fwiw my folding solution above yields the expected result. On Sat, Nov 27, 2010 at 7:07 PM, Benny Tsai <benny.t...@gmail.com> wrote:
> > Subvec, however, isn't lazy. > > That's true. I just realized there's another problem with my approach > as well: it does not preserve elements before the first true index. > > user=> (partition-when true? [false true]) > ([true]) > > When the result should probably be: > > user=> (partition-when true? [false true]) > ((false) (true)) > > On Nov 27, 2:05 pm, Ken Wesson <kwess...@gmail.com> wrote: > > Subvec, however, isn't lazy. This is: > > > > (defn split-when [pred coll] > > (let [ipred (complement pred) > > bits (iterate > > (fn [[out coll]] > > (let [[a b] (split-with ipred (rest coll))] > > [(cons (first coll) a) b])) > > [nil coll])] > > (map #(first (first %)) > > (take-while #(seq (second (second %))) (map vector (rest bits) > bits))))) > > > > user=> (take 10 (split-when #(= 0 (rem % 3)) (iterate inc 1))) > > ((1 2) > > (3 4 5) > > (6 7 8) > > (9 10 11) > > (12 13 14) > > (15 16 17) > > (18 19 20) > > (21 22 23) > > (24 25 26) > > (27 28 29)) > > -- > 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<clojure%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > -- 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
