less OverlappingInstances noise

servant-blaze/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-blaze/servant-blaze.cabal

@@ -30,3 +30,4 @@ library
                      , blaze-html
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include

servant-blaze/src/Servant/HTML/Blaze.hs

@@ -3,10 +3,8 @@
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings     #-}
-#if !MIN_VERSION_base(4,8,0)
-{-# LANGUAGE OverlappingInstances  #-}
-#endif
 
+#include "overlapping-compat.h"
 -- | An @HTML@ empty data type with `MimeRender` instances for @blaze-html@'s
 -- `ToMarkup` class and `Html` datatype.
 -- You should only need to import this module for it's instances and the
@@ -29,17 +27,9 @@ data HTML deriving Typeable
 instance Accept HTML where
     contentType _ = "text" M.// "html" M./: ("charset", "utf-8")
 
-instance
+instance OVERLAPPABLE_ ToMarkup a => MimeRender HTML a where
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ToMarkup a => MimeRender HTML a where
     mimeRender _ = renderHtml . toHtml
 
-instance
+instance OVERLAPPING_ MimeRender HTML Html where
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender HTML Html where
     mimeRender _ = renderHtml
 

servant-cassava/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-cassava/servant-cassava.cabal

@@ -27,3 +27,4 @@ library
                      , vector
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include

servant-client/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-client/servant-client.cabal

@@ -49,6 +49,7 @@ library
   hs-source-dirs: src
   default-language: Haskell2010
   ghc-options: -Wall
+  include-dirs: include
 
 test-suite spec
   type: exitcode-stdio-1.0

servant-client/src/Servant/Client.hs

@@ -8,9 +8,8 @@
 {-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE TypeOperators        #-}
 {-# LANGUAGE UndecidableInstances #-}
-#if !MIN_VERSION_base(4,8,0)
+
-{-# LANGUAGE OverlappingInstances #-}
+#include "overlapping-compat.h"
-#endif
 -- | This module provides 'client' which can automatically generate
 -- querying functions for each endpoint just from the type representing your
 -- API.
@@ -123,19 +122,13 @@ instance (KnownSymbol capture, ToHttpApiData a, HasClient sublayout)
 -- side querying function that is created when calling 'client'
 -- will just require an argument that specifies the scheme, host
 -- and port to send the request to.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
   (MimeUnrender ct a, cts' ~ (ct ': cts)) => HasClient (Delete cts' a) where
   type Client (Delete cts' a) = ExceptT ServantError IO a
   clientWithRoute Proxy req baseurl manager =
     snd <$> performRequestCT (Proxy :: Proxy ct) H.methodDelete req baseurl manager
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   HasClient (Delete cts ()) where
   type Client (Delete cts ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
@@ -143,10 +136,7 @@ instance
 
 -- | If you have a 'Delete xs (Headers ls x)' endpoint, the client expects the
 -- corresponding headers.
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   ( MimeUnrender ct a, BuildHeadersTo ls, cts' ~ (ct ': cts)
   ) => HasClient (Delete cts' (Headers ls a)) where
   type Client (Delete cts' (Headers ls a)) = ExceptT ServantError IO (Headers ls a)
@@ -160,19 +150,13 @@ instance
 -- side querying function that is created when calling 'client'
 -- will just require an argument that specifies the scheme, host
 -- and port to send the request to.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
   (MimeUnrender ct result) => HasClient (Get (ct ': cts) result) where
   type Client (Get (ct ': cts) result) = ExceptT ServantError IO result
   clientWithRoute Proxy req baseurl manager =
     snd <$> performRequestCT (Proxy :: Proxy ct) H.methodGet req baseurl manager
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   HasClient (Get (ct ': cts) ()) where
   type Client (Get (ct ': cts) ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
@@ -180,10 +164,7 @@ instance
 
 -- | If you have a 'Get xs (Headers ls x)' endpoint, the client expects the
 -- corresponding headers.
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   ( MimeUnrender ct a, BuildHeadersTo ls
   ) => HasClient (Get (ct ': cts) (Headers ls a)) where
   type Client (Get (ct ': cts) (Headers ls a)) = ExceptT ServantError IO (Headers ls a)
@@ -240,19 +221,13 @@ instance (KnownSymbol sym, ToHttpApiData a, HasClient sublayout)
 -- side querying function that is created when calling 'client'
 -- will just require an argument that specifies the scheme, host
 -- and port to send the request to.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
   (MimeUnrender ct a) => HasClient (Post (ct ': cts) a) where
   type Client (Post (ct ': cts) a) = ExceptT ServantError IO a
   clientWithRoute Proxy req baseurl manager =
     snd <$> performRequestCT (Proxy :: Proxy ct) H.methodPost req baseurl manager
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   HasClient (Post (ct ': cts) ()) where
   type Client (Post (ct ': cts) ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
@@ -260,10 +235,7 @@ instance
 
