Fix AMP warnings.

Authored-by: David Luposchainsky <dluposchainsky@gmail.com>
Signed-off-by: Austin Seipp <austin@well-typed.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/utils/ghc-pkg/Main.hs b/utils/ghc-pkg/Main.hs
index 41ed265f4b..30acbe2eb8 100644
--- a/utils/ghc-pkg/Main.hs
+++ b/utils/ghc-pkg/Main.hs
@@ -34,6 +34,7 @@ import Data.Maybe
 
 import Data.Char ( isSpace, toLower )
 import Data.Ord (comparing)
+import Control.Applicative (Applicative(..))
 import Control.Monad
 import System.Directory ( doesDirectoryExist, getDirectoryContents,
                           doesFileExist, renameFile, removeFile,
@@ -1303,6 +1304,13 @@ type ValidateWarning = String
 
 newtype Validate a = V { runValidate :: IO (a, [ValidateError],[ValidateWarning]) }
 
+instance Functor Validate where
+    fmap = liftM
+
+instance Applicative Validate where
+    pure = return
+    (<*>) = ap
+
 instance Monad Validate where
    return a = V $ return (a, [], [])
    m >>= k = V $ do