flatten-routes.clj

(def x [["/foo"
         ["/bar" :bar]
         ["/baz"
          ["/quux" :quux]]]
        ["/yo"
         [["/man" :man]
          ["/manman" :manman]]]])

(require '[clojure.zip :as z]
         '[clojure.string :as str])

(defn flatten-routes [routes]
  (loop [res {} z (z/vector-zip routes)]
    (cond (z/end? z)            res
          (keyword? (z/node z)) (recur (assoc res (str/join (->> z z/path (filter (comp string? first)) (map first))) (z/node z))
                                       (z/next z))
          :otherwise            (recur res (z/next z)))))

(defn flatten-routes [routes]
  (->> (iteration identity
                  :initk (z/vector-zip routes)
                  :kf    z/next
                  :somef (complement z/end?)
                  :vf    #(when (-> % z/node keyword?)
                            [(str/join (->> % z/path (filter (comp string? first)) (map first))) (z/node %)]))
       (into {})))

(flatten-routes x)

produces:

;; => {"/foo/bar" :bar, "/foo/baz/quux" :quux, "/yo/man" :man, "/yo/manman" :manman}