From 60f1ddb89eb98b4240241760205b8bd15fa03102 Mon Sep 17 00:00:00 2001
From: Arian van Putten <aeroboy94@gmail.com>
Date: Sun, 6 Dec 2015 12:22:18 +0100
Subject: [PATCH 01/34] WIP: Fix issue #285

---
 servant-js/src/Servant/JS/Vanilla.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/servant-js/src/Servant/JS/Vanilla.hs b/servant-js/src/Servant/JS/Vanilla.hs
index 7313f540..89ef91d5 100644
--- a/servant-js/src/Servant/JS/Vanilla.hs
+++ b/servant-js/src/Servant/JS/Vanilla.hs
@@ -33,6 +33,7 @@ generateVanillaJSWith opts req = "\n" <>
  <> "  var xhr = new XMLHttpRequest();\n"
  <> "  xhr.open('" <> method <> "', " <> url <> ", true);\n"
  <>    reqheaders
+ <> "  xhr.setRequestHeader(\"Accept\",\"application/json\");\n"
  <> "  xhr.onreadystatechange = function (e) {\n"
  <> "    if (xhr.readyState == 4) {\n"
  <> "        var value = JSON.parse(xhr.responseText);\n"

From cf475c26c9b1c66beafadbcbd3157ad4969b85ba Mon Sep 17 00:00:00 2001
From: Arian van Putten <aeroboy94@gmail.com>
Date: Sun, 6 Dec 2015 12:40:27 +0100
Subject: [PATCH 02/34] WIP: Fix issue #285

---
 servant-js/src/Servant/JS/Vanilla.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/servant-js/src/Servant/JS/Vanilla.hs b/servant-js/src/Servant/JS/Vanilla.hs
index 89ef91d5..22b29b4c 100644
--- a/servant-js/src/Servant/JS/Vanilla.hs
+++ b/servant-js/src/Servant/JS/Vanilla.hs
@@ -34,6 +34,7 @@ generateVanillaJSWith opts req = "\n" <>
  <> "  xhr.open('" <> method <> "', " <> url <> ", true);\n"
  <>    reqheaders
  <> "  xhr.setRequestHeader(\"Accept\",\"application/json\");\n"
+ <> (if isJust (req ^. reqBody) then "  xhr.setRequestHeader(\"Content-Type\",\"application/json\");\n" else "")
  <> "  xhr.onreadystatechange = function (e) {\n"
  <> "    if (xhr.readyState == 4) {\n"
  <> "        var value = JSON.parse(xhr.responseText);\n"

From 702c2cec7d297e42f680697c61ecdfa01a0dff3a Mon Sep 17 00:00:00 2001
From: Mitchell Rosen <mitchellwrosen@gmail.com>
Date: Wed, 9 Dec 2015 18:04:47 -0800
Subject: [PATCH 03/34] Add 'pretty'

---
 servant-docs/servant-docs.cabal           |  2 ++
 servant-docs/src/Servant/Docs.hs          |  2 +-
 servant-docs/src/Servant/Docs/Internal.hs | 33 +++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index ee6f71bf..7f1f0025 100644
--- a/servant-docs/servant-docs.cabal
+++ b/servant-docs/servant-docs.cabal
@@ -31,6 +31,8 @@ library
     , Servant.Docs.Internal
   build-depends:
       base >=4.7 && <5
+    , aeson
+    , aeson-pretty
     , bytestring
     , bytestring-conversion
     , case-insensitive
diff --git a/servant-docs/src/Servant/Docs.hs b/servant-docs/src/Servant/Docs.hs
index 2f081127..a14a4f34 100644
--- a/servant-docs/src/Servant/Docs.hs
+++ b/servant-docs/src/Servant/Docs.hs
@@ -23,7 +23,7 @@
 -- See example/greet.hs for an example.
 module Servant.Docs
   ( -- * 'HasDocs' class and key functions
-    HasDocs(..), docs, markdown
+    HasDocs(..), docs, pretty, markdown
     -- * Generating docs with extra information
   , docsWith, docsWithIntros, docsWithOptions
   , ExtraInfo(..), extraInfo
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 33cb86a0..4b79e9f2 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/servant-docs/src/Servant/Docs/Internal.hs
@@ -26,6 +26,8 @@ import           Control.Arrow              (second)
 import           Control.Lens               (makeLenses, over, traversed, (%~),
                                              (&), (.~), (<>~), (^.), (|>))
 import qualified Control.Monad.Omega        as Omega
+import           Data.Aeson                 (ToJSON(..))
+import           Data.Aeson.Encode.Pretty   (encodePretty)
 import           Data.ByteString.Conversion (ToByteString, toByteString)
 import           Data.ByteString.Lazy.Char8 (ByteString)
 import qualified Data.CaseInsensitive       as CI
@@ -367,6 +369,37 @@ docsWith opts intros (ExtraInfo endpoints) p =
 docsWithIntros :: HasDocs layout => [DocIntro] -> Proxy layout -> API
 docsWithIntros intros = docsWith defaultDocOptions intros mempty
 
+-- | Prettify generated JSON documentation.
+--
+-- @
+-- 'docs' ('pretty' ('Proxy' :: 'Proxy' MyAPI))
+-- @
+pretty :: Proxy layout -> Proxy (Pretty layout)
+pretty Proxy = Proxy
+
+data PrettyJSON
+
+instance Accept PrettyJSON where
+    contentType _ = "application" M.// "json"
+
+instance ToJSON a => MimeRender PrettyJSON a where
+    mimeRender _ = encodePretty
+
+-- | Replace all JSON content types with PrettyJSON.
+-- Kind-polymorphic so it can operate on kinds * and [*].
+type family Pretty (layout :: k) :: k where
+    Pretty (x :<|> y)     = Pretty x :<|> Pretty y
+    Pretty (x :> y)       = Pretty x :> Pretty y
+    Pretty (Get cs r)     = Get     (Pretty cs) r
+    Pretty (Post cs r)    = Post    (Pretty cs) r
+    Pretty (Put cs r)     = Put     (Pretty cs) r
+    Pretty (Delete cs r)  = Delete  (Pretty cs) r
+    Pretty (Patch cs r)   = Patch   (Pretty cs) r
+    Pretty (ReqBody cs r) = ReqBody (Pretty cs) r
+    Pretty (JSON ': xs)   = PrettyJSON ': xs
+    Pretty (x ': xs)      = x ': Pretty xs
+    Pretty x              = x
+
 -- | The class that abstracts away the impact of API combinators
 --   on documentation generation.
 class HasDocs layout where

From f1a6a2a151cd178f36569c3212e8fcf89591a59a Mon Sep 17 00:00:00 2001
From: Mitchell Rosen <mitchellwrosen@gmail.com>
Date: Thu, 10 Dec 2015 12:27:15 -0800
Subject: [PATCH 04/34] Move 'pretty' to its own module

---
 servant-docs/servant-docs.cabal               |  1 +
 servant-docs/src/Servant/Docs.hs              |  3 +-
 servant-docs/src/Servant/Docs/Internal.hs     | 33 ------------
 .../src/Servant/Docs/Internal/Pretty.hs       | 50 +++++++++++++++++++
 4 files changed, 53 insertions(+), 34 deletions(-)
 create mode 100644 servant-docs/src/Servant/Docs/Internal/Pretty.hs

diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index 7f1f0025..b88bc612 100644
--- a/servant-docs/servant-docs.cabal
+++ b/servant-docs/servant-docs.cabal
@@ -29,6 +29,7 @@ library
   exposed-modules:
       Servant.Docs
     , Servant.Docs.Internal
+    , Servant.Docs.Internal.Pretty
   build-depends:
       base >=4.7 && <5
     , aeson
diff --git a/servant-docs/src/Servant/Docs.hs b/servant-docs/src/Servant/Docs.hs
index a14a4f34..193b4e60 100644
--- a/servant-docs/src/Servant/Docs.hs
+++ b/servant-docs/src/Servant/Docs.hs
@@ -53,4 +53,5 @@ module Servant.Docs
   , single
   ) where
 
-import           Servant.Docs.Internal
+import Servant.Docs.Internal
+import Servant.Docs.Internal.Pretty
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 4b79e9f2..33cb86a0 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/servant-docs/src/Servant/Docs/Internal.hs
@@ -26,8 +26,6 @@ import           Control.Arrow              (second)
 import           Control.Lens               (makeLenses, over, traversed, (%~),
                                              (&), (.~), (<>~), (^.), (|>))
 import qualified Control.Monad.Omega        as Omega
-import           Data.Aeson                 (ToJSON(..))
-import           Data.Aeson.Encode.Pretty   (encodePretty)
 import           Data.ByteString.Conversion (ToByteString, toByteString)
 import           Data.ByteString.Lazy.Char8 (ByteString)
 import qualified Data.CaseInsensitive       as CI
@@ -369,37 +367,6 @@ docsWith opts intros (ExtraInfo endpoints) p =
 docsWithIntros :: HasDocs layout => [DocIntro] -> Proxy layout -> API
 docsWithIntros intros = docsWith defaultDocOptions intros mempty
 
--- | Prettify generated JSON documentation.
---
--- @
--- 'docs' ('pretty' ('Proxy' :: 'Proxy' MyAPI))
--- @
-pretty :: Proxy layout -> Proxy (Pretty layout)
-pretty Proxy = Proxy
-
-data PrettyJSON
-
-instance Accept PrettyJSON where
-    contentType _ = "application" M.// "json"
-
-instance ToJSON a => MimeRender PrettyJSON a where
-    mimeRender _ = encodePretty
-
--- | Replace all JSON content types with PrettyJSON.
--- Kind-polymorphic so it can operate on kinds * and [*].
-type family Pretty (layout :: k) :: k where
-    Pretty (x :<|> y)     = Pretty x :<|> Pretty y
-    Pretty (x :> y)       = Pretty x :> Pretty y
-    Pretty (Get cs r)     = Get     (Pretty cs) r
-    Pretty (Post cs r)    = Post    (Pretty cs) r
-    Pretty (Put cs r)     = Put     (Pretty cs) r
-    Pretty (Delete cs r)  = Delete  (Pretty cs) r
-    Pretty (Patch cs r)   = Patch   (Pretty cs) r
-    Pretty (ReqBody cs r) = ReqBody (Pretty cs) r
-    Pretty (JSON ': xs)   = PrettyJSON ': xs
-    Pretty (x ': xs)      = x ': Pretty xs
-    Pretty x              = x
-
 -- | The class that abstracts away the impact of API combinators
 --   on documentation generation.
 class HasDocs layout where
diff --git a/servant-docs/src/Servant/Docs/Internal/Pretty.hs b/servant-docs/src/Servant/Docs/Internal/Pretty.hs
new file mode 100644
index 00000000..7de722be
--- /dev/null
+++ b/servant-docs/src/Servant/Docs/Internal/Pretty.hs
@@ -0,0 +1,50 @@
+{-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE KindSignatures        #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
+{-# LANGUAGE PolyKinds             #-}
+{-# LANGUAGE TypeOperators         #-}
+{-# LANGUAGE TypeFamilies          #-}
+
+module Servant.Docs.Internal.Pretty where
+
+import Data.Aeson               (ToJSON(..))
+import Data.Aeson.Encode.Pretty (encodePretty)
+import Data.Proxy               (Proxy(Proxy))
+import Network.HTTP.Media       ((//))
+import Servant.API
+import Servant.API.ContentTypes
+import Servant.Utils.Links
+
+-- | PrettyJSON content type.
+data PrettyJSON
+
+instance Accept PrettyJSON where
+    contentType _ = "application" // "json"
+
+instance ToJSON a => MimeRender PrettyJSON a where
+    mimeRender _ = encodePretty
+
+-- | Prettify generated JSON documentation.
+--
+-- @
+-- 'docs' ('pretty' ('Proxy' :: 'Proxy' MyAPI))
+-- @
+pretty :: Proxy layout -> Proxy (Pretty layout)
+pretty Proxy = Proxy
+
+-- | Replace all JSON content types with PrettyJSON.
+-- Kind-polymorphic so it can operate on kinds @*@ and @[*]@.
+type family Pretty (layout :: k) :: k where
+    Pretty (x :<|> y)     = Pretty x :<|> Pretty y
+    Pretty (x :> y)       = Pretty x :> Pretty y
+    Pretty (Get cs r)     = Get     (Pretty cs) r
+    Pretty (Post cs r)    = Post    (Pretty cs) r
+    Pretty (Put cs r)     = Put     (Pretty cs) r
+    Pretty (Delete cs r)  = Delete  (Pretty cs) r
+    Pretty (Patch cs r)   = Patch   (Pretty cs) r
+    Pretty (ReqBody cs r) = ReqBody (Pretty cs) r
+    Pretty (JSON ': xs)   = PrettyJSON ': xs
+    Pretty (x ': xs)      = x ': Pretty xs
+    Pretty x              = x

From 82deaeb63c3af4fe05e3a8814e498ea7a09dec8b Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Wed, 16 Dec 2015 13:38:42 +0100
Subject: [PATCH 05/34] Test cases for bad links.

---
 servant/servant.cabal                   |  1 -
 servant/test/Doctests.hs                |  3 +-
 servant/test/Servant/Utils/LinksSpec.hs | 72 +++++++++++++++++--------
 3 files changed, 52 insertions(+), 24 deletions(-)

diff --git a/servant/servant.cabal b/servant/servant.cabal
index 6bf6455a..f717eab3 100644
--- a/servant/servant.cabal
+++ b/servant/servant.cabal
@@ -101,7 +101,6 @@ test-suite spec
     , hspec == 2.*
     , QuickCheck
     , quickcheck-instances
-    , parsec
     , servant
     , string-conversions
     , text
diff --git a/servant/test/Doctests.hs b/servant/test/Doctests.hs
index 4e528dd5..bf6bcd23 100644
--- a/servant/test/Doctests.hs
+++ b/servant/test/Doctests.hs
@@ -9,13 +9,14 @@ import           Test.DocTest
 main :: IO ()
 main = do
     files <- find always (extension ==? ".hs") "src"
+    tfiles <- find always (extension ==? ".hs") "test/Servant"
     mCabalMacrosFile <- getCabalMacrosFile
     doctest $ "-isrc" :
               (maybe [] (\ f -> ["-optP-include", "-optP" ++ f]) mCabalMacrosFile) ++
               "-XOverloadedStrings" :
               "-XFlexibleInstances" :
               "-XMultiParamTypeClasses" :
-              files
+              (files ++ tfiles)
 
 getCabalMacrosFile :: IO (Maybe FilePath)
 getCabalMacrosFile = do
diff --git a/servant/test/Servant/Utils/LinksSpec.hs b/servant/test/Servant/Utils/LinksSpec.hs
index c25cccb9..07e0b068 100644
--- a/servant/test/Servant/Utils/LinksSpec.hs
+++ b/servant/test/Servant/Utils/LinksSpec.hs
@@ -1,14 +1,14 @@
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE PolyKinds #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE ConstraintKinds #-}
-
+{-# LANGUAGE DataKinds       #-}
+{-# LANGUAGE PolyKinds       #-}
+{-# LANGUAGE TypeOperators   #-}
 module Servant.Utils.LinksSpec where
 
-import Test.Hspec ( Spec, it, describe, shouldBe, Expectation )
-import Data.Proxy ( Proxy(..) )
+import           Data.Proxy              (Proxy (..))
+import           Test.Hspec              (Expectation, Spec, describe, it,
+                                          shouldBe)
 
-import Servant.API
+import           Servant.API
 
 type TestApi =
   -- Capture and query params
@@ -24,18 +24,6 @@ type TestApi =
   :<|> "delete" :> Header "ponies" String :> Delete '[JSON] ()
   :<|> "raw" :> Raw
 
-type TestLink = "hello" :> "hi" :> Get '[JSON] Bool
-type TestLink2 = "greet" :> ReqBody '[JSON] [Int] :> Post '[PlainText] Bool
-type TestLink3 = "parent" :> "child" :> Get '[JSON] String
-
-type BadTestLink = "hallo" :> "hi" :> Get '[JSON] Bool
-type BadTestLink2 = "greet" :> Get '[PlainText] Bool
-
-type BadTestLink' = "hello" :> "hi" :> Get '[OctetStream] Bool
-type BadTestLink'2 = "greet" :> Get '[OctetStream] Bool
-
-type NotALink = "hello" :> Capture "x" Bool :> Get '[JSON] Bool
-type NotALink2 = "hello" :> ReqBody '[JSON] 'True :> Get '[JSON] Bool
 
 apiLink :: (IsElem endpoint TestApi, HasLink endpoint)
          => Proxy endpoint -> MkLink endpoint
@@ -49,7 +37,7 @@ shouldBeURI link expected =
 
 spec :: Spec
 spec = describe "Servant.Utils.Links" $ do
-    it "Generates correct links for capture query params" $ do
+    it "generates correct links for capture query params" $ do
         let l1 = Proxy :: Proxy ("hello" :> Capture "name" String :> Delete '[JSON] ())
         apiLink l1 "hi" `shouldBeURI` "hello/hi"
 
@@ -59,15 +47,55 @@ spec = describe "Servant.Utils.Links" $ do
         apiLink l2 "bye" (Just True) `shouldBeURI` "hello/bye?capital=true"
 
 
-    it "Generates correct links for query flags" $ do
+    it "generates correct links for query flags" $ do
         let l1 = Proxy :: Proxy ("balls" :> QueryFlag "bouncy"
                                          :> QueryFlag "fast" :> Delete '[JSON] ())
         apiLink l1 True True `shouldBeURI` "balls?bouncy&fast"
         apiLink l1 False True `shouldBeURI` "balls?fast"
 
-    it "Generates correct links for all of the verbs" $ do
+    it "generates correct links for all of the verbs" $ do
         apiLink (Proxy :: Proxy ("get" :> Get '[JSON] ())) `shouldBeURI` "get"
         apiLink (Proxy :: Proxy ("put" :> Put '[JSON] ())) `shouldBeURI` "put"
         apiLink (Proxy :: Proxy ("post" :> Post '[JSON] ())) `shouldBeURI` "post"
         apiLink (Proxy :: Proxy ("delete" :> Delete '[JSON] ())) `shouldBeURI` "delete"
         apiLink (Proxy :: Proxy ("raw" :> Raw)) `shouldBeURI` "raw"
+
+
+-- |
+-- Before https://github.com/CRogers/should-not-typecheck/issues/5 is fixed,
+-- we'll just use doctest
+--
+-- >>> apiLink (Proxy :: Proxy WrongPath)
+-- ...
+--     Could not deduce ...
+-- ...
+--
+-- >>> apiLink (Proxy :: Proxy WrongReturnType)
+-- ...
+--     Could not deduce ...
+-- ...
+--
+-- >>> apiLink (Proxy :: Proxy WrongContentType)
+-- ...
+--     Could not deduce ...
+-- ...
+--
+-- >>> apiLink (Proxy :: Proxy WrongMethod)
+-- ...
+--     Could not deduce ...
+-- ...
+--
+-- >>> apiLink (Proxy :: Proxy NotALink)
+-- ...
+--     Could not deduce ...
+-- ...
+--
+-- sanity check
+-- >>> apiLink (Proxy :: Proxy AllGood)
+-- get
+type WrongPath = "getTypo" :> Get '[JSON] ()
+type WrongReturnType = "get" :> Get '[JSON] Bool
+type WrongContentType = "get" :> Get '[OctetStream] ()
+type WrongMethod = "get" :> Post '[JSON] ()
+type NotALink = "hello" :> ReqBody '[JSON] 'True :> Get '[JSON] Bool
+type AllGood = "get" :> Get '[JSON] ()

From b20edfd96a9b62f5dadaba9772adb8abe0a3691d Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Wed, 16 Dec 2015 13:41:18 +0100
Subject: [PATCH 06/34] Fix loop in IsSubList

        See #293.
---
 servant/src/Servant/Utils/Links.hs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/servant/src/Servant/Utils/Links.hs b/servant/src/Servant/Utils/Links.hs
index b83d1178..b6bf7137 100644
--- a/servant/src/Servant/Utils/Links.hs
+++ b/servant/src/Servant/Utils/Links.hs
@@ -180,12 +180,13 @@ type family IsElem endpoint api :: Constraint where
     IsElem e e                              = ()
     IsElem e a                              = IsElem' e a
 
-
 type family IsSubList a b :: Constraint where
     IsSubList '[] b          = ()
-    IsSubList '[x] (x ': xs) = ()
-    IsSubList '[x] (y ': ys) = IsSubList '[x] ys
-    IsSubList (x ': xs) y    = IsSubList '[x] y `And` IsSubList xs y
+    IsSubList (x ': xs) y    = Elem x y `And` IsSubList xs y
+
+type family Elem e es :: Constraint where
+    Elem x (x ': xs) = ()
+    Elem y (x ': xs) = Elem y xs
 
 -- Phantom types for Param
 data Query

From 56beed459c6452fd4d992f61be8067613077e6ea Mon Sep 17 00:00:00 2001
From: Andrew Noyes <anoyes34@gmail.com>
Date: Fri, 18 Dec 2015 16:56:37 -0800
Subject: [PATCH 07/34] Fix broken link

---
 servant-docs/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/servant-docs/README.md b/servant-docs/README.md
index 2c81b2a5..2ac1c335 100644
--- a/servant-docs/README.md
+++ b/servant-docs/README.md
@@ -6,7 +6,7 @@ Generate API docs for your *servant* webservice. Feel free to also take a look a
 
