Dijsktra's shortest-path algorithm in Clojure

dijkstra.clj

(require '[clojure.data.priority-map :refer [priority-map]])

(defn map-vals [m f]
  (into {} (for [[k v] m] [k (f v)])))

(defn remove-keys [m pred]
  (select-keys m (filter (complement pred) (keys m))))

(defn dijkstra
  "Computes single-source shortest path distances in a directed graph.

   Given a node n, (f n) should return a map with the successors of n as keys
   and their (non-negative) distance from n as vals.

   Returns a map from nodes to their distance from start."
  [start f]
  (loop [q (priority-map start 0) r {}]
    (if-let [[v d] (peek q)]
      (let [dist (-> (f v) (remove-keys r) (map-vals (partial + d)))]
        (recur (merge-with min (pop q) dist) (assoc r v d)))
      r)))