easy keyword classes

kclass.rb

module KClass
  def self.[](*keywords)
    klass = Class.new
    klass.send(:define_method, :initialize) do |hash|
      keywords.each do |kw|
        instance_variable_set("@#{kw}", hash[kw])
      end
    end

    keywords.each do |kw|
      klass.send :attr_reader, kw
    end

    klass
  end
end

PaymentProcessor = KClass[:order, :user]
class PaymentProcessor
  def put_user
    puts user
  end
end
PaymentProcessor.new(order: 'foo', user: 'bar').put_user