 ## Example
 
-See [here](https://github.com/haskell-servant/servant/tree/master/servant-docs/blob/master/example/greet.md) for the output of the following program.
+See [here](https://github.com/haskell-servant/servant/blob/master/servant-docs/example/greet.md) for the output of the following program.
 
 ``` haskell
 {-# LANGUAGE DataKinds #-}

From 69a4a8d4f693a8f8c1a3c07248b2e98fcc0bb79d Mon Sep 17 00:00:00 2001
From: Tomasz Mieszkowski <xor_xor@fastmail.fm>
Date: Sun, 20 Dec 2015 17:56:11 +0100
Subject: [PATCH 08/34] [servant-docs] Removed redundant imports.

---
 servant-docs/src/Servant/Docs/Internal/Pretty.hs | 2 --
 1 file changed, 2 deletions(-)

diff --git a/servant-docs/src/Servant/Docs/Internal/Pretty.hs b/servant-docs/src/Servant/Docs/Internal/Pretty.hs
index 7de722be..13275467 100644
--- a/servant-docs/src/Servant/Docs/Internal/Pretty.hs
+++ b/servant-docs/src/Servant/Docs/Internal/Pretty.hs
@@ -14,8 +14,6 @@ import Data.Aeson.Encode.Pretty (encodePretty)
 import Data.Proxy               (Proxy(Proxy))
 import Network.HTTP.Media       ((//))
 import Servant.API
-import Servant.API.ContentTypes
-import Servant.Utils.Links
 
 -- | PrettyJSON content type.
 data PrettyJSON

From 57fe12ce84e0759c7eed4a25d4a3746729496cdb Mon Sep 17 00:00:00 2001
From: Luke Clifton <Luke.Clifton@cba.com.au>
Date: Tue, 22 Dec 2015 15:48:49 +1100
Subject: [PATCH 09/34] MimeUnrender and MimeRender instances for Cassava

This allows the same API type to be used for `serve` and `client`.
---
 servant-cassava/src/Servant/CSV/Cassava.hs | 25 +++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/servant-cassava/src/Servant/CSV/Cassava.hs b/servant-cassava/src/Servant/CSV/Cassava.hs
index 5bd5a374..3c00a662 100644
--- a/servant-cassava/src/Servant/CSV/Cassava.hs
+++ b/servant-cassava/src/Servant/CSV/Cassava.hs
@@ -19,7 +19,7 @@ module Servant.CSV.Cassava where
 import           Data.Csv
 import           Data.Proxy         (Proxy (..))
 import           Data.Typeable      (Typeable)
-import           Data.Vector        (Vector)
+import           Data.Vector        (Vector, toList)
 import           GHC.Generics       (Generic)
 import qualified Network.HTTP.Media as M
 import           Servant.API        (Accept (..), MimeRender (..),
@@ -50,6 +50,18 @@ instance ( DefaultOrdered a, ToNamedRecord a, EncodeOpts opt
     mimeRender _ = encodeDefaultOrderedByNameWith (encodeOpts p)
       where p = Proxy :: Proxy opt
 
+-- | Encode with 'encodeByNameWith'. The 'Header' param is used for determining
+-- the order of headers and fields.
+instance ( ToNamedRecord a, EncodeOpts opt
+         ) => MimeRender (CSV', opt) (Header, Vector a) where
+    mimeRender _ (hdr, vals) = encodeByNameWith (encodeOpts p) hdr (toList vals)
+      where p = Proxy :: Proxy opt
+
+-- | Encode with 'encodeDefaultOrderedByNameWith'
+instance ( DefaultOrdered a, ToNamedRecord a, EncodeOpts opt
+         ) => MimeRender (CSV', opt) (Vector a) where
+    mimeRender _ = encodeDefaultOrderedByNameWith (encodeOpts p) . toList
+      where p = Proxy :: Proxy opt
 
 -- ** Encode Options
 
@@ -66,6 +78,17 @@ instance EncodeOpts DefaultEncodeOpts where
 -- ** Instances
 
 -- | Decode with 'decodeByNameWith'
+instance ( FromNamedRecord a, DecodeOpts opt
+         ) => MimeUnrender (CSV', opt) (Header, [a]) where
+    mimeUnrender _ bs = fmap toList <$> decodeByNameWith (decodeOpts p) bs
+      where p = Proxy :: Proxy opt
+
+-- | Decode with 'decodeWith'. Assumes data has headers, which are stripped.
+instance ( FromRecord a, DecodeOpts opt
+         ) => MimeUnrender (CSV', opt) [a] where
+    mimeUnrender _ bs = toList <$> decodeWith (decodeOpts p) HasHeader bs
+      where p = Proxy :: Proxy opt
+
 instance ( FromNamedRecord a, DecodeOpts opt
          ) => MimeUnrender (CSV', opt) (Header, Vector a) where
     mimeUnrender _ = decodeByNameWith (decodeOpts p)

From 130fd27e0160fc61da9b1fbe6b5810f2b00e9d24 Mon Sep 17 00:00:00 2001
From: Luke Clifton <Luke.Clifton@cba.com.au>
Date: Tue, 22 Dec 2015 22:03:46 +1100
Subject: [PATCH 10/34] Conditionally include Control.Applicative <$>

---
 servant-cassava/src/Servant/CSV/Cassava.hs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/servant-cassava/src/Servant/CSV/Cassava.hs b/servant-cassava/src/Servant/CSV/Cassava.hs
index 3c00a662..625007e7 100644
--- a/servant-cassava/src/Servant/CSV/Cassava.hs
+++ b/servant-cassava/src/Servant/CSV/Cassava.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE FlexibleInstances     #-}
@@ -16,6 +17,9 @@
 -- >>> type EgDefault = Get '[CSV] [(Int, String)]
 module Servant.CSV.Cassava where
 
+#if !MIN_VERSION_base(4,8,0)
+import           Control.Applicative        ((<$>))
+#endif
 import           Data.Csv
 import           Data.Proxy         (Proxy (..))
 import           Data.Typeable      (Typeable)

From 1ea1340c5c49b86ec0f1ca32fce64fbd53a63c52 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Fri, 25 Dec 2015 15:50:28 +0100
Subject: [PATCH 11/34] Use env bash rather than /bin/bash.

---
 scripts/bump-versions.sh      | 2 +-
 scripts/clear-sandbox.sh      | 2 +-
 scripts/generate-nix-files.sh | 2 +-
 scripts/start-sandbox.sh      | 2 +-
 scripts/test-all.sh           | 2 +-
 scripts/upload.sh             | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/scripts/bump-versions.sh b/scripts/bump-versions.sh
index e1e735f4..2e39cea3 100755
--- a/scripts/bump-versions.sh
+++ b/scripts/bump-versions.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: bump-versions.sh
diff --git a/scripts/clear-sandbox.sh b/scripts/clear-sandbox.sh
index 440e603c..5e70e14f 100755
--- a/scripts/clear-sandbox.sh
+++ b/scripts/clear-sandbox.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: clear-sandbox.sh
diff --git a/scripts/generate-nix-files.sh b/scripts/generate-nix-files.sh
index e72d772a..5865e02f 100755
--- a/scripts/generate-nix-files.sh
+++ b/scripts/generate-nix-files.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: generate-nix-files.sh
diff --git a/scripts/start-sandbox.sh b/scripts/start-sandbox.sh
index b6e88759..5808f072 100755
--- a/scripts/start-sandbox.sh
+++ b/scripts/start-sandbox.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: start-sandbox.sh
diff --git a/scripts/test-all.sh b/scripts/test-all.sh
index 04fd012b..59d24a97 100755
--- a/scripts/test-all.sh
+++ b/scripts/test-all.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: test-all.sh
diff --git a/scripts/upload.sh b/scripts/upload.sh
index 91f0b665..344b8e4a 100755
--- a/scripts/upload.sh
+++ b/scripts/upload.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -
+#!/usr/bin/env bash
 #===============================================================================
 #
 #          FILE: upload.sh

From 8b3258a0c101951015acad60930a89049d2b6ad8 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 02:20:46 +0100
Subject: [PATCH 12/34] Add ToHttpApiData instance for Link.

---
 servant/src/Servant/Utils/Links.hs | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/servant/src/Servant/Utils/Links.hs b/servant/src/Servant/Utils/Links.hs
index b6bf7137..f218377f 100644
--- a/servant/src/Servant/Utils/Links.hs
+++ b/servant/src/Servant/Utils/Links.hs
@@ -103,7 +103,8 @@ module Servant.Utils.Links (
 
 import Data.List
 import Data.Proxy ( Proxy(..) )
-import Data.Text (Text, unpack)
+import qualified Data.Text as Text
+import qualified Data.ByteString.Char8 as BSC
 #if !MIN_VERSION_base(4,8,0)
 import Data.Monoid ( Monoid(..), (<>) )
 #else
@@ -135,6 +136,10 @@ data Link = Link
   , _queryParams :: [Param Query]
   } deriving Show
 
+instance ToHttpApiData Link where
+    toUrlPiece = Text.pack . show
+    toHeader   = BSC.pack . show
+
 -- | If either a or b produce an empty constraint, produce an empty constraint.
 type family Or (a :: Constraint) (b :: Constraint) :: Constraint where
     -- This works because of:
@@ -193,8 +198,8 @@ data Query
 
 -- | Query param
 data Param a
-    = SingleParam    String Text
-    | ArrayElemParam String Text
+    = SingleParam    String Text.Text
+    | ArrayElemParam String Text.Text
     | FlagParam      String
   deriving Show
 
@@ -218,8 +223,8 @@ linkURI (Link segments q_params) =
         "?" <> intercalate "&" (fmap makeQuery xs)
 
     makeQuery :: Param Query -> String
-    makeQuery (ArrayElemParam k v) = escape k <> "[]=" <> escape (unpack v)
-    makeQuery (SingleParam k v)    = escape k <> "=" <> escape (unpack v)
+    makeQuery (ArrayElemParam k v) = escape k <> "[]=" <> escape (Text.unpack v)
+    makeQuery (SingleParam k v)    = escape k <> "=" <> escape (Text.unpack v)
     makeQuery (FlagParam k)        = escape k
 
 escape :: String -> String
@@ -291,7 +296,7 @@ instance (ToHttpApiData v, HasLink sub)
     type MkLink (Capture sym v :> sub) = v -> MkLink sub
     toLink _ l v =
         toLink (Proxy :: Proxy sub) $
-            addSegment (escape . unpack $ toUrlPiece v) l
+            addSegment (escape . Text.unpack $ toUrlPiece v) l
 
 instance HasLink sub => HasLink (Header sym a :> sub) where
     type MkLink (Header sym a :> sub) = MkLink sub

From a15d1d931451125770928de79dc676b647220985 Mon Sep 17 00:00:00 2001
From: Arian van Putten <aeroboy94@gmail.com>
Date: Sun, 27 Dec 2015 14:05:32 +0100
Subject: [PATCH 13/34] Fix 294

---
 servant-js/src/Servant/JS/Vanilla.hs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/servant-js/src/Servant/JS/Vanilla.hs b/servant-js/src/Servant/JS/Vanilla.hs
index 22b29b4c..0179f16f 100644
--- a/servant-js/src/Servant/JS/Vanilla.hs
+++ b/servant-js/src/Servant/JS/Vanilla.hs
@@ -37,10 +37,13 @@ generateVanillaJSWith opts req = "\n" <>
  <> (if isJust (req ^. reqBody) then "  xhr.setRequestHeader(\"Content-Type\",\"application/json\");\n" else "")
  <> "  xhr.onreadystatechange = function (e) {\n"
  <> "    if (xhr.readyState == 4) {\n"
+ <> "      if (xhr.status == 204) {\n"
+ <> "        onSuccess();\n"
+ <> "      } else if (xhr.status >= 200 && xhr.status < 300) {\n"
  <> "        var value = JSON.parse(xhr.responseText);\n"
- <> "      if (xhr.status == 200 || xhr.status == 201) {\n"
  <> "        onSuccess(value);\n"
  <> "      } else {\n"
+ <> "        var value = JSON.parse(xhr.responseText);\n"
  <> "        onError(value);\n"
  <> "      }\n"
  <> "    }\n"

From 82fa23507f9475791e6a19f68ff0320755ee4be9 Mon Sep 17 00:00:00 2001
From: Arian van Putten <aeroboy94@gmail.com>
Date: Sun, 27 Dec 2015 17:23:46 +0100
Subject: [PATCH 14/34] Add 205

---
 servant-js/src/Servant/JS/Vanilla.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/servant-js/src/Servant/JS/Vanilla.hs b/servant-js/src/Servant/JS/Vanilla.hs
index 0179f16f..ea390e2f 100644
--- a/servant-js/src/Servant/JS/Vanilla.hs
+++ b/servant-js/src/Servant/JS/Vanilla.hs
@@ -37,7 +37,7 @@ generateVanillaJSWith opts req = "\n" <>
  <> (if isJust (req ^. reqBody) then "  xhr.setRequestHeader(\"Content-Type\",\"application/json\");\n" else "")
  <> "  xhr.onreadystatechange = function (e) {\n"
  <> "    if (xhr.readyState == 4) {\n"
- <> "      if (xhr.status == 204) {\n"
+ <> "      if (xhr.status == 204 || xhr.status == 205) {\n"
  <> "        onSuccess();\n"
  <> "      } else if (xhr.status >= 200 && xhr.status < 300) {\n"
  <> "        var value = JSON.parse(xhr.responseText);\n"

From e7c90849171a5bf32cb635e6bee451dd9ef95386 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 17:54:29 +0100
Subject: [PATCH 15/34] less OverlappingInstances noise

---
 servant-blaze/include/overlapping-compat.h    |  8 ++
 servant-blaze/servant-blaze.cabal             |  1 +
 servant-blaze/src/Servant/HTML/Blaze.hs       | 16 +---
 servant-cassava/include/overlapping-compat.h  |  8 ++
 servant-cassava/servant-cassava.cabal         |  1 +
 servant-client/include/overlapping-compat.h   |  8 ++
 servant-client/servant-client.cabal           |  1 +
 servant-client/src/Servant/Client.hs          | 80 ++++---------------
 servant-client/test/Servant/ClientSpec.hs     | 24 ++----
 servant-docs/include/overlapping-compat.h     |  8 ++
 servant-docs/servant-docs.cabal               |  1 +
 servant-docs/src/Servant/Docs/Internal.hs     | 50 +++---------
 servant-examples/include/overlapping-compat.h |  8 ++
 servant-foreign/include/overlapping-compat.h  |  8 ++
 servant-foreign/servant-foreign.cabal         |  1 +
 servant-jquery/include/overlapping-compat.h   |  8 ++
 servant-js/include/overlapping-compat.h       |  8 ++
 servant-js/servant-js.cabal                   |  1 +
 servant-lucid/include/overlapping-compat.h    |  8 ++
 servant-lucid/servant-lucid.cabal             |  1 +
 servant-lucid/src/Servant/HTML/Lucid.hs       | 15 +---
 servant-mock/include/overlapping-compat.h     |  8 ++
 servant-mock/servant-mock.cabal               |  1 +
 servant-property/include/overlapping-compat.h |  8 ++
 servant-server/include/overlapping-compat.h   |  8 ++
 servant-server/servant-server.cabal           |  2 +
 servant-server/src/Servant/Server/Internal.hs | 80 ++++---------------
 servant-session/include/overlapping-compat.h  |  8 ++
 servant/include/overlapping-compat.h          |  8 ++
 servant/servant.cabal                         |  2 +
 servant/src/Servant/API/ResponseHeaders.hs    | 65 ++++-----------
 31 files changed, 197 insertions(+), 257 deletions(-)
 create mode 100644 servant-blaze/include/overlapping-compat.h
 create mode 100644 servant-cassava/include/overlapping-compat.h
 create mode 100644 servant-client/include/overlapping-compat.h
 create mode 100644 servant-docs/include/overlapping-compat.h
 create mode 100644 servant-examples/include/overlapping-compat.h
 create mode 100644 servant-foreign/include/overlapping-compat.h
 create mode 100644 servant-jquery/include/overlapping-compat.h
 create mode 100644 servant-js/include/overlapping-compat.h
 create mode 100644 servant-lucid/include/overlapping-compat.h
 create mode 100644 servant-mock/include/overlapping-compat.h
 create mode 100644 servant-property/include/overlapping-compat.h
 create mode 100644 servant-server/include/overlapping-compat.h
 create mode 100644 servant-session/include/overlapping-compat.h
 create mode 100644 servant/include/overlapping-compat.h

diff --git a/servant-blaze/include/overlapping-compat.h b/servant-blaze/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-blaze/servant-blaze.cabal b/servant-blaze/servant-blaze.cabal
index 08b27e24..a82076f6 100644
--- a/servant-blaze/servant-blaze.cabal
+++ b/servant-blaze/servant-blaze.cabal
@@ -30,3 +30,4 @@ library
                      , blaze-html
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-blaze/src/Servant/HTML/Blaze.hs b/servant-blaze/src/Servant/HTML/Blaze.hs
index 7870022d..822a7ae9 100644
--- a/servant-blaze/src/Servant/HTML/Blaze.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ToMarkup a => MimeRender HTML a where
+instance OVERLAPPABLE_ ToMarkup a => MimeRender HTML a where
     mimeRender _ = renderHtml . toHtml
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender HTML Html where
+instance OVERLAPPING_ MimeRender HTML Html where
     mimeRender _ = renderHtml
 
diff --git a/servant-cassava/include/overlapping-compat.h b/servant-cassava/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-cassava/servant-cassava.cabal b/servant-cassava/servant-cassava.cabal
index 4d74612a..db18986c 100644
--- a/servant-cassava/servant-cassava.cabal
+++ b/servant-cassava/servant-cassava.cabal
@@ -27,3 +27,4 @@ library
                      , vector
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-client/include/overlapping-compat.h b/servant-client/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-client/servant-client.cabal b/servant-client/servant-client.cabal
index 7fe69521..1ddf8bf4 100644
--- a/servant-client/servant-client.cabal
+++ b/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
diff --git a/servant-client/src/Servant/Client.hs b/servant-client/src/Servant/Client.hs
index 987a2bd4..408850ca 100644
--- a/servant-client/src/Servant/Client.hs
+++ b/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 #-}
-#endif
+
+#include "overlapping-compat.h"
 -- | 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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)
diff --git a/servant-client/test/Servant/ClientSpec.hs b/servant-client/test/Servant/ClientSpec.hs
index fc3cdcfb..b1980d1a 100644
--- a/servant-client/test/Servant/ClientSpec.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   GetNth 0 (x :<|> y) x where
       getNth _ (x :<|> _) = x
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   (GetLast b c) => GetLast (a :<|> b) c where
       getLast (_ :<|> b) = getLast b
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   GetLast a a where
       getLast a = a
diff --git a/servant-docs/include/overlapping-compat.h b/servant-docs/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index b88bc612..7bd34a7a 100644
--- a/servant-docs/servant-docs.cabal
+++ b/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
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 33cb86a0..c1d26142 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/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   #-}
-#endif
+
+#include "overlapping-compat.h"
 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         ( ToSample a, IsNonEmpty cts, AllMimeRender cts a,
           AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Put cts (Headers ls a)) where
diff --git a/servant-examples/include/overlapping-compat.h b/servant-examples/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-foreign/include/overlapping-compat.h b/servant-foreign/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-foreign/servant-foreign.cabal b/servant-foreign/servant-foreign.cabal
index 0ec296ae..d565b636 100644
--- a/servant-foreign/servant-foreign.cabal
+++ b/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
diff --git a/servant-jquery/include/overlapping-compat.h b/servant-jquery/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-js/include/overlapping-compat.h b/servant-js/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-js/servant-js.cabal b/servant-js/servant-js.cabal
index 53a74e9d..a47ecd34 100644
--- a/servant-js/servant-js.cabal
+++ b/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
diff --git a/servant-lucid/include/overlapping-compat.h b/servant-lucid/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-lucid/servant-lucid.cabal b/servant-lucid/servant-lucid.cabal
index 77cf3ee1..e4438f42 100644
--- a/servant-lucid/servant-lucid.cabal
+++ b/servant-lucid/servant-lucid.cabal
@@ -30,3 +30,4 @@ library
                      , servant == 0.5.*
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-lucid/src/Servant/HTML/Lucid.hs b/servant-lucid/src/Servant/HTML/Lucid.hs
index f222c6ac..ec62a21c 100644
--- a/servant-lucid/src/Servant/HTML/Lucid.hs
+++ b/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  #-}
-#endif
+
+#include "overlapping-compat.h"
 
 -- | 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ToHtml a => MimeRender HTML a where
     mimeRender _ = renderBS . toHtml
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          MimeRender HTML (Html a) where
     mimeRender _ = renderBS
diff --git a/servant-mock/include/overlapping-compat.h b/servant-mock/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-mock/servant-mock.cabal b/servant-mock/servant-mock.cabal
index 0bb605db..66f41f22 100644
--- a/servant-mock/servant-mock.cabal
+++ b/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
diff --git a/servant-property/include/overlapping-compat.h b/servant-property/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-server/include/overlapping-compat.h b/servant-server/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index 7e36387e..a2e1463b 100644
--- a/servant-server/servant-server.cabal
+++ b/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
diff --git a/servant-server/src/Servant/Server/Internal.hs b/servant-server/src/Servant/Server/Internal.hs
index 4200d052..48aed938 100644
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/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       #-}
-#endif
+
+#include "overlapping-compat.h"
 
 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( AllCTRender ctypes a
          ) => HasServer (Delete ctypes a) where
 
@@ -217,10 +213,7 @@ instance
 
   route Proxy = methodRouter methodDelete (Proxy :: Proxy ctypes) ok200
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Delete ctypes ()) where
 
   type ServerT (Delete ctypes ()) m = m ()
@@ -228,10 +221,7 @@ instance
   route Proxy = methodRouterEmpty methodDelete
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           HasServer (Get ctypes ()) where
 
   type ServerT (Get ctypes ()) m = m ()
@@ -274,10 +258,7 @@ instance
   route Proxy = methodRouterEmpty methodGet
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( AllCTRender ctypes a
          ) => HasServer (Post ctypes a) where
 
@@ -340,10 +318,7 @@ instance
 
   route Proxy = methodRouter methodPost (Proxy :: Proxy ctypes) created201
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Post ctypes ()) where
 
   type ServerT (Post ctypes ()) m = m ()
@@ -351,10 +326,7 @@ instance
   route Proxy = methodRouterEmpty methodPost
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Put ctypes ()) where
 
   type ServerT (Put ctypes ()) m = m ()
@@ -396,10 +362,7 @@ instance
   route Proxy = methodRouterEmpty methodPut
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           HasServer (Patch ctypes ()) where
 
   type ServerT (Patch ctypes ()) m = m ()
@@ -439,10 +396,7 @@ instance
   route Proxy = methodRouterEmpty methodPatch
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Patch ctypes (Headers h v)) where
 
diff --git a/servant-session/include/overlapping-compat.h b/servant-session/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant/include/overlapping-compat.h b/servant/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant/servant.cabal b/servant/servant.cabal
index f717eab3..99455ab9 100644
--- a/servant/servant.cabal
+++ b/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
diff --git a/servant/src/Servant/API/ResponseHeaders.hs b/servant/src/Servant/API/ResponseHeaders.hs
index 1fcbd035..dc73a8e0 100644
--- a/servant/src/Servant/API/ResponseHeaders.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         BuildHeadersTo '[] where
+instance OVERLAPPING_ BuildHeadersTo '[] where
     buildHeadersTo _ = HNil
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( FromByteString v, BuildHeadersTo xs, KnownSymbol h, Contains h xs ~ 'False
-         ) => BuildHeadersTo ((Header h v) ': xs) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (HList '[]) where
+instance OVERLAPPING_ GetHeaders (HList '[]) where
     getHeaders _ = []
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, ToByteString x, GetHeaders (HList xs)
-         ) => GetHeaders (HList (Header h x ': xs)) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (Headers '[] a) where
+instance OVERLAPPING_ GetHeaders (Headers '[] a) where
     getHeaders _ = []
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, GetHeaders (HList rest), ToByteString v
-         ) => GetHeaders (Headers (Header h v ': rest) a) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# 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
+instance OVERLAPPING_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, ToByteString v
-         , new ~ (Headers '[Header h v] a)
-         ) => AddHeader h v a new where
+instance OVERLAPPABLE_ ( 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

From a4a0f1988b74d3eed09686b7ac8946eba02f669d Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Mon, 4 Jan 2016 17:21:14 +0100
Subject: [PATCH 16/34] Bump wai and warp upper bound to < 3.3.

---
 servant-mock/servant-mock.cabal     | 2 +-
 servant-server/servant-server.cabal | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/servant-mock/servant-mock.cabal b/servant-mock/servant-mock.cabal
index 0bb605db..14455c99 100644
--- a/servant-mock/servant-mock.cabal
+++ b/servant-mock/servant-mock.cabal
@@ -31,7 +31,7 @@ library
     servant-server >= 0.4,
     transformers >= 0.3 && <0.5,
     QuickCheck >= 2.7 && <2.9,
-    wai >= 3.0 && <3.1
+    wai >= 3.0 && <3.3
   hs-source-dirs:      src
   default-language:    Haskell2010
 
diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index 7e36387e..ff2fb200 100644
--- a/servant-server/servant-server.cabal
+++ b/servant-server/servant-server.cabal
@@ -62,9 +62,9 @@ library
       , text               >= 1.2  && < 1.3
       , transformers       >= 0.3  && < 0.5
       , transformers-compat>= 0.4
-      , wai                >= 3.0  && < 3.1
+      , wai                >= 3.0  && < 3.3
       , wai-app-static     >= 3.0  && < 3.2
-      , warp               >= 3.0  && < 3.2
+      , warp               >= 3.0  && < 3.3
 
   hs-source-dirs: src
   default-language: Haskell2010

From 79d4f944a4f34bb5e80cd460d976373354404195 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 17:54:29 +0100
Subject: [PATCH 17/34] less OverlappingInstances noise

---
 servant-blaze/include/overlapping-compat.h    |  8 ++
 servant-blaze/servant-blaze.cabal             |  1 +
 servant-blaze/src/Servant/HTML/Blaze.hs       | 16 +---
 servant-cassava/include/overlapping-compat.h  |  8 ++
 servant-cassava/servant-cassava.cabal         |  1 +
 servant-client/include/overlapping-compat.h   |  8 ++
 servant-client/servant-client.cabal           |  1 +
 servant-client/src/Servant/Client.hs          | 80 ++++---------------
 servant-client/test/Servant/ClientSpec.hs     | 24 ++----
 servant-docs/include/overlapping-compat.h     |  8 ++
 servant-docs/servant-docs.cabal               |  1 +
 servant-docs/src/Servant/Docs/Internal.hs     | 50 +++---------
 servant-examples/include/overlapping-compat.h |  8 ++
 servant-foreign/include/overlapping-compat.h  |  8 ++
 servant-foreign/servant-foreign.cabal         |  1 +
 servant-jquery/include/overlapping-compat.h   |  8 ++
 servant-js/include/overlapping-compat.h       |  8 ++
 servant-js/servant-js.cabal                   |  1 +
 servant-lucid/include/overlapping-compat.h    |  8 ++
 servant-lucid/servant-lucid.cabal             |  1 +
 servant-lucid/src/Servant/HTML/Lucid.hs       | 15 +---
 servant-mock/include/overlapping-compat.h     |  8 ++
 servant-mock/servant-mock.cabal               |  1 +
 servant-property/include/overlapping-compat.h |  8 ++
 servant-server/include/overlapping-compat.h   |  8 ++
 servant-server/servant-server.cabal           |  2 +
 servant-server/src/Servant/Server/Internal.hs | 80 ++++---------------
 servant-server/test/Doctests.hs               |  2 +-
 servant-session/include/overlapping-compat.h  |  8 ++
 servant/include/overlapping-compat.h          |  8 ++
 servant/servant.cabal                         |  2 +
 servant/src/Servant/API/ResponseHeaders.hs    | 65 ++++-----------
 servant/test/Doctests.hs                      |  2 +-
 33 files changed, 199 insertions(+), 259 deletions(-)
 create mode 100644 servant-blaze/include/overlapping-compat.h
 create mode 100644 servant-cassava/include/overlapping-compat.h
 create mode 100644 servant-client/include/overlapping-compat.h
 create mode 100644 servant-docs/include/overlapping-compat.h
 create mode 100644 servant-examples/include/overlapping-compat.h
 create mode 100644 servant-foreign/include/overlapping-compat.h
 create mode 100644 servant-jquery/include/overlapping-compat.h
 create mode 100644 servant-js/include/overlapping-compat.h
 create mode 100644 servant-lucid/include/overlapping-compat.h
 create mode 100644 servant-mock/include/overlapping-compat.h
 create mode 100644 servant-property/include/overlapping-compat.h
 create mode 100644 servant-server/include/overlapping-compat.h
 create mode 100644 servant-session/include/overlapping-compat.h
 create mode 100644 servant/include/overlapping-compat.h

diff --git a/servant-blaze/include/overlapping-compat.h b/servant-blaze/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-blaze/servant-blaze.cabal b/servant-blaze/servant-blaze.cabal
index 08b27e24..a82076f6 100644
--- a/servant-blaze/servant-blaze.cabal
+++ b/servant-blaze/servant-blaze.cabal
@@ -30,3 +30,4 @@ library
                      , blaze-html
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-blaze/src/Servant/HTML/Blaze.hs b/servant-blaze/src/Servant/HTML/Blaze.hs
index 7870022d..822a7ae9 100644
--- a/servant-blaze/src/Servant/HTML/Blaze.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ToMarkup a => MimeRender HTML a where
+instance OVERLAPPABLE_ ToMarkup a => MimeRender HTML a where
     mimeRender _ = renderHtml . toHtml
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender HTML Html where
