Explicitly export Options fields so they appear in documentation

Author: Lysxia

Data/Aeson/Types.hs

@@ -104,7 +104,19 @@ module Data.Aeson.Types
     , listParser
 
     -- * Generic and TH encoding configuration
-    , Options(..)
+    , Options
+
+    -- ** Options fields
+    -- $optionsFields
+    , fieldLabelModifier
+    , constructorTagModifier
+    , allNullaryToStringTag
+    , omitNothingFields
+    , sumEncoding
+    , unwrapUnaryRecords
+    , tagSingleConstructors
+
+    -- ** Options utilities
     , SumEncoding(..)
     , camelTo
     , camelTo2
@@ -124,3 +136,6 @@ import Data.Foldable (toList)
 foldable :: (Foldable t, ToJSON a) => t a -> Encoding
 foldable = toEncoding . toList
 {-# INLINE foldable #-}
+
+-- $optionsFields
+-- The functions here are in fact record fields of the 'Options' type.

Data/Aeson/Types/Internal.hs

@@ -531,6 +531,9 @@ parserCatchError (Parser p) handler = Parser $ \path kf ks ->
 --------------------------------------------------------------------------------
 
 -- | Options that specify how to encode\/decode your datatype to\/from JSON.
+--
+-- Options can be set using record syntax on 'defaultOptions' with the fields
+-- below.
 data Options = Options
     { fieldLabelModifier :: String -> String
       -- ^ Function applied to field labels.