[Haskell-cafe] Re: Function to detect duplicates

Rafael Gustavo da Cunha Pereira Pinto wrote:

While solving a puzzle, I was posed the problem of finding if there was no duplicates on a list.

First I used:

noneRepeated=null.(filter (>1)).(map length).group.sort

But this seemed very unneficient, so I thought that I could detect the duplicates while sorting, and devised this:

import Control.Monad import Data.Maybe

noneRepeated=isNothing . (foldl merge (Just [])) . (map sort) . pairs

import Data.List noneRepeated xs = xs == nub xs Greets Ertugrul -- nightmare = unsafePerformIO (getWrongWife >>= sex) http://blog.ertes.de/