class Module

  private

  # Creates a new method for a pre-existing method.
  #
  # If _aka_ is given, then the method being redefined will
  # first be aliased to this name.
  #
  #   class Greeter
  #     def hello ; "Hello" ; end
  #   end
  #
  #   Greeter.new.hello   #=> "Hello"
  #
  #   class Greeter
  #     redefine_method( :hello, :hi ) do
  #       hi + ", friend!"
  #     end
  #   end
  #
  #   Greeter.new.hello   #=> "Hello, friend!"
  #
  def redefine_method( sym, aka=nil, &blk )
    raise ArgumentError, "method does not exist" unless method_defined?( sym )
    alias_method( aka, sym ) if aka
    undef_method( sym )
    define_method( sym, &blk )
  end

end


#  _____         _
# |_   _|__  ___| |_
#   | |/ _ \/ __| __|
#   | |  __/\__ \ |_
#   |_|\___||___/\__|
#
=begin test

  require 'test/unit'

  class TCModule < Test::Unit::TestCase

    def fixture_method; "a"; end

    redefine_method( :fixture_method ) { nil }

    def test_redefine_method
      assert_equal( nil, fixture_method )
    end

  end

=end