pfds 2.1 suffixes sml

2.1.suffix.clj

(defn suffixes
  "Recursive suffixes"
  [xs]
  (if-let [xs (seq xs)]
    (cons xs (suffixes (rest xs)))
    [()]))


(defn suffixes
  "Tail-recursive suffixes"
  [xs]
  (letfn [(f [xs rs]
            (if (seq xs)
              (recur (rest xs) (conj rs xs))
              (conj rs [])))]
    (f xs [])))