2010/2/23 Jonas Almström Duregård <jonas.dureg...@gmail.com>: > Hi Rafael, > > I assume you will perform this operation on some very large lists, or > performance would not be an issue. Have you tested if your optimized > version is better than your initial one? > > You should compare your implementation against something like this: > > import qualified Data.Set as Set > noneRepeated :: (Ord a) => [a] -> Bool > noneRepeated = accum Set.empty where > accum _ [] = True > accum s (x:xs) > | Set.member x s = False > | otherwise = accum (Set.insert x s) xs > > Also there is some discussion about the nub function that relates to > this topic, e.g. http://buffered.io/2008/07/28/a-better-nub/. > > /Jonas
Or better yet, http://www.haskell.org/pipermail/libraries/2008-October/010778.html Much more thorough and practical w/r/t to actually getting faster nubs in the libraries. -- gwern _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
