Haskell：将类型别名更改为新类型会产生错误

在我的库中，我想向文档中的用户公开底层单子状态的名称，但是我不希望他们能够将其拆开-我想制作一个黑匣子。

因此，我从使用以下类型别名的完整代码开始：

type Surge e c z m = ErrorT (Failure z) (ReaderT (SurgeChan e c) (Parser' ByteString m))

然后，为了使其更强大，我将其更改为newtype并启用了GeneralizedNewtypeDeriving：

newtype Surge e c z m a = Surge
    { runSurge' :: ErrorT (Failure z) (ReaderT (SurgeChan e c) (Parser' ByteString m)) a }
    deriving (Monad, Applicative, Functor)

我还有一些其他的代码需要像这样调整：

res <- flip St.evalStateT prod . flip runReaderT sc . runErrorT $ pipeline

==>

res <- flip St.evalStateT prod . flip runReaderT sc . runErrorT . runSurge' $ pipeline

不幸的是，由于某种原因，在我进行type->newtype更改后，并非所有代码都会进行类型检查。这部分代码特别是：

{-# INLINE decodeAndHandlePacket #-}
decodeAndHandlePacket
    = handlePacket ~< errorP (lift.lift.liftM (first DecodeFailure) . decodeGet $ decodePacket)

...现在无法进行类型检查，出现了很长的错误，而以前却没有：

src/Surge/Internal.hs:101:27:
    Couldn't match type ‘ErrorT
                           (Failure z0) (t0 (St.StateT (Producer ByteString m0 x0) m0))’
                  with ‘Surge e c z m’
    Expected type: Proxy a' a () p' (Surge e c z m) ByteString
      Actual type: Proxy
                     a'
                     a
                     ()
                     p'
                     (ErrorT
                        (Failure z0) (t0 (St.StateT (Producer ByteString m0 x0) m0)))
                     ByteString
    Relevant bindings include
      decodeAndHandlePacket :: Proxy a' a () p' (Surge e c z m) ()
        (bound at src/Surge/Internal.hs:100:5)
      handleCommand :: Handler c p' (Surge e c z m)
        (bound at src/Surge/Internal.hs:84:7)
      handleEvent :: Handler e p' (Surge e c z m)
        (bound at src/Surge/Internal.hs:84:7)
      handlePacket :: Handler ByteString p' (Surge e c z m)
        (bound at src/Surge/Internal.hs:84:7)
      stage :: Stage ByteString p' e c (Surge e c z m)
               -> Producer ByteString (Surge e c z m) ()
        (bound at src/Surge/Internal.hs:84:1)
    In the second argument of ‘(~<)’, namely
      ‘errorP
         (lift . lift . liftM (first DecodeFailure) . decodeGet
          $ decodePacket)’
    In the expression:
      handlePacket
      ~<
        errorP
          (lift . lift . liftM (first DecodeFailure) . decodeGet
           $ decodePacket)

我不知道该怎么做。双方看起来与我相同。

完整代码可从http://lpaste.net/109472获得。谢谢。