another block exercise

gistfile1.rb

class Configuration
  attr_accessor :tail_logs, :max_connections, :admin_password

  class AppServerConfig
    attr_accessor :port, :admin_password
  end 

  def app_server
    yield(@app_server ||= AppServerConfig.new) if block_given?
    @app_server
  end
end

def configure 
  yield(c = Configuration.new)
  c
end

configuration = configure do |config|  
  config.tail_logs = true  
  config.max_connections = 55  
  config.admin_password = 'secret'  
  config.app_server do |app_server_config|  
    app_server_config.port = 8808  
    app_server_config.admin_password = config.admin_password  
  end  
end  
  
configuration.class # => Configuration  
configuration.tail_logs # => true  
configuration.app_server.admin_password # => 'secret'