Merge intervals

merge-intervals.clj

(defn ival [start finish] [start finish])

(defn mergeTwo [[a0 a1 :as a] [b0 b1 :as b]]
  (if (< b0 a0)
    (mergeTwo b a)
    (if (>= a1 b0)
      (list [a0 (max a1 b1)])
      (list a b))))

(defn concatMerge [acc ival]
  (if
    (empty? acc) (list ival)
    (concat (rest acc)
      (mergeTwo (first acc) ival))))

(defn mergeIval [ivalList ival]
  (if (empty? ivalList)
    (list ival)
    (let [sorted (sort-by first (conj ivalList ival))]
      (reduce concatMerge (list) sorted))))