adv2015_day06_benchmarking.clj

;; input is from https://adventofcode.com/2015/day/6

(def W 1000)
(def input (clojure.string/split-lines (slurp "d06.txt")))

(defmacro control-lights [lights x1 y1 x2 y2 f]
  (let [i (gensym)]
    `(doseq [ x# (range ~x1 (inc ~x2))
              y# (range ~y1 (inc ~y2))
              :let [ ~i (+ (* y# W) x#) ] ]
       (aset ~lights ~i
         ~(eval `(~f '(aget ~lights ~i)))))))

(time
  (printf "unreadable macro: %d\n"
    (let [lights (boolean-array (* W W))]
      (doseq [s input]
        (let [ m (re-matches #"(turn on|turn off|toggle) (\d+),(\d+) through (\d+),(\d+)" s)
               command (get m 1)
               x1 (Integer/parseInt (get m 2))
               y1 (Integer/parseInt (get m 3))
               x2 (Integer/parseInt (get m 4))
               y2 (Integer/parseInt (get m 5)) ]
          (cond
            (= command "turn on") (control-lights lights x1 y1 x2 y2 (fn [v] `true))
            (= command "turn off") (control-lights lights x1 y1 x2 y2 (fn [v] `false))
            (= command "toggle") (control-lights lights x1 y1 x2 y2 (fn [v] `(not ~v)))
            )))
      (count (filter identity lights)))))

(time
  (printf "clean code: %d\n"
    (let [lights (boolean-array (* W W))]
      (doseq [s input]
        (println s)
        (let [ m (re-matches #"(turn on|turn off|toggle) (\d+),(\d+) through (\d+),(\d+)" s)
               command (get m 1)
               compute (case command
                         "turn on" (constantly true)
                         "turn off" (constantly false)
                         "toggle" not)
               x1 (Integer/parseInt (get m 2))
               y1 (Integer/parseInt (get m 3))
               x2 (Integer/parseInt (get m 4))
               y2 (Integer/parseInt (get m 5)) ]
          (doseq [ x (range x1 (inc x2))
                   y (range y1 (inc y2))
                   :let [i (+ (* y W) x)] ]
            (aset lights i (compute (aget lights i))))
            ))
      (count (filter identity lights)))))