Projectionist

Class#initialize_with

class Class
  def initialize_with(*params, &block)
    attr_reader *params
    define_method(:initialize) do |*args|
      params.zip(args).each do |param, arg|
        instance_variable_set("@#{param}", arg)
      end
      instance_eval(&block) if block_given?
    end
  end
end

class Account
  initialize_with :username, :password do
    p "Initializing..."
    # Initialization code
  end
end

Account.new 'joe', 'secret'
"Initializing..."
# => #<Account @password="secret", @username="joe">