race.rb

time = 5
car_positions = [1, 1, 1]
while time >= 0 do
  time = time -1; puts # newline
  car_positions.each_with_index do |pos, index|
    if Random.rand > 0.3
      car_positions[index] += 1
    end
    print '-' * car_positions[index];puts # newline
  end
end

VS

def move_cars(car_positions, time)
  { cars: car_positions.map { |pos| pos += 1 ? Random.rand > 0.3 : pos },
    time: time - 1 }
end

def output_car car_position
  puts '-' * car_position
end

def run_step_of_race state
  move_cars(state[:cars], state[:time])
end

def draw car_positions
  car_positions.each { |c| output_car c }
end

def race car_positions, time
  draw car_positions
  state = move_cars car_positions, 
  race(run_step_of_race(state)[:cars],run_step_of_race(state)[:time]) ? state[:time] >= 0
end

race [1, 1, 1], 5