合并排序仅涉及几个简单步骤：

1. 检查列表是否为空或具有单个元素。如果是这样，则返回列表不变。

2. 将列表分成两半。合并两个部分。

3. 通过重复从两个列表中删除较小的元素来合并列表。由于零件列表已经排序，因此只需查看两个列表中的第一个元素并选择较小的即可。

4. 返回合并列表。

结果，您将获得一个按最小元素顺序排序的链表。

Haskell中的代码示例：

import Data.List(splitAt)

--Mergesorts a list by smallest element first.
sort :: Ord a => [a] -> [a]
sort = sortBy (<)

--Generic sort that can sort in any order.
sortBy :: (a -> a -> Bool) -> [a] -> [a]
sortBy _ [] = []
sortBy _ [x] = [x]
sortBy f xs = merge f (sortBy f first) (sortBy f second)
    where
        (first,second) = split xs

--Splits a list in half.
split :: [a] -> ([a],[a])
split xs = splitAt (halfLength xs) xs

--Returns a lists length divided by two as a whole number (rounded).
halfLength :: [a] -> Int
halfLength = round . (/2) . fromIntegral . length

--Merges two lists in the provided order.
merge :: (a -> a -> Bool) -> [a] -> [a] -> [a]
merge _ [] [] = []
merge _ [] (y:ys) = y:ys
merge _ (x:xs) [] = x:xs
merge f (x:xs) (y:ys) =
    if f x y
        then x : merge f xs (y:ys)
        else y : merge f (x:xs) ys