How can I get the nested keys of a map in clojure?

Question

if my structure is

{ :a :A
  :b :B
  :c {
       :d :D
     }
  :e {
       :f {
            :g :G
            :h :H
          }
     }
}

I

Answer 1

This answer of mine is just to illustrate how NOT to do it since it is still procedural.

(defn keys-in [data] (genkeys [] data))

(defn genkeys [parent data]
  (let [mylist (transient [])]
    (doseq [k (keys data)]
      (do
        (if ( = (class (k data)) clojure.lang.PersistentHashMap )
          (#(reduce conj! %1 %2) mylist (genkeys (conj parent  k ) (k data) ))
          (conj! mylist  (conj parent  k ) )
          )))
    (persistent! mylist)))