a10n.clj

a10n.clj

(ns a10n
  (:require [clojure.set :as set]
            [clojure.string :as str]))

(defn i4t [t2e w2d val]
  (if (empty? w2d)
    (assoc t2e :end val)
    (update t2e
            (first w2d)
            i4t (rest w2d) val)))

(defn b3d [w3s]
  (reduce #(i4t %1 %2 %2) {} w3s))

(defn e4d [t2e w2d]
  (cond
    (empty? w2d)
    (if (contains? t2e :end) #{(get t2e :end)} #{})
    (= \. (first w2d))
    (apply set/union (map #(e4d % (rest w2d)) (filter map? (vals t2e))))
    :else
    (e4d (get t2e (first w2d)) (rest w2d))))

(defn c4r [w2d ixs]
  (apply str (map-indexed #(if (ixs %1) %2 \.) w2d)))

(defn s6s? [t2e orig w2d]
  (letfn [(miss [t2e part]
            (cond
              (empty? part)
              (when-let [e (:end t2e)] (not= orig e))
              (= \. (first part))
              (some #(miss % (rest part)) (filter map? (vals t2e)))
              :else
              (miss (get t2e (first part)) (rest part))))]
    (not (miss t2e w2d))))

(defn m6e [t2e w2d]
  (let [unique? (memoize
                 (fn [ixs]
                   (s6s? t2e w2d (c4r w2d ixs))))
        best (fn [rec ixs]
               (let [children (map #(disj ixs %) ixs)
                     uniques (filter unique? children)]
                 (if (empty? uniques)
                   ixs
                   (apply min-key count (doall (map (partial rec rec) uniques))))))]
      (best (memoize best) (set (range 0 (count w2d))))))

(defn c6s [w2d]
  (when-not (empty? w2d)
    (let [[d2s w2d] (split-with #{\.} w2d)
          [l5s w2d] (split-with (complement #{\.}) w2d)]
      (str (when (seq d2s) (count d2s))
           (apply str l5s)
           (c6s w2d)))))

(defn dec6s [w2d]
  (when-not (empty? w2d)
    (let [digit? #{\0 \1 \2 \3 \4 \5 \6 \7 \8 \9}
          [d4s w2d] (split-with digit? w2d)
          [l5s w2d] (split-with (complement digit?) w2d)]
      (str (when (seq d4s) (apply str (repeat (parse-long (apply str d4s)) \.)))
           (apply str l5s)
           (dec6s w2d)))))

(def w3s (delay (b3d (str/split-lines (slurp "/usr/share/dict/words")))))

(defn a8e [w2d]
  (->> (m6e @w3s w2d)
       (c4r w2d)
       c6s))

(defn una8e [w2d]
  (->> (dec6s w2d)
       (e4d @w3s)))

(comment
  (a8e "cybernetics")
  ;; => "cy5t3"
  (a8e "international")
  ;; => "2t4t4l"
  (una8e "c9h")
  ;; => #{"cheesecloth" "cottonmouth" "choreograph"}
  (a8e "choreograph")
  ;; => "1h7p1"
  )