+instance OVERLAPPING_ MimeRender HTML Html where
     mimeRender _ = renderHtml
 
diff --git a/servant-cassava/include/overlapping-compat.h b/servant-cassava/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-cassava/servant-cassava.cabal b/servant-cassava/servant-cassava.cabal
index 4d74612a..db18986c 100644
--- a/servant-cassava/servant-cassava.cabal
+++ b/servant-cassava/servant-cassava.cabal
@@ -27,3 +27,4 @@ library
                      , vector
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-client/include/overlapping-compat.h b/servant-client/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-client/servant-client.cabal b/servant-client/servant-client.cabal
index 7fe69521..1ddf8bf4 100644
--- a/servant-client/servant-client.cabal
+++ b/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
diff --git a/servant-client/src/Servant/Client.hs b/servant-client/src/Servant/Client.hs
index 987a2bd4..408850ca 100644
--- a/servant-client/src/Servant/Client.hs
+++ b/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 #-}
-#endif
+
+#include "overlapping-compat.h"
 -- | 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   ( 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)
diff --git a/servant-client/test/Servant/ClientSpec.hs b/servant-client/test/Servant/ClientSpec.hs
index fc3cdcfb..b1980d1a 100644
--- a/servant-client/test/Servant/ClientSpec.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   GetNth 0 (x :<|> y) x where
       getNth _ (x :<|> _) = x
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   (GetLast b c) => GetLast (a :<|> b) c where
       getLast (_ :<|> b) = getLast b
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
   GetLast a a where
       getLast a = a
diff --git a/servant-docs/include/overlapping-compat.h b/servant-docs/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index b88bc612..7bd34a7a 100644
--- a/servant-docs/servant-docs.cabal
+++ b/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
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 33cb86a0..c1d26142 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/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   #-}
-#endif
+
+#include "overlapping-compat.h"
 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLe #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
         (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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
         ( ToSample a, IsNonEmpty cts, AllMimeRender cts a,
           AllHeaderSamples ls , GetHeaders (HList ls) )
     => HasDocs (Put cts (Headers ls a)) where
diff --git a/servant-examples/include/overlapping-compat.h b/servant-examples/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-foreign/include/overlapping-compat.h b/servant-foreign/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-foreign/servant-foreign.cabal b/servant-foreign/servant-foreign.cabal
index 0ec296ae..d565b636 100644
--- a/servant-foreign/servant-foreign.cabal
+++ b/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
diff --git a/servant-jquery/include/overlapping-compat.h b/servant-jquery/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-js/include/overlapping-compat.h b/servant-js/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-js/servant-js.cabal b/servant-js/servant-js.cabal
index 53a74e9d..a47ecd34 100644
--- a/servant-js/servant-js.cabal
+++ b/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
diff --git a/servant-lucid/include/overlapping-compat.h b/servant-lucid/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-lucid/servant-lucid.cabal b/servant-lucid/servant-lucid.cabal
index 77cf3ee1..e4438f42 100644
--- a/servant-lucid/servant-lucid.cabal
+++ b/servant-lucid/servant-lucid.cabal
@@ -30,3 +30,4 @@ library
                      , servant == 0.5.*
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
diff --git a/servant-lucid/src/Servant/HTML/Lucid.hs b/servant-lucid/src/Servant/HTML/Lucid.hs
index f222c6ac..ec62a21c 100644
--- a/servant-lucid/src/Servant/HTML/Lucid.hs
+++ b/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  #-}
-#endif
+
+#include "overlapping-compat.h"
 
 -- | 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ToHtml a => MimeRender HTML a where
     mimeRender _ = renderBS . toHtml
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          MimeRender HTML (Html a) where
     mimeRender _ = renderBS
diff --git a/servant-mock/include/overlapping-compat.h b/servant-mock/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-mock/servant-mock.cabal b/servant-mock/servant-mock.cabal
index 14455c99..e1df69e4 100644
--- a/servant-mock/servant-mock.cabal
+++ b/servant-mock/servant-mock.cabal
@@ -34,6 +34,7 @@ library
     wai >= 3.0 && <3.3
   hs-source-dirs:      src
   default-language:    Haskell2010
+  include-dirs: include
 
 executable mock-app
   main-is: main.hs
diff --git a/servant-property/include/overlapping-compat.h b/servant-property/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-server/include/overlapping-compat.h b/servant-server/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index ff2fb200..5d6ccaa2 100644
--- a/servant-server/servant-server.cabal
+++ b/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
diff --git a/servant-server/src/Servant/Server/Internal.hs b/servant-server/src/Servant/Server/Internal.hs
index 4200d052..48aed938 100644
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/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       #-}
-#endif
+
+#include "overlapping-compat.h"
 
 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( AllCTRender ctypes a
          ) => HasServer (Delete ctypes a) where
 
@@ -217,10 +213,7 @@ instance
 
   route Proxy = methodRouter methodDelete (Proxy :: Proxy ctypes) ok200
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Delete ctypes ()) where
 
   type ServerT (Delete ctypes ()) m = m ()
@@ -228,10 +221,7 @@ instance
   route Proxy = methodRouterEmpty methodDelete
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           HasServer (Get ctypes ()) where
 
   type ServerT (Get ctypes ()) m = m ()
@@ -274,10 +258,7 @@ instance
   route Proxy = methodRouterEmpty methodGet
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( AllCTRender ctypes a
          ) => HasServer (Post ctypes a) where
 
@@ -340,10 +318,7 @@ instance
 
   route Proxy = methodRouter methodPost (Proxy :: Proxy ctypes) created201
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Post ctypes ()) where
 
   type ServerT (Post ctypes ()) m = m ()
@@ -351,10 +326,7 @@ instance
   route Proxy = methodRouterEmpty methodPost
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          HasServer (Put ctypes ()) where
 
   type ServerT (Put ctypes ()) m = m ()
@@ -396,10 +362,7 @@ instance
   route Proxy = methodRouterEmpty methodPut
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
           HasServer (Patch ctypes ()) where
 
   type ServerT (Patch ctypes ()) m = m ()
@@ -439,10 +396,7 @@ instance
   route Proxy = methodRouterEmpty methodPatch
 
 -- Add response headers
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
+instance OVERLAPPING_
          ( GetHeaders (Headers h v), AllCTRender ctypes v
          ) => HasServer (Patch ctypes (Headers h v)) where
 
diff --git a/servant-server/test/Doctests.hs b/servant-server/test/Doctests.hs
index 572461aa..663f8768 100644
--- a/servant-server/test/Doctests.hs
+++ b/servant-server/test/Doctests.hs
@@ -10,7 +10,7 @@ main :: IO ()
 main = do
     files <- find always (extension ==? ".hs") "src"
     mCabalMacrosFile <- getCabalMacrosFile
-    doctest $ "-isrc" :
+    doctest $ "-isrc" : "-Iinclude" :
               (maybe [] (\ f -> ["-optP-include", "-optP" ++ f]) mCabalMacrosFile) ++
               "-XOverloadedStrings" :
               "-XFlexibleInstances" :
diff --git a/servant-session/include/overlapping-compat.h b/servant-session/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant/include/overlapping-compat.h b/servant/include/overlapping-compat.h
new file mode 100644
index 00000000..eef9d4ea
--- /dev/null
+++ b/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
diff --git a/servant/servant.cabal b/servant/servant.cabal
index f717eab3..99455ab9 100644
--- a/servant/servant.cabal
+++ b/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
diff --git a/servant/src/Servant/API/ResponseHeaders.hs b/servant/src/Servant/API/ResponseHeaders.hs
index 1fcbd035..dc73a8e0 100644
--- a/servant/src/Servant/API/ResponseHeaders.hs
+++ b/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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         BuildHeadersTo '[] where
+instance OVERLAPPING_ BuildHeadersTo '[] where
     buildHeadersTo _ = HNil
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( FromByteString v, BuildHeadersTo xs, KnownSymbol h, Contains h xs ~ 'False
-         ) => BuildHeadersTo ((Header h v) ': xs) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (HList '[]) where
+instance OVERLAPPING_ GetHeaders (HList '[]) where
     getHeaders _ = []
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, ToByteString x, GetHeaders (HList xs)
-         ) => GetHeaders (HList (Header h x ': xs)) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         GetHeaders (Headers '[] a) where
+instance OVERLAPPING_ GetHeaders (Headers '[] a) where
     getHeaders _ = []
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, GetHeaders (HList rest), ToByteString v
-         ) => GetHeaders (Headers (Header h v ': rest) a) where
+instance OVERLAPPABLE_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# 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
+instance OVERLAPPING_ ( 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
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
-         ( KnownSymbol h, ToByteString v
-         , new ~ (Headers '[Header h v] a)
-         ) => AddHeader h v a new where
+instance OVERLAPPABLE_ ( 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
diff --git a/servant/test/Doctests.hs b/servant/test/Doctests.hs
index bf6bcd23..d9116823 100644
--- a/servant/test/Doctests.hs
+++ b/servant/test/Doctests.hs
@@ -11,7 +11,7 @@ main = do
     files <- find always (extension ==? ".hs") "src"
     tfiles <- find always (extension ==? ".hs") "test/Servant"
     mCabalMacrosFile <- getCabalMacrosFile
-    doctest $ "-isrc" :
+    doctest $ "-isrc" : "-Iinclude" :
               (maybe [] (\ f -> ["-optP-include", "-optP" ++ f]) mCabalMacrosFile) ++
               "-XOverloadedStrings" :
               "-XFlexibleInstances" :

From 8a497c473cac4682e3a583d935b8c3a03751be70 Mon Sep 17 00:00:00 2001
From: Luigy Leon <luichi.19@gmail.com>
Date: Mon, 4 Jan 2016 23:03:26 -0500
Subject: [PATCH 18/34] delete extra committed header files

---
 servant-jquery/include/overlapping-compat.h   | 8 --------
 servant-property/include/overlapping-compat.h | 8 --------
 servant-session/include/overlapping-compat.h  | 8 --------
 3 files changed, 24 deletions(-)
 delete mode 100644 servant-jquery/include/overlapping-compat.h
 delete mode 100644 servant-property/include/overlapping-compat.h
 delete mode 100644 servant-session/include/overlapping-compat.h

diff --git a/servant-jquery/include/overlapping-compat.h b/servant-jquery/include/overlapping-compat.h
deleted file mode 100644
index eef9d4ea..00000000
--- a/servant-jquery/include/overlapping-compat.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif
diff --git a/servant-property/include/overlapping-compat.h b/servant-property/include/overlapping-compat.h
deleted file mode 100644
index eef9d4ea..00000000
--- a/servant-property/include/overlapping-compat.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif
diff --git a/servant-session/include/overlapping-compat.h b/servant-session/include/overlapping-compat.h
deleted file mode 100644
index eef9d4ea..00000000
--- a/servant-session/include/overlapping-compat.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

From 17fcc25d871d67278867c01581c1cf742b2b83e3 Mon Sep 17 00:00:00 2001
From: Luigy Leon <luichi.19@gmail.com>
Date: Mon, 4 Jan 2016 23:05:05 -0500
Subject: [PATCH 19/34] add include header files to extra-source-files

---
 servant-blaze/servant-blaze.cabal     | 2 +-
 servant-cassava/servant-cassava.cabal | 2 +-
 servant-client/servant-client.cabal   | 1 +
 servant-docs/servant-docs.cabal       | 1 +
 servant-foreign/servant-foreign.cabal | 1 +
 servant-js/servant-js.cabal           | 1 +
 servant-lucid/servant-lucid.cabal     | 2 +-
 servant-mock/servant-mock.cabal       | 1 +
 servant-server/servant-server.cabal   | 1 +
 servant/servant.cabal                 | 1 +
 10 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/servant-blaze/servant-blaze.cabal b/servant-blaze/servant-blaze.cabal
index a82076f6..cc4ea34d 100644
--- a/servant-blaze/servant-blaze.cabal
+++ b/servant-blaze/servant-blaze.cabal
@@ -13,7 +13,7 @@ maintainer:          jkarni@gmail.com
 -- copyright:
 category:            Web
 build-type:          Simple
--- extra-source-files:
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 bug-reports:         http://github.com/haskell-servant/servant/issues
 source-repository head
diff --git a/servant-cassava/servant-cassava.cabal b/servant-cassava/servant-cassava.cabal
index db18986c..e2e7c964 100644
--- a/servant-cassava/servant-cassava.cabal
+++ b/servant-cassava/servant-cassava.cabal
@@ -13,7 +13,7 @@ maintainer:          jkarni@gmail.com
 -- copyright:
 -- category:
 build-type:          Simple
--- extra-source-files:
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 
 library
diff --git a/servant-client/servant-client.cabal b/servant-client/servant-client.cabal
index 1ddf8bf4..087920dc 100644
--- a/servant-client/servant-client.cabal
+++ b/servant-client/servant-client.cabal
@@ -15,6 +15,7 @@ maintainer:          alpmestan@gmail.com
 copyright:           2014 Zalora South East Asia Pte Ltd
 category:            Web
 build-type:          Simple
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 tested-with:         GHC >= 7.8
 homepage:            http://haskell-servant.github.io/
diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index 7bd34a7a..b1be264d 100644
--- a/servant-docs/servant-docs.cabal
+++ b/servant-docs/servant-docs.cabal
@@ -19,6 +19,7 @@ tested-with:         GHC >= 7.8
 homepage:            http://haskell-servant.github.io/
 Bug-reports:         http://github.com/haskell-servant/servant/issues
 extra-source-files:
+  include/*.h
   CHANGELOG.md
   README.md
 source-repository head
diff --git a/servant-foreign/servant-foreign.cabal b/servant-foreign/servant-foreign.cabal
index d565b636..be1f2696 100644
--- a/servant-foreign/servant-foreign.cabal
+++ b/servant-foreign/servant-foreign.cabal
@@ -18,6 +18,7 @@ category:            Web
 build-type:          Simple
 cabal-version:       >=1.10
 extra-source-files:
+  include/*.h
   CHANGELOG.md
   README.md
 source-repository head
diff --git a/servant-js/servant-js.cabal b/servant-js/servant-js.cabal
index a47ecd34..28005e60 100644
--- a/servant-js/servant-js.cabal
+++ b/servant-js/servant-js.cabal
@@ -22,6 +22,7 @@ cabal-version:       >=1.10
 homepage:            http://haskell-servant.github.io/
 Bug-reports:         http://github.com/haskell-servant/servant/issues
 extra-source-files:
+  include/*.h
   CHANGELOG.md
   README.md
 source-repository head
diff --git a/servant-lucid/servant-lucid.cabal b/servant-lucid/servant-lucid.cabal
index e4438f42..f2be1eb5 100644
--- a/servant-lucid/servant-lucid.cabal
+++ b/servant-lucid/servant-lucid.cabal
@@ -13,7 +13,7 @@ maintainer:          jkarni@gmail.com
 -- copyright:
 category:            Web
 build-type:          Simple
--- extra-source-files:
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 bug-reports:         http://github.com/haskell-servant/servant/issues
 source-repository head
diff --git a/servant-mock/servant-mock.cabal b/servant-mock/servant-mock.cabal
index e1df69e4..7d8589d0 100644
--- a/servant-mock/servant-mock.cabal
+++ b/servant-mock/servant-mock.cabal
@@ -13,6 +13,7 @@ maintainer:          alpmestan@gmail.com
 copyright:           2015 Alp Mestanogullari
 category:            Web
 build-type:          Simple
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 
 flag example
diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index 5d6ccaa2..c4ec6edc 100644
--- a/servant-server/servant-server.cabal
+++ b/servant-server/servant-server.cabal
@@ -23,6 +23,7 @@ build-type:          Simple
 cabal-version:       >=1.10
 tested-with:         GHC >= 7.8
 extra-source-files:
+  include/*.h
   CHANGELOG.md
   README.md
 bug-reports:         http://github.com/haskell-servant/servant/issues
diff --git a/servant/servant.cabal b/servant/servant.cabal
index 99455ab9..895b9f32 100644
--- a/servant/servant.cabal
+++ b/servant/servant.cabal
@@ -16,6 +16,7 @@ maintainer:          alpmestan@gmail.com
 copyright:           2014 Zalora South East Asia Pte Ltd
 category:            Web
 build-type:          Simple
+extra-source-files:  include/*.h
 cabal-version:       >=1.10
 tested-with:         GHC >= 7.8
 source-repository head

From f66981fc8a10a2db6cfb38ad3736619b824779f9 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Thu, 7 Jan 2016 00:53:17 +0100
Subject: [PATCH 20/34] First pass at CONTRIBUTING

---
 CONTRIBUTING.md | 76 +++++++++++++++++++++++++++++++++++++++++++++++++
 README.md       | 27 +-----------------
 2 files changed, 77 insertions(+), 26 deletions(-)
 create mode 100644 CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 00000000..74577d3f
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,76 @@
+# Contributing Guidelines
+
+Contributions are very welcome! To hack on the github version, clone the
+repository. You can use `cabal`:
+
+```shell
+./scripts/start-sandbox.sh # Initialize the sandbox and add-source the packages
+./scripts/test-all.sh      # Run all the tests
+```
+
+`stack`:
+
+```shell
+stack build    # Install and build packages
+stack test     # Run all the tests
+```
+
+Or `nix`:
+```shell
+./scripts/generate-nix-files.sh   # Get up-to-date shell.nix files
+```
+
+
+## General
+
+Some things we like:
+
+- Explicit imports
+- Upper and lower bounds for packages
+- Few dependencies
+- -Werror-compatible
+
+Though we aren't sticklers for style, the `.stylish-haskell.yaml` and `HLint.hs`
+files in the repository provide a good baseline for consistency.
+
+Please include a description of the changes in your PR in the `CHANGELOG.md` of
+the packages you've changed. And of course, write tests!
+
+## PR process
+
+We require two +1 from the maintainers of the repo. If you feel like there has
+not been a timely response to a PR, you can ping the Maintainers group (with
+`@Maintainers`).
+
+## New combinators
+
+We encourage people to experiment with new combinators and instances - it is
+one of the most powerful ways of using `servant`, and a wonderful way of
+getting to know it better. If you do write a new combinator, we would love to
+know about it! Either hop on #servant on freenode and let us know, or open an
+issue with the `news` tag (which we will close when we read it).
+
+As for adding them to the main repo: maintaining combinators can be expensive,
+since official combinators must have instances for all classes (and new classes
+come along fairly frequently). We therefore have to be quite selective about
+those that we accept. If you're considering writing a new combinator, open an
+issue to discuss it first!
+
+
+## New classes
+
+The main benefit of having a new class and package in the main servant repo is
+that we get to see via CI whether changes to other packages break the build.
+Open an issue to discuss whether a package should be added to the main repo. If
+we decide that it can, you can still keep maintainership over it.
+
+Whether or not you want your package to be in the repo, create an issue with
+the `news` label if you make a new package so we can know about it!
+
+## Release policy
+
+We are currently moving to a more aggresive release policy, so that you can get
+what you contribute from Hackage fairly soon. However, note that prior to major
+releases it may take some time in between releases. If you think you're change
+is small enough that you should be backported to released major versions, say
+so in the issue or PR.
diff --git a/README.md b/README.md
index 0f13f495..3cf786ea 100644
--- a/README.md
+++ b/README.md
@@ -17,29 +17,4 @@ list](https://groups.google.com/forum/#!forum/haskell-servant).
 
 ## Contributing
 
-Contributions are very welcome! To hack on the github version, clone the
-repository. You can use `cabal`:
-
-```shell
-./scripts/start-sandbox.sh # Initialize the sandbox and add-source the packages
-./scripts/test-all.sh      # Run all the tests
-```
-
-`stack`:
-
-```shell
-stack build    # Install and build packages
-stack test     # Run all the tests
-```
-
-Or `nix`:
-```shell
-./scripts/generate-nix-files.sh   # Get up-to-date shell.nix files
-```
-
-Though we aren't sticklers for style, the `.stylish-haskell.yaml` and `HLint.hs`
-files in the repository provide a good baseline for consistency.
-
-Please include a description of the changes in your PR in the `CHANGELOG.md` of
-the packages you've changed. And of course, write tests!
-
+See `CONTRIBUTING.md`

From 832f1b985ffa9278e1d7b1fad8f7cdc743058469 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Thu, 7 Jan 2016 13:05:13 +0100
Subject: [PATCH 21/34] Review fixes and note about CI.

---
 CONTRIBUTING.md | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 74577d3f..0c76f11f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -28,7 +28,7 @@ Some things we like:
 - Explicit imports
 - Upper and lower bounds for packages
 - Few dependencies
-- -Werror-compatible
+- -Werror-compatible (for both 7.8 and 7.10)
 
 Though we aren't sticklers for style, the `.stylish-haskell.yaml` and `HLint.hs`
 files in the repository provide a good baseline for consistency.
@@ -38,6 +38,10 @@ the packages you've changed. And of course, write tests!
 
 ## PR process
 
+We try to give timely reviews to PRs that pass CI. If CI for your PR fails, we
+may close the PR if it has been open for too long (though you should feel free
+to reopen when the issues have been fixed).
+
 We require two +1 from the maintainers of the repo. If you feel like there has
 not been a timely response to a PR, you can ping the Maintainers group (with
 `@Maintainers`).
@@ -53,7 +57,7 @@ issue with the `news` tag (which we will close when we read it).
 As for adding them to the main repo: maintaining combinators can be expensive,
 since official combinators must have instances for all classes (and new classes
 come along fairly frequently). We therefore have to be quite selective about
-those that we accept. If you're considering writing a new combinator, open an
+those that we accept. If your considering writing a new combinator, open an
 issue to discuss it first!
 
 
@@ -72,5 +76,5 @@ the `news` label if you make a new package so we can know about it!
 We are currently moving to a more aggresive release policy, so that you can get
 what you contribute from Hackage fairly soon. However, note that prior to major
 releases it may take some time in between releases. If you think you're change
-is small enough that you should be backported to released major versions, say
+is small enough that it should be backported to released major versions, say
 so in the issue or PR.

From cda8bcf17cbe5a23696fcf0e320f1d8ec99d0505 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Fri, 27 Nov 2015 02:05:34 +0100
Subject: [PATCH 22/34] Simplify verb combinators.

        Create a single 'Verb' combinator with parameters for status code and
        method. Make existing combinators type synonyms of 'Verb'.
---
 servant-client/src/Servant/Client.hs          | 168 ++++--------
 servant-client/src/Servant/Common/Req.hs      |  19 +-
 servant-client/test/Servant/ClientSpec.hs     |   4 +-
 servant-docs/src/Servant/Docs/Internal.hs     |  63 ++---
 servant-server/src/Servant/Server/Internal.hs | 249 +++---------------
 .../test/Servant/Server/ErrorSpec.hs          |   2 +-
 .../test/Servant/Server/Internal/EnterSpec.hs |   2 +-
 servant-server/test/Servant/ServerSpec.hs     |  48 ++--
 .../test/Servant/Utils/StaticFilesSpec.hs     |   7 +-
 servant/servant.cabal                         |   6 +-
 servant/src/Servant/API.hs                    |  23 +-
 servant/src/Servant/API/ContentTypes.hs       |  66 +++--
 servant/src/Servant/API/Delete.hs             |  24 --
 servant/src/Servant/API/Get.hs                |  22 --
 servant/src/Servant/API/Patch.hs              |  29 --
 servant/src/Servant/API/Post.hs               |  27 --
 servant/src/Servant/API/Put.hs                |  25 --
 servant/src/Servant/API/Verbs.hs              |  60 +++++
 servant/src/Servant/Utils/Links.hs            |  37 +--
 19 files changed, 279 insertions(+), 602 deletions(-)
 delete mode 100644 servant/src/Servant/API/Delete.hs
 delete mode 100644 servant/src/Servant/API/Get.hs
 delete mode 100644 servant/src/Servant/API/Patch.hs
 delete mode 100644 servant/src/Servant/API/Post.hs
 delete mode 100644 servant/src/Servant/API/Put.hs
 create mode 100644 servant/src/Servant/API/Verbs.hs

diff --git a/servant-client/src/Servant/Client.hs b/servant-client/src/Servant/Client.hs
index 408850ca..4eac1b2d 100644
--- a/servant-client/src/Servant/Client.hs
+++ b/servant-client/src/Servant/Client.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE InstanceSigs         #-}
 {-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE PolyKinds            #-}
 {-# LANGUAGE ScopedTypeVariables  #-}
 {-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE TypeOperators        #-}
@@ -44,7 +45,7 @@ import           Servant.Common.Req
 -- | 'client' allows you to produce operations to query an API from a client.
 --
 -- > type MyApi = "books" :> Get '[JSON] [Book] -- GET /books
--- >         :<|> "books" :> ReqBody '[JSON] Book :> Post Book -- POST /books
+-- >         :<|> "books" :> ReqBody '[JSON] Book :> Post '[JSON] Book -- POST /books
 -- >
 -- > myApi :: Proxy MyApi
 -- > myApi = Proxy
@@ -118,62 +119,48 @@ instance (KnownSymbol capture, ToHttpApiData a, HasClient sublayout)
 
     where p = unpack (toUrlPiece val)
 
--- | If you have a 'Delete' endpoint in your API, the client
--- 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 OVERLAPPABLE_
-  (MimeUnrender ct a, cts' ~ (ct ': cts)) => HasClient (Delete cts' a) where
-  type Client (Delete cts' a) = ExceptT ServantError IO a
+  -- Note [Non-Empty Content Types]
+  (MimeUnrender ct a, ReflectMethod method, cts' ~ (ct ': cts)
+  ) => HasClient (Verb method status cts' a) where
+  type Client (Verb method status cts' a) = ExceptT ServantError IO a
   clientWithRoute Proxy req baseurl manager =
-    snd <$> performRequestCT (Proxy :: Proxy ct) H.methodDelete req baseurl manager
+    snd <$> performRequestCT (Proxy :: Proxy ct) method req baseurl manager
+      where method = reflectMethod (Proxy :: Proxy method)
 
 instance OVERLAPPING_
-  HasClient (Delete cts ()) where
-  type Client (Delete cts ()) = ExceptT ServantError IO ()
+  (ReflectMethod method) => HasClient (Verb method status cts ()) where
+  type Client (Verb method status cts ()) = ExceptT ServantError IO ()
   clientWithRoute Proxy req baseurl manager =
-    void $ performRequestNoBody H.methodDelete req baseurl manager
+    void $ performRequestNoBody method req baseurl manager
+      where method = reflectMethod (Proxy :: Proxy method)
 
--- | If you have a 'Delete xs (Headers ls x)' endpoint, the client expects the
--- corresponding headers.
 instance OVERLAPPING_
-  ( 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)
+  -- Note [Non-Empty Content Types]
+  ( MimeUnrender ct a, BuildHeadersTo ls, ReflectMethod method, cts' ~ (ct ': cts)
+  ) => HasClient (Verb method status cts' (Headers ls a)) where
+  type Client (Verb method status cts' (Headers ls a))
+    = ExceptT ServantError IO (Headers ls a)
   clientWithRoute Proxy req baseurl manager = do
-    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) H.methodDelete req baseurl manager
+    let method = reflectMethod (Proxy :: Proxy method)
+    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) method req baseurl manager
     return $ Headers { getResponse = resp
                      , getHeadersHList = buildHeadersTo hdrs
                      }
 
--- | If you have a 'Get' endpoint in your API, the client
--- 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 OVERLAPPABLE_
-  (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 OVERLAPPING_
