attr_sec_accessor module add-on

class Module
  def attr_sec_accessor(sym, default = 0)
    attr_writer sym
    attr_sec_reader sym, default
  end

  def attr_sec_reader(sym, default = 0)
    sym = sym.id2name
    string = "def #{sym};" +
             "  @#{sym} = #{default}  if @#{sym}.nil?;" +
             "  @#{sym};" +
             "end;"
    module_eval(string)
  end
end