roll_my_own_attr_accessor.rb

class Foo
  def my_attr_accessor(*args)
    args.each do |arg|
      # def the_arg
      #   @the_arg
      # end
      self.instance_eval("def #{arg}; @#{arg}; end")

      # def the_arg=(the_arg)
      #   @the_arg = the_arg
      # end
      self.instance_eval("def #{arg}=(#{arg}); @#{arg}=#{arg}; end")
    end
  end

  def method_missing(method, *args)
    if (/^set_/.match(method.to_s))
      arg = method.to_s[4..method.to_s.length]
      self.instance_eval("@attrs = {} if @attrs.nil?; @attrs['#{arg}'] = '#{args[0]}'")
    elsif (/^get_/.match(method.to_s))
      arg = method.to_s[4..method.to_s.length]
      self.instance_eval("@attrs['#{arg}']")
    else
      super
    end
  end
end

f = Foo.new

f.my_attr_accessor :a, :b, :c
f.a = "hello"
f.a # <= "hello"

f.set_bob("steve")
f.get_bob