Code Kata1 in Clojure

kata1.clj

(defn _midpoint [vec]
  (quot (+ (.start vec) (.end vec)) 2))

(defn _chop [item list]
  (cond
     (empty? list) -1
     (= 1 (count list) ) (if (= item (first list)) (.start list) -1)
     :else (let [mid (_midpoint list)]
         (let [val (get (.v list) mid)]
         (cond
            (= item val) mid
            (< item val) (_chop item (subvec list (.start list) mid))
            (> item val) (_chop item (subvec list (inc mid))))
         ))))


(defn chop [item list] (
  _chop item (subvec list 0)))

passes all these tests:

(deftest test-chop
  (is (= -1 (chop 3 [])))
  (is (= -1 (chop 3 [ 1 ])))
  (is (= 0  (chop 1 [ 1 ])))
  (is (= 0  (chop 1 [1 3 5])))
  (is (= 1  (chop 3 [1 3 5])))
  (is (= 2  (chop 5 [1 3 5])))
  (is (= -1 (chop 0 [1 3 5])))
  (is (= -1 (chop 2 [1 3 5])))
  (is (= -1 (chop 4 [1 3 5])))
  (is (= -1 (chop 6 [1 3 5])))
  (is (= 0  (chop 1 [1 3 5 7])))
  (is (= 1  (chop 3 [1 3 5 7])))
  (is (= 2  (chop 5 [1 3 5 7])))
  (is (= 3  (chop 7 [1 3 5 7])))
  (is (= -1 (chop 0 [1 3 5 7])))
  (is (= -1 (chop 2 [1 3 5 7])))
  (is (= -1 (chop 4 [1 3 5 7])))
  (is (= -1 (chop 6 [1 3 5 7])))
  (is (= -1 (chop 8 [1 3 5 7])))
  )

Sauce: http://codekata.com/kata/kata02-karate-chop/