gistfile1.builder

class Bar
  attr_reader :hash
  def method_missing(m, *args)
    if m.to_s =~ /((set|get)_(.+))/
      func =
        case $2
        when 'set' then lambda {|value| @hash ||= {}; @hash[$3] = value}
        when 'get' then lambda {@hash ||= {};  @hash[$3]}
      end
      self.class.send(:define_method, $1, &func)
      send(m,*args)
    else
      super
    end
  end
end