H%5: map-while

map-while-spec.clj

(ns ex5.map-while-spec
  (:use ex5.map-while)
  (:use clojure.test))
  
(deftest test-map-while-1
  (let [f #(* % %)
        s (range 100)
        pred #(< % 50)
        result (map-while-1 f s pred)]
    (is (= (count result) 50))
    (is (= (first result) 0))
    (is (= (last result) (f 49)))))
  
(deftest test-map-while-2
  (let [f #(* % %)
        s (range 100)
        pred #(< % 50)
        result (map-while-2 f s pred)]
    (is (= (count result) 50))
    (is (= (first result) 0))
    (is (= (last result) (f 49)))))
  
(deftest test-map-while-1-again
  (let [f #(* % %)
        s '(20 40 60 35 10)
        pred #(< % 50)
        result (map-while-1 f s pred)]
    (is (= (count result) 2))
    (is (= (first result) (f 20)))
    (is (= (last result) (f 40)))))
  
(deftest test-map-while-2-again
  (let [f #(* % %)
        s '(20 40 60 35 10)
        pred #(< % 50)
        result (map-while-2 f s pred)]
    (is (= (count result) 2))
    (is (= (first result) (f 20)))
    (is (= (last result) (f 40)))))

map-while.clj

(ns ex5.map-while)

(defn map-while-1 [f s pred]
  (for [x s :while (pred x)] (f x)))

(defn map-while-2 [f s pred]
  (map f (take-while pred s)))