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14-15

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This commit is contained in:
devmeyster 2016-04-10 21:29:55 -07:00
parent 3c92967e74
commit db99c57eb1
2 changed files with 24 additions and 14 deletions
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18
src/koans/14_recursion.clj
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@ -3,21 +3,29 @@
(defn is-even? [n] (defn is-even? [n]
(if (= n 0) (if (= n 0)
__ true
(___ (is-even? (dec n))))) (not (is-even? (dec n)))))
(defn is-even-bigint? [n] (defn is-even-bigint? [n]
(loop [n n (loop [n n
acc true] acc true]
(if (= n 0) (if (= n 0)
__ false
(recur (dec n) (not acc))))) (recur (dec n) (not acc)))))
(defn recursive-reverse [coll] (defn recursive-reverse [coll]
__) (loop [coll coll
reversed '()]
(if (empty? coll)
reversed
(recur (rest coll) (cons (first coll) reversed)))))
(defn factorial [n] (defn factorial [n]
__) (loop [n n
res 1]
(if (= 0 n)
res
(recur (dec n) (* n res)))))
(meditations (meditations
"Recursion ends with a base case" "Recursion ends with a base case"

20
src/koans/15_destructuring.clj
View file

@ -8,37 +8,39 @@
(meditations (meditations
"Destructuring is an arbiter: it breaks up arguments" "Destructuring is an arbiter: it breaks up arguments"
(= __ ((fn [[a b]] (str b a)) (= ":bar:foo" ((fn [[a b]] (str b a))[:foo :bar]))
[:foo :bar]))
"Whether in function definitions" "Whether in function definitions"
(= (str "An Oxford comma list of apples, " (= (str "An Oxford comma list of apples, "
"oranges, " "oranges, "
"and pears.") "and pears.")
((fn [[a b c]] __) ((fn [[a b c]] (str "An Oxford comma list of " a ", " b ", and " c "."))
["apples" "oranges" "pears"])) ["apples" "oranges" "pears"]))
"Or in let expressions" "Or in let expressions"
(= "Rich Hickey aka The Clojurer aka Go Time aka Lambda Guru" (= "Rich Hickey aka The Clojurer aka Go Time aka Lambda Guru"
(let [[first-name last-name & aliases] (let [[first-name last-name & aliases]
(list "Rich" "Hickey" "The Clojurer" "Go Time" "Lambda Guru")] (list "Rich" "Hickey" "The Clojurer" "Go Time" "Lambda Guru")]
__)) (apply str (interpose " aka " (cons (str first-name " " last-name) aliases)))))
"You can regain the full argument if you like arguing" "You can regain the full argument if you like arguing"
(= {:original-parts ["Stephen" "Hawking"] :named-parts {:first "Stephen" :last "Hawking"}} (= {:original-parts ["Stephen" "Hawking"] :named-parts {:first "Stephen" :last "Hawking"}}
(let [[first-name last-name :as full-name] ["Stephen" "Hawking"]] (let [[first-name last-name :as full-name] ["Stephen" "Hawking"]]
__)) (hash-map :original-parts full-name :named-parts (hash-map :first first-name :last last-name))))
"Break up maps by key" "Break up maps by key"
(= "123 Test Lane, Testerville, TX" (= "123 Test Lane, Testerville, TX"
(let [{street-address :street-address, city :city, state :state} test-address] (let [{street-address :street-address, city :city, state :state} test-address]
__)) (apply str (interpose ", " (list street-address city state)))))
"Or more succinctly" "Or more succinctly"
(= "123 Test Lane, Testerville, TX" (= "123 Test Lane, Testerville, TX"
(let [{:keys [street-address __ __]} test-address] (let [{:keys [street-address city state]} test-address]
__)) (apply str (interpose ", " (list street-address city state)))))
"All together now!" "All together now!"
(= "Test Testerson, 123 Test Lane, Testerville, TX" (= "Test Testerson, 123 Test Lane, Testerville, TX"
(___ ["Test" "Testerson"] test-address))) ((fn [[a b] {:keys [street-address city state]}]
(apply str (interpose ", " (list (str a " " b) street-address city state))))
["Test" "Testerson"] test-address))