 -- | If you have a 'Post xs (Headers ls x)' endpoint, the client expects the
 -- corresponding headers.
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   ( MimeUnrender ct a, BuildHeadersTo ls
   ) => HasClient (Post (ct ': cts) (Headers ls a)) where
   type Client (Post (ct ': cts) (Headers ls a)) = ExceptT ServantError IO (Headers ls a)
@@ -277,19 +249,13 @@ instance
 -- side querying function that is created when calling 'client'
 -- will just require an argument that specifies the scheme, host
 -- and port to send the request to.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
   (MimeUnrender ct a) => HasClient (Put (ct ': cts) a) where
   type Client (Put (ct ': cts) a) = ExceptT ServantError IO a
   clientWithRoute Proxy req baseurl manager =
     snd <$> performRequestCT (Proxy :: Proxy ct) H.methodPut req baseurl manager
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   HasClient (Put (ct ': cts) ()) where
   type Client (Put (ct ': cts) ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
@@ -297,10 +263,7 @@ instance
 
 -- | If you have a 'Put xs (Headers ls x)' endpoint, the client expects the
 -- corresponding headers.
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   ( MimeUnrender ct a, BuildHeadersTo ls
   ) => HasClient (Put (ct ': cts) (Headers ls a)) where
   type Client (Put (ct ': cts) (Headers ls a)) = ExceptT ServantError IO (Headers ls a)
@@ -314,19 +277,13 @@ instance
 -- side querying function that is created when calling 'client'
 -- will just require an argument that specifies the scheme, host
 -- and port to send the request to.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
   (MimeUnrender ct a) => HasClient (Patch (ct ': cts) a) where
   type Client (Patch (ct ': cts) a) = ExceptT ServantError IO a
   clientWithRoute Proxy req baseurl manager =
     snd <$> performRequestCT (Proxy :: Proxy ct) H.methodPatch req baseurl manager
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   HasClient (Patch (ct ': cts) ()) where
   type Client (Patch (ct ': cts) ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
@@ -334,10 +291,7 @@ instance
 
 -- | If you have a 'Patch xs (Headers ls x)' endpoint, the client expects the
 -- corresponding headers.
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   ( MimeUnrender ct a, BuildHeadersTo ls
   ) => HasClient (Patch (ct ': cts) (Headers ls a)) where
   type Client (Patch (ct ': cts) (Headers ls a)) = ExceptT ServantError IO (Headers ls a)

servant-client/test/Servant/ClientSpec.hs

@@ -6,9 +6,6 @@
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE GADTs                  #-}
 {-# LANGUAGE MultiParamTypeClasses  #-}
-#if !MIN_VERSION_base(4,8,0)
-{-# LANGUAGE OverlappingInstances   #-}
-#endif
 {-# LANGUAGE OverloadedStrings      #-}
 {-# LANGUAGE PolyKinds              #-}
 {-# LANGUAGE RecordWildCards        #-}
@@ -20,6 +17,7 @@
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
+#include "overlapping-compat.h"
 module Servant.ClientSpec where
 
 #if !MIN_VERSION_base(4,8,0)
@@ -323,33 +321,21 @@ pathGen = fmap NonEmpty path
 class GetNth (n :: Nat) a b | n a -> b where
     getNth :: Proxy n -> a -> b
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   GetNth 0 (x :<|> y) x where
       getNth _ (x :<|> _) = x
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   (GetNth (n - 1) x y) => GetNth n (a :<|> x) y where
       getNth _ (_ :<|> x) = getNth (Proxy :: Proxy (n - 1)) x
 
 class GetLast a b | a -> b where
     getLast :: a -> b
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   (GetLast b c) => GetLast (a :<|> b) c where
       getLast (_ :<|> b) = getLast b
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
   GetLast a a where
       getLast a = a

servant-docs/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-docs/servant-docs.cabal

@@ -49,6 +49,7 @@ library
   hs-source-dirs: src
   default-language: Haskell2010
   ghc-options: -Wall
+  include-dirs: include
 
 executable greet-docs
   main-is: greet.hs

servant-docs/src/Servant/Docs/Internal.hs

@@ -16,9 +16,8 @@
 {-# LANGUAGE TypeFamilies           #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
-#if !MIN_VERSION_base(4,8,0)
+
-{-# LANGUAGE OverlappingInstances   #-}
+#include "overlapping-compat.h"
-#endif
 module Servant.Docs.Internal where
 
 import           Control.Applicative
@@ -661,10 +660,7 @@ markdown api = unlines $
 
