Copyright	(c) Anton Gushcha 2016
License	MIT
Maintainer	ncrashed@gmail.com
Stability	experimental
Portability	Portable
Safe Haskell	None
Language	Haskell2010

Data.Aeson.Unit

Description

Common problem in REST interfaces when you need to return nothing as result, usage of () will produce `[]` JSON. That causes problems in some JSON parsers in other languages.

So, Unit serialises into empty JSON object:

>>> encode Unit
"{}"

Synopsis

data Unit = Unit

Documentation

data Unit Source #

Data type that serialise into empty object in aeson

>>> encode Unit
"{}"

>>> encode $ toSchema (Proxy :: Proxy Unit)
"{\"type\":\"object\"}"

Also the FromJSON instance is just `pure Unit`, so it never fails.

Constructors

Unit

Instances

Instances details

Bounded Unit Source #
Instance details Defined in Data.Aeson.Unit Methods minBound :: Unit # maxBound :: Unit #
Enum Unit Source #
Instance details Defined in Data.Aeson.Unit Methods succ :: Unit -> Unit # pred :: Unit -> Unit # toEnum :: Int -> Unit # fromEnum :: Unit -> Int # enumFrom :: Unit -> [Unit] # enumFromThen :: Unit -> Unit -> [Unit] # enumFromTo :: Unit -> Unit -> [Unit] # enumFromThenTo :: Unit -> Unit -> Unit -> [Unit] #
Eq Unit Source #
Instance details Defined in Data.Aeson.Unit Methods (==) :: Unit -> Unit -> Bool # (/=) :: Unit -> Unit -> Bool #
Read Unit Source #
Instance details Defined in Data.Aeson.Unit Methods readsPrec :: Int -> ReadS Unit # readList :: ReadS [Unit] # readPrec :: ReadPrec Unit # readListPrec :: ReadPrec [Unit] #
Show Unit Source #
Instance details Defined in Data.Aeson.Unit Methods showsPrec :: Int -> Unit -> ShowS # show :: Unit -> String # showList :: [Unit] -> ShowS #
Generic Unit Source #
Instance details Defined in Data.Aeson.Unit Associated Types type Rep Unit :: Type -> Type # Methods from :: Unit -> Rep Unit x # to :: Rep Unit x -> Unit #
ToJSON Unit Source #
Instance details Defined in Data.Aeson.Unit Methods toJSON :: Unit -> Value # toEncoding :: Unit -> Encoding # toJSONList :: [Unit] -> Value # toEncodingList :: [Unit] -> Encoding #
FromJSON Unit Source #	Always a success parse
Instance details Defined in Data.Aeson.Unit Methods parseJSON :: Value -> Parser Unit # parseJSONList :: Value -> Parser [Unit] #
ToSchema Unit Source #
Instance details Defined in Data.Aeson.Unit Methods declareNamedSchema :: Proxy Unit -> Declare (Definitions Schema) NamedSchema #
type Rep Unit Source #
Instance details Defined in Data.Aeson.Unit type Rep Unit = D1 ('MetaData "Unit" "Data.Aeson.Unit" "aeson-injector-2.0.0.0-inplace" 'False) (C1 ('MetaCons "Unit" 'PrefixI 'False) (U1 :: Type -> Type))