Merge pull request #399 from eskimor/master

Make ServantErr throwable

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

@@ -1,9 +1,12 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
+{-# LANGUAGE DeriveDataTypeable #-}
 module Servant.Server.Internal.ServantErr where
 
+import           Control.Exception (Exception)
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.ByteString.Lazy  as LBS
+import           Data.Typeable (Typeable)
 import qualified Network.HTTP.Types    as HTTP
 import           Network.Wai           (Response, responseLBS)
 
@@ -11,7 +14,9 @@ data ServantErr = ServantErr { errHTTPCode     :: Int
                              , errReasonPhrase :: String
                              , errBody         :: LBS.ByteString
                              , errHeaders      :: [HTTP.Header]
-                             } deriving (Show, Eq, Read)
+                             } deriving (Show, Eq, Read, Typeable)
+
+instance Exception ServantErr
 
 responseServantErr :: ServantErr -> Response
 responseServantErr ServantErr{..} = responseLBS status errHeaders errBody