bisect-left in Clojure

bisect-left.clj

(defn binary-search-gte
  [items value]
  (letfn
    [(do-search
      [low high]
      (if (< low high)
        (let [mid (quot (+ low high) 2)]
          (if (> value (items mid))
            (recur (inc mid) high)
            (recur low mid)))
        low))]
    (do-search 0 (count items))))

(binary-search-gte [] 42)
(binary-search-gte [1 2] 3)

(defn linear-search
  [items value]
  (letfn
    [(do-search
      [items index]
      (cond
       (empty? items) -1
       (= value (first items)) index
       :else (recur (rest items) (inc index))))]
    (do-search items 0)))

(let
  [xs (into [](->> (repeatedly (fn [] (int (* (rand) 100)))) (take 1000) (sort)))]
  (every? #(= (linear-search xs %)
              (binary-search-gte xs %))
          xs))