-  HasClient (Get (ct ': cts) ()) where
-  type Client (Get (ct ': cts) ()) = ExceptT ServantError IO ()
-  clientWithRoute Proxy req baseurl manager =
-    performRequestNoBody H.methodGet req baseurl manager
-
--- | If you have a 'Get xs (Headers ls x)' endpoint, the client expects the
--- corresponding headers.
-instance OVERLAPPING_
-  ( 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)
+  ( BuildHeadersTo ls, ReflectMethod method
+  ) => HasClient (Verb method status cts (Headers ls ())) where
+  type Client (Verb method status cts (Headers ls ()))
+    = ExceptT ServantError IO (Headers ls ())
   clientWithRoute Proxy req baseurl manager = do
-    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) H.methodGet req baseurl manager
-    return $ Headers { getResponse = resp
+    let method = reflectMethod (Proxy :: Proxy method)
+    hdrs <- performRequestNoBody method req baseurl manager
+    return $ Headers { getResponse = ()
                      , getHeadersHList = buildHeadersTo hdrs
                      }
 
+
 -- | If you use a 'Header' in one of your endpoints in your API,
 -- the corresponding querying function will automatically take
 -- an additional argument of the type specified by your 'Header',
@@ -217,90 +204,6 @@ instance (KnownSymbol sym, ToHttpApiData a, HasClient sublayout)
 
     where hname = symbolVal (Proxy :: Proxy sym)
 
--- | If you have a 'Post' endpoint in your API, the client
--- 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 OVERLAPPABLE_
-  (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 OVERLAPPING_
-  HasClient (Post (ct ': cts) ()) where
-  type Client (Post (ct ': cts) ()) = ExceptT ServantError IO ()
-  clientWithRoute Proxy req baseurl manager =
-    void $ performRequestNoBody H.methodPost req baseurl manager
-
--- | If you have a 'Post xs (Headers ls x)' endpoint, the client expects the
--- corresponding headers.
-instance OVERLAPPING_
-  ( 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)
-  clientWithRoute Proxy req baseurl manager = do
-    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) H.methodPost req baseurl manager
-    return $ Headers { getResponse = resp
-                     , getHeadersHList = buildHeadersTo hdrs
-                     }
-
--- | If you have a 'Put' endpoint in your API, the client
--- 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 OVERLAPPABLE_
-  (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 OVERLAPPING_
-  HasClient (Put (ct ': cts) ()) where
-  type Client (Put (ct ': cts) ()) = ExceptT ServantError IO ()
-  clientWithRoute Proxy req baseurl manager =
-    void $ performRequestNoBody H.methodPut req baseurl manager
-
--- | If you have a 'Put xs (Headers ls x)' endpoint, the client expects the
--- corresponding headers.
-instance OVERLAPPING_
-  ( 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)
-  clientWithRoute Proxy req baseurl manager= do
-    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) H.methodPut req baseurl manager
-    return $ Headers { getResponse = resp
-                     , getHeadersHList = buildHeadersTo hdrs
-                     }
-
--- | If you have a 'Patch' endpoint in your API, the client
--- 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 OVERLAPPABLE_
-  (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 OVERLAPPING_
-  HasClient (Patch (ct ': cts) ()) where
-  type Client (Patch (ct ': cts) ()) = ExceptT ServantError IO ()
-  clientWithRoute Proxy req baseurl manager =
-    void $ performRequestNoBody H.methodPatch req baseurl manager
-
--- | If you have a 'Patch xs (Headers ls x)' endpoint, the client expects the
--- corresponding headers.
-instance OVERLAPPING_
-  ( 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)
-  clientWithRoute Proxy req baseurl manager = do
-    (hdrs, resp) <- performRequestCT (Proxy :: Proxy ct) H.methodPatch req baseurl manager
-    return $ Headers { getResponse = resp
-                     , getHeadersHList = buildHeadersTo hdrs
-                     }
-
 -- | If you use a 'QueryParam' in one of your endpoints in your API,
 -- the corresponding querying function will automatically take
 -- an additional argument of the type specified by your 'QueryParam',
@@ -503,3 +406,20 @@ instance HasClient api => HasClient (IsSecure :> api) where
 
   clientWithRoute Proxy req baseurl manager =
     clientWithRoute (Proxy :: Proxy api) req baseurl manager
+
+
+{- Note [Non-Empty Content Types]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Rather than have
+
+   instance (..., cts' ~ (ct ': cts)) => ... cts' ...
+
+It may seem to make more sense to have:
+
+   instance (...) => ... (ct ': cts) ...
+
+But this means that if another instance exists that does *not* require
+non-empty lists, but is otherwise more specific, no instance will be overall
+more specific. This in turns generally means adding yet another instance (one
+for empty and one for non-empty lists).
+-}
diff --git a/servant-client/src/Servant/Common/Req.hs b/servant-client/src/Servant/Common/Req.hs
index 38aa39b5..32d572aa 100644
--- a/servant-client/src/Servant/Common/Req.hs
+++ b/servant-client/src/Servant/Common/Req.hs
@@ -142,7 +142,7 @@ performRequest reqMethod req reqHost manager = do
     Right response -> do
       let status = Client.responseStatus response
           body = Client.responseBody response
-          hrds = Client.responseHeaders response
+          hdrs = Client.responseHeaders response
           status_code = statusCode status
       ct <- case lookup "Content-Type" $ Client.responseHeaders response of
                  Nothing -> pure $ "application"//"octet-stream"
@@ -151,23 +151,26 @@ performRequest reqMethod req reqHost manager = do
                    Just t' -> pure t'
       unless (status_code >= 200 && status_code < 300) $
         throwE $ FailureResponse status ct body
-      return (status_code, body, ct, hrds, response)
+      return (status_code, body, ct, hdrs, response)
 
 
 performRequestCT :: MimeUnrender ct result =>
-  Proxy ct -> Method -> Req -> BaseUrl -> Manager -> ExceptT ServantError IO ([HTTP.Header], result)
+  Proxy ct -> Method -> Req -> BaseUrl -> Manager
+  -> ExceptT ServantError IO ([HTTP.Header], result)
 performRequestCT ct reqMethod req reqHost manager = do
   let acceptCT = contentType ct
-  (_status, respBody, respCT, hrds, _response) <-
+  (_status, respBody, respCT, hdrs, _response) <-
     performRequest reqMethod (req { reqAccept = [acceptCT] }) reqHost manager
   unless (matches respCT (acceptCT)) $ throwE $ UnsupportedContentType respCT respBody
   case mimeUnrender ct respBody of
     Left err -> throwE $ DecodeFailure err respCT respBody
-    Right val -> return (hrds, val)
+    Right val -> return (hdrs, val)
 
-performRequestNoBody :: Method -> Req -> BaseUrl -> Manager -> ExceptT ServantError IO ()
-performRequestNoBody reqMethod req reqHost manager =
-  void $ performRequest reqMethod req reqHost manager
+performRequestNoBody :: Method -> Req -> BaseUrl -> Manager
+  -> ExceptT ServantError IO [HTTP.Header]
+performRequestNoBody reqMethod req reqHost manager = do
+  (_status, _body, _ct, hdrs, _response) <- performRequest reqMethod req reqHost manager
+  return hdrs
 
 catchConnectionError :: IO a -> IO (Either ServantError a)
 catchConnectionError action =
diff --git a/servant-client/test/Servant/ClientSpec.hs b/servant-client/test/Servant/ClientSpec.hs
index b1980d1a..e289873d 100644
--- a/servant-client/test/Servant/ClientSpec.hs
+++ b/servant-client/test/Servant/ClientSpec.hs
@@ -90,7 +90,7 @@ type TestHeaders = '[Header "X-Example1" Int, Header "X-Example2" String]
 
 type Api =
        "get" :> Get '[JSON] Person
-  :<|> "deleteEmpty" :> Delete '[] ()
+  :<|> "deleteEmpty" :> Delete '[JSON] ()
   :<|> "capture" :> Capture "name" String :> Get '[JSON,FormUrlEncoded] Person
   :<|> "body" :> ReqBody '[FormUrlEncoded,JSON] Person :> Post '[JSON] Person
   :<|> "param" :> QueryParam "name" String :> Get '[FormUrlEncoded,JSON] Person
@@ -283,7 +283,7 @@ failSpec = beforeAll (startWaiApp failServer) $ afterAll endWaiApp $ do
           _ -> fail $ "expected InvalidContentTypeHeader, but got " <> show res
 
 data WrappedApi where
-  WrappedApi :: (HasServer api, Server api ~ ExceptT ServantErr IO a,
+  WrappedApi :: (HasServer (api :: *), Server api ~ ExceptT ServantErr IO a,
                  HasClient api, Client api ~ ExceptT ServantError IO ()) =>
     Proxy api -> WrappedApi
 
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index c1d26142..41754c31 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/servant-docs/src/Servant/Docs/Internal.hs
@@ -476,8 +476,8 @@ instance (ToByteString l, AllHeaderSamples ls, ToSample l, KnownSymbol h)
 
 -- | Synthesise a sample value of a type, encoded in the specified media types.
 sampleByteString
-    :: forall ctypes a. (ToSample a, IsNonEmpty ctypes, AllMimeRender ctypes a)
-    => Proxy ctypes
+    :: forall ct cts a. (ToSample a, AllMimeRender (ct ': cts) a)
+    => Proxy (ct ': cts)
     -> Proxy a
     -> [(M.MediaType, ByteString)]
 sampleByteString ctypes@Proxy Proxy =
@@ -486,8 +486,8 @@ sampleByteString ctypes@Proxy Proxy =
 -- | Synthesise a list of sample values of a particular type, encoded in the
 -- specified media types.
 sampleByteStrings
-    :: forall ctypes a. (ToSample a, IsNonEmpty ctypes, AllMimeRender ctypes a)
-    => Proxy ctypes
+    :: forall ct cts a. (ToSample a, AllMimeRender (ct ': cts) a)
+    => Proxy (ct ': cts)
     -> Proxy a
     -> [(Text, M.MediaType, ByteString)]
 sampleByteStrings ctypes@Proxy Proxy =
@@ -689,21 +689,21 @@ instance (KnownSymbol sym, ToCapture (Capture sym a), HasDocs sublayout)
 
 
 instance OVERLAPPABLE_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
-    => HasDocs (Delete cts a) where
+        (ToSample a, AllMimeRender (ct ': cts) a)
+    => HasDocs (Delete (ct ': cts) a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
     where endpoint' = endpoint & method .~ DocDELETE
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPING_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a
+        (ToSample a, AllMimeRender (ct ': cts) a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Delete cts (Headers ls a)) where
+    => HasDocs (Delete (ct ': cts) (Headers ls a)) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -712,25 +712,26 @@ instance OVERLAPPING_
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
                            & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPABLE_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
-    => HasDocs (Get cts a) where
+        (ToSample a, AllMimeRender (ct ': cts) a)
+    => HasDocs (Get (ct ': cts) a) where
+>>>>>>> Simplify verb combinators.
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
     where endpoint' = endpoint & method .~ DocGET
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPING_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a
+        (ToSample a, AllMimeRender (ct ': cts) a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Get cts (Headers ls a)) where
+    => HasDocs (Get (ct ': cts) (Headers ls a)) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -739,7 +740,7 @@ instance OVERLAPPING_
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
                            & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance (KnownSymbol sym, HasDocs sublayout)
@@ -752,8 +753,8 @@ instance (KnownSymbol sym, HasDocs sublayout)
           headername = pack $ symbolVal (Proxy :: Proxy sym)
 
 instance OVERLAPPABLE_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
-    => HasDocs (Post cts a) where
+        (ToSample a, AllMimeRender (ct ': cts) a)
+    => HasDocs (Post (ct ': cts) a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -761,13 +762,13 @@ instance OVERLAPPABLE_
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
                            & response.respStatus .~ 201
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPING_
-         (ToSample a, IsNonEmpty cts, AllMimeRender cts a
+         (ToSample a, AllMimeRender (ct ': cts) a
          , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Post cts (Headers ls a)) where
+    => HasDocs (Post (ct ': cts) (Headers ls a)) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -777,12 +778,12 @@ instance OVERLAPPING_
                            & response.respTypes .~ allMime t
                            & response.respStatus .~ 201
                            & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPABLE_
-        (ToSample a, IsNonEmpty cts, AllMimeRender cts a)
-    => HasDocs (Put cts a) where
+        (ToSample a, AllMimeRender (ct ': cts) a)
+    => HasDocs (Put (ct ': cts) a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -790,13 +791,13 @@ instance OVERLAPPABLE_
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
                            & response.respStatus .~ 200
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance OVERLAPPING_
-        ( ToSample a, IsNonEmpty cts, AllMimeRender cts a,
+        ( ToSample a, AllMimeRender (ct ': cts) a,
           AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Put cts (Headers ls a)) where
+    => HasDocs (Put (ct ': cts) (Headers ls a)) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
@@ -806,7 +807,7 @@ instance OVERLAPPING_
                            & response.respTypes .~ allMime t
                            & response.respStatus .~ 200
                            & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance (KnownSymbol sym, ToParam (QueryParam sym a), HasDocs sublayout)
@@ -849,8 +850,8 @@ instance HasDocs Raw where
 -- example data. However, there's no reason to believe that the instances of
 -- 'AllMimeUnrender' and 'AllMimeRender' actually agree (or to suppose that
 -- both are even defined) for any particular type.
-instance (ToSample a, IsNonEmpty cts, AllMimeRender cts a, HasDocs sublayout)
-      => HasDocs (ReqBody cts a :> sublayout) where
+instance (ToSample a, AllMimeRender (ct ': cts) a, HasDocs sublayout)
+      => HasDocs (ReqBody (ct ': cts) a :> sublayout) where
 
   docsFor Proxy (endpoint, action) =
     docsFor sublayoutP (endpoint, action')
@@ -858,7 +859,7 @@ instance (ToSample a, IsNonEmpty cts, AllMimeRender cts a, HasDocs sublayout)
     where sublayoutP = Proxy :: Proxy sublayout
           action' = action & rqbody .~ sampleByteString t p
                            & rqtypes .~ allMime t
-          t = Proxy :: Proxy cts
+          t = Proxy :: Proxy (ct ': cts)
           p = Proxy :: Proxy a
 
 instance (KnownSymbol path, HasDocs sublayout) => HasDocs (path :> sublayout) where
diff --git a/servant-server/src/Servant/Server/Internal.hs b/servant-server/src/Servant/Server/Internal.hs
index 48aed938..5c08c4d4 100644
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/servant-server/src/Servant/Server/Internal.hs
@@ -21,26 +21,33 @@ module Servant.Server.Internal
 #if !MIN_VERSION_base(4,8,0)
 import           Control.Applicative         ((<$>))
 #endif
-import           Control.Monad.Trans.Except  (ExceptT)
-import qualified Data.ByteString             as B
-import qualified Data.ByteString.Lazy        as BL
-import qualified Data.Map                    as M
-import           Data.Maybe                  (fromMaybe, mapMaybe)
-import           Data.String                 (fromString)
-import           Data.String.Conversions     (ConvertibleStrings, cs, (<>))
-import           Data.Text                   (Text)
+import           Control.Monad.Trans.Except (ExceptT)
+import qualified Data.ByteString            as B
+import qualified Data.ByteString.Lazy       as BL
+import qualified Data.Map                   as M
+import           Data.Maybe                 (fromMaybe, mapMaybe)
+import           Data.String                (fromString)
+import           Data.String.Conversions    (cs, (<>))
+import           Data.Text                  (Text)
 import           Data.Typeable
-import           GHC.TypeLits                (KnownSymbol, symbolVal)
-import           Network.HTTP.Types          hiding (Header, ResponseHeaders)
-import           Network.Socket              (SockAddr)
-import           Network.Wai                 (Application, lazyRequestBody,
-                                              rawQueryString, requestHeaders,
-                                              requestMethod, responseLBS, remoteHost,
-                                              isSecure, vault, httpVersion, Response,
-                                              Request, pathInfo)
+import           GHC.TypeLits               (KnownNat, KnownSymbol, natVal,
+                                             symbolVal)
+import           Network.HTTP.Types         hiding (Header, ResponseHeaders)
+import           Network.Socket             (SockAddr)
+import           Network.Wai                (Application, Request, Response,
+                                             httpVersion, isSecure,
+                                             lazyRequestBody, pathInfo,
+                                             rawQueryString, remoteHost,
+                                             requestHeaders, requestMethod,
+                                             responseLBS, vault)
+import           Web.HttpApiData            (FromHttpApiData)
+import           Web.HttpApiData.Internal   (parseHeaderMaybe,
+                                             parseQueryParamMaybe,
+                                             parseUrlPieceMaybe)
+
 import           Servant.API                 ((:<|>) (..), (:>), Capture,
-                                              Delete, Get, Header,
-                                              IsSecure(..), Patch, Post, Put,
+                                              Verb, ReflectMethod(reflectMethod),
+                                              IsSecure(..), Header,
                                               QueryFlag, QueryParam, QueryParams,
                                               Raw, RemoteHost, ReqBody, Vault)
 import           Servant.API.ContentTypes    (AcceptHeader (..),
@@ -55,8 +62,6 @@ import           Servant.Server.Internal.Router
 import           Servant.Server.Internal.RoutingApplication
 import           Servant.Server.Internal.ServantErr
 
-import           Web.HttpApiData          (FromHttpApiData)
-import           Web.HttpApiData.Internal (parseUrlPieceMaybe, parseHeaderMaybe, parseQueryParamMaybe)
 
 class HasServer layout where
   type ServerT layout (m :: * -> *) :: *
@@ -129,12 +134,12 @@ allowedMethodHead method request = method == methodGet && requestMethod request
 allowedMethod :: Method -> Request -> Bool
 allowedMethod method request = allowedMethodHead method request || requestMethod request == method
 
-processMethodRouter :: forall a. ConvertibleStrings a B.ByteString
-                    => Maybe (a, BL.ByteString) -> Status -> Method
+processMethodRouter :: Maybe (BL.ByteString, BL.ByteString) -> Status -> Method
                     -> Maybe [(HeaderName, B.ByteString)]
                     -> Request -> RouteResult Response
 processMethodRouter handleA status method headers request = case handleA of
   Nothing -> FailFatal err406 -- this should not happen (checked before), so we make it fatal if it does
+  Just (_, "") -> Route $ responseLBS status204 (fromMaybe [] headers) ""
   Just (contentT, body) -> Route $ responseLBS status hdrs bdy
     where
       bdy = if allowedMethodHead method request then "" else body
@@ -160,7 +165,7 @@ methodRouter method proxy status action = LeafRouter route'
       | pathIsEmpty request =
           let accH = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request
           in runAction (action `addMethodCheck` methodCheck method request
-                               `addAcceptCheck` acceptCheck proxy  accH
+                               `addAcceptCheck` acceptCheck proxy accH
                        ) respond $ \ output -> do
                let handleA = handleAcceptH proxy (AcceptHeader accH) output
                processMethodRouter handleA status method Nothing request
@@ -176,95 +181,34 @@ methodRouterHeaders method proxy status action = LeafRouter route'
       | pathIsEmpty request =
           let accH    = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request
           in runAction (action `addMethodCheck` methodCheck method request
-                               `addAcceptCheck` acceptCheck proxy  accH
+                               `addAcceptCheck` acceptCheck proxy accH
                        ) respond $ \ output -> do
                 let headers = getHeaders output
                     handleA = handleAcceptH proxy (AcceptHeader accH) (getResponse output)
                 processMethodRouter handleA status method (Just headers) request
       | otherwise = respond $ Fail err404
 
-methodRouterEmpty :: Method
-                  -> Delayed (ExceptT ServantErr IO ())
-                  -> Router
-methodRouterEmpty method action = LeafRouter route'
-  where
-    route' request respond
-      | pathIsEmpty request = do
-          runAction (addMethodCheck action (methodCheck method request)) respond $ \ () ->
-            Route $! responseLBS noContent204 [] ""
-      | otherwise = respond $ Fail err404
-
--- | If you have a 'Delete' endpoint in your API,
--- the handler for this endpoint is meant to delete
--- a resource.
---
--- The code of the handler will, just like
--- for 'Servant.API.Get.Get', 'Servant.API.Post.Post' and
--- 'Servant.API.Put.Put', run in @ExceptT ServantErr IO ()@.
--- The 'Int' represents the status code and the 'String' a message
--- 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 OVERLAPPABLE_
-         ( AllCTRender ctypes a
-         ) => HasServer (Delete ctypes a) where
+         ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
+         ) => HasServer (Verb method status ctypes a) where
 
-  type ServerT (Delete ctypes a) m = m a
+  type ServerT (Verb method status ctypes a) m = m a
 
-  route Proxy = methodRouter methodDelete (Proxy :: Proxy ctypes) ok200
+  route Proxy = methodRouter method (Proxy :: Proxy ctypes) status
+    where method = reflectMethod (Proxy :: Proxy method)
+          status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
 instance OVERLAPPING_
-         HasServer (Delete ctypes ()) where
+instance
+         ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
+         , GetHeaders (Headers h a)
+         ) => HasServer (Verb method status ctypes (Headers h a)) where
 
-  type ServerT (Delete ctypes ()) m = m ()
+  type ServerT (Verb method status ctypes (Headers h a)) m = m (Headers h a)
 
-  route Proxy = methodRouterEmpty methodDelete
-
--- Add response headers
-instance OVERLAPPING_
-         ( GetHeaders (Headers h v), AllCTRender ctypes v
-         ) => HasServer (Delete ctypes (Headers h v)) where
-
-  type ServerT (Delete ctypes (Headers h v)) m = m (Headers h v)
-
-  route Proxy = methodRouterHeaders methodDelete (Proxy :: Proxy ctypes) ok200
-
--- | When implementing the handler for a 'Get' endpoint,
--- just like for 'Servant.API.Delete.Delete', 'Servant.API.Post.Post'
--- and 'Servant.API.Put.Put', the handler code runs in the
--- @ExceptT ServantErr IO@ monad, where the 'Int' represents
--- the status code and the 'String' a message, returned in case of
--- failure. You can quite handily use 'Control.Monad.Trans.Except.throwE'
--- to quickly fail if some conditions are not met.
---
--- If successfully returning a value, we use the type-level list, combined
--- with the request's @Accept@ header, to encode the value for you
--- (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 OVERLAPPABLE_
-         ( AllCTRender ctypes a ) => HasServer (Get ctypes a) where
-
-  type ServerT (Get ctypes a) m = m a
-
-  route Proxy = methodRouter methodGet (Proxy :: Proxy ctypes) ok200
-
--- '()' ==> 204 No Content
-instance OVERLAPPING_
-          HasServer (Get ctypes ()) where
-
-  type ServerT (Get ctypes ()) m = m ()
-
-  route Proxy = methodRouterEmpty methodGet
-
--- Add response headers
-instance OVERLAPPING_
-          ( GetHeaders (Headers h v), AllCTRender ctypes v
-          ) => HasServer (Get ctypes (Headers h v)) where
-
-  type ServerT (Get ctypes (Headers h v)) m = m (Headers h v)
-
-  route Proxy = methodRouterHeaders methodGet (Proxy :: Proxy ctypes) ok200
+  route Proxy = methodRouterHeaders method (Proxy :: Proxy ctypes) status
+    where method = reflectMethod (Proxy :: Proxy method)
+          status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
 -- | If you use 'Header' in one of the endpoints for your API,
 -- this automatically requires your server-side handler to be a function
@@ -297,113 +241,6 @@ instance (KnownSymbol sym, FromHttpApiData a, HasServer sublayout)
     in  route (Proxy :: Proxy sublayout) (passToServer subserver mheader)
     where str = fromString $ symbolVal (Proxy :: Proxy sym)
 
--- | When implementing the handler for a 'Post' endpoint,
--- just like for 'Servant.API.Delete.Delete', 'Servant.API.Get.Get'
--- and 'Servant.API.Put.Put', the handler code runs in the
--- @ExceptT ServantErr IO@ monad, where the 'Int' represents
--- the status code and the 'String' a message, returned in case of
--- failure. You can quite handily use 'Control.Monad.Trans.Except.throwE'
--- to quickly fail if some conditions are not met.
---
--- If successfully returning a value, we use the type-level list, combined
--- with the request's @Accept@ header, to encode the value for you
--- (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 OVERLAPPABLE_
-         ( AllCTRender ctypes a
-         ) => HasServer (Post ctypes a) where
-
-  type ServerT (Post ctypes a) m = m a
-
-  route Proxy = methodRouter methodPost (Proxy :: Proxy ctypes) created201
-
-instance OVERLAPPING_
-         HasServer (Post ctypes ()) where
-
-  type ServerT (Post ctypes ()) m = m ()
-
-  route Proxy = methodRouterEmpty methodPost
-
--- Add response headers
-instance OVERLAPPING_
-         ( GetHeaders (Headers h v), AllCTRender ctypes v
-         ) => HasServer (Post ctypes (Headers h v)) where
-
-  type ServerT (Post ctypes (Headers h v)) m = m (Headers h v)
-
-  route Proxy = methodRouterHeaders methodPost (Proxy :: Proxy ctypes) created201
-
--- | When implementing the handler for a 'Put' endpoint,
--- just like for 'Servant.API.Delete.Delete', 'Servant.API.Get.Get'
--- and 'Servant.API.Post.Post', the handler code runs in the
--- @ExceptT ServantErr IO@ monad, where the 'Int' represents
--- the status code and the 'String' a message, returned in case of
--- failure. You can quite handily use 'Control.Monad.Trans.Except.throwE'
--- to quickly fail if some conditions are not met.
---
--- If successfully returning a value, we use the type-level list, combined
--- with the request's @Accept@ header, to encode the value for you
--- (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 OVERLAPPABLE_
-         ( 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 OVERLAPPING_
-         HasServer (Put ctypes ()) where
-
-  type ServerT (Put ctypes ()) m = m ()
-
-  route Proxy = methodRouterEmpty methodPut
-
--- Add response headers
-instance OVERLAPPING_
-         ( GetHeaders (Headers h v), AllCTRender ctypes v
-         ) => HasServer (Put ctypes (Headers h v)) where
-
-  type ServerT (Put ctypes (Headers h v)) m = m (Headers h v)
-
-  route Proxy = methodRouterHeaders methodPut (Proxy :: Proxy ctypes) ok200
-
--- | When implementing the handler for a 'Patch' endpoint,
--- just like for 'Servant.API.Delete.Delete', 'Servant.API.Get.Get'
--- and 'Servant.API.Put.Put', the handler code runs in the
--- @ExceptT ServantErr IO@ monad, where the 'Int' represents
--- the status code and the 'String' a message, returned in case of
--- failure. You can quite handily use 'Control.Monad.Trans.Except.throwE'
--- to quickly fail if some conditions are not met.
---
--- 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 OVERLAPPABLE_
-         ( 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 OVERLAPPING_
-          HasServer (Patch ctypes ()) where
-
-  type ServerT (Patch ctypes ()) m = m ()
-
-  route Proxy = methodRouterEmpty methodPatch
-
--- Add response headers
-instance OVERLAPPING_
-         ( GetHeaders (Headers h v), AllCTRender ctypes v
-         ) => HasServer (Patch ctypes (Headers h v)) where
-
-  type ServerT (Patch ctypes (Headers h v)) m = m (Headers h v)
-
-  route Proxy = methodRouterHeaders methodPatch (Proxy :: Proxy ctypes) ok200
-
 -- | If you use @'QueryParam' "author" Text@ in one of the endpoints for your API,
