fixed unsafe idiom. see: http://blog.darevay.com/2011/10/clojure-upda…

…te-literacy/

src/clj_automata/core.clj

@@ -145,7 +145,7 @@
         ;; Our initial state is a single row of random 0s and 1s
         initial (repeatedly height #(rand-int 2))
         sim (simulation (rule rule-num) initial)
-        ;; We use partition as a sliding wintdow here. Since sim is
+        ;; We use partition as a sliding window here. Since sim is
         ;; an infinite lazy sequence of future rows we use the 3-arity
         ;; version of partition here to create a 2D view of the visible range
         ;; of results. Since this is the 3-arity version of partition, with 1
@@ -168,7 +168,7 @@
               ;; tail recursive loop and not-utilizing the draw callback, but that's left
               ;; as an excercise for the reader.
               (draw-buffer (first @time-slices) scale)
-              (swap! time-slices (fn [_] (rest @time-slices))))
+              (swap! time-slices rest))
       :size [(* scale width) (* scale height)])))
 
 (defn -main [rule-num & args]