gistfile1.rb

module Config

  class Storage

    def initialize(name, value = nil, parent = nil)
      @_name = (parent ? "#{parent}." : '') + name
      @_value = value
    end

    def method_missing(sym, *args)
      method(sym).call
    rescue
      name = sym.to_s.gsub(/(=)\z/, '')
      value = $1 ? args.shift : nil
      child = self.class.new(name, value, @_name)
      metaclass.__send__(:define_method, name) { value ? value : child }
      child
    end

    def set_default(name, value)
      method(name)
    rescue
      instance_variable_set("@#{name.to_s}", value)
      metaclass.__send__(:attr_reader, name.to_sym)
    ensure
      nil
    end

    def inspect; "#{@_name}" end
    def nil?; @_value.nil?  end

    def metaclass; class << self; self end end
    private :metaclass
  end

  class << self
    _instance = Storage.new('config')
    define_method(:instance) { _instance }
  end
end