aeson-1.5.6.0: Fast JSON parsing and encoding
Copyright(c) 2011-2016 Bryan O'Sullivan
(c) 2011 MailRank Inc.
LicenseBSD3
MaintainerBryan O'Sullivan <bos@serpentine.com>
Stabilityexperimental
Portabilityportable
Safe HaskellNone
LanguageHaskell2010

Data.Aeson.Types

Description

Types for working with JSON data.

Synopsis

Core JSON types

data Value #

A JSON value represented as a Haskell value.

Instances

Instances details
Eq Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(==) :: Value -> Value -> Bool #

(/=) :: Value -> Value -> Bool #

Data Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Value -> c Value #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Value #

toConstr :: Value -> Constr #

dataTypeOf :: Value -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Value) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Value) #

gmapT :: (forall b. Data b => b -> b) -> Value -> Value #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Value -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Value -> r #

gmapQ :: (forall d. Data d => d -> u) -> Value -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Value -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Value -> m Value #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Value -> m Value #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Value -> m Value #

Ord Value #

The ordering is total, consistent with Eq instance. However, nothing else about the ordering is specified, and it may change from environment to environment and version to version of either this package or its dependencies (hashable and 'unordered-containers').

Since: 1.5.2.0

Instance details

Defined in Data.Aeson.Types.Internal

Methods

compare :: Value -> Value -> Ordering #

(<) :: Value -> Value -> Bool #

(<=) :: Value -> Value -> Bool #

(>) :: Value -> Value -> Bool #

(>=) :: Value -> Value -> Bool #

max :: Value -> Value -> Value #

min :: Value -> Value -> Value #

Read Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Show Value #

Since version 1.5.6.0 version object values are printed in lexicographic key order

>>> toJSON $ H.fromList [("a", True), ("z", False)]
Object (fromList [("a",Bool True),("z",Bool False)])
>>> toJSON $ H.fromList [("z", False), ("a", True)]
Object (fromList [("a",Bool True),("z",Bool False)])
Instance details

Defined in Data.Aeson.Types.Internal

Methods

showsPrec :: Int -> Value -> ShowS #

show :: Value -> String #

showList :: [Value] -> ShowS #

IsString Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fromString :: String -> Value #

Generic Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Associated Types

type Rep Value :: Type -> Type #

Methods

from :: Value -> Rep Value x #

to :: Rep Value x -> Value #

NFData Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

rnf :: Value -> () #

Hashable Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

hashWithSalt :: Int -> Value -> Int #

hash :: Value -> Int #

FromJSON Value # 
Instance details

Defined in Data.Aeson.Types.FromJSON

KeyValue Pair # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Pair #

KeyValue Object #

Constructs a singleton HashMap. For calling functions that demand an Object for constructing objects. To be used in conjunction with mconcat. Prefer to use object where possible.

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Object #

ToJSON Value # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Lift Value # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

lift :: Value -> Q Exp #

liftTyped :: Value -> Q (TExp Value) #

GToJSON' Value arity (U1 :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value arity a -> U1 a -> Value

GToJSON' Value arity (V1 :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value arity a -> V1 a -> Value

GToJSON' Encoding arity (U1 :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Encoding arity a -> U1 a -> Encoding

ToJSON1 f => GToJSON' Value One (Rec1 f) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value One a -> Rec1 f a -> Value

ToJSON1 f => GToJSON' Encoding One (Rec1 f) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Encoding One a -> Rec1 f a -> Encoding

(WriteProduct arity a, WriteProduct arity b, ProductSize a, ProductSize b) => GToJSON' Value arity (a :*: b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value arity a0 -> (a :*: b) a0 -> Value

ToJSON a => GToJSON' Value arity (K1 i a :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value arity a0 -> K1 i a a0 -> Value

(EncodeProduct arity a, EncodeProduct arity b) => GToJSON' Encoding arity (a :*: b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Encoding arity a0 -> (a :*: b) a0 -> Encoding

ToJSON a => GToJSON' Encoding arity (K1 i a :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Encoding arity a0 -> K1 i a a0 -> Encoding

(ToJSON1 f, GToJSON' Value One g) => GToJSON' Value One (f :.: g) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Value One a -> (f :.: g) a -> Value

(ToJSON1 f, GToJSON' Encoding One g) => GToJSON' Encoding One (f :.: g) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

gToJSON :: Options -> ToArgs Encoding One a -> (f :.: g) a -> Encoding

type Rep Value # 
Instance details

Defined in Data.Aeson.Types.Internal

type Encoding = Encoding' Value #

Often used synonym for Encoding'.

unsafeToEncoding :: Builder -> Encoding' a #

Make Encoding from Builder.

