20091201-libsvm-model-parser.clj

(defn combine [A B]
  (loop [a+ A
         b+ B
         acc []]
    (let [a (first a+)
          b (first b+)]
      (if (not a) ;; list a ended
        (concat acc b+)
        (if (not b) ;; list b ended
          (concat acc a+)
          (if (= a b) ;; items are the same
            (recur (next a+) (next b+) (conj acc a))
            (if (< a b) ;; either way
              (recur (next a+) b+ (conj acc a))
              (recur a+ (next b+) (conj acc b)))))))))