util.clj

(defn apply-if
  "if(p(m)) then f(m, ...args) else m

  Useful for `maybe-*` like updates."
  [m p f & args]
  (if (p m)
    (apply f m args)
    m))

(defn fork [l c r]
  #(->> % ((juxt l r)) (apply c)))

(defn avg [a]
  ((fork (partial apply +) / count) a))

(defn unique? [a]
  ((fork count = (comp count set)) a))