Use with care! You have to make sure that the passed Builder is a valid JSON Encoding!

fromEncoding :: Encoding' tag -> Builder #

Acquire the underlying bytestring builder.

data Series #

A series of values that, when encoded, should be separated by commas. Since 0.11.0.0, the .= operator is overloaded to create either (Text, Value) or Series. You can use Series when encoding directly to a bytestring builder as in the following example:

toEncoding (Person name age) = pairs ("name" .= name <> "age" .= age)

Instances

Instances details
Semigroup Series # 
Instance details

Defined in Data.Aeson.Encoding.Internal

Monoid Series # 
Instance details

Defined in Data.Aeson.Encoding.Internal

KeyValue Series # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Series #

type Array = Vector Value #

A JSON "array" (sequence).

emptyArray :: Value #

The empty array.

type Pair = (Text, Value) #

A key/value pair for an Object.

type Object = HashMap Text Value #

A JSON "object" (key/value map).

emptyObject :: Value #

The empty object.

Convenience types and functions

newtype DotNetTime #

A newtype wrapper for UTCTime that uses the same non-standard serialization format as Microsoft .NET, whose System.DateTime type is by default serialized to JSON as in the following example:

/Date(1302547608878)/

The number represents milliseconds since the Unix epoch.

Constructors

DotNetTime 

Fields

Instances

Instances details
Eq DotNetTime # 
Instance details

Defined in Data.Aeson.Types.Internal

Ord DotNetTime # 
Instance details

Defined in Data.Aeson.Types.Internal

Read DotNetTime # 
Instance details

Defined in Data.Aeson.Types.Internal

Show DotNetTime # 
Instance details

Defined in Data.Aeson.Types.Internal

FormatTime DotNetTime # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

formatCharacter :: Bool -> Char -> Maybe (FormatOptions -> DotNetTime -> String) #

FromJSON DotNetTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

ToJSON DotNetTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

typeMismatch #

Arguments

:: String

The name of the JSON type being parsed ("Object", "Array", "String", "Number", "Boolean", or "Null").

-> Value

The actual value encountered.

-> Parser a 

Fail parsing due to a type mismatch, with a descriptive message.

The following wrappers should generally be prefered: withObject, withArray, withText, withBool.

Error message example

typeMismatch "Object" (String "oops")
-- Error: "expected Object, but encountered String"

unexpected :: Value -> Parser a #

Fail parsing due to a type mismatch, when the expected types are implicit.

Error message example

unexpected (String "oops")
-- Error: "unexpected String"

Type conversion

data Parser a #

A JSON parser. N.B. This might not fit your usual understanding of "parser". Instead you might like to think of Parser as a "parse result", i.e. a parser to which the input has already been applied.

Instances

Instances details
Monad Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(>>=) :: Parser a -> (a -> Parser b) -> Parser b #

(>>) :: Parser a -> Parser b -> Parser b #

return :: a -> Parser a #

Functor Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fmap :: (a -> b) -> Parser a -> Parser b #

(<$) :: a -> Parser b -> Parser a #

MonadFail Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fail :: String -> Parser a #

Applicative Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

pure :: a -> Parser a #

(<*>) :: Parser (a -> b) -> Parser a -> Parser b #

liftA2 :: (a -> b -> c) -> Parser a -> Parser b -> Parser c #

(*>) :: Parser a -> Parser b -> Parser b #

(<*) :: Parser a -> Parser b -> Parser a #

Alternative Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

empty :: Parser a #

(<|>) :: Parser a -> Parser a -> Parser a #

some :: Parser a -> Parser [a] #

many :: Parser a -> Parser [a] #

MonadPlus Parser # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

mzero :: Parser a #

mplus :: Parser a -> Parser a -> Parser a #

Semigroup (Parser a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(<>) :: Parser a -> Parser a -> Parser a #

sconcat :: NonEmpty (Parser a) -> Parser a #

stimes :: Integral b => b -> Parser a -> Parser a #

Monoid (Parser a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

mempty :: Parser a #

mappend :: Parser a -> Parser a -> Parser a #

mconcat :: [Parser a] -> Parser a #

data Result a #

The result of running a Parser.

