parser.rb

class Parser
  	def initalize()
  	end

  	public

  	def parse(input)
  		case input
  			when "go"
  				go_response
  			when "get"
  				get_response
  			when "put"
  				put_response
  			else
  				bad_response
  		end
  	end

  	private

  	def go_response
		puts "Where would you like to go?"
	end
 
	def get_response
		puts "Get what?"
	end

	def put_response
		puts "Put what, exactly?"
	end

	def bad_response
		puts "I don't know about that."
	end

end

parser = Parser.new

loop do
	puts ":"
	input = gets.chomp
	input.downcase!
	break if input == "quit"
	parser.parse(input)
end