Hi, Am 29.01.2010 um 16:25 schrieb Wilson MacGyver:
> I saw this on twitter. > > http://pastie.org/796264 > > The problem: given a list of strings, produce a list where sequential > non-empty strings are concatenated > > # Conditions: Do not use iteration. > # > # Example: glom (["a", "b", "c"]) = ["abc"] > # glom (["a", "", "b"]) = ["a", "b"] > # glom (["a", "b", "", "c"]) = ["ab", "c"] > # glom (["a", "b", "", "", "c"]) = ["ab", "c"] > > > The author had rules like, don't use iteration and avoid recursion. > > anyone have any clever solutions? My first reaction was to use reduce, but > I'm not sure how that'd work. I don't know the definition of iteration, but for my (naive, hobbyist) understanding you won't get around it. Recursion is just another form. A map call is just another form. A reduce call is just another form. You have to walk the sequence in one way or the other and I would call that „iteration“. But I called the shot already in the sieve thread. So I will shut up now. Please enlighten me if this is totally wrong. Here a recursive definition. (defn glom [coll] (lazy-seq (when-let [s (seq coll)] (let [[items tail] (split-with (complement empty?) s) tail (drop-while empty? tail)] (cons (apply str items) (glom tail)))))) Sincerely Meikel -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
