On 12 Dec 2008, at 23:10, Mark Fredrickson wrote: >> For (2), say I want to insert 3 before every item less than or equal >> to 5 in a seq: > > Again reduce to the rescue: > > (reduce into (map (fn [i] (if (<= i 5) [3 i] [i])) [24 6 5 5 7 5 8 > 2]))
Could use mapcat: (def bar [24 6 5 5 7 5 8 2]) (defn insert-before-if [pred ins lst] (mapcat #(if (pred %) [ins %] [%]) lst)) (insert-before-if #(<= 5 %) 3 bar) => (3 24 3 6 3 5 3 5 3 7 3 5 3 8 2) stephen --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---