class Module

def memoize_function(*function_ids)
  function_ids.extend(ExtractLastArgumentOptions)
  function_ids, opts = function_ids.extract_last_argument_options
  mc = __memoize_cache__
  function_ids.each do |method_id|
    method_id = method_id.to_s.to_sym
    orig_method = instance_method(method_id)
    __send__(:define_method, method_id) do |*args|
      if mc.key?(method_id) and result = mc[method_id][args]
        result
      else
        (mc[method_id] ||= {})[args] = result = orig_method.bind(self).call(*args)
        opts[:freeze] and result.freeze
        $DEBUG and warn "#{self.class} cached function #{method_id}(#{args.inspect unless args.empty?}) = #{result.inspect}"
      end
      result
    end
  end
end

def memoize_method(*method_ids)
  method_ids.extend(ExtractLastArgumentOptions)
  method_ids, opts = method_ids.extract_last_argument_options
  include CacheMethods
  method_ids.each do |method_id|
    method_id = method_id.to_s.to_sym
    orig_method = instance_method(method_id)
    __send__(:define_method, method_id) do |*args|
      mc = __memoize_cache__
      if mc.key?(method_id) and result = mc[method_id][args]
        result
      else
        (mc[method_id] ||= {})[args] = result = orig_method.bind(self).call(*args)
        $DEBUG and warn "#{self.class} cached method #{method_id}(#{args.inspect unless args.empty?}) = #{result.inspect} [#{__id__}]"
        opts[:freeze] and result.freeze
      end
      result
    end
  end
end

def named(name, method, *args, &named_block)
  include Module.new {
    define_method(name) do |*rest, &block|
      block = named_block if named_block
      __send__(method, *(args + rest), &block)
    end
  }
end

def named(name, method, *args, &block)
  include Module.new { define_method(name) { |*rest| __send__(method, *(args + rest), &block) } }
end