Zuhlke UK coding night - parse binary string

binary.clj

(ns zuhlke.codingnight.binary)
;
; Coding night challenge - Binary
; Convert string of binary digits to int
;

(defn binary-str-to-int [s]
	(loop [s   (reverse s)
		   acc 0
		   pwr 1]
		   (if-let [x (first s)]
		   	(recur (rest s)
		   		(+ acc (* pwr (Integer. (str x))))
		   		(* 2 pwr))
		   	acc)))

; Tests

(require '[clojure.test.check :as tc])
(require '[clojure.test.check.generators :as gen])
(require '[clojure.test.check.properties :as prop])

(def binary-digit (gen/elements [\0 \1]))

(def binary-string
	(->>
		(gen/vector binary-digit 1 62)
		(gen/fmap clojure.string/join)))

(tc/quick-check 1000 
	(prop/for-all [s binary-string]
		(= (BigInteger. s 2) (binary-str-to-int s))))