Insitux tic-tac-toe

ttt.ix

(function check
  (let [[a _ x] [_ b] [z _ c]] board)
  ;Check diagonals
  (when (or (= a b c) (= x b z)) (return b))
  ;Check horizontals and verticals
  (let board+T (into board (.. map vec board)))
  (when (let [w] (find (.. =) board+T)) w))

(function place n xo
  (var! board (set-at [(// n 3) (rem n 3)] xo)))

(function handler input
  ;Parse the input
  (let [n xo] input)
  ;Initialise if not already done or requested
  (if (or (! ((symbols) "board")) (= input "new"))
    (var board (partition 3 (range 9))))
  ;Print instructions on bad input
  (if! (["o" "x"] xo)
    (print "Send e.g. \"!ttt 5x\" or \"!ttt 4o\" or \"!ttt new\""))
  ;Place the character
  (when (and n (let n (to-num n)) xo)
    (place n xo))
  ;Check if there was a winner
  (when (let winner (check))
    (print winner " wins!"))
  ;Render the board
  (join "\n" (map (join " ") board)))