RosettaCodeData/Task/Population-count/Clojure/population-count.clj

29 lines
666 B
Clojure

(defn population-count [n]
(Long/bitCount n)) ; use Java inter-op
(defn exp [n pow]
(reduce * (repeat pow n)))
(defn evil? [n]
(even? (population-count n)))
(defn odious? [n]
(odd? (population-count n)))
;;
;; Clojure's support for generating "lazily-evaluated" infinite sequences can
;; be used to generate the requested output sets. We'll create some infinite
;; sequences, and only as many items will be computed as are "pulled" by 'take'.
;;
(defn integers []
(iterate inc 0))
(defn powers-of-n [n]
(map #(exp n %) (integers)))
(defn evil-numbers []
(filter evil? (integers)))
(defn odious-numbers []
(filter odious? (integers)))