gistfile1.txt

(def bt {:left {:value 3}
         :value 5
         :right {:left {:value 2}
                 :value :foo
                 :right {:left {:value :bar}
                         :value :quux
                         :right {:value 10}}}})

(loop [bt bt
       q (clojure.lang.PersistentQueue/EMPTY)]
  (let [{:keys [left right value]} bt]
    (if left
      (recur left (into q [{:value value} right]))
      (do (println value)
          (cond right (recur right q)
                (empty? q) :done
                :else (recur (peek q) (pop q)))))))