From: Paul Brannan <pbrannan@...>
Date: 2002-07-25T23:25:48+09:00
Subject: Re: A Code Challenge

I will first answer your question with a question:

  *** WHY!?! ***

But here's a solution, just for fun (based off the same idea as
[ruby-talk:29122]):

  class Object
    def append_to_method(method_name, p)
      m = method(:x)
      mod = Module.new
      mod.send(:define_method, :x) do |*args|
        m.call(*args)
        p.call(*args)
      end
      extend(mod)
    end
  end

  class O
    def x(a)
      puts "do something with #{a}"
    end
  end

  o = O.new
  p = Proc.new { |a| puts "do something else with #{a}" }
  o.append_to_method(:x, p)
  o.x("foo")

The only disadvantage I can think of is that if x takes a block, you can
now no longer pass it a block.  I figure this probably isn't a problem
anyway since you are appending a proc to it, which cannot take a block.

Paul