> > For (1), it seems you generally resort to some kind of recursion with > loop/recur. Say we wish to find the max value in a list (without using > 'max'):
I can do this with reduce: user=> (defn my-max [lst] (reduce (fn [x a] (if (> x a) x a)) (first lst) (rest lst))) #'user/my-max user=> (my-max '(2 4 12 3 4)) 12 For more complex data that you need to bring along, use a list or map. > 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])) This is still O(n) - though it needs to iterate the vector twice. The second version shows off Clojure's nice improvement to reduce (vis-a- vis fold in Scheme): grabbing the first item from the head of the list/ vec/seq. The down side is I can't write multi-sequence reduce calls like Scheme, but c'est la vie. I could write O(n) versions with continuations in Scheme, but I think loop/recur would be required in Clojure. Cheers, -Mark --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
