gistfile1.clj

(defmacro rec-seq
 [binding-name & body]
  `(let [s# (atom nil)]
     (reset! s# (lazy-seq (let [~binding-name @s#] ~@body)))))
             
(defmacro rec-cat
 [binding-name & exprs]
  `(rec-seq ~binding-name (lazy-cat ~@exprs)))

;; Fibonacci
(take 10 (rec-cat [1 2] (map + s (next s))))
;; Gives (1 2 3 5 8 13 21 34 55 89)