 -- | The generated docs for @a ':<|>' b@ just appends the docs
 --   for @a@ with the docs for @b@.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          (HasDocs layout1, HasDocs layout2)
       => HasDocs (layout1 :<|> layout2) where
 
@@ -692,10 +688,7 @@ instance (KnownSymbol sym, ToCapture (Capture sym a), HasDocs sublayout)
           symP = Proxy :: Proxy sym
 
 
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
     => HasDocs (Delete cts a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
@@ -707,10 +700,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Delete cts (Headers ls a)) where
@@ -725,10 +715,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
     => HasDocs (Get cts a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
@@ -740,10 +727,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Get cts (Headers ls a)) where
@@ -767,10 +751,7 @@ instance (KnownSymbol sym, HasDocs sublayout)
           action' = over headers (|> headername) action
           headername = pack $ symbolVal (Proxy :: Proxy sym)
 
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
     => HasDocs (Post cts a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
@@ -783,10 +764,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          (ToSample a, IsNonEmpty cts, AllMimeRender cts a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Post cts (Headers ls a)) where
@@ -802,10 +780,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
         (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
     => HasDocs (Put cts a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
@@ -818,10 +793,7 @@ instance
           t = Proxy :: Proxy cts
           p = Proxy :: Proxy a
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
         ( ToSample a, IsNonEmpty cts, AllMimeRender cts a,
           AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Put cts (Headers ls a)) where

servant-examples/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-foreign/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-foreign/servant-foreign.cabal

@@ -33,6 +33,7 @@ library
   hs-source-dirs:      src
   default-language:    Haskell2010
   ghc-options:         -Wall
+  include-dirs: include
 
 
 test-suite spec

servant-jquery/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-js/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-js/servant-js.cabal

@@ -49,6 +49,7 @@ library
   hs-source-dirs:      src
   default-language:    Haskell2010
   ghc-options:         -Wall
+  include-dirs: include
 
 executable counter
   main-is: counter.hs

servant-lucid/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-lucid/servant-lucid.cabal

@@ -30,3 +30,4 @@ library
                      , servant == 0.5.*
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include

servant-lucid/src/Servant/HTML/Lucid.hs

@@ -3,9 +3,8 @@
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings     #-}
-#if !MIN_VERSION_base(4,8,0)
+
-{-# LANGUAGE OverlappingInstances  #-}
+#include "overlapping-compat.h"
-#endif
 
 -- | An @HTML@ empty data type with `MimeRender` instances for @lucid@'s
 -- `ToHtml` class and `Html` datatype.
@@ -28,16 +27,10 @@ data HTML deriving Typeable
 instance Accept HTML where
     contentType _ = "text" M.// "html" M./: ("charset", "utf-8")
 
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ToHtml a => MimeRender HTML a where
     mimeRender _ = renderBS . toHtml
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          MimeRender HTML (Html a) where
     mimeRender _ = renderBS

servant-mock/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-mock/servant-mock.cabal

@@ -34,6 +34,7 @@ library
     wai >= 3.0 && <3.1
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
 
 executable mock-app
   main-is: main.hs

servant-property/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-server/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant-server/servant-server.cabal

@@ -69,6 +69,7 @@ library
   hs-source-dirs: src
   default-language: Haskell2010
   ghc-options: -Wall
+  include-dirs: include
 
 executable greet
   main-is: greet.hs
@@ -134,3 +135,4 @@ test-suite doctests
  buildable: True
  default-language: Haskell2010
  ghc-options: -threaded
+ include-dirs: include

servant-server/src/Servant/Server/Internal.hs

@@ -8,9 +8,8 @@
 {-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE TypeOperators              #-}
-#if !MIN_VERSION_base(4,8,0)
+
-{-# LANGUAGE OverlappingInstances       #-}
+#include "overlapping-compat.h"
-#endif
 
 module Servant.Server.Internal
   ( module Servant.Server.Internal
@@ -206,10 +205,7 @@ methodRouterEmpty method action = LeafRouter route'
 -- to be returned. You can use 'Control.Monad.Trans.Except.throwE' to
 -- painlessly error out if the conditions for a successful deletion
 -- are not met.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ( AllCTRender ctypes a
          ) => HasServer (Delete ctypes a) where
 
