Langton's ant: Difference between revisions

=={{header|Clojure}}==

In keeping with the spirit of Clojure, this program eschews mutable state entirely. Instead, all computation occurs within a single recursive loop whose "variables" are "adjusted" at each iteration, a natural fit for this particular execution model.

<lang Clojure>(let [bounds (set (range 100))

xs [1 0 -1 0] ys [0 -1 0 1]]

(loop [dir 0 x 50 y 50

grid {[x y] false}]

(if (and (bounds x) (bounds y))

(let [cur (not (grid [x y]))

dir (mod (+ dir (if cur -1 1)) 4)]

(recur dir (+ x (xs dir)) (+ y (ys dir))

(merge grid {[x y] cur})))

(doseq [col (range 100)]

(println

(apply str

(map #(if (grid [% col]) \# \.)

(range 100))))))))</lang>