conway.clj

(ns conways.core
  (:gen-class))

(def board [5 5])

(def coords (for [x (range (first board)) y (range (second board))] [y x]))

(def neighbour-coords [[-1 -1] [0 -1] [1 -1]
                       [-1  0]        [1  0]
                       [-1  1] [0  1] [1  1]])
                     
(defn life [_ n] (get [0 0 1 1] n 0))

(defn neighbours [world [x y]]
  (->> neighbour-coords
       (map (fn [[x' y']] [(+ x x') (+ y y')]))
       (keep (partial get-in world))
       (apply +)))

(defn next-world [world new-world coord]
  (update-in new-world coord life (neighbours world coord)))

(defn tick [world]
  (reduce (partial next-world world) world coords))

(-> [[0 1 1 1 0] 
     [0 0 0 0 0] 
     [0 0 0 0 0] 
     [0 0 0 0 0]
     [0 0 0 0 0]] 
    tick 
    tick 
    tick 
    tick 
    tick 
    tick
    tick
    tick
    tick)
  ;;=> [[1 1 1 1 1] [0 0 0 0 0] [1 0 1 0 1] [0 0 0 0 0] [1 1 1 1 1]]