Final version of booleans task

src/i_am_a_horse_in_the_land_of_booleans.clj

@@ -1,28 +1,52 @@
 (ns i-am-a-horse-in-the-land-of-booleans
   (:refer-clojure :exclude [boolean]))
 
-(defn boolean [x]
-  ":(")
-
-(defn abs [x]
-  ":(")
-
-(defn divides? [divisor n]
-  ":(")
-
-(defn fizzbuzz [n]
-  ":(")
-
-(defn teen? [age]
-  ":(")
-
-(defn not-teen? [age]
-  ":(")
-
-(defn generic-doublificate [x]
-  ":(")
-
-(defn leap-year? [year]
-  ":(")
+  (defn boolean [x]
+    (if (or (= x nil) (= x false))
+      false
+      true))
+
+  (defn abs [x]
+    (if (>= x 0)
+      x
+      (* x -1)))
+
+  (defn divides? [divisor n]
+    (if (== 0 (mod n divisor))
+      true
+      false))
+
+  (defn fizzbuzz [n]
+    (cond
+      (= true (and (divides? 3 n) (divides? 5 n))) "gotcha!"
+      (divides? 5 n) "buzz"
+      (divides? 3 n) "fizz"
+      :else ""
+      ))
+
+  (defn teen? [age]
+    (if (and (> age 12) (< age 20))
+      true
+      false))
+
+  (defn not-teen? [age]
+    (if (not (teen? age))
+      true
+      false))
+
+  (defn generic-doublificate [x]
+    (cond
+      (number? x) (* 2 x)
+      (empty? x) nil
+      (or (list? x) (vector? x)) (* 2 (count x))
+      :else true
+      ))
+
+  (defn leap-year? [year]
+    (cond
+      (divides? 400 year) true
+      (= (divides? 4 year) (divides? 100 year)) false
+      (divides? 4 year) true
+      ))
 
 ; '_______'