scalarProduct = sum . map (×) . zip
quickSort [] = [] quickSort (x1:xs) = quickSort [x | x<-xs, x<=x1] ++ [x1] ++ quickSort [x | x<-xs, x>x1]
quickSort :: Ord a => [a] -> [a]
<=
>
sortBy :: (a -> a -> Ordering) -> [a] -> [a]
void *
means "a pointer to anything".