@@ -217,10 +213,7 @@ instance
 
   route Proxy = methodRouter methodDelete (Proxy :: Proxy ctypes) ok200
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          HasServer (Delete ctypes ()) where
 
   type ServerT (Delete ctypes ()) m = m ()
@@ -228,10 +221,7 @@ instance
   route Proxy = methodRouterEmpty methodDelete
 
 -- Add response headers
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Delete ctypes (Headers h v)) where
 
@@ -252,10 +242,7 @@ instance
 -- (returning a status code of 200). If there was no @Accept@ header or it
 -- was @*\/\*@, we return encode using the first @Content-Type@ type on the
 -- list.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ( AllCTRender ctypes a ) => HasServer (Get ctypes a) where
 
   type ServerT (Get ctypes a) m = m a
@@ -263,10 +250,7 @@ instance
   route Proxy = methodRouter methodGet (Proxy :: Proxy ctypes) ok200
 
 -- '()' ==> 204 No Content
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
           HasServer (Get ctypes ()) where
 
   type ServerT (Get ctypes ()) m = m ()
@@ -274,10 +258,7 @@ instance
   route Proxy = methodRouterEmpty methodGet
 
 -- Add response headers
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
           ( GetHeaders (Headers h v), AllCTRender ctypes v
           ) => HasServer (Get ctypes (Headers h v)) where
 
@@ -329,10 +310,7 @@ instance (KnownSymbol sym, FromHttpApiData a, HasServer sublayout)
 -- (returning a status code of 201). If there was no @Accept@ header or it
 -- was @*\/\*@, we return encode using the first @Content-Type@ type on the
 -- list.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ( AllCTRender ctypes a
          ) => HasServer (Post ctypes a) where
 
@@ -340,10 +318,7 @@ instance
 
   route Proxy = methodRouter methodPost (Proxy :: Proxy ctypes) created201
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          HasServer (Post ctypes ()) where
 
   type ServerT (Post ctypes ()) m = m ()
@@ -351,10 +326,7 @@ instance
   route Proxy = methodRouterEmpty methodPost
 
 -- Add response headers
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Post ctypes (Headers h v)) where
 
@@ -375,20 +347,14 @@ instance
 -- (returning a status code of 200). If there was no @Accept@ header or it
 -- was @*\/\*@, we return encode using the first @Content-Type@ type on the
 -- list.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ( AllCTRender ctypes a) => HasServer (Put ctypes a) where
 
   type ServerT (Put ctypes a) m = m a
 
   route Proxy = methodRouter methodPut (Proxy :: Proxy ctypes) ok200
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          HasServer (Put ctypes ()) where
 
   type ServerT (Put ctypes ()) m = m ()
@@ -396,10 +362,7 @@ instance
   route Proxy = methodRouterEmpty methodPut
 
 -- Add response headers
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Put ctypes (Headers h v)) where
 
@@ -418,20 +381,14 @@ instance
 -- If successfully returning a value, we just require that its type has
 -- a 'ToJSON' instance and servant takes care of encoding it for you,
 -- yielding status code 200 along the way.
-instance
+instance OVERLAPPABLE_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
          ( AllCTRender ctypes a) => HasServer (Patch ctypes a) where
 
   type ServerT (Patch ctypes a) m = m a
 
   route Proxy = methodRouter methodPatch (Proxy :: Proxy ctypes) ok200
 
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
           HasServer (Patch ctypes ()) where
 
   type ServerT (Patch ctypes ()) m = m ()
@@ -439,10 +396,7 @@ instance
   route Proxy = methodRouterEmpty methodPatch
 
 -- Add response headers
-instance
+instance OVERLAPPING_
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Patch ctypes (Headers h v)) where
 

servant-session/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant/include/overlapping-compat.h

@@ -0,0 +1,8 @@
+#if __GLASGOW_HASKELL__ >= 710
+#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
+#define OVERLAPPING_  {-# OVERLAPPING #-}
+#else
+{-# LANGUAGE OverlappingInstances #-}
+#define OVERLAPPABLE_
+#define OVERLAPPING_
+#endif

servant/servant.cabal

@@ -81,6 +81,7 @@ library
                   , TypeSynonymInstances
                   , UndecidableInstances
   ghc-options: -Wall
+  include-dirs: include
 
 test-suite spec
   type: exitcode-stdio-1.0
@@ -118,3 +119,4 @@ test-suite doctests
  buildable: True
  default-language: Haskell2010
  ghc-options: -threaded
+ include-dirs: include

servant/src/Servant/API/ResponseHeaders.hs

@@ -12,11 +12,9 @@
 {-# LANGUAGE TypeFamilies           #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
-#if !MIN_VERSION_base(4,8,0)
-{-# LANGUAGE OverlappingInstances   #-}
-#endif
 {-# OPTIONS_HADDOCK not-home        #-}
 
