that also avoids the
|problems with infinite loops that can arise with renaming in
|subclasses.

How about this?  Although it's bit ugly.

$hook_table = {}
class Module
  def hook(name, block)
    n = format("%s#%s", self.name, name)
    $hook_table[n] = instance_method(name)
    module_eval %{
      def #{name}(*args)
	m = $hook_table["#{n}"]
	lambda{#{block}}.call(m.bind(self), *args)
      end
    }
  end
end

class String
  hook :upcase, %{|upcase, *rest|
    upcase.call(*rest).tr '_', '~'
  }
end

p "foo_".upcase

							matz.