Pacman metaphor

pacman.clj

(require '[clojure.data.csv :as csv]
         '[clojure.java.io :as io])

;; avoid REPL timeouts by large data output (during testing)
;;
(set! *print-length* 10)

;; download from https://s3.amazonaws.com/hw-sandbox/tutorial1/NYSE-2000-2001.tsv.gz
;; 812,990 data records, 40 MB on disk
;;
(def in-file "/path/to/datafile/NYSE-2000-2001.tsv")
(def in-seq (line-seq (io/reader in-file)))
;; yes it is:
(coll? in-seq)


;; Do-Nothing-Pacman
;;
(defn f [m]
  (let [rem (:remaining m)]
    (cond (nil? rem) {:end true}
          (= 1 (count rem)) {:yield "OK"}
          :else {:remaining (rest rem)})))


(defn parse [f coll]
  (->> coll
       (iterate f)
       (take-while #(not (contains? % :end)))
       (map :yield)
       (filter #(not (nil? %)))))


(defn make-m [coll] (hash-map :remaining coll))

(defn measure [f n seq]
  (time (first (parse f (make-m (take n seq))))))

;; you may want to start manually because of runtime duration:
;;
(measure f 10 in-seq)
;; ...
(measure f 100000 in-seq)