On Thu, Jan 1, 2009 at 10:14 PM, Andrew Baine <andrew.ba...@gmail.com> wrote: > I want to get a seq of successive rests of the given seq: > user> (defn f [seq] > (if (empty? seq) > nil > (lazy-cons seq (f (rest seq))))) > #'user/f > user> (f '(1 2 3 4)) > ((1 2 3 4) (2 3 4) (3 4) (4))
Hi, Haskell has "tails" in the Data.List module which is similar, though it includes a null-list as a final value: *Main> Data.List.tails [1..4] [[1,2,3,4],[2,3,4],[3,4],[4],[]] *Main> take 10 . map (take 5) . Data.List.tails $ iterate (+1) 1 [[1,2,3,4,5],[2,3,4,5,6],[3,4,5,6,7],[4,5,6,7,8],[5,6,7,8,9],[6,7,8,9,10],[7,8,9,10,11],[8,9,10,11,12],[9,10,11,12,13],[10,11,12,13,14]] "Rests" makes good sense as a Clojure-name, IMO, as does not including a null-value at the end. Graham > user> (take 10 (map #(take 5 %) (f (iterate inc 1)))) > ((1 2 3 4 5) (2 3 4 5 6) (3 4 5 6 7) (4 5 6 7 8) (5 6 7 8 9) (6 7 8 9 10) (7 > 8 9 10 11) (8 9 10 11 12) (9 10 11 12 13) (10 11 12 13 14)) > Does this fn already exist in clojure? If not what would an idiomatic name > be for it from Haskell or CL? > Andrew > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
