# http://pastie.caboo.se/36010 evolved
# vjt@openssl.it
# 
require 'blank' # http://pastie.caboo.se/26558

module Decorator
  def self.build *attributes, &block
    slate = Blank()
    slate.class_eval do
      def initialize(object)
        @_object = object
      end
      def method_missing(meth, *args, &block)
        @_object.send meth, *args, &block
      end
    end
    attributes.each { |attr| slate.send :attr_accessor, attr }
    slate.class_eval &block if block
    slate
  end

  def self.wrap object, *attributes, &block
    build(*attributes, &block).new(object)
  end
end

base = SomeClass.some_method

wrapper = Decorator.build(:attribute, :another_attr) do
  def some_useful_method # actually useless
  end
  define_method(:abc) {}
end

wrapped = wrapper.new(base)
# or
wrapped = Decorator.wrap(base)

wrapped.attribute          # => nil
wrapped.some_useful_method # =>  "
wrapped.another_attr = SomeStuff.new