用Array来实现OrderedHash

偶然发现电脑的角落里有这样的一段代码.功能是用Array实现的OrderedHash.
google了没找到出处,应该是自己写的了.贴出来,把文件删掉.

class OrderedOptions < Array
  def []=(key, value)
    key = key.to_sym

    if pair = find_pair(key)
      pair.pop
      pair << value
    else
      self << [key, value]
    end
  end

  def [](key)
    pair = find_pair(key.to_sym)
    pair ? pair.last : nil
  end

  def method_missing(name, *args)
    if name.to_s =~ /(.*)=$/
      self[$1.to_sym] = args.first
    else
      self[name]
    end
  end

  private
  def find_pair(key)
    self.each { |i| return i if i.first == key }
    return false
  end
end