[commit: packages/haskeline] master: MonadFix instance for InputT (13d2bd1)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/haskeline

On branch  : master
Link       : http://git.haskell.org/packages/haskeline.git/commitdiff/13d2bd1d4bd02a89026f26ec02510e40b872ce34

>---------------------------------------------------------------

commit 13d2bd1d4bd02a89026f26ec02510e40b872ce34
Author: Alexander Vieth <alexander.vieth at mail.mcgill.ca>
Date:   Tue Jun 21 18:16:37 2016 -0400

    MonadFix instance for InputT


>---------------------------------------------------------------

13d2bd1d4bd02a89026f26ec02510e40b872ce34
 System/Console/Haskeline/InputT.hs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/System/Console/Haskeline/InputT.hs b/System/Console/Haskeline/InputT.hs
index c1ee55e..1fcd4cc 100644
--- a/System/Console/Haskeline/InputT.hs
+++ b/System/Console/Haskeline/InputT.hs
@@ -15,6 +15,7 @@ import System.Directory(getHomeDirectory)
 import System.FilePath
 import Control.Applicative
 import Control.Monad (liftM, ap)
+import Control.Monad.Fix
 import System.IO
 import Data.IORef
 
@@ -56,6 +57,9 @@ newtype InputT m a = InputT {unInputT ::
 instance MonadTrans InputT where
     lift = InputT . lift . lift . lift . lift . lift
 
+instance ( MonadFix m ) => MonadFix (InputT m) where
+    mfix f = InputT (mfix (unInputT . f))
+
 -- | Get the current line input history.
 getHistory :: MonadIO m => InputT m History
 getHistory = InputT get