Merge pull request #1278 from Dridus/except-instances

Add instance of MonadHandler and MonadWidget for ExceptT
yesodweb · Sep 25, 2016 · 06a6fbd · 06a6fbd
2 parents d1495ba + 09c37eb
commit 06a6fbd
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/yesod-core/Yesod/Core/Class/Handler.hs b/yesod-core/Yesod/Core/Class/Handler.hs
@@ -24,6 +24,9 @@ import Control.Monad.Trans.Identity ( IdentityT)
 import Control.Monad.Trans.List     ( ListT    )
 import Control.Monad.Trans.Maybe    ( MaybeT   )
 import Control.Monad.Trans.Error    ( ErrorT, Error)
+#if MIN_VERSION_transformers(0,4,0)
+import Control.Monad.Trans.Except   ( ExceptT  )
+#endif
 import Control.Monad.Trans.Reader   ( ReaderT  )
 import Control.Monad.Trans.State    ( StateT   )
 import Control.Monad.Trans.Writer   ( WriterT  )
@@ -55,6 +58,9 @@ GO(IdentityT)
 GO(ListT)
 GO(MaybeT)
 GOX(Error e, ErrorT e)
+#if MIN_VERSION_transformers(0,4,0)
+GO(ExceptT e)
+#endif
 GO(ReaderT r)
 GO(StateT s)
 GOX(Monoid w, WriterT w)
@@ -78,6 +84,9 @@ GO(IdentityT)
 GO(ListT)
 GO(MaybeT)
 GOX(Error e, ErrorT e)
+#if MIN_VERSION_transformers(0,4,0)
+GO(ExceptT e)
+#endif
 GO(ReaderT r)
 GO(StateT s)
 GOX(Monoid w, WriterT w)