
Yesterday I rewrote `*>` for Data.Sequence (again), using an internal function cycleN :: Int -> Seq a -> Seq a The name of the function is based on that of Data.Sequence.iterateN. cycleN takes a sequence and cycles it as many times as requested: cycleN 0 $ fromList [1,2] = [] cycleN 5 $ fromList [1,2] = [1,2,1,2,1,2,1,2,1,2] The function is written to maximize sharing in the result sequence and to minimize construction time. Specifically, cycleN n xs should take something like O(|xs| + log n) space (of which all but O(log |xs| + log n) is shared with the structure of xs) and O(log |xs| + log n) time. With current (on GitHub) Data.Sequence exports, the only way to get this functionality with these time and space bounds is to combine replicate with *> : cycleN n xs = replicate n () *> xs This strikes me as a bit unpleasant. David