R-r-r-r-r-ruby Racer!

racer_utils.rb

class Die
  def initialize(sides = 6)
    @sides = sides
  end
  
  # Remember: rand(N) randomly returns one of N consecutive integers, starting at 0
  # So rand(N) returns a random integer in (0..N-1)
  # And 1 + rand(N) returns a random integer in (1..N)
  # See: http://www.ruby-doc.org/core-1.9.3/Kernel.html#method-i-rand
  def roll
    1 + rand(@sides)
  end
end

# Use "reputs" to print over a previously printed line,
# assuming the cursor is positioned appropriately.
def reputs(str = '')
  puts "\e[0K" + str
end

# Clear the screen
def clear_screen!
  print "\e[2J"
end

# Moves cursor to the top left of the terminal
def move_to_home!
  print "\e[H"
end

# Flushes the STDOUT buffer.
# By default STDOUT is only flushed when it encounters a newline (\n) character
def flush!
  $stdout.flush
end

ruby_racer.rb

require_relative 'racer_utils'

class RubyRacer
  attr_reader :players, :length

  def initialize(players, length = 30)
  end
  
  # Returns +true+ if one of the players has reached 
  # the finish line, +false+ otherwise
  def finished?
  end
  
  # Returns the winner if there is one, +nil+ otherwise
  def winner
  end
  
  # Rolls the dice and advances +player+ accordingly
  def advance_player!(player)
  end
  
  # Prints the current game board
  # The board should have the same dimensions each time
  # and you should use the "reputs" helper to print over
  # the previous board
  def print_board
  end
end

players = ['a', 'b']

game = RubyRacer.new(players)

# This clears the screen, so the fun can begin
clear_screen!

until game.finished?
  players.each do |player|
    # This moves the cursor back to the upper-left of the screen
    move_to_home!
  
    # We print the board first so we see the initial, starting board
    game.print_board
    game.advance_player!(player)
    
    # We need to sleep a little, otherwise the game will blow right past us.
    # See http://www.ruby-doc.org/core-1.9.3/Kernel.html#method-i-sleep
    sleep(0.5)
  end
end

# The game is over, so we need to print the "winning" board
game.print_board

puts "Player '#{game.winner}' has won!"