gistfile1.hs

import Prelude hiding (span, head, null)
import Control.Monad (liftM2)
import Data.Vector (Vector, null, empty, cons, span, head, thaw, freeze)
import qualified Data.Vector.Algorithms.Intro as Intro (sort)

group :: Eq a => Vector a -> Vector (Vector a)
group vs | null vs   = empty
         | otherwise = a `cons` group b where (a, b) = span (== head vs) vs

sort :: Ord a => Vector a -> IO (Vector a)
sort vs = thaw vs >>= liftM2 (>>) Intro.sort freeze