Remove base-compat dependency from servant (#1744)

* Remove base-compat dependency from servant

* Reinstate CPP

Author: tchoutri

servant/servant.cabal

@@ -100,8 +100,7 @@ library
   -- Other dependencies: Lower bound around what is in the latest Stackage LTS.
   -- Here can be exceptions if we really need features from the newer versions.
   build-depends:
-      base-compat            >= 0.10.5   && < 0.14
-    , aeson                  >= 1.4.1.0  && < 2.3
+      aeson                  >= 1.4.1.0  && < 2.3
     , attoparsec             >= 0.13.2.2 && < 0.15
     , bifunctors             >= 5.5.3    && < 5.7
     , case-insensitive       >= 1.2.0.11 && < 1.3

servant/src/Servant/API/Alternative.hs

@@ -15,8 +15,6 @@ import           Data.Bitraversable
                  (Bitraversable (..))
 import           Data.Typeable
                  (Typeable)
-import           Prelude ()
-import           Prelude.Compat
 
 -- | Union of two APIs, first takes precedence in case of overlap.
 --

servant/src/Servant/API/ContentTypes.hs

@@ -71,7 +71,6 @@ module Servant.API.ContentTypes
 
 import           Control.Arrow
                  (left)
-import           Control.Monad.Compat
 import           Control.DeepSeq
                  (NFData)
 import           Data.Aeson
@@ -97,8 +96,6 @@ import           GHC.Generics
                  (Generic)
 import qualified GHC.TypeLits                     as TL
 import qualified Network.HTTP.Media               as M
-import           Prelude ()
-import           Prelude.Compat
 import           Web.FormUrlEncoded
                  (FromForm, ToForm, urlDecodeAsForm, urlEncodeAsForm)
 
@@ -299,7 +296,7 @@ instance {-# OVERLAPPING #-} ( Accept ctyp ) => AllMimeRender '[ctyp] NoContent
 instance {-# OVERLAPPING #-}
          ( AllMime (ctyp ': ctyp' ': ctyps)
          ) => AllMimeRender (ctyp ': ctyp' ': ctyps) NoContent where
-    allMimeRender p _ = zip (allMime p) (repeat "")
+    allMimeRender p _ = map (, "") (allMime p)
 
 --------------------------------------------------------------------------
 -- Check that all elements of list are instances of MimeUnrender

servant/src/Servant/API/Empty.hs

@@ -2,10 +2,7 @@
 {-# OPTIONS_HADDOCK not-home    #-}
 module Servant.API.Empty(EmptyAPI(..)) where
 
-import           Data.Typeable
-                 (Typeable)
-import           Prelude ()
-import           Prelude.Compat
+import           Data.Typeable (Typeable)
 
 -- | An empty API: one which serves nothing. Morally speaking, this should be
 -- the unit of ':<|>'. Implementors of interpretations of API types should

servant/src/Servant/API/ResponseHeaders.hs

@@ -3,11 +3,10 @@
 {-# LANGUAGE DeriveFunctor          #-}
 {-# LANGUAGE FlexibleContexts       #-}
 {-# LANGUAGE FlexibleInstances      #-}
-{-# LANGUAGE GADTs                  #-}
 {-# LANGUAGE FunctionalDependencies #-}
+{-# LANGUAGE GADTs                  #-}
 {-# LANGUAGE PolyKinds              #-}
 {-# LANGUAGE ScopedTypeVariables    #-}
-
 {-# LANGUAGE TypeFamilyDependencies #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
@@ -53,8 +52,6 @@ import qualified Network.HTTP.Types.Header as HTTP
 import           Web.HttpApiData
                  (FromHttpApiData, ToHttpApiData, parseHeader, toHeader)
 
-import           Prelude ()
-import           Prelude.Compat
 import           Servant.API.Header
                  (Header')
 import           Servant.API.Modifiers

servant/src/Servant/Links.hs

@@ -1,19 +1,21 @@
 {-# LANGUAGE AllowAmbiguousTypes    #-}
-{-# LANGUAGE CPP    #-}
-{-# LANGUAGE ConstraintKinds        #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE FlexibleContexts       #-}
 {-# LANGUAGE FlexibleInstances      #-}
 {-# LANGUAGE InstanceSigs           #-}
 {-# LANGUAGE PolyKinds              #-}
-{-# LANGUAGE QuantifiedConstraints    #-}
+{-# LANGUAGE QuantifiedConstraints  #-}
 {-# LANGUAGE ScopedTypeVariables    #-}
 {-# LANGUAGE TypeApplications       #-}
 {-# LANGUAGE TypeFamilies           #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
+
 {-# OPTIONS_HADDOCK not-home        #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
+{-# OPTIONS_GHC -Wno-missing-methods #-}
 
 -- | Type safe generation of internal links.
 --
@@ -145,8 +147,6 @@ import           GHC.TypeLits
                  (KnownSymbol, TypeError, symbolVal)
 import           Network.URI
                  (URI (..), escapeURIString, isUnreserved)
-import           Prelude ()
-import           Prelude.Compat
 
 import           Servant.API.Alternative
                  ((:<|>) ((:<|>)))
@@ -660,19 +660,19 @@ simpleToLink _ toA _ = toLink toA (Proxy :: Proxy sub)
 -- >>> import Data.Text (Text)
 
 -- Erroring instance for 'HasLink' when a combinator is not fully applied
-instance TypeError (PartialApplication 
+instance TypeError (PartialApplication
 #if __GLASGOW_HASKELL__ >= 904
-                    @(Type -> Constraint) 
+                    @(Type -> Constraint)
 #endif
                     HasLink arr) => HasLink ((arr :: a -> b) :> sub)
   where
     type MkLink (arr :> sub) _ = TypeError (PartialApplication (HasLink :: Type -> Constraint) arr)
     toLink = error "unreachable"
 
 -- Erroring instances for 'HasLink' for unknown API combinators
-instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub 
+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub
 #if __GLASGOW_HASKELL__ >= 904
-                                         @(Type -> Constraint) 
+                                         @(Type -> Constraint)
 #endif
                                          HasLink ty) => HasLink (ty :> sub)
 

servant/src/Servant/Types/SourceT.hs

@@ -18,9 +18,7 @@ import           Data.Functor.Classes
                  (Show1 (..), showsBinaryWith, showsPrec1, showsUnaryWith)
 import           Data.Functor.Identity
                  (Identity (..))
-import           Prelude ()
-import           Prelude.Compat             hiding
-                 (readFile)
+import           Prelude hiding (readFile)
 import           System.IO
                  (Handle, IOMode (..), withFile)
 import qualified Test.QuickCheck            as QC