RosettaCodeData/Task/Rock-paper-scissors/Elixir/rock-paper-scissors.ex

49 lines
1.3 KiB
Elixir

defmodule Rock_paper_scissors do
def play, do: loop([1,1,1])
defp loop([r,p,s]=odds) do
IO.gets("What is your move? (R,P,S,Q) ") |> String.upcase |> String.first
|> case do
"Q" -> IO.puts "Good bye!"
human when human in ["R","P","S"] ->
IO.puts "Your move is #{play_to_string(human)}."
computer = select_play(odds)
IO.puts "My move is #{play_to_string(computer)}"
case beats(human,computer) do
true -> IO.puts "You win!"
false -> IO.puts "I win!"
_ -> IO.puts "Draw"
end
case human do
"R" -> loop([r+1,p,s])
"P" -> loop([r,p+1,s])
"S" -> loop([r,p,s+1])
end
_ ->
IO.puts "Invalid play"
loop(odds)
end
end
defp beats("R","S"), do: true
defp beats("P","R"), do: true
defp beats("S","P"), do: true
defp beats(x,x), do: :draw
defp beats(_,_), do: false
defp play_to_string("R"), do: "Rock"
defp play_to_string("P"), do: "Paper"
defp play_to_string("S"), do: "Scissors"
defp select_play([r,p,s]) do
n = :rand.uniform(r+p+s)
cond do
n <= r -> "P"
n <= r+p -> "S"
true -> "R"
end
end
end
Rock_paper_scissors.play