fielded.hs

-- | JSON parse helper.                                                
--                                                                     
-- data Foo = Foo { fooIntBar :: Int, fooStringBar :: String }               
--   deriving (Generic)                                                
--                                                                     
-- -- This will make 'Foo''s fields get parsed as                      
-- -- 'int_bar', 'string_bar', etc.                                    
-- instance FromJSON Foo where                                         
-- parseJSON = parseJSONFielded                                        
parseJSONFielded :: forall a. (Generic a, Typeable a, AE.GFromJSON AE.Z
ero (Rep a)) => AE.Value -> AE.Parser a                                
parseJSONFielded =                                                     
  let tyConLength = List.length                                        
        . Typeable.tyConName                                           
        . Typeable.typeRepTyCon                                        
        $ (Typeable.typeRep (Proxy @a))                                
  in AE.genericParseJSON AE.defaultOptions                             
       { AE.fieldLabelModifier = AE.camelTo2 '_' . List.drop tyConLengt
h }