Rubyで自由な形式のConfigファイルを読み込めるようにしてみる ref: http://qiita.com/foostan/items/6619624d30b5820d93e4

.config.rb

class User
  def hello
    puts 'Hello World!'
  end
end
config.user = User.new

appconfig.rb

require 'hashie'

module AppConfig
  extend self

  AppConfig.load(File.read(File.expand_path('~/.config.rb')))

  def load(file)
    # default
    config = Hashie::Mash.new
    config.user = {
      name: 'foo',
      age: 25
    }

    # overwirte
    instance_eval(file)

    config.each do |key, value|
      attr_accessor key
      send("#{key}=", value)
    end
  end
end

main.rb

require '/path/to/appconfig.rb'

AppConfig.user.hello