gistfile1.txt

module Merge where

merge :: (Ord a) => [a] -> [a] -> [a]
merge xs [] = xs
merge [] ys = ys
merge l@(x:xs) r@(y:ys) 
  | x < y     = x: merge xs r
  | otherwise = y: merge l ys

msort :: Ord a => [a] -> [a]
msort []  = []
msort [x] = [x]
msort xs = merge (msort left) (msort right)
  where 
    n = length xs `div` 2
    left  = take n xs
    right = drop n xs