spiral.clj

(ns spiral)
  (def matrix1 [[1 2 3][8 9 4][7 6 5]])
  (def matrix2 [[1 2 3 4][12 13 14 5][11 16 15 6][10 9 8 7]])
  (defn spiral-print [matrix]
    (let [ [row & rows] (seq matrix)]
      (doseq [el row] (print (str " " el)))
        (when (seq rows)
          (->> rows (apply map vector) reverse recur))))
  (spiral-print matrix1)
  (spiral-print matrix2)

[[1 2 3] [[4 5] [[6 7] [[8]
[8 9 4] -> [9 6] -> [9 8]] -> [9]] -> [[9]]
[7 6 5]] [8 7]]

(defn spiral
  [matrix]
  (let [[row & rows] (seq matrix)]
    (doseq [el row] (print el))
    (when (seq rows)
      (->> rows (apply map vector) reverse recur))))

;; Evil version
(->> rows
     (apply map vector)
     reverse
     recur
     (when (seq rows))
     (let [[row & rows] (seq matrix)] (doseq [el row] (print el)))
     (defn spiral [matrix]))

This is really tricky :)