4 files changed, 38 insertions, 3 deletions
diff --git a/compiler/main/CmdLineParser.hs b/compiler/main/CmdLineParser.hs
index 252a376432..6681186246 100644
--- a/compiler/main/CmdLineParser.hs
+++ b/compiler/main/CmdLineParser.hs
@@ -30,6 +30,9 @@ import SrcLoc
 import Data.Function
 import Data.List
 
+import Control.Monad (liftM, ap)
+import Control.Applicative (Applicative(..))
+
 
 --------------------------------------------------------
 --         The Flag and OptKind types
@@ -72,6 +75,13 @@ newtype EwM m a = EwM { unEwM :: Located String -- Current parse arg
                               -> Errs -> Warns
                               -> m (Errs, Warns, a) }
 
+instance Monad m => Functor (EwM m) where
+    fmap = liftM
+
+instance Monad m => Applicative (EwM m) where
+    pure = return
+    (<*>) = ap
+
 instance Monad m => Monad (EwM m) where
     (EwM f) >>= k = EwM (\l e w -> do (e', w', r) <- f l e w
                                       unEwM (k r) l e' w')
@@ -108,6 +118,13 @@ liftEwM action = EwM (\_ es ws -> do { r <- action; return (es, ws, r) })
 -- (CmdLineP s) typically instantiates the 'm' in (EwM m) and (OptKind m)
 newtype CmdLineP s a = CmdLineP { runCmdLine :: s -> (a, s) }
 
+instance Functor (CmdLineP s) where
+    fmap = liftM
+
+instance Applicative (CmdLineP s) where
+    pure = return
+    (<*>) = ap
+
 instance Monad (CmdLineP s) where
     m >>= k = CmdLineP $ \s ->
                   let (a, s') = runCmdLine m s
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index 7c5bc90647..a6567c8c39 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -669,6 +669,13 @@ newtype CompPipeline a = P { unP :: PipeEnv -> PipeState -> IO (PipeState, a) }
 evalP :: CompPipeline a -> PipeEnv -> PipeState -> IO a
 evalP f env st = liftM snd $ unP f env st
 
+instance Functor CompPipeline where
+    fmap = liftM
+
+instance Applicative CompPipeline where
+    pure = return
+    (<*>) = ap
+
 instance Monad CompPipeline where
   return a = P $ \_env state -> return (state, a)
   P m >>= k = P $ \env state -> do (state',a) <- m env state
diff --git a/compiler/main/HscMain.hs b/compiler/main/HscMain.hs
index ad1b7c503a..774f5be488 100644
--- a/compiler/main/HscMain.hs
+++ b/compiler/main/HscMain.hs
@@ -194,6 +194,13 @@ knownKeyNames =              -- where templateHaskellNames are defined
 
 newtype Hsc a = Hsc (HscEnv -> WarningMessages -> IO (a, WarningMessages))
 
+instance Functor Hsc where
+    fmap = liftM
+
+instance Applicative Hsc where
+    pure = return
+    (<*>) = ap
+
 instance Monad Hsc where
     return a    = Hsc $ \_ w -> return (a, w)
     Hsc m >>= k = Hsc $ \e w -> do (a, w1) <- m e w
@@ -203,9 +210,6 @@ instance Monad Hsc where
 instance MonadIO Hsc where
     liftIO io = Hsc $ \_ w -> do a <- io; return (a, w)
 
-instance Functor Hsc where
-    fmap f m = m >>= \a -> return $ f a
-
 runHsc :: HscEnv -> Hsc a -> IO a
 runHsc hsc_env (Hsc hsc) = do
     (a, w) <- hsc hsc_env emptyBag
diff --git a/compiler/main/TidyPgm.lhs b/compiler/main/TidyPgm.lhs
index d6a3da13e6..9886fe394f 100644
--- a/compiler/main/TidyPgm.lhs
+++ b/compiler/main/TidyPgm.lhs
@@ -749,6 +749,13 @@ newtype DFFV a
       -> (VarSet, [Var])      -- Input State: (set, list) of free vars so far
       -> ((VarSet,[Var]),a))  -- Output state
 
+instance Functor DFFV where
+    fmap = liftM
+
+instance Applicative DFFV where
+    pure = return
+    (<*>) = ap
+
 instance Monad DFFV where
   return a = DFFV $ \_ st -> (st, a)
   (DFFV m) >>= k = DFFV $ \env st ->