gistfile1.clj

(ns scratch.core
  (:use midje.sweet
        [clojure.set :only [union intersection]]
        :reload))

(unfinished newborns)

(defn survivable? [cell living-cells])

;; (fact "A cell is survivable if 2 or 3 of its neighbors are alive"
;;   (survivable? ..cell.. ..living-cells..) => truthy
;;   (provided
;;     (intersection (neighborhood ..cell..) ..living-cells..) => ...living-cells-in-that-neighborhood..)


(defn survivors [living-cells]
  (map (fn [cell] (survivable? cell living-cells))
       living-cells))

(defn tick [living-cells]
  (union (set (newborns living-cells))
         (set (survivors living-cells))))

;.;. For every disciplined effort, there is a multiple reward. -- Rohn
(fact "the tick produces newborn cells and surviving cells"
  (tick ..living-cells..) => (just [..newborn.. ..survivor..]
                                   :in-any-order)
  (provided
    (newborns ..living-cells..) => [..newborn.. ..survivor..]
    (survivors ..living-cells..) => [..survivor..]))


(defn generations [living-cells]
  (rest (iterate tick living-cells)))

(fact "generations are produced by the tick function"
  (first (generations ..living-cells..)) => ..generation-1..
  (provided
    (tick ..living-cells..) => ..generation-1..)

  (second (generations ..living-cells..)) => ..generation-2..
  (provided
    (tick (tick ..living-cells..)) => ..generation-2..))
  

(future-fact "blinkers blink")