define_method.rb

#かなり雑だけどこんな書き方もできる
class Bar
  def initialize(options={})
    @options = options
  end

  def method_missing(name, *args)
    if name =~ /=$/
      @options[name.to_s.chop.to_sym] = args.first
    else
      @options[name.to_sym]
    end
  end
end

bar = Bar.new(:name => 'Hoge')
p bar.name #=> Hoge
bar.name = 'Mark'
p bar.name #=> Mark

# define_methodを使った例
class Foo
  def initialize(options={})
    @options = options
    @options.each_key {|key| Foo.define(key)}
  end

  def self.define(name)
    define_method(name) do
      @options[name]
    end

    define_method("#{name}=") do |arg|
      @options[name] = arg
    end
  end
end

foo = Foo.new(:name => "original value")
puts foo.name #=> original value
foo.name = "Mark"
puts foo.name #=> Mark