fix given code of lecture 7 due to breaking changes in haskell (thanks Giacomo Cavalieri!! :D)

1 files changed, 2 insertions, 1 deletions

diff --git a/lec07/Editor.hs b/lec07/Editor.hs
index 8f35414..8271118 100644
--- a/lec07/Editor.hs
+++ b/lec07/Editor.hs
@@ -10,6 +10,7 @@ import Buffer
 import Control.Exception
 import Control.Monad.State
 
+import Control.Monad (when, zipWithM_)
 import Control.Applicative
 import Control.Arrow       (first, second)
 
@@ -35,7 +36,7 @@ commands = map show [View, Edit, Next, Prev, Quit]
 -- Editor monad
 
 newtype Editor b a = Editor (StateT (b,Int) IO a)
-  deriving (Functor, Monad, MonadIO, MonadState (b,Int))
+  deriving (Functor, Applicative, Monad, MonadIO, MonadState (b,Int))
 
 runEditor :: Buffer b => Editor b a -> b -> IO a
 runEditor (Editor e) b = evalStateT e (b,0)