+#include "overlapping-compat.h"
 -- | This module provides facilities for adding headers to a response.
 --
 -- >>> let headerVal = addHeader "some-url" 5 :: Headers '[Header "Location" String] Int
@@ -68,19 +66,12 @@ class BuildHeadersTo hs where
     -- the values are interspersed with commas before deserialization (see
     -- <http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2 RFC2616 Sec 4.2>)
 
-instance
+instance OVERLAPPING_ BuildHeadersTo '[] where
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         BuildHeadersTo '[] where
     buildHeadersTo _ = HNil
 
-instance
+instance OVERLAPPABLE_ ( FromByteString v, BuildHeadersTo xs, KnownSymbol h
-#if MIN_VERSION_base(4,8,0)
+                       , Contains h xs ~ 'False)
-         {-# OVERLAPPABLE #-}
+         => BuildHeadersTo ((Header h v) ': xs) where
-#endif
-         ( FromByteString v, BuildHeadersTo xs, KnownSymbol h, Contains h xs ~ 'False
-         ) => BuildHeadersTo ((Header h v) ': xs) where
     buildHeadersTo headers =
       let wantedHeader = CI.mk . pack $ symbolVal (Proxy :: Proxy h)
           matching = snd <$> filter (\(h, _) -> h == wantedHeader) headers
@@ -96,38 +87,22 @@ instance
 class GetHeaders ls where
     getHeaders :: ls -> [HTTP.Header]
 
-instance
+instance OVERLAPPING_ GetHeaders (HList '[]) where
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (HList '[]) where
     getHeaders _ = []
 
-instance
+instance OVERLAPPABLE_ ( KnownSymbol h, ToByteString x, GetHeaders (HList xs))
-#if MIN_VERSION_base(4,8,0)
+         => GetHeaders (HList (Header h x ': xs)) where
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, ToByteString x, GetHeaders (HList xs)
-         ) => GetHeaders (HList (Header h x ': xs)) where
     getHeaders hdrs = case hdrs of
         Header val `HCons` rest -> (headerName , toByteString' val):getHeaders rest
         UndecodableHeader h `HCons` rest -> (headerName,  h) : getHeaders rest
         MissingHeader `HCons` rest -> getHeaders rest
       where headerName = CI.mk . pack $ symbolVal (Proxy :: Proxy h)
 
-instance
+instance OVERLAPPING_ GetHeaders (Headers '[] a) where
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (Headers '[] a) where
     getHeaders _ = []
 
-instance
+instance OVERLAPPABLE_ ( KnownSymbol h, GetHeaders (HList rest), ToByteString v)
-#if MIN_VERSION_base(4,8,0)
+         => GetHeaders (Headers (Header h v ': rest) a) where
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, GetHeaders (HList rest), ToByteString v
-         ) => GetHeaders (Headers (Header h v ': rest) a) where
     getHeaders hs = getHeaders $ getHeadersHList hs
 
 -- * Adding
@@ -138,21 +113,13 @@ class AddHeader h v orig new
   addHeader :: v -> orig -> new  -- ^ N.B.: The same header can't be added multiple times
 
 
-instance
+instance OVERLAPPING_ ( KnownSymbol h, ToByteString v, Contains h (fst ': rest) ~ 'False)
-#if MIN_VERSION_base(4,8,0)
+         => AddHeader h v (Headers (fst ': rest)  a) (Headers (Header h v  ': fst ': rest) a) where
-         {-# OVERLAPPING #-}
-#endif
-         ( KnownSymbol h, ToByteString v, Contains h (fst ': rest) ~ 'False
-         ) => AddHeader h v (Headers (fst ': rest)  a) (Headers (Header h v  ': fst ': rest) a) where
     addHeader a (Headers resp heads) = Headers resp (HCons (Header a) heads)
 
-instance
+instance OVERLAPPABLE_ ( KnownSymbol h, ToByteString v
-#if MIN_VERSION_base(4,8,0)
+                       , new ~ (Headers '[Header h v] a))
-         {-# OVERLAPPABLE #-}
+         => AddHeader h v a new where
-#endif
-         ( KnownSymbol h, ToByteString v
-         , new ~ (Headers '[Header h v] a)
-         ) => AddHeader h v a new where
     addHeader a resp = Headers resp (HCons (Header a) HNil)
 
 type family Contains x xs where