device_class_chain.rb

module VersionFlat043
  BLOCK = Proc.new do
    class IO
      def self.a; puts "Device Included Class a"; end
      def b; puts "Device Included Instance b"; end
    end
  end
  def self.flat klass
    klass.class_eval &BLOCK
  end
end

module Device
  API_VERSION="0.4.3"
  VERSION="0.4.3"
  IO = ::IO
  class IO
    def self.a; puts "Device Class a"; end
    def b; puts "Device Instance b"; end
  end

  class Network
    def self.init; puts "Device Network init"; end
    def self.finish; puts "Device Network finish"; end
  end

  def self.flat_api
    klass_version = self::VERSION.gsub(".", "")
    if self::VERSION == "0.4.3"
      puts "#{self.name}"
      const_get("VersionFlat#{klass_version}").flat self
    end
  end
end

class Network
  def self.init; puts "PAX Network"; end
end

class PAX < Device
  VERSION="0.4.4"
  Network = Class.new(::Network, Device::) do
    def self.init; puts "PAX Network"; end
  end
  #class Network < Device::Network
    #def self.init; puts "PAX Network"; end
  #end

  class IO < Device::IO
    def self.a; puts "PAX Class a"; end
  end

  flat_api
end

OldDevice = Device
Device = PAX

puts OldDevice.object_id
puts Device.object_id
puts PAX.object_id
puts Device

OldDevice::IO.a
Device::IO.a
Device::IO.new(1).b
Device::Network.init
Device::Network.finish
p Device::IO.ancestors