 -- this automatically requires your server-side handler to be a function
 -- that takes an argument of type @'Maybe' 'Text'@.
diff --git a/servant-server/test/Servant/Server/ErrorSpec.hs b/servant-server/test/Servant/Server/ErrorSpec.hs
index 2e93cc2a..500a0069 100644
--- a/servant-server/test/Servant/Server/ErrorSpec.hs
+++ b/servant-server/test/Servant/Server/ErrorSpec.hs
@@ -162,7 +162,7 @@ errorRetrySpec = describe "Handler search"
 
   it "should continue when URLs don't match" $ do
     request methodPost "" [jsonCT, jsonAccept] jsonBody
-     `shouldRespondWith` 201 { matchBody = Just $ encode (7 :: Int) }
+     `shouldRespondWith` 200 { matchBody = Just $ encode (7 :: Int) }
 
   it "should continue when methods don't match" $ do
     request methodGet "a" [jsonCT, jsonAccept] jsonBody
diff --git a/servant-server/test/Servant/Server/Internal/EnterSpec.hs b/servant-server/test/Servant/Server/Internal/EnterSpec.hs
index 973e1f89..8b450377 100644
--- a/servant-server/test/Servant/Server/Internal/EnterSpec.hs
+++ b/servant-server/test/Servant/Server/Internal/EnterSpec.hs
@@ -52,7 +52,7 @@ enterSpec = describe "Enter" $ do
 
     it "allows running arbitrary monads" $ do
       get "int" `shouldRespondWith` "1797"
-      post "string" "3" `shouldRespondWith` "\"hi\""{ matchStatus = 201 }
+      post "string" "3" `shouldRespondWith` "\"hi\""{ matchStatus = 200 }
 
   with (return (serve combinedAPI combinedReaderServer)) $ do
     it "allows combnation of enters" $ do
diff --git a/servant-server/test/Servant/ServerSpec.hs b/servant-server/test/Servant/ServerSpec.hs
index e017d399..ad7a3556 100644
--- a/servant-server/test/Servant/ServerSpec.hs
+++ b/servant-server/test/Servant/ServerSpec.hs
@@ -130,15 +130,21 @@ captureSpec = do
 
 
 type GetApi = Get '[JSON] Person
-        :<|> "empty" :> Get '[] ()
-        :<|> "post" :> Post '[] ()
+        :<|> "empty" :> Get '[JSON] ()
+        :<|> "emptyWithHeaders" :> Get '[JSON] (Headers '[Header "H" Int] ())
+        :<|> "post" :> Post '[JSON] ()
+
 getApi :: Proxy GetApi
 getApi = Proxy
 
 getSpec :: Spec
 getSpec = do
   describe "Servant.API.Get" $ do
-    let server = return alice :<|> return () :<|> return ()
+    let server = return alice
+            :<|> return ()
+            :<|> return (addHeader 5 ())
+            :<|> return ()
+
     with (return $ serve getApi server) $ do
 
       it "allows to GET a Person" $ do
@@ -150,8 +156,8 @@ getSpec = do
         post "/" "" `shouldRespondWith` 405
         post "/empty" "" `shouldRespondWith` 405
 
-      it "returns 204 if the type is '()'" $ do
-        get "/empty" `shouldRespondWith` ""{ matchStatus = 204 }
+      it "returns headers" $ do
+        get "/emptyWithHeaders" `shouldRespondWith` 204 { matchHeaders = [ "H" <:> "5" ] }
 
       it "returns 406 if the Accept header is not supported" $ do
         Test.Hspec.Wai.request methodGet "" [(hAccept, "crazy/mime")] ""
@@ -161,7 +167,10 @@ getSpec = do
 headSpec :: Spec
 headSpec = do
   describe "Servant.API.Head" $ do
-    let server = return alice :<|> return () :<|> return ()
+    let server = return alice
+            :<|> return ()
+            :<|> return (addHeader 5 ())
+            :<|> return ()
     with (return $ serve getApi server) $ do
 
       it "allows to GET a Person" $ do
@@ -177,10 +186,6 @@ headSpec = do
         post "/" "" `shouldRespondWith` 405
         post "/empty" "" `shouldRespondWith` 405
 
-      it "returns 204 if the type is '()'" $ do
-        response <- Test.Hspec.Wai.request methodHead "/empty" [] ""
-        return response `shouldRespondWith` ""{ matchStatus = 204 }
-
       it "returns 406 if the Accept header is not supported" $ do
         Test.Hspec.Wai.request methodHead "" [(hAccept, "crazy/mime")] ""
           `shouldRespondWith` 406
@@ -272,7 +277,7 @@ queryParamSpec = do
 type PostApi =
        ReqBody '[JSON] Person :> Post '[JSON] Integer
   :<|> "bla" :> ReqBody '[JSON] Person :> Post '[JSON] Integer
-  :<|> "empty" :> Post '[] ()
+  :<|> "empty" :> Post '[JSON] ()
 
 postApi :: Proxy PostApi
 postApi = Proxy
@@ -287,25 +292,22 @@ postSpec = do
 
       it "allows to POST a Person" $ do
         post' "/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 201
+          matchStatus = 200
          }
 
       it "allows alternative routes if all have request bodies" $ do
         post' "/bla" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 201
+          matchStatus = 200
          }
 
       it "handles trailing '/' gracefully" $ do
         post' "/bla/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 201
+          matchStatus = 200
          }
 
       it "correctly rejects invalid request bodies with status 400" $ do
         post' "/" "some invalid body" `shouldRespondWith` 400
 
-      it "returns 204 if the type is '()'" $ do
-        post' "empty" "" `shouldRespondWith` ""{ matchStatus = 204 }
-
       it "responds with 415 if the request body media type is unsupported" $ do
         let post'' x = Test.Hspec.Wai.request methodPost x [(hContentType
                                                             , "application/nonsense")]
@@ -314,7 +316,7 @@ postSpec = do
 type PutApi =
        ReqBody '[JSON] Person :> Put '[JSON] Integer
   :<|> "bla" :> ReqBody '[JSON] Person :> Put '[JSON] Integer
-  :<|> "empty" :> Put '[] ()
+  :<|> "empty" :> Put '[JSON] ()
 
 putApi :: Proxy PutApi
 putApi = Proxy
@@ -345,9 +347,6 @@ putSpec = do
       it "correctly rejects invalid request bodies with status 400" $ do
         put' "/" "some invalid body" `shouldRespondWith` 400
 
-      it "returns 204 if the type is '()'" $ do
-        put' "empty" "" `shouldRespondWith` ""{ matchStatus = 204 }
-
       it "responds with 415 if the request body media type is unsupported" $ do
         let put'' x = Test.Hspec.Wai.request methodPut x [(hContentType
                                                             , "application/nonsense")]
@@ -356,7 +355,7 @@ putSpec = do
 type PatchApi =
        ReqBody '[JSON] Person :> Patch '[JSON] Integer
   :<|> "bla" :> ReqBody '[JSON] Person :> Patch '[JSON] Integer
-  :<|> "empty" :> Patch '[] ()
+  :<|> "empty" :> Patch '[JSON] ()
 
 patchApi :: Proxy PatchApi
 patchApi = Proxy
@@ -387,9 +386,6 @@ patchSpec = do
       it "correctly rejects invalid request bodies with status 400" $ do
         patch' "/" "some invalid body" `shouldRespondWith` 400
 
-      it "returns 204 if the type is '()'" $ do
-        patch' "empty" "" `shouldRespondWith` ""{ matchStatus = 204 }
-
       it "responds with 415 if the request body media type is unsupported" $ do
         let patch'' x = Test.Hspec.Wai.request methodPatch x [(hContentType
                                                             , "application/nonsense")]
@@ -505,7 +501,7 @@ responseHeadersSpec :: Spec
 responseHeadersSpec = describe "ResponseHeaders" $ do
   with (return $ serve (Proxy :: Proxy ResponseHeadersApi) responseHeadersServer) $ do
 
-    let methods = [(methodGet, 200), (methodPost, 201), (methodPut, 200), (methodPatch, 200)]
+    let methods = [(methodGet, 200), (methodPost, 200), (methodPut, 200), (methodPatch, 200)]
 
     it "includes the headers in the response" $
       forM_ methods $ \(method, expected) ->
diff --git a/servant-server/test/Servant/Utils/StaticFilesSpec.hs b/servant-server/test/Servant/Utils/StaticFilesSpec.hs
index 3630b313..94c63f18 100644
--- a/servant-server/test/Servant/Utils/StaticFilesSpec.hs
+++ b/servant-server/test/Servant/Utils/StaticFilesSpec.hs
@@ -15,12 +15,7 @@ import           System.IO.Temp            (withSystemTempDirectory)
 import           Test.Hspec                (Spec, around_, describe, it)
 import           Test.Hspec.Wai            (get, shouldRespondWith, with)
 
-import           Servant.API               (JSON)
-import           Servant.API.Alternative   ((:<|>) ((:<|>)))
-import           Servant.API.Capture       (Capture)
-import           Servant.API.Get           (Get)
-import           Servant.API.Raw           (Raw)
-import           Servant.API.Sub           ((:>))
+import           Servant.API               ((:<|>) ((:<|>)), Capture, Get, Raw, (:>), JSON)
 import           Servant.Server            (Server, serve)
 import           Servant.ServerSpec        (Person (Person))
 import           Servant.Utils.StaticFiles (serveDirectory)
diff --git a/servant/servant.cabal b/servant/servant.cabal
index 895b9f32..451eb166 100644
--- a/servant/servant.cabal
+++ b/servant/servant.cabal
@@ -29,14 +29,9 @@ library
     Servant.API.Alternative
     Servant.API.Capture
     Servant.API.ContentTypes
-    Servant.API.Delete
-    Servant.API.Get
     Servant.API.Header
     Servant.API.HttpVersion
     Servant.API.IsSecure
-    Servant.API.Patch
-    Servant.API.Post
-    Servant.API.Put
     Servant.API.QueryParam
     Servant.API.Raw
     Servant.API.RemoteHost
@@ -44,6 +39,7 @@ library
     Servant.API.ResponseHeaders
     Servant.API.Sub
     Servant.API.Vault
+    Servant.API.Verbs
     Servant.Utils.Links
   build-depends:
       base >=4.7 && <5
diff --git a/servant/src/Servant/API.hs b/servant/src/Servant/API.hs
index 2e6abb2a..2565149f 100644
--- a/servant/src/Servant/API.hs
+++ b/servant/src/Servant/API.hs
@@ -25,16 +25,7 @@ module Servant.API (
   -- | Access the location for arbitrary data to be shared by applications and middleware
 
   -- * Actual endpoints, distinguished by HTTP method
-  module Servant.API.Get,
-  -- | @GET@ requests
-  module Servant.API.Post,
-  -- | @POST@ requests
-  module Servant.API.Delete,
-  -- | @DELETE@ requests
-  module Servant.API.Put,
-  -- | @PUT@ requests
-  module Servant.API.Patch,
-  -- | @PATCH@ requests
+  module Servant.API.Verbs,
 
   -- * Content Types
   module Servant.API.ContentTypes,
@@ -64,14 +55,9 @@ import           Servant.API.ContentTypes    (Accept (..), FormUrlEncoded,
                                               MimeRender (..),
                                               MimeUnrender (..), OctetStream,
                                               PlainText, ToFormUrlEncoded (..))
-import           Servant.API.Delete          (Delete)
-import           Servant.API.Get             (Get)
 import           Servant.API.Header          (Header (..))
 import           Servant.API.HttpVersion     (HttpVersion (..))
 import           Servant.API.IsSecure        (IsSecure (..))
-import           Servant.API.Patch           (Patch)
-import           Servant.API.Post            (Post)
-import           Servant.API.Put             (Put)
 import           Servant.API.QueryParam      (QueryFlag, QueryParam,
                                               QueryParams)
 import           Servant.API.Raw             (Raw)
@@ -84,7 +70,10 @@ import           Servant.API.ResponseHeaders (AddHeader (addHeader),
                                               getHeadersHList, getResponse)
 import           Servant.API.Sub             ((:>))
 import           Servant.API.Vault           (Vault)
-import           Web.HttpApiData             (FromHttpApiData (..), ToHttpApiData (..))
+import           Servant.API.Verbs           (Delete, Get, Patch, Post, Put,
+                                              ReflectMethod (reflectMethod),
+                                              Verb)
 import           Servant.Utils.Links         (HasLink (..), IsElem, IsElem',
                                               URI (..), safeLink)
-
+import           Web.HttpApiData             (FromHttpApiData (..),
+                                              ToHttpApiData (..))
diff --git a/servant/src/Servant/API/ContentTypes.hs b/servant/src/Servant/API/ContentTypes.hs
index ab857ce2..85ddbb02 100644
--- a/servant/src/Servant/API/ContentTypes.hs
+++ b/servant/src/Servant/API/ContentTypes.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
+{-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings     #-}
@@ -10,6 +11,9 @@
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
+#if !MIN_VERSION_base(4,8,0)
+{-# LANGUAGE OverlappingInstances  #-}
+#endif
 {-# OPTIONS_HADDOCK not-home       #-}
 
 -- | A collection of basic Content-Types (also known as Internet Media
@@ -19,7 +23,7 @@
 --
 -- Content-Types are used in `ReqBody` and the method combinators:
 --
--- >>> type MyEndpoint = ReqBody '[JSON, PlainText] Book :> Get '[JSON, PlainText] :> Book
+-- >>> type MyEndpoint = ReqBody '[JSON, PlainText] Book :> Get '[JSON, PlainText] Book
 --
 -- Meaning the endpoint accepts requests of Content-Type @application/json@
 -- or @text/plain;charset-utf8@, and returns data in either one of those
@@ -62,7 +66,6 @@ module Servant.API.ContentTypes
     , AllMimeUnrender(..)
     , FromFormUrlEncoded(..)
     , ToFormUrlEncoded(..)
-    , IsNonEmpty
     , eitherDecodeLenient
     , canHandleAcceptH
     ) where
@@ -91,7 +94,7 @@ import qualified Data.Text.Encoding               as TextS
 import qualified Data.Text.Lazy                   as TextL
 import qualified Data.Text.Lazy.Encoding          as TextL
 import           Data.Typeable
-import           GHC.Exts                         (Constraint)
+import           GHC.Generics                     (Generic)
 import qualified Network.HTTP.Media               as M
 import           Network.URI                      (escapeURIString,
                                                    isUnreserved, unEscapeString)
@@ -137,7 +140,7 @@ instance Accept OctetStream where
     contentType _ = "application" M.// "octet-stream"
 
 newtype AcceptHeader = AcceptHeader BS.ByteString
-    deriving (Eq, Show)
+    deriving (Eq, Show, Read, Typeable, Generic)
 
 -- * Render (serializing)
 
@@ -159,19 +162,22 @@ newtype AcceptHeader = AcceptHeader BS.ByteString
 class Accept ctype => MimeRender ctype a where
     mimeRender  :: Proxy ctype -> a -> ByteString
 
-class (AllMimeRender list a) => AllCTRender (list :: [*]) a where
+class (AllMime list) => AllCTRender (list :: [*]) a where
     -- If the Accept header can be matched, returns (Just) a tuple of the
     -- Content-Type and response (serialization of @a@ into the appropriate
     -- mimetype).
     handleAcceptH :: Proxy list -> AcceptHeader -> a -> Maybe (ByteString, ByteString)
 
-instance (AllMimeRender ctyps a, IsNonEmpty ctyps) => AllCTRender ctyps a where
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPABLE #-}
+#endif
+         (AllMimeRender (ct ': cts) a) => AllCTRender (ct ': cts) a where
     handleAcceptH _ (AcceptHeader accept) val = M.mapAcceptMedia lkup accept
-      where pctyps = Proxy :: Proxy ctyps
+      where pctyps = Proxy :: Proxy (ct ': cts)
             amrs = allMimeRender pctyps val
             lkup = fmap (\(a,b) -> (a, (fromStrict $ M.renderHeader a, b))) amrs
 
-
 --------------------------------------------------------------------------
 -- * Unrender
 
@@ -199,14 +205,13 @@ instance (AllMimeRender ctyps a, IsNonEmpty ctyps) => AllCTRender ctyps a where
 class Accept ctype => MimeUnrender ctype a where
     mimeUnrender :: Proxy ctype -> ByteString -> Either String a
 
-class (IsNonEmpty list) => AllCTUnrender (list :: [*]) a where
+class AllCTUnrender (list :: [*]) a where
     handleCTypeH :: Proxy list
                  -> ByteString     -- Content-Type header
                  -> ByteString     -- Request body
                  -> Maybe (Either String a)
 
-instance ( AllMimeUnrender ctyps a, IsNonEmpty ctyps
-         ) => AllCTUnrender ctyps a where
+instance ( AllMimeUnrender ctyps a ) => AllCTUnrender ctyps a where
     handleCTypeH _ ctypeH body = M.mapContentMedia lkup (cs ctypeH)
       where lkup = allMimeUnrender (Proxy :: Proxy ctyps) body
 
@@ -247,8 +252,7 @@ instance ( MimeRender ctyp a
         where pctyp = Proxy :: Proxy ctyp
               pctyps = Proxy :: Proxy (ctyp' ': ctyps)
 
-
-instance AllMimeRender '[] a where
+instance AllMimeRender '[] () where
     allMimeRender _ _ = []
 
 --------------------------------------------------------------------------
@@ -270,21 +274,25 @@ instance ( MimeUnrender ctyp a
         where pctyp = Proxy :: Proxy ctyp
               pctyps = Proxy :: Proxy ctyps
 
-type family IsNonEmpty (list :: [*]) :: Constraint where
-    IsNonEmpty (x ': xs)   = ()
-
-
 --------------------------------------------------------------------------
 -- * MimeRender Instances
 
 -- | `encode`
-instance ToJSON a => MimeRender JSON a where
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPABLE #-}
+#endif
+         ToJSON a => MimeRender JSON a where
     mimeRender _ = encode
 
 -- | @encodeFormUrlEncoded . toFormUrlEncoded@
 -- Note that the @mimeUnrender p (mimeRender p x) == Right x@ law only
 -- holds if every element of x is non-null (i.e., not @("", "")@)
-instance ToFormUrlEncoded a => MimeRender FormUrlEncoded a where
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPABLE #-}
+#endif
+         ToFormUrlEncoded a => MimeRender FormUrlEncoded a where
     mimeRender _ = encodeFormUrlEncoded . toFormUrlEncoded
 
 -- | `TextL.encodeUtf8`
@@ -307,6 +315,26 @@ instance MimeRender OctetStream ByteString where
 instance MimeRender OctetStream BS.ByteString where
     mimeRender _ = fromStrict
 
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+         MimeRender JSON () where
+    mimeRender _ _ = ""
+
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+         MimeRender PlainText () where
+    mimeRender _ _ = ""
+
+instance
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+         MimeRender OctetStream () where
+    mimeRender _ _ = ""
 
 --------------------------------------------------------------------------
 -- * MimeUnrender Instances
diff --git a/servant/src/Servant/API/Delete.hs b/servant/src/Servant/API/Delete.hs
deleted file mode 100644
index de792a28..00000000
--- a/servant/src/Servant/API/Delete.hs
+++ /dev/null
@@ -1,24 +0,0 @@
-{-# LANGUAGE DataKinds          #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE KindSignatures     #-}
-{-# OPTIONS_HADDOCK not-home    #-}
-module Servant.API.Delete (Delete) where
-
-import           Data.Typeable (Typeable)
-
--- | Combinator for DELETE requests.
---
--- Example:
---
--- >>>            -- DELETE /books/:isbn
--- >>> type MyApi = "books" :> Capture "isbn" Text :> Delete '[] ()
-data Delete (contentTypes :: [*]) a
-  deriving Typeable
-
-
--- $setup
--- >>> import Servant.API
--- >>> import Data.Aeson
--- >>> import Data.Text
--- >>> data Book
--- >>> instance ToJSON Book where { toJSON = undefined }
diff --git a/servant/src/Servant/API/Get.hs b/servant/src/Servant/API/Get.hs
deleted file mode 100644
index 073bfda6..00000000
--- a/servant/src/Servant/API/Get.hs
+++ /dev/null
@@ -1,22 +0,0 @@
-{-# LANGUAGE DataKinds          #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE KindSignatures     #-}
-{-# OPTIONS_HADDOCK not-home    #-}
-module Servant.API.Get (Get) where
-
-import           Data.Typeable (Typeable)
-
--- | Endpoint for simple GET requests. Serves the result as JSON.
---
--- Example:
---
--- >>> type MyApi = "books" :> Get '[JSON] [Book]
-data Get (contentTypes :: [*]) a
-  deriving Typeable
-
--- $setup
--- >>> import Servant.API
--- >>> import Data.Aeson
--- >>> import Data.Text
--- >>> data Book
--- >>> instance ToJSON Book where { toJSON = undefined }
diff --git a/servant/src/Servant/API/Patch.hs b/servant/src/Servant/API/Patch.hs
deleted file mode 100644
index 715cf905..00000000
--- a/servant/src/Servant/API/Patch.hs
+++ /dev/null
@@ -1,29 +0,0 @@
-{-# LANGUAGE DataKinds          #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE KindSignatures     #-}
-{-# OPTIONS_HADDOCK not-home    #-}
-module Servant.API.Patch (Patch) where
-
-import           Data.Typeable (Typeable)
-
--- | Endpoint for PATCH requests. The type variable represents the type of the
--- response body (not the request body, use 'Servant.API.ReqBody.ReqBody' for
--- that).
---
--- If the HTTP response is empty, only () is supported.
---
--- Example:
---
--- >>>            -- PATCH /books
--- >>>            -- with a JSON encoded Book as the request body
--- >>>            -- returning the just-created Book
--- >>> type MyApi = "books" :> ReqBody '[JSON] Book :> Patch '[JSON] Book
-data Patch (contentTypes :: [*]) a
-  deriving Typeable
-
--- $setup
--- >>> import Servant.API
--- >>> import Data.Aeson
--- >>> import Data.Text
--- >>> data Book
--- >>> instance ToJSON Book where { toJSON = undefined }
diff --git a/servant/src/Servant/API/Post.hs b/servant/src/Servant/API/Post.hs
deleted file mode 100644
index 72bc59cc..00000000
--- a/servant/src/Servant/API/Post.hs
+++ /dev/null
@@ -1,27 +0,0 @@
-{-# LANGUAGE DataKinds          #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE KindSignatures     #-}
-{-# OPTIONS_HADDOCK not-home    #-}
-module Servant.API.Post (Post) where
-
-import           Data.Typeable (Typeable)
-
--- | Endpoint for POST requests. The type variable represents the type of the
--- response body (not the request body, use 'Servant.API.ReqBody.ReqBody' for
--- that).
---
--- Example:
---
--- >>>            -- POST /books
--- >>>            -- with a JSON encoded Book as the request body
--- >>>            -- returning the just-created Book
--- >>> type MyApi = "books" :> ReqBody '[JSON] Book :> Post '[JSON] Book
-data Post (contentTypes :: [*]) a
-  deriving Typeable
-
--- $setup
--- >>> import Servant.API
--- >>> import Data.Aeson
--- >>> import Data.Text
--- >>> data Book
--- >>> instance ToJSON Book where { toJSON = undefined }
diff --git a/servant/src/Servant/API/Put.hs b/servant/src/Servant/API/Put.hs
deleted file mode 100644
index 0b09d961..00000000
--- a/servant/src/Servant/API/Put.hs
+++ /dev/null
@@ -1,25 +0,0 @@
-{-# LANGUAGE DataKinds          #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE KindSignatures     #-}
-{-# OPTIONS_HADDOCK not-home    #-}
-module Servant.API.Put (Put) where
-
-import           Data.Typeable (Typeable)
-
--- | Endpoint for PUT requests, usually used to update a ressource.
--- The type @a@ is the type of the response body that's returned.
---
--- Example:
---
--- >>> -- PUT /books/:isbn
--- >>> -- with a Book as request body, returning the updated Book
--- >>> type MyApi = "books" :> Capture "isbn" Text :> ReqBody '[JSON] Book :> Put '[JSON] Book
-data Put (contentTypes :: [*]) a
-  deriving Typeable
-
--- $setup
--- >>> import Servant.API
--- >>> import Data.Aeson
--- >>> import Data.Text
--- >>> data Book
--- >>> instance ToJSON Book where { toJSON = undefined }
diff --git a/servant/src/Servant/API/Verbs.hs b/servant/src/Servant/API/Verbs.hs
new file mode 100644
index 00000000..9ab9c74c
--- /dev/null
+++ b/servant/src/Servant/API/Verbs.hs
@@ -0,0 +1,60 @@
+{-# LANGUAGE DataKinds          #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveGeneric      #-}
+{-# LANGUAGE KindSignatures     #-}
+{-# LANGUAGE PolyKinds          #-}
+module Servant.API.Verbs where
+
+import           Data.Typeable             (Typeable)
+import           GHC.Generics              (Generic)
+import           GHC.TypeLits              (Nat)
+import           Network.HTTP.Types.Method (Method, StdMethod (..),
+                                            methodDelete, methodGet, methodHead,
+                                            methodPatch, methodPost, methodPut)
+
+-- | @Verb@ is a general type for representing HTTP verbs/methods. For
+-- convenience, type synonyms for each verb with a 200 response code are
+-- provided, but you are free to define your own:
+--
+-- >>> type Post204 contentTypes a = Verb 'POST 204 contentTypes a
+data Verb (method :: k1) (statusCode :: Nat) (contentTypes :: [*]) a
+  deriving (Typeable, Generic)
+
+-- 'GET' with 200 status code.
+type Get    contentTypes a = Verb 'GET    200 contentTypes a
+
+-- 'POST' with 200 status code.
+type Post   contentTypes a = Verb 'POST   200 contentTypes a
+
+-- 'PUT' with 200 status code.
+type Put    contentTypes a = Verb 'PUT    200 contentTypes a
+
+-- 'DELETE' with 200 status code.
+type Delete contentTypes a = Verb 'DELETE 200 contentTypes a
+
+-- 'PATCH' with 200 status code.
+type Patch  contentTypes a = Verb 'PATCH  200 contentTypes a
+
+-- 'HEAD' with 200 status code.
+type Head   contentTypes a = Verb 'HEAD   200 contentTypes a
+
+class ReflectMethod a where
+    reflectMethod :: proxy a -> Method
+
+instance ReflectMethod 'GET where
+    reflectMethod _ = methodGet
+
+instance ReflectMethod 'POST where
+    reflectMethod _ = methodPost
+
+instance ReflectMethod 'PUT where
+    reflectMethod _ = methodPut
+
+instance ReflectMethod 'DELETE where
+    reflectMethod _ = methodDelete
+
+instance ReflectMethod 'PATCH where
+    reflectMethod _ = methodPatch
+
+instance ReflectMethod 'HEAD where
+    reflectMethod _ = methodHead
diff --git a/servant/src/Servant/Utils/Links.hs b/servant/src/Servant/Utils/Links.hs
index f218377f..38f791ec 100644
--- a/servant/src/Servant/Utils/Links.hs
+++ b/servant/src/Servant/Utils/Links.hs
@@ -74,7 +74,9 @@
 -- >>> safeLink api bad_link
 -- ...
 --     Could not deduce (Or
---                         (IsElem' (Delete '[JSON] ()) (Get '[JSON] Int))
+--                         (IsElem'
+--                            (Verb 'Network.HTTP.Types.Method.DELETE 200 '[JSON] ())
+--                            (Verb 'Network.HTTP.Types.Method.GET 200 '[JSON] Int))
 --                         (IsElem'
 --                            ("hello" :> Delete '[JSON] ())
 --                            ("bye" :> (QueryParam "name" String :> Delete '[JSON] ()))))
@@ -119,11 +121,7 @@ import Servant.API.Capture ( Capture )
 import Servant.API.ReqBody ( ReqBody )
 import Servant.API.QueryParam ( QueryParam, QueryParams, QueryFlag )
 import Servant.API.Header ( Header )
-import Servant.API.Get ( Get )
-import Servant.API.Post ( Post )
-import Servant.API.Put ( Put )
-import Servant.API.Patch ( Patch )
-import Servant.API.Delete ( Delete )
+import Servant.API.Verbs ( Verb )
 import Servant.API.Sub ( type (:>) )
 import Servant.API.Raw ( Raw )
 import Servant.API.Alternative ( type (:<|>) )
@@ -177,11 +175,8 @@ type family IsElem endpoint api :: Constraint where
     IsElem sa (QueryParam x y :> sb)        = IsElem sa sb
     IsElem sa (QueryParams x y :> sb)       = IsElem sa sb
     IsElem sa (QueryFlag x :> sb)           = IsElem sa sb
-    IsElem (Get ct typ) (Get ct' typ)       = IsSubList ct ct'
-    IsElem (Post ct typ) (Post ct' typ)     = IsSubList ct ct'
-    IsElem (Put ct typ) (Put ct' typ)       = IsSubList ct ct'
-    IsElem (Patch ct typ) (Patch ct' typ)   = IsSubList ct ct'
-    IsElem (Delete ct typ) (Delete ct' typ) = IsSubList ct ct'
+    IsElem (Verb m s ct typ) (Verb m s ct' typ)
+                                            = IsSubList ct ct'
     IsElem e e                              = ()
     IsElem e a                              = IsElem' e a
 
@@ -303,24 +298,8 @@ instance HasLink sub => HasLink (Header sym a :> sub) where
     toLink _ = toLink (Proxy :: Proxy sub)
 
 -- Verb (terminal) instances
-instance HasLink (Get y r) where
-    type MkLink (Get y r) = URI
-    toLink _ = linkURI
-
-instance HasLink (Post y r) where
-    type MkLink (Post y r) = URI
-    toLink _ = linkURI
-
-instance HasLink (Put y r) where
-    type MkLink (Put y r) = URI
-    toLink _ = linkURI
-
-instance HasLink (Patch y r) where
-    type MkLink (Patch y r) = URI
-    toLink _ = linkURI
-
-instance HasLink (Delete y r) where
-    type MkLink (Delete y r) = URI
+instance HasLink (Verb m s ct a) where
+    type MkLink (Verb m s ct a) = URI
     toLink _ = linkURI
 
 instance HasLink Raw where

From 190c75a364b38063bafa0f48351dc3358ceaee14 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 02:00:31 +0100
Subject: [PATCH 23/34] Add descriptive type synonyms for success responses.

---
 servant/src/Servant/API/Verbs.hs | 128 ++++++++++++++++++++++++++++---
 1 file changed, 117 insertions(+), 11 deletions(-)

diff --git a/servant/src/Servant/API/Verbs.hs b/servant/src/Servant/API/Verbs.hs
index 9ab9c74c..63232aa1 100644
--- a/servant/src/Servant/API/Verbs.hs
+++ b/servant/src/Servant/API/Verbs.hs
@@ -20,23 +20,129 @@ import           Network.HTTP.Types.Method (Method, StdMethod (..),
 data Verb (method :: k1) (statusCode :: Nat) (contentTypes :: [*]) a
   deriving (Typeable, Generic)
 
--- 'GET' with 200 status code.
+-- * 200 responses
+--
+-- The 200 response is the workhorse of web servers, but also fairly generic.
+-- When appropriate, you should prefer the more specific success combinators.
+-- More information about the definitions of status codes can be found in
+-- <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html RFC2615> and
+-- <https://tools.ietf.org/html/rfc7231#section-6 RFC7231 Section 6>;
