meisuu.clj

(use 'clojure.contrib.str-utils)

(def digits {\零 0 \一 1 \二 2 \三 3 \四 4 \五 5 \六 6 \七 7 \八 8 \九 9})

(def n-keta {\千 1000, \百 100, \十 10})

(defn digit-and-rest [s & rest]
  (if-let [n (digits s)]
    [n rest]
    [1 (cons s rest)]))

(defn- trans-keta [s]
  (if (seq s)
    (let [[n [keta & rest]] (apply digit-and-rest s)]
      (+ (* n (n-keta keta 1)) (trans-keta rest)))
    0))

(defn- split-keta [s]
  (partition-all 2 (rest (re-partition #"[零一二三四五六七八九十百千]+" s))))

(defn- ruijou [a n]
  (reduce * (repeat n a)))

(def meisuu    {"万"        4
		"億"        8   
		"兆"       12  
		"京"       16
		"垓"       20
		"叙"       24
		"穣"       28
		"溝"       32
		"澗"       36
		"正"       40
		"載"       44
		"極"       48
		"恒河沙"   52
		"阿僧祇"   56
		"那由多"   60
		"不可思議" 64
		"無量大数" 68})

(defn kanji->number [[kazu tanni]]
  (* (trans-keta kazu) (ruijou 10 (meisuu tanni 0))))

(defn trans-meisuu [s]
  (reduce + (map kanji->number (split-keta s))))

; (trans-meisuu "千")
; (trans-meisuu "十億二千万八百五")