Splits coll by pred. Returns a vector with a vector where (pred item) returns true followed by a vector where (pred item) returns false.

split_by.clj

(defn split-by
  "Splits coll by pred. Returns a vector with a vector where (pred item) returns
  true followed by a vector where (pred item) returns false.

  Example:
  (split-by pos? [0 1 2 -1 3 -2 4 -3])
  => [[1 2 3 4] [0 -1 -2 -3]]"
  [pred coll]
  (reduce (fn [split item]
            (update split (if (pred item) 0 1) conj item))
          [[] []]
          coll))