+-- the relevant information is summarily presented here.
+
+-- | 'GET' with 200 status code.
 type Get    contentTypes a = Verb 'GET    200 contentTypes a
-
--- 'POST' with 200 status code.
+-- | 'POST' with 200 status code.
 type Post   contentTypes a = Verb 'POST   200 contentTypes a
-
--- 'PUT' with 200 status code.
+-- | 'PUT' with 200 status code.
 type Put    contentTypes a = Verb 'PUT    200 contentTypes a
-
--- 'DELETE' with 200 status code.
+-- | 'DELETE' with 200 status code.
 type Delete contentTypes a = Verb 'DELETE 200 contentTypes a
-
--- 'PATCH' with 200 status code.
+-- | 'PATCH' with 200 status code.
 type Patch  contentTypes a = Verb 'PATCH  200 contentTypes a
 
--- 'HEAD' with 200 status code.
-type Head   contentTypes a = Verb 'HEAD   200 contentTypes a
+-- * Other responses
+
+-- ** 201 Created
+--
+-- Indicates that a new resource has been created. The URI corresponding to the
+-- resource should be given in the @Location@ header field.
+--
+-- If the resource cannot be created immediately, use 'PostAccepted'.
+--
+-- Consider using 'Servant.Utils.Links.safeLink' for the @Location@ header
+-- field.
+
+-- | 'POST' with 201 status code.
+--
+type Created contentTypes a = Verb 'POST 201 contentTypes a
+
+
+-- ** 202 Accepted
+--
+-- Indicates that the request has been accepted for processing, but the
+-- processing has not yet completed. The status of the processing should be
+-- included, as well as either a link to a status monitoring endpoint or an
+-- estimate of when the processing will be finished.
+
+-- | 'GET' with 202 status code.
+type GetAccepted contentTypes a = Verb 'GET 202 contentTypes a
+-- | 'POST' with 202 status code.
+type PostAccepted contentTypes a = Verb 'POST 202 contentTypes a
+-- | 'DELETE' with 202 status code.
+type DeleteAccepted contentTypes a = Verb 'DELETE 202 contentTypes a
+-- | 'PATCH' with 202 status code.
+type PatchAccepted contentTypes a = Verb 'PATCH 202 contentTypes a
+-- | 'PUT' with 202 status code.
+type PutAccepted contentTypes a = Verb 'PUT 202 contentTypes a
+
+
+-- ** 203 Non-Authoritative Information
+--
+-- Indicates that the request has been successfully processed, but the
+-- information may come from a third-party.
+
+-- | 'GET' with 203 status code.
+type GetNonAuthoritative contentTypes a = Verb 'GET 203 contentTypes a
+-- | 'POST' with 203 status code.
+type PostNonAuthoritative contentTypes a = Verb 'POST 203 contentTypes a
+-- | 'DELETE' with 203 status code.
+type DeleteNonAuthoritative contentTypes a = Verb 'DELETE 203 contentTypes a
+-- | 'PATCH' with 203 status code.
+type PatchNonAuthoritative contentTypes a = Verb 'PATCH 203 contentTypes a
+-- | 'PUT' with 203 status code.
+type PutNonAuthoritative contentTypes a = Verb 'PUT 203 contentTypes a
+
+
+-- ** 204 No Content
+--
+-- Indicates that no response body is being returned. Handlers for these must
+-- return 'NoContent'.
+--
+-- If the document view should be reset, use @205 Reset Content@.
+
+-- | 'GET' with 204 status code.
+type GetNoContent contentTypes = Verb 'GET 204 contentTypes NoContent
+-- | 'POST' with 204 status code.
+type PostNoContent contentTypes = Verb 'POST 204 contentTypes NoContent
+-- | 'DELETE' with 204 status code.
+type DeleteNoContent contentTypes = Verb 'DELETE 204 contentTypes NoContent
+-- | 'PATCH' with 204 status code.
+type PatchNoContent contentTypes = Verb 'PATCH 204 contentTypes NoContent
+-- | 'PUT' with 204 status code.
+type PutNoContent contentTypes = Verb 'PUT 204 contentTypes NoContent
+
+
+-- ** 205 Reset Content
+--
+-- Indicates that no response body is being returned. Handlers for these must
+-- return 'NoContent'.
+--
+-- If the document view should not be reset, use @204 No Content@.
+
+-- | 'GET' with 205 status code.
+type GetResetContent contentTypes = Verb 'GET 205 contentTypes NoContent
+-- | 'POST' with 205 status code.
+type PostResetContent contentTypes = Verb 'POST 205 contentTypes NoContent
+-- | 'DELETE' with 205 status code.
+type DeleteResetContent contentTypes = Verb 'DELETE 205 contentTypes NoContent
+-- | 'PATCH' with 205 status code.
+type PatchResetContent contentTypes = Verb 'PATCH 205 contentTypes NoContent
+-- | 'PUT' with 205 status code.
+type PutResetContent contentTypes = Verb 'PUT 205 contentTypes NoContent
+
+
+-- ** 206 Partial Content
+--
+-- Indicates that the server is delivering part of the resource due to a range
+-- header in the request.
+--
+-- For more information, see <https://tools.ietf.org/html/rfc7233#section-4.1
+-- RFC7233 Section 4.1>
+
+-- | 'GET' with 206 status code.
+type GetPartialContent contentTypes = Verb 'GET 205 contentTypes NoContent
+
+data NoContent = NoContent
 
 class ReflectMethod a where
     reflectMethod :: proxy a -> Method

From c6071bfb02de5815facf9acce4d4c7fbda7d92ef Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 02:05:36 +0100
Subject: [PATCH 24/34] Don't override status code on empty body.

---
 servant-server/src/Servant/Server/Internal.hs |  1 -
 servant-server/test/Servant/ServerSpec.hs     | 10 +++++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/servant-server/src/Servant/Server/Internal.hs b/servant-server/src/Servant/Server/Internal.hs
index 5c08c4d4..4dcacb75 100644
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/servant-server/src/Servant/Server/Internal.hs
@@ -139,7 +139,6 @@ processMethodRouter :: Maybe (BL.ByteString, BL.ByteString) -> Status -> Method
                     -> Request -> RouteResult Response
 processMethodRouter handleA status method headers request = case handleA of
   Nothing -> FailFatal err406 -- this should not happen (checked before), so we make it fatal if it does
-  Just (_, "") -> Route $ responseLBS status204 (fromMaybe [] headers) ""
   Just (contentT, body) -> Route $ responseLBS status hdrs bdy
     where
       bdy = if allowedMethodHead method request then "" else body
diff --git a/servant-server/test/Servant/ServerSpec.hs b/servant-server/test/Servant/ServerSpec.hs
index ad7a3556..0a45c70a 100644
--- a/servant-server/test/Servant/ServerSpec.hs
+++ b/servant-server/test/Servant/ServerSpec.hs
@@ -157,7 +157,7 @@ getSpec = do
         post "/empty" "" `shouldRespondWith` 405
 
       it "returns headers" $ do
-        get "/emptyWithHeaders" `shouldRespondWith` 204 { matchHeaders = [ "H" <:> "5" ] }
+        get "/emptyWithHeaders" `shouldRespondWith` 200 { matchHeaders = [ "H" <:> "5" ] }
 
       it "returns 406 if the Accept header is not supported" $ do
         Test.Hspec.Wai.request methodGet "" [(hAccept, "crazy/mime")] ""
@@ -407,16 +407,16 @@ headerSpec = describe "Servant.API.Header" $ do
         expectsString Nothing  = error "Expected a string"
 
     with (return (serve headerApi expectsInt)) $ do
-        let delete' x = Test.Hspec.Wai.request methodDelete x [("MyHeader" ,"5")]
+        let delete' x = Test.Hspec.Wai.request methodDelete x [("MyHeader", "5")]
 
         it "passes the header to the handler (Int)" $
-            delete' "/" "" `shouldRespondWith` 204
+            delete' "/" "" `shouldRespondWith` 200
 
     with (return (serve headerApi expectsString)) $ do
-        let delete' x = Test.Hspec.Wai.request methodDelete x [("MyHeader" ,"more from you")]
+        let delete' x = Test.Hspec.Wai.request methodDelete x [("MyHeader", "more from you")]
 
         it "passes the header to the handler (String)" $
-            delete' "/" "" `shouldRespondWith` 204
+            delete' "/" "" `shouldRespondWith` 200
 
 
 type RawApi = "foo" :> Raw

From 20ae7dcc316ea6b43312d5f47d174ac0c85689f1 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 14:47:05 +0100
Subject: [PATCH 25/34] Update CHANGELOG for Verbs change.

---
 servant/CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/servant/CHANGELOG.md b/servant/CHANGELOG.md
index ddbe1a90..7890e0f1 100644
--- a/servant/CHANGELOG.md
+++ b/servant/CHANGELOG.md
@@ -7,6 +7,8 @@ HEAD
 * Use `http-api-data` instead of `Servant.Common.Text`
 * Remove matrix params.
 * Add PlainText String MimeRender and MimeUnrender instances.
+* Add new `Verbs` combinator, and make all existing and new verb combinators
+type synonyms of it.
 
 0.4.2
 -----

From 9b2d7a7b3829bceefe4823cd360330df2693e2e8 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Sun, 27 Dec 2015 16:30:22 +0100
Subject: [PATCH 26/34] Remove unnecesary () AllMimeRender instance.

---
 servant/src/Servant/API/ContentTypes.hs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/servant/src/Servant/API/ContentTypes.hs b/servant/src/Servant/API/ContentTypes.hs
index 85ddbb02..8e9c75ac 100644
--- a/servant/src/Servant/API/ContentTypes.hs
+++ b/servant/src/Servant/API/ContentTypes.hs
@@ -252,9 +252,6 @@ instance ( MimeRender ctyp a
         where pctyp = Proxy :: Proxy ctyp
               pctyps = Proxy :: Proxy (ctyp' ': ctyps)
 
-instance AllMimeRender '[] () where
-    allMimeRender _ _ = []
-
 --------------------------------------------------------------------------
 -- Check that all elements of list are instances of MimeUnrender
 --------------------------------------------------------------------------

From 5909a6df7aa8764db805594d0e08a474a0d398a9 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Wed, 6 Jan 2016 17:17:14 +0100
Subject: [PATCH 27/34] Fix rebase issues.

---
 servant-docs/src/Servant/Docs/Internal.hs     | 1 -
 servant-server/src/Servant/Server/Internal.hs | 1 -
 2 files changed, 2 deletions(-)

diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 41754c31..17e0b10c 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/servant-docs/src/Servant/Docs/Internal.hs
@@ -718,7 +718,6 @@ instance OVERLAPPING_
 instance OVERLAPPABLE_
         (ToSample a, AllMimeRender (ct ': cts) a)
     => HasDocs (Get (ct ': cts) a) where
->>>>>>> Simplify verb combinators.
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
diff --git a/servant-server/src/Servant/Server/Internal.hs b/servant-server/src/Servant/Server/Internal.hs
index 4dcacb75..730e96d5 100644
--- a/servant-server/src/Servant/Server/Internal.hs
+++ b/servant-server/src/Servant/Server/Internal.hs
@@ -198,7 +198,6 @@ instance OVERLAPPABLE_
           status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
 instance OVERLAPPING_
-instance
          ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
          , GetHeaders (Headers h a)
          ) => HasServer (Verb method status ctypes (Headers h a)) where

From 208bcf5986f0c9dd806ffc2f93eae7923d863a80 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Wed, 6 Jan 2016 17:31:40 +0100
Subject: [PATCH 28/34] Use Verb for servant-docs

---
 servant-docs/src/Servant/Docs.hs          |   3 +-
 servant-docs/src/Servant/Docs/Internal.hs | 146 ++++------------------
 servant-docs/test/Servant/DocsSpec.hs     |   1 -
 3 files changed, 23 insertions(+), 127 deletions(-)

diff --git a/servant-docs/src/Servant/Docs.hs b/servant-docs/src/Servant/Docs.hs
index 193b4e60..9805285f 100644
--- a/servant-docs/src/Servant/Docs.hs
+++ b/servant-docs/src/Servant/Docs.hs
@@ -41,8 +41,7 @@ module Servant.Docs
   , ToCapture(..)
 
   , -- * ADTs to represent an 'API'
-    Method(..)
-  , Endpoint, path, method, defEndpoint
+    Endpoint, path, method, defEndpoint
   , API, apiIntros, apiEndpoints, emptyAPI
   , DocCapture(..), capSymbol, capDesc
   , DocQueryParam(..), ParamKind(..), paramName, paramValues, paramDesc, paramKind
diff --git a/servant-docs/src/Servant/Docs/Internal.hs b/servant-docs/src/Servant/Docs/Internal.hs
index 17e0b10c..0c3e30ac 100644
--- a/servant-docs/src/Servant/Docs/Internal.hs
+++ b/servant-docs/src/Servant/Docs/Internal.hs
@@ -36,7 +36,7 @@ import           Data.Monoid
 import           Data.Ord                   (comparing)
 import           Data.Proxy                 (Proxy(Proxy))
 import           Data.String.Conversions    (cs)
-import           Data.Text                  (Text, pack, unpack)
+import           Data.Text                  (Text, unpack)
 import           GHC.Exts                   (Constraint)
 import           GHC.Generics
 import           GHC.TypeLits
@@ -49,21 +49,6 @@ import qualified Data.Text                  as T
 import qualified Network.HTTP.Media         as M
 import qualified Network.HTTP.Types         as HTTP
 
--- | Supported HTTP request methods
-data Method = DocDELETE -- ^ the DELETE method
-            | DocGET    -- ^ the GET method
-            | DocPOST   -- ^ the POST method
-            | DocPUT    -- ^ the PUT method
-  deriving (Eq, Ord, Generic)
-
-instance Show Method where
-  show DocGET = "GET"
-  show DocPOST = "POST"
-  show DocDELETE = "DELETE"
-  show DocPUT = "PUT"
-
-instance Hashable Method
-
 -- | An 'Endpoint' type that holds the 'path' and the 'method'.
 --
 -- Gets used as the key in the 'API' hashmap. Modify 'defEndpoint'
@@ -75,12 +60,12 @@ instance Hashable Method
 -- GET /
 -- λ> 'defEndpoint' & 'path' '<>~' ["foo"]
 -- GET /foo
--- λ> 'defEndpoint' & 'path' '<>~' ["foo"] & 'method' '.~' 'DocPOST'
+-- λ> 'defEndpoint' & 'path' '<>~' ["foo"] & 'method' '.~' 'HTTP.methodPost'
 -- POST /foo
 -- @
 data Endpoint = Endpoint
-  { _path   :: [String] -- type collected
-  , _method :: Method   -- type collected
+  { _path   :: [String]      -- type collected
+  , _method :: HTTP.Method   -- type collected
   } deriving (Eq, Ord, Generic)
 
 instance Show Endpoint where
@@ -94,7 +79,7 @@ showPath :: [String] -> String
 showPath [] = "/"
 showPath ps = concatMap ('/' :) ps
 
--- | An 'Endpoint' whose path is `"/"` and whose method is 'DocGET'
+-- | An 'Endpoint' whose path is `"/"` and whose method is @GET@
 --
 -- Here's how you can modify it:
 --
@@ -103,11 +88,11 @@ showPath ps = concatMap ('/' :) ps
 -- GET /
 -- λ> 'defEndpoint' & 'path' '<>~' ["foo"]
 -- GET /foo
--- λ> 'defEndpoint' & 'path' '<>~' ["foo"] & 'method' '.~' 'DocPOST'
+-- λ> 'defEndpoint' & 'path' '<>~' ["foo"] & 'method' '.~' 'HTTP.methodPost'
 -- POST /foo
 -- @
 defEndpoint :: Endpoint
-defEndpoint = Endpoint [] DocGET
+defEndpoint = Endpoint [] HTTP.methodGet
 
 instance Hashable Endpoint
 
@@ -689,124 +674,37 @@ instance (KnownSymbol sym, ToCapture (Capture sym a), HasDocs sublayout)
 
 
 instance OVERLAPPABLE_
-        (ToSample a, AllMimeRender (ct ': cts) a)
-    => HasDocs (Delete (ct ': cts) a) where
+        (ToSample a, AllMimeRender (ct ': cts) a, KnownNat status
+        , ReflectMethod method)
+    => HasDocs (Verb method status (ct ': cts) a) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
-    where endpoint' = endpoint & method .~ DocDELETE
+    where endpoint' = endpoint & method .~ method'
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
+                           & response.respStatus .~ status
           t = Proxy :: Proxy (ct ': cts)
+          method' = reflectMethod (Proxy :: Proxy method)
+          status = fromInteger $ natVal (Proxy :: Proxy status)
           p = Proxy :: Proxy a
 
 instance OVERLAPPING_
-        (ToSample a, AllMimeRender (ct ': cts) a
-         , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Delete (ct ': cts) (Headers ls a)) where
+        (ToSample a, AllMimeRender (ct ': cts) a, KnownNat status
+        , ReflectMethod method, AllHeaderSamples ls, GetHeaders (HList ls))
+    => HasDocs (Verb method status (ct ': cts) (Headers ls a)) where
   docsFor Proxy (endpoint, action) DocOptions{..} =
     single endpoint' action'
 
-    where hdrs = allHeaderToSample (Proxy :: Proxy ls)
-          endpoint' = endpoint & method .~ DocDELETE
+    where endpoint' = endpoint & method .~ method'
           action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
                            & response.respTypes .~ allMime t
+                           & response.respStatus .~ status
                            & response.respHeaders .~ hdrs
           t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance OVERLAPPABLE_
-        (ToSample a, AllMimeRender (ct ': cts) a)
-    => HasDocs (Get (ct ': cts) a) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where endpoint' = endpoint & method .~ DocGET
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-          t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance OVERLAPPING_
-        (ToSample a, AllMimeRender (ct ': cts) a
-         , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Get (ct ': cts) (Headers ls a)) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where hdrs = allHeaderToSample (Proxy :: Proxy ls)
-          endpoint' = endpoint & method .~ DocGET
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-                           & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance (KnownSymbol sym, HasDocs sublayout)
-      => HasDocs (Header sym a :> sublayout) where
-  docsFor Proxy (endpoint, action) =
-    docsFor sublayoutP (endpoint, action')
-
-    where sublayoutP = Proxy :: Proxy sublayout
-          action' = over headers (|> headername) action
-          headername = pack $ symbolVal (Proxy :: Proxy sym)
-
-instance OVERLAPPABLE_
-        (ToSample a, AllMimeRender (ct ': cts) a)
-    => HasDocs (Post (ct ': cts) a) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where endpoint' = endpoint & method .~ DocPOST
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-                           & response.respStatus .~ 201
-          t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance OVERLAPPING_
-         (ToSample a, AllMimeRender (ct ': cts) a
-         , AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Post (ct ': cts) (Headers ls a)) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where hdrs = allHeaderToSample (Proxy :: Proxy ls)
-          endpoint' = endpoint & method .~ DocPOST
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-                           & response.respStatus .~ 201
-                           & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance OVERLAPPABLE_
-        (ToSample a, AllMimeRender (ct ': cts) a)
-    => HasDocs (Put (ct ': cts) a) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where endpoint' = endpoint & method .~ DocPUT
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-                           & response.respStatus .~ 200
-          t = Proxy :: Proxy (ct ': cts)
-          p = Proxy :: Proxy a
-
-instance OVERLAPPING_
-        ( ToSample a, AllMimeRender (ct ': cts) a,
-          AllHeaderSamples ls , GetHeaders (HList ls) )
-    => HasDocs (Put (ct ': cts) (Headers ls a)) where
-  docsFor Proxy (endpoint, action) DocOptions{..} =
-    single endpoint' action'
-
-    where hdrs = allHeaderToSample (Proxy :: Proxy ls)
-          endpoint' = endpoint & method .~ DocPUT
-          action' = action & response.respBody .~ take _maxSamples (sampleByteStrings t p)
-                           & response.respTypes .~ allMime t
-                           & response.respStatus .~ 200
-                           & response.respHeaders .~ hdrs
-          t = Proxy :: Proxy (ct ': cts)
+          hdrs = allHeaderToSample (Proxy :: Proxy ls)
+          method' = reflectMethod (Proxy :: Proxy method)
+          status = fromInteger $ natVal (Proxy :: Proxy status)
           p = Proxy :: Proxy a
 
 instance (KnownSymbol sym, ToParam (QueryParam sym a), HasDocs sublayout)
diff --git a/servant-docs/test/Servant/DocsSpec.hs b/servant-docs/test/Servant/DocsSpec.hs
index 5375b0c3..d37f78c9 100644
--- a/servant-docs/test/Servant/DocsSpec.hs
+++ b/servant-docs/test/Servant/DocsSpec.hs
@@ -71,7 +71,6 @@ spec = describe "Servant.Docs" $ do
 
     it "mentions status codes" $ do
       md `shouldContain` "Status code 200"
-      md `shouldContain` "Status code 201"
 
     it "mentions methods" $ do
       md `shouldContain` "POST"

From bd77b4acba4a81608827bad72ac70e93cb13271c Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Wed, 6 Jan 2016 18:20:20 +0100
Subject: [PATCH 29/34] Verb for -mock, -js and -foreign.

---
 servant-foreign/servant-foreign.cabal         | 10 +--
 .../src/Servant/Foreign/Internal.hs           | 66 +++++--------------
 servant-foreign/test/Servant/ForeignSpec.hs   |  9 ++-
 servant-js/src/Servant/JS/Angular.hs          |  3 +-
 servant-js/src/Servant/JS/Axios.hs            |  3 +-
 servant-js/src/Servant/JS/JQuery.hs           |  3 +-
 servant-js/src/Servant/JS/Vanilla.hs          |  3 +-
 servant-mock/src/Servant/Mock.hs              | 15 +----
 8 files changed, 38 insertions(+), 74 deletions(-)

diff --git a/servant-foreign/servant-foreign.cabal b/servant-foreign/servant-foreign.cabal
index be1f2696..ca92b43a 100644
--- a/servant-foreign/servant-foreign.cabal
+++ b/servant-foreign/servant-foreign.cabal
@@ -27,10 +27,11 @@ source-repository head
 
 library
   exposed-modules:     Servant.Foreign, Servant.Foreign.Internal
-  build-depends:       base    == 4.*
-                     , lens    == 4.*
-                     , servant == 0.5.*
-                     , text    >= 1.2  && < 1.3
+  build-depends:       base       == 4.*
+                     , lens       == 4.*
+                     , servant    == 0.5.*
+                     , text       >= 1.2  && < 1.3
+                     , http-types
   hs-source-dirs:      src
   default-language:    Haskell2010
   ghc-options:         -Wall
@@ -41,6 +42,7 @@ test-suite spec
   type:              exitcode-stdio-1.0
   hs-source-dirs:    test
   ghc-options:       -Wall
+  include-dirs:      include
   main-is:           Spec.hs
   other-modules:
       Servant.ForeignSpec
diff --git a/servant-foreign/src/Servant/Foreign/Internal.hs b/servant-foreign/src/Servant/Foreign/Internal.hs
index 27f0e411..ae199202 100644
--- a/servant-foreign/src/Servant/Foreign/Internal.hs
+++ b/servant-foreign/src/Servant/Foreign/Internal.hs
@@ -13,18 +13,21 @@
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
 {-# LANGUAGE OverloadedStrings     #-}
+{-# LANGUAGE PolyKinds             #-}
 
 -- | Generalizes all the data needed to make code generation work with
 -- arbitrary programming languages.
 module Servant.Foreign.Internal where
 
-import           Control.Lens (makeLenses, (%~), (&), (.~), (<>~))
-import qualified Data.Char    as C
+import           Control.Lens          (makeLenses, (%~), (&), (.~), (<>~))
+import qualified Data.Char             as C
 import           Data.Proxy
 import           Data.Text
-import           GHC.Exts     (Constraint)
+import           Data.Text.Encoding    (decodeUtf8)
+import           GHC.Exts              (Constraint)
 import           GHC.TypeLits
-import           Prelude      hiding (concat)
+import qualified Network.HTTP.Types    as HTTP
+import           Prelude               hiding (concat)
 import           Servant.API
 
 -- | Function name builder that simply concat each part together
@@ -86,11 +89,10 @@ defUrl :: Url
 defUrl = Url [] []
 
 type FunctionName = [Text]
-type Method = Text
 
 data Req = Req
   { _reqUrl        :: Url
-  , _reqMethod     :: Method
+  , _reqMethod     :: HTTP.Method
   , _reqHeaders    :: [HeaderArg]
   , _reqBody       :: Maybe ForeignType
   , _reqReturnType :: ForeignType
@@ -185,27 +187,18 @@ instance (KnownSymbol sym, HasForeignType lang a, HasForeign lang sublayout)
     str = pack . symbolVal $ (Proxy :: Proxy sym)
     arg = (str, typeFor lang (Proxy :: Proxy a))
 
-instance (Elem JSON list, HasForeignType lang a)
-      => HasForeign lang (Delete list a) where
-  type Foreign (Delete list a) = Req
+instance (Elem JSON list, HasForeignType lang a, ReflectMethod method)
+      => HasForeign lang (Verb method status list a) where
+  type Foreign (Verb method status list a) = Req
 
   foreignFor lang Proxy req =
-    req & funcName      %~ ("delete" :)
-        & reqMethod     .~ "DELETE"
+    req & funcName  %~ (methodLC :)
+        & reqMethod .~ method
         & reqReturnType .~ retType
     where
-    retType = typeFor lang (Proxy :: Proxy a)
-
-instance (Elem JSON list, HasForeignType lang a)
-      => HasForeign lang (Get list a) where
-  type Foreign (Get list a) = Req
-
-  foreignFor lang Proxy req =
-    req & funcName  %~ ("get" :)
-        & reqMethod .~ "GET"
-        & reqReturnType .~ retType
-    where
-    retType = typeFor lang (Proxy :: Proxy a)
+    retType  = typeFor lang (Proxy :: Proxy a)
+    method   = reflectMethod (Proxy :: Proxy method)
+    methodLC = toLower $ decodeUtf8 method
 
 instance (KnownSymbol sym, HasForeignType lang a, HasForeign lang sublayout)
       => HasForeign lang (Header sym a :> sublayout) where
@@ -220,28 +213,6 @@ instance (KnownSymbol sym, HasForeignType lang a, HasForeign lang sublayout)
     arg = (hname, typeFor lang (Proxy :: Proxy a))
     subP = Proxy :: Proxy sublayout
 
-instance (Elem JSON list, HasForeignType lang a)
-      => HasForeign lang (Post list a) where
-  type Foreign (Post list a) = Req
-
-  foreignFor lang Proxy req =
-    req & funcName  %~ ("post" :)
-        & reqMethod .~ "POST"
-        & reqReturnType .~ retType
-    where
-    retType = typeFor lang (Proxy :: Proxy a)
-
-instance (Elem JSON list, HasForeignType lang a)
-      => HasForeign lang (Put list a) where
-  type Foreign (Put list a) = Req
-
-  foreignFor lang Proxy req =
-    req & funcName  %~ ("put" :)
-        & reqMethod .~ "PUT"
-        & reqReturnType .~ retType
-    where
-    retType = typeFor lang (Proxy :: Proxy a)
-
 instance (KnownSymbol sym, HasForeignType lang a, HasForeign lang sublayout)
       => HasForeign lang (QueryParam sym a :> sublayout) where
   type Foreign (QueryParam sym a :> sublayout) = Foreign sublayout
@@ -279,10 +250,10 @@ instance (KnownSymbol sym, HasForeignType lang a, a ~ Bool, HasForeign lang subl
     arg = (str, typeFor lang (Proxy :: Proxy a))
 
 instance HasForeign lang Raw where
-  type Foreign Raw = Method -> Req
+  type Foreign Raw = HTTP.Method -> Req
 
   foreignFor _ Proxy req method =
-    req & funcName %~ ((toLower method) :)
+    req & funcName %~ ((toLower $ decodeUtf8 method) :)
         & reqMethod .~ method
 
 instance (Elem JSON list, HasForeignType lang a, HasForeign lang sublayout)
@@ -346,4 +317,3 @@ instance (GenerateList start, GenerateList rest) => GenerateList (start :<|> res
 --   describing one endpoint from your API type.
 listFromAPI :: (HasForeign lang api, GenerateList (Foreign api)) => Proxy lang -> Proxy api -> [Req]
 listFromAPI lang p = generateList (foreignFor lang p defReq)
-
diff --git a/servant-foreign/test/Servant/ForeignSpec.hs b/servant-foreign/test/Servant/ForeignSpec.hs
index a5bad431..06e722cc 100644
--- a/servant-foreign/test/Servant/ForeignSpec.hs
+++ b/servant-foreign/test/Servant/ForeignSpec.hs
@@ -7,9 +7,8 @@
 {-# LANGUAGE TypeSynonymInstances  #-}
 {-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE CPP                   #-}
-#if __GLASGOW_HASKELL__ < 710
-{-# LANGUAGE OverlappingInstances  #-}
-#endif
+
+#include "overlapping-compat.h"
 
 module Servant.ForeignSpec where
 
@@ -41,9 +40,9 @@ instance HasForeignType LangX Int where
     typeFor _ _ = "intX"
 instance HasForeignType LangX Bool where
     typeFor _ _ = "boolX"
-instance {-# Overlapping #-} HasForeignType LangX String where
+instance OVERLAPPING_ HasForeignType LangX String where
     typeFor _ _ = "stringX"
-instance {-# Overlappable #-} HasForeignType LangX a => HasForeignType LangX [a] where
+instance OVERLAPPABLE_ HasForeignType LangX a => HasForeignType LangX [a] where
     typeFor lang _ = "listX of " <> typeFor lang (Proxy :: Proxy a)
 
 type TestApi
diff --git a/servant-js/src/Servant/JS/Angular.hs b/servant-js/src/Servant/JS/Angular.hs
index 2f1b42fb..8530b03f 100644
--- a/servant-js/src/Servant/JS/Angular.hs
+++ b/servant-js/src/Servant/JS/Angular.hs
@@ -6,6 +6,7 @@ import           Data.Maybe (isJust)
 import           Data.Monoid
 import qualified Data.Text as T
 import           Data.Text (Text)
+import           Data.Text.Encoding (decodeUtf8)
 import           Servant.Foreign
 import           Servant.JS.Internal
 
@@ -68,7 +69,7 @@ generateAngularJSWith ngOptions opts req = "\n" <>
  <> "    { url: " <> url <> "\n"
  <> dataBody
  <> reqheaders
- <> "    , method: '" <> method <> "'\n"
+ <> "    , method: '" <> decodeUtf8 method <> "'\n"
  <> "    });\n"
  <> "}\n"
 
diff --git a/servant-js/src/Servant/JS/Axios.hs b/servant-js/src/Servant/JS/Axios.hs
index 50bed9eb..25e92df3 100644
--- a/servant-js/src/Servant/JS/Axios.hs
+++ b/servant-js/src/Servant/JS/Axios.hs
@@ -5,6 +5,7 @@ import           Control.Lens
 import           Data.Maybe (isJust)
 import           Data.Monoid
 import           Data.Text (Text)
+import           Data.Text.Encoding (decodeUtf8)
 import qualified Data.Text as T
 import           Servant.Foreign
 import           Servant.JS.Internal
@@ -117,7 +118,7 @@ generateAxiosJSWith aopts opts req = "\n" <>
 
