Use DeriveFunctor throughout the codebase (#15654)

2 files changed, 4 insertions, 8 deletions

diff --git a/compiler/ghci/ByteCodeAsm.hs b/compiler/ghci/ByteCodeAsm.hs
index 0776e406d6..fb38ca1c02 100644
--- a/compiler/ghci/ByteCodeAsm.hs
+++ b/compiler/ghci/ByteCodeAsm.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns, CPP, MagicHash, RecordWildCards #-}
+{-# LANGUAGE BangPatterns, CPP, DeriveFunctor, MagicHash, RecordWildCards #-}
 {-# OPTIONS_GHC -optc-DNON_POSIX_SOURCE #-}
 --
 --  (c) The University of Glasgow 2002-2006
@@ -224,9 +224,7 @@ data Assembler a
   | AllocLabel Word16 (Assembler a)
   | Emit Word16 [Operand] (Assembler a)
   | NullAsm a
-
-instance Functor Assembler where
-    fmap = liftM
+  deriving (Functor)
 
 instance Applicative Assembler where
     pure = NullAsm
diff --git a/compiler/ghci/ByteCodeGen.hs b/compiler/ghci/ByteCodeGen.hs
index c4a08c4e40..33ae172d71 100644
--- a/compiler/ghci/ByteCodeGen.hs
+++ b/compiler/ghci/ByteCodeGen.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP, MagicHash, RecordWildCards, BangPatterns #-}
+{-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# OPTIONS_GHC -fprof-auto-top #-}
 --
@@ -1861,7 +1862,7 @@ data BcM_State
           -- See Note [generating code for top-level string literal bindings].
         }
 
-newtype BcM r = BcM (BcM_State -> IO (BcM_State, r))
+newtype BcM r = BcM (BcM_State -> IO (BcM_State, r)) deriving (Functor)
 
 ioToBc :: IO a -> BcM a
 ioToBc io = BcM $ \st -> do
@@ -1891,9 +1892,6 @@ thenBc_ (BcM expr) (BcM cont) = BcM $ \st0 -> do
 returnBc :: a -> BcM a
 returnBc result = BcM $ \st -> (return (st, result))
 
-instance Functor BcM where
-    fmap = liftM
-
 instance Applicative BcM where
     pure = returnBc
     (<*>) = ap