Flattens a nested map structure.

unnest.clj

(defn unnest-keys [x]
  (into {} (mapcat (fn [[k v]]
                     (if (map? v)
                       (map (fn [[k' v']]
                              [(str (name k) "." k') v'])
                            (unnest-keys v))
                       [[(name k) v]]))
                   x)))