Add (de)serialization functions to most datasources

Summary: Add serialization and deserialization functions to non-risk datasources that don't require special treatment (like CacheClient, etc), for use with D2628780

Reviewed By: simonmar

Differential Revision: D2645436

fbshipit-source-id: 2777dbfbb11528bc079e2e82e88ebbdc880a8914

Haxl/Core/Exception.hs

@@ -5,6 +5,7 @@
 -- found in the LICENSE file. An additional grant of patent rights can
 -- be found in the PATENTS file.
 
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE DeriveDataTypeable #-}
@@ -65,6 +66,7 @@ module Haxl.Core.Exception (
 
 import Control.Exception
 import Data.Aeson
+import Data.Binary (Binary)
 import Data.Typeable
 import Data.Text (Text)
 
@@ -189,16 +191,16 @@ logicErrorFromException x = do
 
 -- | Generic \"critical\" exception. Something internal is
 -- borked. Panic.
-data CriticalError = CriticalError Text
-  deriving (Typeable, Eq, Show)
+newtype CriticalError = CriticalError Text
+  deriving (Typeable, Binary, Eq, Show)
 
 instance Exception CriticalError where
   toException   = internalErrorToException
   fromException = internalErrorFromException
 
 -- | Generic \"something was not found\" exception.
-data NotFound = NotFound Text
-  deriving (Typeable, Eq, Show)
+newtype NotFound = NotFound Text
+  deriving (Typeable, Binary, Eq, Show)
 
 instance Exception NotFound where
   toException = logicErrorToException

tests/TestTypes.hs

@@ -10,6 +10,7 @@ module TestTypes
    ) where
 
 import Data.Aeson
+import Data.Binary (Binary)
 import Data.Text (Text)
 import qualified Data.Text as Text
 import qualified Data.HashMap.Strict as HashMap
@@ -36,7 +37,7 @@ lookupInput field = do
 
 
 newtype Id = Id Int
-  deriving (Eq, Ord, Enum, Num, Integral, Real, Hashable, Typeable,
+  deriving (Eq, Ord, Binary, Enum, Num, Integral, Real, Hashable, Typeable,
             ToJSON, FromJSON)
 
 instance Show Id where