use base-compat

servant/servant.cabal

@@ -47,6 +47,7 @@ library
     Servant.Utils.Links
   build-depends:
       base >=4.7 && <5
+    , base-compat >= 0.8
     , aeson >= 0.7
     , attoparsec >= 0.12
     , bytestring == 0.10.*

servant/src/Servant/API/Alternative.hs

@@ -9,12 +9,9 @@
 {-# OPTIONS_HADDOCK not-home    #-}
 module Servant.API.Alternative ((:<|>)(..)) where
 
-#if !MIN_VERSION_base(4,8,0)
-import           Data.Monoid      (Monoid (..))
-import           Data.Traversable (Traversable)
-import           Data.Foldable    (Foldable)
-#endif
 import           Data.Typeable    (Typeable)
+import           Prelude.Compat (Monoid(..), Traversable, Foldable)
+
 -- | Union of two APIs, first takes precedence in case of overlap.
 --
 -- Example:

servant/src/Servant/API/ContentTypes.hs

@@ -72,11 +72,8 @@ module Servant.API.ContentTypes
     , canHandleAcceptH
     ) where
 
-#if !MIN_VERSION_base(4,8,0)
-import           Control.Applicative              ((*>), (<*))
-#endif
 import           Control.Arrow                    (left)
-import           Control.Monad
+import           Control.Monad.Compat             hiding (mapM)
 import           Data.Aeson                       (FromJSON(..), ToJSON(..), encode)
 import           Data.Aeson.Parser                (value)
 import           Data.Aeson.Types                 (parseEither)
@@ -88,7 +85,7 @@ import           Data.ByteString.Lazy             (ByteString, fromStrict,
 import qualified Data.ByteString.Lazy             as B
 import qualified Data.ByteString.Lazy.Char8       as BC
 import           Data.Maybe                       (isJust)
-import           Data.Monoid
+import           Data.Monoid.Compat
 import           Data.String.Conversions          (cs)
 import qualified Data.Text                        as TextS
 import qualified Data.Text.Encoding               as TextS
@@ -99,6 +96,7 @@ import           GHC.Generics                     (Generic)
 import qualified Network.HTTP.Media               as M
 import           Network.URI                      (escapeURIString,
                                                    isUnreserved, unEscapeString)
+import           Prelude.Compat                   ((<*), (*>))
 
 -- * Provided content types
 data JSON deriving Typeable

servant/src/Servant/API/Internal/Test/ComprehensiveAPI.hs

@@ -7,7 +7,6 @@
 module Servant.API.Internal.Test.ComprehensiveAPI where
 
 import           Data.Proxy
-
 import           Servant.API
 
 type GET = Get '[JSON] ()

servant/src/Servant/API/ResponseHeaders.hs

@@ -30,9 +30,6 @@ module Servant.API.ResponseHeaders
     , HList(..)
     ) where
 
-#if !MIN_VERSION_base(4,8,0)
-import           Control.Applicative         ((<$>))
-#endif
 import           Data.ByteString.Char8       as BS (pack, unlines, init)
 import           Data.ByteString.Conversion  (ToByteString, toByteString',
                                               FromByteString, fromByteString)
@@ -42,6 +39,7 @@ import           GHC.TypeLits                (KnownSymbol, symbolVal)
 import qualified Network.HTTP.Types.Header   as HTTP
 
 import           Servant.API.Header          (Header (..))
+import           Prelude.Compat
 
 -- | Response Header objects. You should never need to construct one directly.
 -- Instead, use 'addHeader'.

servant/src/Servant/Utils/Links.hs

@@ -105,11 +105,7 @@ import Data.List
 import Data.Proxy ( Proxy(..) )
 import qualified Data.Text as Text
 import qualified Data.ByteString.Char8 as BSC
-#if !MIN_VERSION_base(4,8,0)
+import Data.Monoid.Compat ( Monoid(..), (<>) )
-import Data.Monoid ( Monoid(..), (<>) )
-#else
-import Data.Monoid ( (<>) )
-#endif
 import Network.URI ( URI(..), escapeURIString, isUnreserved )
 import GHC.TypeLits ( KnownSymbol, symbolVal )
 import GHC.Exts(Constraint)

stack-ghc-7.8.4.yaml

@@ -12,6 +12,7 @@ packages:
 - servant-mock/
 - servant-server/
 extra-deps:
+- base-compat-0.9.0
 - hspec-2.2.0
 - hspec-core-2.2.0
 - hspec-discover-2.2.0