Implement generics/TH support for lifted typeclasses

Data/Aeson.hs

@@ -55,15 +55,30 @@ module Data.Aeson
     , FromJSON(..)
     , Result(..)
     , fromJSON
+    , FromJSON1(..)
+    , parseJSON1
+    , FromJSON2(..)
+    , parseJSON2
     , ToJSON(..)
+    , ToJSON1(..)
+    , toJSON1
+    , toEncoding1
+    , ToJSON2(..)
+    , toJSON2
+    , toEncoding2
     , KeyValue(..)
     -- ** Generic JSON classes and options
     , GFromJSON(..)
     , GToJSON(..)
     , GToEncoding(..)
+    , Zero
+    , One
     , genericToJSON
+    , genericLiftToJSON
     , genericToEncoding
+    , genericLiftToEncoding
     , genericParseJSON
+    , genericLiftParseJSON
     , defaultOptions
 
     -- * Inspecting @'Value's@

Data/Aeson/Encode/Functions.hs

@@ -4,6 +4,7 @@ module Data.Aeson.Encode.Functions
     (
       brackets
     , builder
+    , builderWith
     , char7
     , encode
     , foldable
@@ -26,9 +27,13 @@ import Data.Monoid (mempty)
 #endif
 
 builder :: ToJSON a => a -> Builder
-builder = fromEncoding . toEncoding
+builder = builderWith toEncoding
 {-# INLINE builder #-}
 
+builderWith :: (a -> Encoding) -> a -> Builder
+builderWith te = fromEncoding . te
+{-# INLINE builderWith #-}
+
 -- | Efficiently serialize a JSON value as a lazy 'L.ByteString'.
 --
 -- This is implemented in terms of the 'ToJSON' class's 'toEncoding' method.