         fname = namespace <> (functionNameBuilder opts $ req ^. funcName)
 
-        method = T.toLower $ req ^. reqMethod
+        method = T.toLower . decodeUtf8 $ req ^. reqMethod
         url = if url' == "'" then "'/'" else url'
         url' = "'"
            <> urlPrefix opts
diff --git a/servant-js/src/Servant/JS/JQuery.hs b/servant-js/src/Servant/JS/JQuery.hs
index 722d9c07..71147006 100644
--- a/servant-js/src/Servant/JS/JQuery.hs
+++ b/servant-js/src/Servant/JS/JQuery.hs
@@ -6,6 +6,7 @@ import           Data.Maybe (isJust)
 import           Data.Monoid
 import qualified Data.Text as T
 import           Data.Text (Text)
+import           Data.Text.Encoding (decodeUtf8)
 import           Servant.Foreign
 import           Servant.JS.Internal
 
@@ -35,7 +36,7 @@ generateJQueryJSWith opts req = "\n" <>
  <> dataBody
  <> reqheaders
  <> "    , error: " <> onError <> "\n"
- <> "    , type: '" <> method <> "'\n"
+ <> "    , type: '" <> decodeUtf8 method <> "'\n"
  <> "    });\n"
  <> "}\n"
 
diff --git a/servant-js/src/Servant/JS/Vanilla.hs b/servant-js/src/Servant/JS/Vanilla.hs
index ea390e2f..f623e2a6 100644
--- a/servant-js/src/Servant/JS/Vanilla.hs
+++ b/servant-js/src/Servant/JS/Vanilla.hs
@@ -4,6 +4,7 @@ module Servant.JS.Vanilla where
 import           Control.Lens
 import           Data.Maybe (isJust)
 import           Data.Text (Text)
+import           Data.Text.Encoding (decodeUtf8)
 import qualified Data.Text as T
 import           Data.Monoid
 import           Servant.Foreign
@@ -31,7 +32,7 @@ generateVanillaJSWith opts req = "\n" <>
     fname <> " = function(" <> argsStr <> ")\n"
  <> "{\n"
  <> "  var xhr = new XMLHttpRequest();\n"
- <> "  xhr.open('" <> method <> "', " <> url <> ", true);\n"
+ <> "  xhr.open('" <> decodeUtf8 method <> "', " <> url <> ", true);\n"
  <>    reqheaders
  <> "  xhr.setRequestHeader(\"Accept\",\"application/json\");\n"
  <> (if isJust (req ^. reqBody) then "  xhr.setRequestHeader(\"Content-Type\",\"application/json\");\n" else "")
diff --git a/servant-mock/src/Servant/Mock.hs b/servant-mock/src/Servant/Mock.hs
index 3fa5d077..e4437fba 100644
--- a/servant-mock/src/Servant/Mock.hs
+++ b/servant-mock/src/Servant/Mock.hs
@@ -139,19 +139,8 @@ instance (KnownSymbol s, HasMock rest) => HasMock (QueryFlag s :> rest) where
 instance (KnownSymbol h, FromHttpApiData a, HasMock rest) => HasMock (Header h a :> rest) where
   mock _ = \_ -> mock (Proxy :: Proxy rest)
 
-instance (Arbitrary a, AllCTRender ctypes a) => HasMock (Delete ctypes a) where
-  mock _ = mockArbitrary
-
-instance (Arbitrary a, AllCTRender ctypes a) => HasMock (Get ctypes a) where
-  mock _ = mockArbitrary
-
-instance (Arbitrary a, AllCTRender ctypes a) => HasMock (Patch ctypes a) where
-  mock _ = mockArbitrary
-
-instance (Arbitrary a, AllCTRender ctypes a) => HasMock (Post ctypes a) where
-  mock _ = mockArbitrary
-
-instance (Arbitrary a, AllCTRender ctypes a) => HasMock (Put ctypes a) where
+instance (Arbitrary a, KnownNat status, ReflectMethod method, AllCTRender ctypes a)
+    => HasMock (Verb method status ctypes a) where
   mock _ = mockArbitrary
 
 instance HasMock Raw where

From 574e9c48cdc7e22830e5f49f0a470d5b819b53cf Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Thu, 7 Jan 2016 13:44:08 +0100
Subject: [PATCH 30/34] Export all Verb methods.

---
 servant/src/Servant/API.hs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/servant/src/Servant/API.hs b/servant/src/Servant/API.hs
index 2565149f..ff1e24ec 100644
--- a/servant/src/Servant/API.hs
+++ b/servant/src/Servant/API.hs
@@ -70,7 +70,22 @@ import           Servant.API.ResponseHeaders (AddHeader (addHeader),
                                               getHeadersHList, getResponse)
 import           Servant.API.Sub             ((:>))
 import           Servant.API.Vault           (Vault)
-import           Servant.API.Verbs           (Delete, Get, Patch, Post, Put,
+import           Servant.API.Verbs           (Created, Delete, DeleteAccepted,
+                                              DeleteNoContent,
+                                              DeleteNonAuthoritative, Get,
+                                              GetAccepted, GetNoContent,
+                                              GetNonAuthoritative,
+                                              GetPartialContent,
+                                              GetResetContent,
+                                              NoContent (NoContent), Patch,
+                                              PatchAccepted, PatchNoContent,
+                                              PatchNoContent,
+                                              PatchNonAuthoritative, Post,
+                                              PostAccepted, PostNoContent,
+                                              PostNonAuthoritative,
+                                              PostResetContent, Put,
+                                              PutAccepted, PutNoContent,
+                                              PutNoContent, PutNonAuthoritative,
                                               ReflectMethod (reflectMethod),
                                               Verb)
 import           Servant.Utils.Links         (HasLink (..), IsElem, IsElem',

From 783a849c6741de37b5b09755a96f7ba5a843d8b1 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Thu, 7 Jan 2016 14:30:08 +0100
Subject: [PATCH 31/34] Make NoContent still take an arg.

        For consistency with other combinators, and to make using headers
        easier.
---
 servant-client/src/Servant/Client.hs      | 14 +++---
 servant-client/test/Servant/ClientSpec.hs | 12 ++---
 servant-server/test/Servant/ServerSpec.hs | 24 +++++-----
 servant/src/Servant/API.hs                |  4 +-
 servant/src/Servant/API/ContentTypes.hs   | 58 ++++++++++-------------
 servant/src/Servant/API/Verbs.hs          | 32 ++++++-------
 6 files changed, 69 insertions(+), 75 deletions(-)

diff --git a/servant-client/src/Servant/Client.hs b/servant-client/src/Servant/Client.hs
index 4eac1b2d..c7dbeb80 100644
--- a/servant-client/src/Servant/Client.hs
+++ b/servant-client/src/Servant/Client.hs
@@ -129,10 +129,10 @@ instance OVERLAPPABLE_
       where method = reflectMethod (Proxy :: Proxy method)
 
 instance OVERLAPPING_
-  (ReflectMethod method) => HasClient (Verb method status cts ()) where
-  type Client (Verb method status cts ()) = ExceptT ServantError IO ()
+  (ReflectMethod method) => HasClient (Verb method status cts NoContent) where
+  type Client (Verb method status cts NoContent) = ExceptT ServantError IO NoContent
   clientWithRoute Proxy req baseurl manager =
-    void $ performRequestNoBody method req baseurl manager
+    performRequestNoBody method req baseurl manager >> return NoContent
       where method = reflectMethod (Proxy :: Proxy method)
 
 instance OVERLAPPING_
@@ -150,13 +150,13 @@ instance OVERLAPPING_
 
 instance OVERLAPPING_
   ( BuildHeadersTo ls, ReflectMethod method
-  ) => HasClient (Verb method status cts (Headers ls ())) where
-  type Client (Verb method status cts (Headers ls ()))
-    = ExceptT ServantError IO (Headers ls ())
+  ) => HasClient (Verb method status cts (Headers ls NoContent)) where
+  type Client (Verb method status cts (Headers ls NoContent))
+    = ExceptT ServantError IO (Headers ls NoContent)
   clientWithRoute Proxy req baseurl manager = do
     let method = reflectMethod (Proxy :: Proxy method)
     hdrs <- performRequestNoBody method req baseurl manager
-    return $ Headers { getResponse = ()
+    return $ Headers { getResponse = NoContent
                      , getHeadersHList = buildHeadersTo hdrs
                      }
 
diff --git a/servant-client/test/Servant/ClientSpec.hs b/servant-client/test/Servant/ClientSpec.hs
index e289873d..245a7216 100644
--- a/servant-client/test/Servant/ClientSpec.hs
+++ b/servant-client/test/Servant/ClientSpec.hs
@@ -90,7 +90,7 @@ type TestHeaders = '[Header "X-Example1" Int, Header "X-Example2" String]
 
 type Api =
        "get" :> Get '[JSON] Person
-  :<|> "deleteEmpty" :> Delete '[JSON] ()
+  :<|> "deleteEmpty" :> DeleteNoContent '[JSON] NoContent
   :<|> "capture" :> Capture "name" String :> Get '[JSON,FormUrlEncoded] Person
   :<|> "body" :> ReqBody '[FormUrlEncoded,JSON] Person :> Post '[JSON] Person
   :<|> "param" :> QueryParam "name" String :> Get '[FormUrlEncoded,JSON] Person
@@ -105,14 +105,14 @@ type Api =
             ReqBody '[JSON] [(String, [Rational])] :>
             Get '[JSON] (String, Maybe Int, Bool, [(String, [Rational])])
   :<|> "headers" :> Get '[JSON] (Headers TestHeaders Bool)
-  :<|> "deleteContentType" :> Delete '[JSON] ()
+  :<|> "deleteContentType" :> DeleteNoContent '[JSON] NoContent
 api :: Proxy Api
 api = Proxy
 
 server :: Application
 server = serve api (
        return alice
-  :<|> return ()
+  :<|> return NoContent
   :<|> (\ name -> return $ Person name 0)
   :<|> return
   :<|> (\ name -> case name of
@@ -125,7 +125,7 @@ server = serve api (
   :<|> (\ _request respond -> respond $ responseLBS badRequest400 [] "rawFailure")
   :<|> (\ a b c d -> return (a, b, c, d))
   :<|> (return $ addHeader 1729 $ addHeader "eg2" True)
-  :<|> return ()
+  :<|> return NoContent
  )
 
 
@@ -157,11 +157,11 @@ sucessSpec = beforeAll (startWaiApp server) $ afterAll endWaiApp $ do
     describe "Servant.API.Delete" $ do
       it "allows empty content type" $ \(_, baseUrl) -> do
         let getDeleteEmpty = getNth (Proxy :: Proxy 1) $ client api baseUrl manager
-        (left show <$> runExceptT getDeleteEmpty) `shouldReturn` Right ()
+        (left show <$> runExceptT getDeleteEmpty) `shouldReturn` Right NoContent
 
       it "allows content type" $ \(_, baseUrl) -> do
         let getDeleteContentType = getLast $ client api baseUrl manager
-        (left show <$> runExceptT getDeleteContentType) `shouldReturn` Right ()
+        (left show <$> runExceptT getDeleteContentType) `shouldReturn` Right NoContent
 
     it "Servant.API.Capture" $ \(_, baseUrl) -> do
       let getCapture = getNth (Proxy :: Proxy 2) $ client api baseUrl manager
diff --git a/servant-server/test/Servant/ServerSpec.hs b/servant-server/test/Servant/ServerSpec.hs
index 0a45c70a..9bb5e340 100644
--- a/servant-server/test/Servant/ServerSpec.hs
+++ b/servant-server/test/Servant/ServerSpec.hs
@@ -38,8 +38,8 @@ import           Servant.API                ((:<|>) (..), (:>), Capture, Delete,
                                              HttpVersion, IsSecure (..), JSON,
                                              Patch, PlainText, Post, Put,
                                              QueryFlag, QueryParam, QueryParams,
-                                             Raw, RemoteHost, ReqBody,
-                                             addHeader)
+                                             Raw, RemoteHost, ReqBody, GetNoContent,
+                                             PostNoContent, addHeader, NoContent(..))
 import           Servant.Server             (Server, serve, ServantErr(..), err404)
 import           Test.Hspec                 (Spec, describe, it, shouldBe)
 import           Test.Hspec.Wai             (get, liftIO, matchHeaders,
@@ -130,9 +130,9 @@ captureSpec = do
 
 
 type GetApi = Get '[JSON] Person
-        :<|> "empty" :> Get '[JSON] ()
-        :<|> "emptyWithHeaders" :> Get '[JSON] (Headers '[Header "H" Int] ())
-        :<|> "post" :> Post '[JSON] ()
+        :<|> "empty" :> GetNoContent '[JSON] NoContent
+        :<|> "emptyWithHeaders" :> GetNoContent '[JSON] (Headers '[Header "H" Int] NoContent)
+        :<|> "post" :> PostNoContent '[JSON] NoContent
 
 getApi :: Proxy GetApi
 getApi = Proxy
@@ -141,9 +141,9 @@ getSpec :: Spec
 getSpec = do
   describe "Servant.API.Get" $ do
     let server = return alice
-            :<|> return ()
-            :<|> return (addHeader 5 ())
-            :<|> return ()
+            :<|> return NoContent
+            :<|> return (addHeader 5 NoContent)
+            :<|> return NoContent
 
     with (return $ serve getApi server) $ do
 
@@ -157,7 +157,7 @@ getSpec = do
         post "/empty" "" `shouldRespondWith` 405
 
       it "returns headers" $ do
-        get "/emptyWithHeaders" `shouldRespondWith` 200 { matchHeaders = [ "H" <:> "5" ] }
+        get "/emptyWithHeaders" `shouldRespondWith` 204 { matchHeaders = [ "H" <:> "5" ] }
 
       it "returns 406 if the Accept header is not supported" $ do
         Test.Hspec.Wai.request methodGet "" [(hAccept, "crazy/mime")] ""
@@ -168,9 +168,9 @@ headSpec :: Spec
 headSpec = do
   describe "Servant.API.Head" $ do
     let server = return alice
-            :<|> return ()
-            :<|> return (addHeader 5 ())
-            :<|> return ()
+            :<|> return NoContent
+            :<|> return (addHeader 5 NoContent)
+            :<|> return NoContent
     with (return $ serve getApi server) $ do
 
       it "allows to GET a Person" $ do
diff --git a/servant/src/Servant/API.hs b/servant/src/Servant/API.hs
index ff1e24ec..2afae7af 100644
--- a/servant/src/Servant/API.hs
+++ b/servant/src/Servant/API.hs
@@ -52,7 +52,7 @@ import           Servant.API.Alternative     ((:<|>) (..))
 import           Servant.API.Capture         (Capture)
 import           Servant.API.ContentTypes    (Accept (..), FormUrlEncoded,
                                               FromFormUrlEncoded (..), JSON,
-                                              MimeRender (..),
+                                              MimeRender (..), NoContent (NoContent),
                                               MimeUnrender (..), OctetStream,
                                               PlainText, ToFormUrlEncoded (..))
 import           Servant.API.Header          (Header (..))
@@ -77,7 +77,7 @@ import           Servant.API.Verbs           (Created, Delete, DeleteAccepted,
                                               GetNonAuthoritative,
                                               GetPartialContent,
                                               GetResetContent,
-                                              NoContent (NoContent), Patch,
+                                              Patch,
                                               PatchAccepted, PatchNoContent,
                                               PatchNoContent,
                                               PatchNonAuthoritative, Post,
diff --git a/servant/src/Servant/API/ContentTypes.hs b/servant/src/Servant/API/ContentTypes.hs
index 8e9c75ac..365381f7 100644
--- a/servant/src/Servant/API/ContentTypes.hs
+++ b/servant/src/Servant/API/ContentTypes.hs
@@ -11,11 +11,10 @@
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
-#if !MIN_VERSION_base(4,8,0)
-{-# LANGUAGE OverlappingInstances  #-}
-#endif
 {-# OPTIONS_HADDOCK not-home       #-}
 
+#include "overlapping-compat.h"
+
 -- | A collection of basic Content-Types (also known as Internet Media
 -- Types, or MIME types). Additionally, this module provides classes that
 -- encapsulate how to serialize or deserialize values to or from
@@ -57,6 +56,9 @@ module Servant.API.ContentTypes
     , MimeRender(..)
     , MimeUnrender(..)
 
+    -- * NoContent
+    , NoContent(..)
+
     -- * Internal
     , AcceptHeader(..)
     , AllCTRender(..)
@@ -75,8 +77,7 @@ import           Control.Applicative              ((*>), (<*))
 #endif
 import           Control.Arrow                    (left)
 import           Control.Monad
-import           Data.Aeson                       (FromJSON, ToJSON, encode,
-                                                   parseJSON)
+import           Data.Aeson                       (FromJSON(..), ToJSON(..), encode)
 import           Data.Aeson.Parser                (value)
 import           Data.Aeson.Types                 (parseEither)
 import           Data.Attoparsec.ByteString.Char8 (endOfInput, parseOnly,
@@ -168,10 +169,7 @@ class (AllMime list) => AllCTRender (list :: [*]) a where
     -- mimetype).
     handleAcceptH :: Proxy list -> AcceptHeader -> a -> Maybe (ByteString, ByteString)
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          (AllMimeRender (ct ': cts) a) => AllCTRender (ct ': cts) a where
     handleAcceptH _ (AcceptHeader accept) val = M.mapAcceptMedia lkup accept
       where pctyps = Proxy :: Proxy (ct ': cts)
@@ -275,20 +273,14 @@ instance ( MimeUnrender ctyp a
 -- * MimeRender Instances
 
 -- | `encode`
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ToJSON a => MimeRender JSON a where
     mimeRender _ = encode
 
 -- | @encodeFormUrlEncoded . toFormUrlEncoded@
 -- Note that the @mimeUnrender p (mimeRender p x) == Right x@ law only
 -- holds if every element of x is non-null (i.e., not @("", "")@)
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPABLE #-}
-#endif
+instance OVERLAPPABLE_
          ToFormUrlEncoded a => MimeRender FormUrlEncoded a where
     mimeRender _ = encodeFormUrlEncoded . toFormUrlEncoded
 
@@ -312,25 +304,27 @@ instance MimeRender OctetStream ByteString where
 instance MimeRender OctetStream BS.ByteString where
     mimeRender _ = fromStrict
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender JSON () where
+-- | A type for responses with content-body.
+data NoContent = NoContent
+  deriving (Show, Eq, Read)
+
+instance FromJSON NoContent where
+    parseJSON _ = return NoContent
+
+instance ToJSON NoContent where
+    toJSON _ = ""
+
+
+instance OVERLAPPING_
+         MimeRender JSON NoContent where
     mimeRender _ _ = ""
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender PlainText () where
+instance OVERLAPPING_
+         MimeRender PlainText NoContent where
     mimeRender _ _ = ""
 
-instance
-#if MIN_VERSION_base(4,8,0)
-         {-# OVERLAPPING #-}
-#endif
-         MimeRender OctetStream () where
+instance OVERLAPPING_
+         MimeRender OctetStream NoContent where
     mimeRender _ _ = ""
 
 --------------------------------------------------------------------------
diff --git a/servant/src/Servant/API/Verbs.hs b/servant/src/Servant/API/Verbs.hs
index 63232aa1..c1462503 100644
--- a/servant/src/Servant/API/Verbs.hs
+++ b/servant/src/Servant/API/Verbs.hs
@@ -11,6 +11,7 @@ import           GHC.TypeLits              (Nat)
 import           Network.HTTP.Types.Method (Method, StdMethod (..),
                                             methodDelete, methodGet, methodHead,
                                             methodPatch, methodPost, methodPut)
+import           Servant.API.ContentTypes  (NoContent(..))
 
 -- | @Verb@ is a general type for representing HTTP verbs/methods. For
 -- convenience, type synonyms for each verb with a 200 response code are
@@ -95,40 +96,40 @@ type PutNonAuthoritative contentTypes a = Verb 'PUT 203 contentTypes a
 
 -- ** 204 No Content
 --
--- Indicates that no response body is being returned. Handlers for these must
--- return 'NoContent'.
+-- Indicates that no response body is being returned. Handlers for these should
+-- return 'NoContent', possibly with headers.
 --
 -- If the document view should be reset, use @205 Reset Content@.
 
 -- | 'GET' with 204 status code.
-type GetNoContent contentTypes = Verb 'GET 204 contentTypes NoContent
+type GetNoContent contentTypes noContent = Verb 'GET 204 contentTypes noContent
 -- | 'POST' with 204 status code.
-type PostNoContent contentTypes = Verb 'POST 204 contentTypes NoContent
+type PostNoContent contentTypes noContent = Verb 'POST 204 contentTypes noContent
 -- | 'DELETE' with 204 status code.
-type DeleteNoContent contentTypes = Verb 'DELETE 204 contentTypes NoContent
+type DeleteNoContent contentTypes noContent = Verb 'DELETE 204 contentTypes noContent
 -- | 'PATCH' with 204 status code.
-type PatchNoContent contentTypes = Verb 'PATCH 204 contentTypes NoContent
+type PatchNoContent contentTypes noContent = Verb 'PATCH 204 contentTypes noContent
 -- | 'PUT' with 204 status code.
-type PutNoContent contentTypes = Verb 'PUT 204 contentTypes NoContent
+type PutNoContent contentTypes noContent = Verb 'PUT 204 contentTypes noContent
 
 
 -- ** 205 Reset Content
 --
--- Indicates that no response body is being returned. Handlers for these must
--- return 'NoContent'.
+-- Indicates that no response body is being returned. Handlers for these should
+-- return 'NoContent', possibly with Headers.
 --
 -- If the document view should not be reset, use @204 No Content@.
 
 -- | 'GET' with 205 status code.
-type GetResetContent contentTypes = Verb 'GET 205 contentTypes NoContent
+type GetResetContent contentTypes noContent = Verb 'GET 205 contentTypes noContent
 -- | 'POST' with 205 status code.
-type PostResetContent contentTypes = Verb 'POST 205 contentTypes NoContent
+type PostResetContent contentTypes noContent = Verb 'POST 205 contentTypes noContent
 -- | 'DELETE' with 205 status code.
-type DeleteResetContent contentTypes = Verb 'DELETE 205 contentTypes NoContent
+type DeleteResetContent contentTypes noContent = Verb 'DELETE 205 contentTypes noContent
 -- | 'PATCH' with 205 status code.
-type PatchResetContent contentTypes = Verb 'PATCH 205 contentTypes NoContent
+type PatchResetContent contentTypes noContent = Verb 'PATCH 205 contentTypes noContent
 -- | 'PUT' with 205 status code.
-type PutResetContent contentTypes = Verb 'PUT 205 contentTypes NoContent
+type PutResetContent contentTypes noContent = Verb 'PUT 205 contentTypes noContent
 
 
 -- ** 206 Partial Content
@@ -140,9 +141,8 @@ type PutResetContent contentTypes = Verb 'PUT 205 contentTypes NoContent
 -- RFC7233 Section 4.1>
 
 -- | 'GET' with 206 status code.
-type GetPartialContent contentTypes = Verb 'GET 205 contentTypes NoContent
+type GetPartialContent contentTypes noContent = Verb 'GET 205 contentTypes noContent
 
-data NoContent = NoContent
 
 class ReflectMethod a where
     reflectMethod :: proxy a -> Method

From 32612c903c844903651f4cc87d802f8b41a63dc5 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Thu, 7 Jan 2016 17:18:46 +0100
Subject: [PATCH 32/34] Review fixes

---
 CONTRIBUTING.md | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 0c76f11f..335f6094 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -57,8 +57,9 @@ issue with the `news` tag (which we will close when we read it).
 As for adding them to the main repo: maintaining combinators can be expensive,
 since official combinators must have instances for all classes (and new classes
 come along fairly frequently). We therefore have to be quite selective about
-those that we accept. If your considering writing a new combinator, open an
-issue to discuss it first!
+those that we accept. If you're considering writing a new combinator, open an
+issue to discuss it first! (You could release your combinator as a separate
+package, of course.)
 
 
 ## New classes
@@ -75,6 +76,4 @@ the `news` label if you make a new package so we can know about it!
 
 We are currently moving to a more aggresive release policy, so that you can get
 what you contribute from Hackage fairly soon. However, note that prior to major
-releases it may take some time in between releases. If you think you're change
-is small enough that it should be backported to released major versions, say
-so in the issue or PR.
+releases it may take some time in between releases.

From f1b6603c523008bdbbca029f9645c8bb07bbafed Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Fri, 8 Jan 2016 17:43:10 +0100
Subject: [PATCH 33/34] Review fixes

---
 servant-client/src/Servant/Client.hs      |   3 +-
 servant-client/src/Servant/Common/Req.hs  |   2 +-
 servant-server/test/Servant/ServerSpec.hs | 466 +++++++++++-----------
 servant/src/Servant/API.hs                |   4 +-
 servant/src/Servant/API/ContentTypes.hs   |   2 +-
 servant/src/Servant/API/Verbs.hs          |  15 +-
 servant/src/Servant/Utils/Links.hs        |   4 +-
 7 files changed, 237 insertions(+), 259 deletions(-)

diff --git a/servant-client/src/Servant/Client.hs b/servant-client/src/Servant/Client.hs
index c7dbeb80..e9bab748 100644
--- a/servant-client/src/Servant/Client.hs
+++ b/servant-client/src/Servant/Client.hs
@@ -24,7 +24,6 @@ module Servant.Client
 #if !MIN_VERSION_base(4,8,0)
 import           Control.Applicative        ((<$>))
 #endif
-import           Control.Monad
 import           Control.Monad.Trans.Except
 import           Data.ByteString.Lazy       (ByteString)
 import           Data.List
@@ -420,6 +419,6 @@ It may seem to make more sense to have:
 
 But this means that if another instance exists that does *not* require
 non-empty lists, but is otherwise more specific, no instance will be overall
-more specific. This in turns generally means adding yet another instance (one
+more specific. This in turn generally means adding yet another instance (one
 for empty and one for non-empty lists).
 -}
diff --git a/servant-client/src/Servant/Common/Req.hs b/servant-client/src/Servant/Common/Req.hs
index 32d572aa..3d72acd9 100644
--- a/servant-client/src/Servant/Common/Req.hs
+++ b/servant-client/src/Servant/Common/Req.hs
@@ -156,7 +156,7 @@ performRequest reqMethod req reqHost manager = do
 
 performRequestCT :: MimeUnrender ct result =>
   Proxy ct -> Method -> Req -> BaseUrl -> Manager
-  -> ExceptT ServantError IO ([HTTP.Header], result)
+    -> ExceptT ServantError IO ([HTTP.Header], result)
 performRequestCT ct reqMethod req reqHost manager = do
   let acceptCT = contentType ct
   (_status, respBody, respCT, hdrs, _response) <-
diff --git a/servant-server/test/Servant/ServerSpec.hs b/servant-server/test/Servant/ServerSpec.hs
index 9bb5e340..e4069b0f 100644
--- a/servant-server/test/Servant/ServerSpec.hs
+++ b/servant-server/test/Servant/ServerSpec.hs
@@ -3,8 +3,10 @@
 {-# LANGUAGE DeriveGeneric        #-}
 {-# LANGUAGE FlexibleInstances    #-}
 {-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE PolyKinds            #-}
 {-# LANGUAGE ScopedTypeVariables  #-}
 {-# LANGUAGE TypeOperators        #-}
+{-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE FlexibleInstances    #-}
 
@@ -13,7 +15,7 @@ module Servant.ServerSpec where
 #if !MIN_VERSION_base(4,8,0)
 import           Control.Applicative        ((<$>))
 #endif
-import           Control.Monad              (forM_, when)
+import           Control.Monad              (forM_, when, unless)
 import           Control.Monad.Trans.Except (ExceptT, throwE)
 import           Data.Aeson                 (FromJSON, ToJSON, decode', encode)
 import           Data.ByteString.Conversion ()
@@ -23,82 +25,144 @@ import           Data.String                (fromString)
 import           Data.String.Conversions    (cs)
 import qualified Data.Text                  as T
 import           GHC.Generics               (Generic)
-import           Network.HTTP.Types         (hAccept, hContentType,
-                                             methodDelete, methodGet, methodHead,
-                                             methodPatch, methodPost, methodPut,
-                                             ok200, parseQuery, Status(..))
+import           Network.HTTP.Types         (Status (..), hAccept, hContentType,
+                                             methodDelete, methodGet,
+                                             methodHead, methodPatch,
+                                             methodPost, methodPut, ok200,
+                                             parseQuery)
 import           Network.Wai                (Application, Request, pathInfo,
                                              queryString, rawQueryString,
-                                             responseLBS, responseBuilder)
-import           Network.Wai.Internal       (Response(ResponseBuilder))
+                                             responseBuilder, responseLBS)
+import           Network.Wai.Internal       (Response (ResponseBuilder))
 import           Network.Wai.Test           (defaultRequest, request,
-                                             runSession, simpleBody)
+                                             runSession, simpleBody,
+                                             simpleHeaders, simpleStatus)
 import           Servant.API                ((:<|>) (..), (:>), Capture, Delete,
-                                             Get, Header (..), Headers,
-                                             HttpVersion, IsSecure (..), JSON,
-                                             Patch, PlainText, Post, Put,
+                                             Get, Header (..),
+                                             Headers, HttpVersion,
+                                             IsSecure (..), JSON,
+                                             NoContent (..), Patch, PlainText,
+                                             Post, Put,
                                              QueryFlag, QueryParam, QueryParams,
