FRACTRAN

code:fractran.clj

(ns prime

(:require

;; エラトステネスの篩で素數列を生成する

(deftype Primes

clojure.lang.ISeq

;; cons は意味を成さない

(more

(split-at 1))]

(Primes. prime numbers)))

(next

(split-at 1))]

(Primes. prime numbers)))

(def primes

"エラトステネスの篩で素數列を生成する"

(Primes. 2 (drop 2 (range))))

(defn composite

"素因數の指數列から自然數を復元する

(->> factors

(map vector primes)

int))

(defn factorization

"素因數分解し、指數を素數列の昇順に竝べた列

(loop [factors []

primes primes

n n]

(if (= n 1)

factors

n n]

(if (zero? (mod n prime))

(recur (inc factor)

(/ n prime))

(recur (conj factors factor)

(drop 1 primes)

n))))))

(defn product

"積

(range (max (count l) (count r)))))

(ns rational

"素因數分解された分子と分母の組

(defn reduction

"約分"

n d

[(->> n

(map vector (range))

reverse

reverse)

(->> d

(map vector (range))

reverse

reverse)])

(defn clj->rational

"Clojure の有理數から、素因數分解された有理數に變換する"

[(prime/factorization (if (integer? clj-rational) clj-rational (numerator clj-rational)))

(prime/factorization (if (integer? clj-rational) 1 (denominator clj-rational)))])

(defn rational->clj

"素因數分解された有理數から、Clojure の有理數に變換する"

n d

(/ (prime/composite n) (prime/composite d)))

(defn product

"積"

ln ld] [rn rd

(reduction [(prime/product ln rn)

(prime/product ld rd)]))

(defn integerr?

"整數? 分母が 1?"

n d

(= (count d) 0))

(ns fractran

(:require

(defn- fractran-in-rational

""

(->> program

first

(if (nil? n)

input

(fractran-in-rational program n))))))

(defn fractran

"FRACTRAN.

(nth (fractran-in-rational (map rational/clj->rational program)

[input []])

0))

(ns user)

(defn eval-print-fractran

"FRACTRAN を實行し、結果を表示する"

(println "program: " program)

(println "input: " input)

(println "output: " (fractran/fractran program input))

(println))

(println "加算")

(println "乘算")

(println "除算")