yasuto
on Wed, 25 May 2011
;; Sieve of Eratosthenes by using 'keep'.
(defn keep-mcdr [f coll]
(lazy-seq
(when-let [x (first coll)]
(cons x (keep-mcdr f (f x (rest coll)))))))
(defn prime-number [n]
(cons 1
(keep-mcdr
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 n))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
yasuto
on Wed, 25 May 2011
(defn keep-mcdr [f coll]
(lazy-seq
(when-let [x (first coll)]
(cons x (keep-mcdr f (f x (rest coll)))))))
(defn prime-number [n]
(cons 1
(keep-mcdr
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 n))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
yasuto
on Wed, 25 May 2011
(defn keep-mcdr [f coll]
(lazy-seq
(when-let [x (first coll)]
(cons x (keep-mcdr f (f x (rest coll)))))))
(defn prime-number [num]
(cons 1
(keep-mcdr
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 num))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
yasuto
on Wed, 25 May 2011
(defn keep-mcdr [f coll]
(lazy-seq
(when-let [x (first coll)]
(cons x (keep-mcdr f (f x (rest coll)))))))
(defn prime-number [num]
(cons 1
(keep-mcdr
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 num))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
yasuto
on Wed, 25 May 2011
(defn keep-mcdr [f coll]
(lazy-seq
(when (and (not-empty coll) (first coll))
(let [x (first coll)
xs (rest coll)]
(cons x (keep-mcdr f (f x xs)))))))
(defn prime-number [num]
(cons 1
(keep-mcdr
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 num))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)
yasuto
on Wed, 25 May 2011
(defn keep-mcdr [f coll]
(lazy-seq
(when (and (not-empty coll) (first coll))
(let [x (first coll)
xs (rest coll)]
(cons x (keep-mcdr f (f x xs)))))))
(defn prime-number [num]
(cons 1
(keep-list
(fn[x xs] (if (not-empty xs)
(keep #(if-not (zero? (rem % x)) %)
xs)))
(range 2 num))))
user> (prime-number 100)
(1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97)