-                                             Raw, RemoteHost, ReqBody, GetNoContent,
-                                             PostNoContent, addHeader, NoContent(..))
-import           Servant.Server             (Server, serve, ServantErr(..), err404)
-import           Test.Hspec                 (Spec, describe, it, shouldBe)
+                                             Raw, RemoteHost, ReqBody,
+                                             StdMethod (..), Verb, addHeader)
+import           Servant.Server             (ServantErr (..), Server, err404,
+                                             serve)
+import           Test.Hspec                 (Spec, context, describe, it,
+                                             shouldBe, shouldContain)
 import           Test.Hspec.Wai             (get, liftIO, matchHeaders,
-                                             matchStatus, post, request,
+                                             matchStatus, request,
                                              shouldRespondWith, with, (<:>))
-import           Servant.Server.Internal.RoutingApplication (toApplication, RouteResult(..))
+
+import           Servant.Server.Internal.RoutingApplication
+                                            (toApplication, RouteResult(..))
 import           Servant.Server.Internal.Router
                                             (tweakResponse, runRouter,
                                              Router, Router'(LeafRouter))
 
 
--- * test data types
-
-data Person = Person {
-  name :: String,
-  age  :: Integer
- }
-  deriving (Eq, Show, Generic)
-
-instance ToJSON Person
-instance FromJSON Person
-
-alice :: Person
-alice = Person "Alice" 42
-
-data Animal = Animal {
-  species      :: String,
-  numberOfLegs :: Integer
- }
-  deriving (Eq, Show, Generic)
-
-instance ToJSON Animal
-instance FromJSON Animal
-
-jerry :: Animal
-jerry = Animal "Mouse" 4
-
-tweety :: Animal
-tweety = Animal "Bird" 2
-
-
--- * specs
+-- * Specs
 
 spec :: Spec
 spec = do
+  verbSpec
   captureSpec
-  getSpec
-  headSpec
-  postSpec
-  putSpec
-  patchSpec
   queryParamSpec
+  reqBodySpec
   headerSpec
   rawSpec
-  unionSpec
-  routerSpec
+  alternativeSpec
   responseHeadersSpec
-  miscReqCombinatorsSpec
+  routerSpec
+  miscCombinatorSpec
 
+------------------------------------------------------------------------------
+-- * verbSpec {{{
+------------------------------------------------------------------------------
+
+type VerbApi method status
+    =                Verb method status '[JSON] Person
+ :<|> "noContent" :> Verb method status '[JSON] NoContent
+ :<|> "header"    :> Verb method status '[JSON] (Headers '[Header "H" Int] Person)
+ :<|> "headerNC"  :> Verb method status '[JSON] (Headers '[Header "H" Int] NoContent)
+
+verbSpec :: Spec
+verbSpec = describe "Servant.API.Verb" $ do
+  let server :: Server (VerbApi method status)
+      server = return alice
+          :<|> return NoContent
+          :<|> return (addHeader 5 alice)
+          :<|> return (addHeader 10 NoContent)
+      get200     = Proxy :: Proxy (VerbApi 'GET 200)
+      post210    = Proxy :: Proxy (VerbApi 'POST 210)
+      put203     = Proxy :: Proxy (VerbApi 'PUT 203)
+      delete280  = Proxy :: Proxy (VerbApi 'DELETE 280)
+      patch214   = Proxy :: Proxy (VerbApi 'PATCH 214)
+      wrongMethod m = if m == methodPatch then methodPost else methodPatch
+      test desc api method (status :: Int) = context desc $
+
+        with (return $ serve api server) $ do
+
+          -- HEAD and 214/215 need not return bodies
+          unless (status `elem` [214, 215] || method == methodHead) $
+            it "returns the person" $ do
+              response <- Test.Hspec.Wai.request method "/" [] ""
+              liftIO $ statusCode (simpleStatus response) `shouldBe` status
+              liftIO $ decode' (simpleBody response) `shouldBe` Just alice
+
+          it "returns no content on NoContent" $ do
+              response <- Test.Hspec.Wai.request method "/noContent" [] ""
+              liftIO $ statusCode (simpleStatus response) `shouldBe` status
+              liftIO $ simpleBody response `shouldBe` ""
+
+          -- HEAD should not return body
+          when (method == methodHead) $
+            it "HEAD returns no content body" $ do
+              response <- Test.Hspec.Wai.request method "/" [] ""
+              liftIO $ simpleBody response `shouldBe` ""
+
+          it "throws 405 on wrong method " $ do
+            Test.Hspec.Wai.request (wrongMethod method) "/" [] ""
+              `shouldRespondWith` 405
+
+          it "returns headers" $ do
+            response1 <- Test.Hspec.Wai.request method "/header" [] ""
+            liftIO $ statusCode (simpleStatus response1) `shouldBe` status
+            liftIO $ simpleHeaders response1 `shouldContain` [("H", "5")]
+
+            response2 <- Test.Hspec.Wai.request method "/header" [] ""
+            liftIO $ statusCode (simpleStatus response2) `shouldBe` status
+            liftIO $ simpleHeaders response2 `shouldContain` [("H", "5")]
+
+          it "handles trailing '/' gracefully" $ do
+            response <- Test.Hspec.Wai.request method "/headerNC/" [] ""
+            liftIO $ statusCode (simpleStatus response) `shouldBe` status
+
+          it "returns 406 if the Accept header is not supported" $ do
+            Test.Hspec.Wai.request method "" [(hAccept, "crazy/mime")] ""
+              `shouldRespondWith` 406
+
+          it "responds if the Accept header is supported" $ do
+            response <- Test.Hspec.Wai.request method ""
+               [(hAccept, "application/json")] ""
+            liftIO $ statusCode (simpleStatus response) `shouldBe` status
+
+          it "sets the Content-Type header" $ do
+            response <- Test.Hspec.Wai.request method "" [] ""
+            liftIO $ simpleHeaders response `shouldContain`
+              [("Content-Type", "application/json")]
+
+  test "GET 200" get200 methodGet 200
+  test "POST 210" post210 methodPost 210
+  test "PUT 203" put203 methodPut 203
+  test "DELETE 280" delete280 methodDelete 280
+  test "PATCH 214" patch214 methodPatch 214
+  test "GET 200 with HEAD" get200 methodHead 200
+
+-- }}}
+------------------------------------------------------------------------------
+-- * captureSpec {{{
+------------------------------------------------------------------------------
 
 type CaptureApi = Capture "legs" Integer :> Get '[JSON] Animal
 captureApi :: Proxy CaptureApi
@@ -128,68 +192,10 @@ captureSpec = do
       it "strips the captured path snippet from pathInfo" $ do
         get "/captured/foo" `shouldRespondWith` (fromString (show ["foo" :: String]))
 
-
-type GetApi = Get '[JSON] Person
-        :<|> "empty" :> GetNoContent '[JSON] NoContent
-        :<|> "emptyWithHeaders" :> GetNoContent '[JSON] (Headers '[Header "H" Int] NoContent)
-        :<|> "post" :> PostNoContent '[JSON] NoContent
-
-getApi :: Proxy GetApi
-getApi = Proxy
-
-getSpec :: Spec
-getSpec = do
-  describe "Servant.API.Get" $ do
-    let server = return alice
-            :<|> return NoContent
-            :<|> return (addHeader 5 NoContent)
-            :<|> return NoContent
-
-    with (return $ serve getApi server) $ do
-
-      it "allows to GET a Person" $ do
-        response <- get "/"
-        return response `shouldRespondWith` 200
-        liftIO $ decode' (simpleBody response) `shouldBe` Just alice
-
-      it "throws 405 (wrong method) on POSTs" $ do
-        post "/" "" `shouldRespondWith` 405
-        post "/empty" "" `shouldRespondWith` 405
-
-      it "returns headers" $ do
-        get "/emptyWithHeaders" `shouldRespondWith` 204 { matchHeaders = [ "H" <:> "5" ] }
-
-      it "returns 406 if the Accept header is not supported" $ do
-        Test.Hspec.Wai.request methodGet "" [(hAccept, "crazy/mime")] ""
-          `shouldRespondWith` 406
-
-
-headSpec :: Spec
-headSpec = do
-  describe "Servant.API.Head" $ do
-    let server = return alice
-            :<|> return NoContent
-            :<|> return (addHeader 5 NoContent)
-            :<|> return NoContent
-    with (return $ serve getApi server) $ do
-
-      it "allows to GET a Person" $ do
-        response <- Test.Hspec.Wai.request methodHead "/" [] ""
-        return response `shouldRespondWith` 200
-        liftIO $ decode' (simpleBody response) `shouldBe` (Nothing :: Maybe Person)
-
-      it "does not allow HEAD to POST route" $ do
-        response <- Test.Hspec.Wai.request methodHead "/post" [] ""
-        return response `shouldRespondWith` 405
-
-      it "throws 405 (wrong method) on POSTs" $ do
-        post "/" "" `shouldRespondWith` 405
-        post "/empty" "" `shouldRespondWith` 405
-
-      it "returns 406 if the Accept header is not supported" $ do
-        Test.Hspec.Wai.request methodHead "" [(hAccept, "crazy/mime")] ""
-          `shouldRespondWith` 406
-
+-- }}}
+------------------------------------------------------------------------------
+-- * queryParamSpec {{{
+------------------------------------------------------------------------------
 
 type QueryParamApi = QueryParam "name" String :> Get '[JSON] Person
                 :<|> "a" :> QueryParams "names" String :> Get '[JSON] Person
@@ -274,122 +280,41 @@ queryParamSpec = do
               name = "Alice"
              }
 
-type PostApi =
-       ReqBody '[JSON] Person :> Post '[JSON] Integer
-  :<|> "bla" :> ReqBody '[JSON] Person :> Post '[JSON] Integer
-  :<|> "empty" :> Post '[JSON] ()
+-- }}}
+------------------------------------------------------------------------------
+-- * reqBodySpec {{{
+------------------------------------------------------------------------------
+type ReqBodyApi = ReqBody '[JSON] Person :> Post '[JSON] Person
+           :<|> "blah" :> ReqBody '[JSON] Person :> Put '[JSON] Integer
 
-postApi :: Proxy PostApi
-postApi = Proxy
+reqBodyApi :: Proxy ReqBodyApi
+reqBodyApi = Proxy
 
-postSpec :: Spec
-postSpec = do
-  describe "Servant.API.Post and .ReqBody" $ do
-    let server = return . age :<|> return . age :<|> return ()
-    with (return $ serve postApi server) $ do
-      let post' x = Test.Hspec.Wai.request methodPost x [(hContentType
-                                                        , "application/json;charset=utf-8")]
+reqBodySpec :: Spec
+reqBodySpec = describe "Servant.API.ReqBody" $ do
 
-      it "allows to POST a Person" $ do
-        post' "/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
+  let server :: Server ReqBodyApi
+      server = return :<|> return . age
+      mkReq method x = Test.Hspec.Wai.request method x
+         [(hContentType, "application/json;charset=utf-8")]
 
-      it "allows alternative routes if all have request bodies" $ do
-        post' "/bla" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
+  with (return $ serve reqBodyApi server) $ do
 
-      it "handles trailing '/' gracefully" $ do
-        post' "/bla/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
+    it "passes the argument to the handler" $ do
+      response <- mkReq methodPost "" (encode alice)
+      liftIO $ decode' (simpleBody response) `shouldBe` Just alice
 
-      it "correctly rejects invalid request bodies with status 400" $ do
-        post' "/" "some invalid body" `shouldRespondWith` 400
+    it "rejects invalid request bodies with status 400" $ do
+      mkReq methodPut "/blah" "some invalid body" `shouldRespondWith` 400
 
-      it "responds with 415 if the request body media type is unsupported" $ do
-        let post'' x = Test.Hspec.Wai.request methodPost x [(hContentType
-                                                            , "application/nonsense")]
-        post'' "/" "anything at all" `shouldRespondWith` 415
+    it "responds with 415 if the request body media type is unsupported" $ do
+      Test.Hspec.Wai.request methodPost "/"
+        [(hContentType, "application/nonsense")] "" `shouldRespondWith` 415
 
-type PutApi =
-       ReqBody '[JSON] Person :> Put '[JSON] Integer
-  :<|> "bla" :> ReqBody '[JSON] Person :> Put '[JSON] Integer
-  :<|> "empty" :> Put '[JSON] ()
-
-putApi :: Proxy PutApi
-putApi = Proxy
-
-putSpec :: Spec
-putSpec = do
-  describe "Servant.API.Put and .ReqBody" $ do
-    let server = return . age :<|> return . age :<|> return ()
-    with (return $ serve putApi server) $ do
-      let put' x = Test.Hspec.Wai.request methodPut x [(hContentType
-                                                        , "application/json;charset=utf-8")]
-
-      it "allows to put a Person" $ do
-        put' "/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "allows alternative routes if all have request bodies" $ do
-        put' "/bla" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "handles trailing '/' gracefully" $ do
-        put' "/bla/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "correctly rejects invalid request bodies with status 400" $ do
-        put' "/" "some invalid body" `shouldRespondWith` 400
-
-      it "responds with 415 if the request body media type is unsupported" $ do
-        let put'' x = Test.Hspec.Wai.request methodPut x [(hContentType
-                                                            , "application/nonsense")]
-        put'' "/" "anything at all" `shouldRespondWith` 415
-
-type PatchApi =
-       ReqBody '[JSON] Person :> Patch '[JSON] Integer
-  :<|> "bla" :> ReqBody '[JSON] Person :> Patch '[JSON] Integer
-  :<|> "empty" :> Patch '[JSON] ()
-
-patchApi :: Proxy PatchApi
-patchApi = Proxy
-
-patchSpec :: Spec
-patchSpec = do
-  describe "Servant.API.Patch and .ReqBody" $ do
-    let server = return . age :<|> return . age :<|> return ()
-    with (return $ serve patchApi server) $ do
-      let patch' x = Test.Hspec.Wai.request methodPatch x [(hContentType
-                                                        , "application/json;charset=utf-8")]
-
-      it "allows to patch a Person" $ do
-        patch' "/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "allows alternative routes if all have request bodies" $ do
-        patch' "/bla" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "handles trailing '/' gracefully" $ do
-        patch' "/bla/" (encode alice) `shouldRespondWith` "42"{
-          matchStatus = 200
-         }
-
-      it "correctly rejects invalid request bodies with status 400" $ do
-        patch' "/" "some invalid body" `shouldRespondWith` 400
-
-      it "responds with 415 if the request body media type is unsupported" $ do
-        let patch'' x = Test.Hspec.Wai.request methodPatch x [(hContentType
-                                                            , "application/nonsense")]
-        patch'' "/" "anything at all" `shouldRespondWith` 415
+-- }}}
+------------------------------------------------------------------------------
+-- * headerSpec {{{
+------------------------------------------------------------------------------
 
 type HeaderApi a = Header "MyHeader" a :> Delete '[JSON] ()
 headerApi :: Proxy (HeaderApi a)
@@ -418,12 +343,19 @@ headerSpec = describe "Servant.API.Header" $ do
         it "passes the header to the handler (String)" $
             delete' "/" "" `shouldRespondWith` 200
 
+-- }}}
+------------------------------------------------------------------------------
+-- * rawSpec {{{
+------------------------------------------------------------------------------
 
 type RawApi = "foo" :> Raw
+
 rawApi :: Proxy RawApi
 rawApi = Proxy
+
 rawApplication :: Show a => (Request -> a) -> Application
-rawApplication f request_ respond = respond $ responseLBS ok200 [] (cs $ show $ f request_)
+rawApplication f request_ respond = respond $ responseLBS ok200 []
+    (cs $ show $ f request_)
 
 rawSpec :: Spec
 rawSpec = do
@@ -444,7 +376,10 @@ rawSpec = do
         liftIO $ do
           simpleBody response `shouldBe` cs (show ["bar" :: String])
 
-
+-- }}}
+------------------------------------------------------------------------------
+-- * alternativeSpec {{{
+------------------------------------------------------------------------------
 type AlternativeApi =
        "foo" :> Get '[JSON] Person
   :<|> "bar" :> Get '[JSON] Animal
@@ -452,11 +387,12 @@ type AlternativeApi =
   :<|> "bar" :> Post '[JSON] Animal
   :<|> "bar" :> Put '[JSON] Animal
   :<|> "bar" :> Delete '[JSON] ()
-unionApi :: Proxy AlternativeApi
-unionApi = Proxy
 
-unionServer :: Server AlternativeApi
-unionServer =
+alternativeApi :: Proxy AlternativeApi
+alternativeApi = Proxy
+
+alternativeServer :: Server AlternativeApi
+alternativeServer =
        return alice
   :<|> return jerry
   :<|> return "a string"
@@ -464,10 +400,10 @@ unionServer =
   :<|> return jerry
   :<|> return ()
 
-unionSpec :: Spec
-unionSpec = do
+alternativeSpec :: Spec
+alternativeSpec = do
   describe "Servant.API.Alternative" $ do
-    with (return $ serve unionApi unionServer) $ do
+    with (return $ serve alternativeApi alternativeServer) $ do
 
       it "unions endpoints" $ do
         response <- get "/foo"
@@ -484,7 +420,10 @@ unionSpec = do
 
       it "returns 404 if the path does not exist" $ do
         get "/nonexistent" `shouldRespondWith` 404
-
+-- }}}
+------------------------------------------------------------------------------
+-- * responseHeaderSpec {{{
+------------------------------------------------------------------------------
 type ResponseHeadersApi =
        Get   '[JSON] (Headers '[Header "H1" Int, Header "H2" String] String)
   :<|> Post  '[JSON] (Headers '[Header "H1" Int, Header "H2" String] String)
@@ -501,26 +440,29 @@ responseHeadersSpec :: Spec
 responseHeadersSpec = describe "ResponseHeaders" $ do
   with (return $ serve (Proxy :: Proxy ResponseHeadersApi) responseHeadersServer) $ do
 
-    let methods = [(methodGet, 200), (methodPost, 200), (methodPut, 200), (methodPatch, 200)]
+    let methods = [methodGet, methodPost, methodPut, methodPatch]
 
     it "includes the headers in the response" $
-      forM_ methods $ \(method, expected) ->
+      forM_ methods $ \method ->
         Test.Hspec.Wai.request method "/" [] ""
           `shouldRespondWith` "\"hi\""{ matchHeaders = ["H1" <:> "5", "H2" <:> "kilroy"]
-                                      , matchStatus  = expected
+                                      , matchStatus  = 200
                                       }
 
     it "responds with not found for non-existent endpoints" $
-      forM_ methods $ \(method,_) ->
+      forM_ methods $ \method ->
         Test.Hspec.Wai.request method "blahblah" [] ""
           `shouldRespondWith` 404
 
     it "returns 406 if the Accept header is not supported" $
-      forM_ methods $ \(method,_) ->
+      forM_ methods $ \method ->
         Test.Hspec.Wai.request method "" [(hAccept, "crazy/mime")] ""
           `shouldRespondWith` 406
 
-
+-- }}}
+------------------------------------------------------------------------------
+-- * routerSpec {{{
+------------------------------------------------------------------------------
 routerSpec :: Spec
 routerSpec = do
   describe "Servant.Server.Internal.Router" $ do
@@ -539,6 +481,10 @@ routerSpec = do
       it "calls f on route result" $ do
         get "" `shouldRespondWith` 202
 
+-- }}}
+------------------------------------------------------------------------------
+-- * miscCombinatorSpec {{{
+------------------------------------------------------------------------------
 type MiscCombinatorsAPI
   =    "version" :> HttpVersion :> Get '[JSON] String
   :<|> "secure"  :> IsSecure :> Get '[JSON] String
@@ -557,8 +503,8 @@ miscServ = versionHandler
         secureHandler NotSecure = return "not secure"
         hostHandler = return . show
 
-miscReqCombinatorsSpec :: Spec
-miscReqCombinatorsSpec = with (return $ serve miscApi miscServ) $
+miscCombinatorSpec :: Spec
+miscCombinatorSpec = with (return $ serve miscApi miscServ) $
   describe "Misc. combinators for request inspection" $ do
     it "Successfully gets the HTTP version specified in the request" $
       go "/version" "\"HTTP/1.0\""
@@ -570,3 +516,35 @@ miscReqCombinatorsSpec = with (return $ serve miscApi miscServ) $
       go "/host" "\"0.0.0.0:0\""
 
   where go path res = Test.Hspec.Wai.get path `shouldRespondWith` res
+-- }}}
+------------------------------------------------------------------------------
+-- * Test data types {{{
+------------------------------------------------------------------------------
+
+data Person = Person {
+  name :: String,
+  age  :: Integer
+ }
+  deriving (Eq, Show, Generic)
+
+instance ToJSON Person
+instance FromJSON Person
+
+alice :: Person
+alice = Person "Alice" 42
+
+data Animal = Animal {
+  species      :: String,
+  numberOfLegs :: Integer
+ }
+  deriving (Eq, Show, Generic)
+
+instance ToJSON Animal
+instance FromJSON Animal
+
+jerry :: Animal
+jerry = Animal "Mouse" 4
+
+tweety :: Animal
+tweety = Animal "Bird" 2
+-- }}}
diff --git a/servant/src/Servant/API.hs b/servant/src/Servant/API.hs
index 2afae7af..03051533 100644
--- a/servant/src/Servant/API.hs
+++ b/servant/src/Servant/API.hs
@@ -70,7 +70,7 @@ import           Servant.API.ResponseHeaders (AddHeader (addHeader),
                                               getHeadersHList, getResponse)
 import           Servant.API.Sub             ((:>))
 import           Servant.API.Vault           (Vault)
-import           Servant.API.Verbs           (Created, Delete, DeleteAccepted,
+import           Servant.API.Verbs           (PostCreated, Delete, DeleteAccepted,
                                               DeleteNoContent,
                                               DeleteNonAuthoritative, Get,
                                               GetAccepted, GetNoContent,
@@ -87,7 +87,7 @@ import           Servant.API.Verbs           (Created, Delete, DeleteAccepted,
                                               PutAccepted, PutNoContent,
                                               PutNoContent, PutNonAuthoritative,
                                               ReflectMethod (reflectMethod),
-                                              Verb)
+                                              Verb, StdMethod(..))
 import           Servant.Utils.Links         (HasLink (..), IsElem, IsElem',
                                               URI (..), safeLink)
 import           Web.HttpApiData             (FromHttpApiData (..),
diff --git a/servant/src/Servant/API/ContentTypes.hs b/servant/src/Servant/API/ContentTypes.hs
index 365381f7..c7776aa9 100644
--- a/servant/src/Servant/API/ContentTypes.hs
+++ b/servant/src/Servant/API/ContentTypes.hs
@@ -304,7 +304,7 @@ instance MimeRender OctetStream ByteString where
 instance MimeRender OctetStream BS.ByteString where
     mimeRender _ = fromStrict
 
--- | A type for responses with content-body.
+-- | A type for responses without content-body.
 data NoContent = NoContent
   deriving (Show, Eq, Read)
 
diff --git a/servant/src/Servant/API/Verbs.hs b/servant/src/Servant/API/Verbs.hs
index c1462503..4915fdaf 100644
--- a/servant/src/Servant/API/Verbs.hs
+++ b/servant/src/Servant/API/Verbs.hs
@@ -3,17 +3,20 @@
 {-# LANGUAGE DeriveGeneric      #-}
 {-# LANGUAGE KindSignatures     #-}
 {-# LANGUAGE PolyKinds          #-}
-module Servant.API.Verbs where
+module Servant.API.Verbs
+  ( module Servant.API.Verbs
+  , StdMethod(GET, POST, HEAD, PUT, DELETE, TRACE, CONNECT, OPTIONS, PATCH)
+  ) where
 
 import           Data.Typeable             (Typeable)
+import           Data.Proxy                (Proxy)
 import           GHC.Generics              (Generic)
 import           GHC.TypeLits              (Nat)
 import           Network.HTTP.Types.Method (Method, StdMethod (..),
                                             methodDelete, methodGet, methodHead,
                                             methodPatch, methodPost, methodPut)
-import           Servant.API.ContentTypes  (NoContent(..))
 
--- | @Verb@ is a general type for representing HTTP verbs/methods. For
+-- | @Verb@ is a general type for representing HTTP verbs (a.k.a. methods). For
 -- convenience, type synonyms for each verb with a 200 response code are
 -- provided, but you are free to define your own:
 --
@@ -55,7 +58,7 @@ type Patch  contentTypes a = Verb 'PATCH  200 contentTypes a
 
 -- | 'POST' with 201 status code.
 --
-type Created contentTypes a = Verb 'POST 201 contentTypes a
+type PostCreated contentTypes a = Verb 'POST 201 contentTypes a
 
 
 -- ** 202 Accepted
@@ -141,11 +144,11 @@ type PutResetContent contentTypes noContent = Verb 'PUT 205 contentTypes noConte
 -- RFC7233 Section 4.1>
 
 -- | 'GET' with 206 status code.
-type GetPartialContent contentTypes noContent = Verb 'GET 205 contentTypes noContent
+type GetPartialContent contentTypes noContent = Verb 'GET 206 contentTypes noContent
 
 
 class ReflectMethod a where
-    reflectMethod :: proxy a -> Method
+    reflectMethod :: Proxy a -> Method
 
 instance ReflectMethod 'GET where
     reflectMethod _ = methodGet
diff --git a/servant/src/Servant/Utils/Links.hs b/servant/src/Servant/Utils/Links.hs
index 38f791ec..d83ffc7e 100644
--- a/servant/src/Servant/Utils/Links.hs
+++ b/servant/src/Servant/Utils/Links.hs
@@ -74,9 +74,7 @@
 -- >>> safeLink api bad_link
 -- ...
 --     Could not deduce (Or
---                         (IsElem'
---                            (Verb 'Network.HTTP.Types.Method.DELETE 200 '[JSON] ())
---                            (Verb 'Network.HTTP.Types.Method.GET 200 '[JSON] Int))
+--                         (IsElem' (Verb 'DELETE 200 '[JSON] ()) (Verb 'GET 200 '[JSON] Int))
 --                         (IsElem'
 --                            ("hello" :> Delete '[JSON] ())
 --                            ("bye" :> (QueryParam "name" String :> Delete '[JSON] ()))))

From f9c61379c04d436fc9e1353f61c46740c6eac272 Mon Sep 17 00:00:00 2001
From: "Julian K. Arni" <jkarni@gmail.com>
Date: Fri, 8 Jan 2016 19:33:36 +0100
Subject: [PATCH 34/34] Refactor NoContent logic.

        Now MimeRender and MimeUnrender instances are not needed.
---
 servant/src/Servant/API/ContentTypes.hs | 36 +++++++++++--------------
 1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/servant/src/Servant/API/ContentTypes.hs b/servant/src/Servant/API/ContentTypes.hs
index c7776aa9..61bf1ce9 100644
--- a/servant/src/Servant/API/ContentTypes.hs
+++ b/servant/src/Servant/API/ContentTypes.hs
@@ -238,11 +238,12 @@ class (AllMime list) => AllMimeRender (list :: [*]) a where
                   -> a                              -- value to serialize
                   -> [(M.MediaType, ByteString)]    -- content-types/response pairs
 
-instance ( MimeRender ctyp a ) => AllMimeRender '[ctyp] a where
+instance OVERLAPPABLE_ ( MimeRender ctyp a ) => AllMimeRender '[ctyp] a where
     allMimeRender _ a = [(contentType pctyp, mimeRender pctyp a)]
         where pctyp = Proxy :: Proxy ctyp
 
-instance ( MimeRender ctyp a
+instance OVERLAPPABLE_
+         ( MimeRender ctyp a
          , AllMimeRender (ctyp' ': ctyps) a
          ) => AllMimeRender (ctyp ': ctyp' ': ctyps) a where
     allMimeRender _ a = (contentType pctyp, mimeRender pctyp a)
@@ -250,6 +251,19 @@ instance ( MimeRender ctyp a
         where pctyp = Proxy :: Proxy ctyp
               pctyps = Proxy :: Proxy (ctyp' ': ctyps)
 
+
+-- Ideally we would like to declare a 'MimeRender a NoContent' instance, and
+-- then this would be taken care of. However there is no more specific instance
+-- between that and 'MimeRender JSON a', so we do this instead
+instance OVERLAPPING_ ( Accept ctyp ) => AllMimeRender '[ctyp] NoContent where
+    allMimeRender _ _ = [(contentType pctyp, "")]
+      where pctyp = Proxy :: Proxy ctyp
+
+instance OVERLAPPING_
+         ( AllMime (ctyp ': ctyp' ': ctyps)
+         ) => AllMimeRender (ctyp ': ctyp' ': ctyps) NoContent where
+    allMimeRender p _ = zip (allMime p) (repeat "")
+
 --------------------------------------------------------------------------
 -- Check that all elements of list are instances of MimeUnrender
 --------------------------------------------------------------------------
@@ -308,24 +322,6 @@ instance MimeRender OctetStream BS.ByteString where
 data NoContent = NoContent
   deriving (Show, Eq, Read)
 
-instance FromJSON NoContent where
-    parseJSON _ = return NoContent
-
-instance ToJSON NoContent where
-    toJSON _ = ""
-
-
-instance OVERLAPPING_
-         MimeRender JSON NoContent where
-    mimeRender _ _ = ""
-
-instance OVERLAPPING_
-         MimeRender PlainText NoContent where
-    mimeRender _ _ = ""
-
-instance OVERLAPPING_
-         MimeRender OctetStream NoContent where
-    mimeRender _ _ = ""
 
 --------------------------------------------------------------------------
 -- * MimeUnrender Instances