Constructors

Error String 
Success a 

Instances

Instances details
Monad Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(>>=) :: Result a -> (a -> Result b) -> Result b #

(>>) :: Result a -> Result b -> Result b #

return :: a -> Result a #

Functor Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fmap :: (a -> b) -> Result a -> Result b #

(<$) :: a -> Result b -> Result a #

MonadFail Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fail :: String -> Result a #

Applicative Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

pure :: a -> Result a #

(<*>) :: Result (a -> b) -> Result a -> Result b #

liftA2 :: (a -> b -> c) -> Result a -> Result b -> Result c #

(*>) :: Result a -> Result b -> Result b #

(<*) :: Result a -> Result b -> Result a #

Foldable Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

fold :: Monoid m => Result m -> m #

foldMap :: Monoid m => (a -> m) -> Result a -> m #

foldMap' :: Monoid m => (a -> m) -> Result a -> m #

foldr :: (a -> b -> b) -> b -> Result a -> b #

foldr' :: (a -> b -> b) -> b -> Result a -> b #

foldl :: (b -> a -> b) -> b -> Result a -> b #

foldl' :: (b -> a -> b) -> b -> Result a -> b #

foldr1 :: (a -> a -> a) -> Result a -> a #

foldl1 :: (a -> a -> a) -> Result a -> a #

toList :: Result a -> [a] #

null :: Result a -> Bool #

length :: Result a -> Int #

elem :: Eq a => a -> Result a -> Bool #

maximum :: Ord a => Result a -> a #

minimum :: Ord a => Result a -> a #

sum :: Num a => Result a -> a #

product :: Num a => Result a -> a #

Traversable Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Result a -> f (Result b) #

sequenceA :: Applicative f => Result (f a) -> f (Result a) #

mapM :: Monad m => (a -> m b) -> Result a -> m (Result b) #

sequence :: Monad m => Result (m a) -> m (Result a) #

Alternative Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

empty :: Result a #

(<|>) :: Result a -> Result a -> Result a #

some :: Result a -> Result [a] #

many :: Result a -> Result [a] #

MonadPlus Result # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

mzero :: Result a #

mplus :: Result a -> Result a -> Result a #

Eq a => Eq (Result a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(==) :: Result a -> Result a -> Bool #

(/=) :: Result a -> Result a -> Bool #

Show a => Show (Result a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

showsPrec :: Int -> Result a -> ShowS #

show :: Result a -> String #

showList :: [Result a] -> ShowS #

Semigroup (Result a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

(<>) :: Result a -> Result a -> Result a #

sconcat :: NonEmpty (Result a) -> Result a #

stimes :: Integral b => b -> Result a -> Result a #

Monoid (Result a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

mempty :: Result a #

mappend :: Result a -> Result a -> Result a #

mconcat :: [Result a] -> Result a #

NFData a => NFData (Result a) # 
Instance details

Defined in Data.Aeson.Types.Internal

Methods

rnf :: Result a -> () #

class FromJSON a where #

A type that can be converted from JSON, with the possibility of failure.

In many cases, you can get the compiler to generate parsing code for you (see below). To begin, let's cover writing an instance by hand.

There are various reasons a conversion could fail. For example, an Object could be missing a required key, an Array could be of the wrong size, or a value could be of an incompatible type.

The basic ways to signal a failed conversion are as follows:

  • fail yields a custom error message: it is the recommended way of reporting a failure;
  • empty (or mzero) is uninformative: use it when the error is meant to be caught by some (<|>);
  • typeMismatch can be used to report a failure when the encountered value is not of the expected JSON type; unexpected is an appropriate alternative when more than one type may be expected, or to keep the expected type implicit.

prependFailure (or modifyFailure) add more information to a parser's error messages.

An example type and instance using typeMismatch and prependFailure:

-- Allow ourselves to write Text literals.
{-# LANGUAGE OverloadedStrings #-}

data Coord = Coord { x :: Double, y :: Double }

instance FromJSON Coord where
    parseJSON (Object v) = Coord
        <$> v .: "x"
        <*> v .: "y"

    -- We do not expect a non-Object value here.
    -- We could use empty to fail, but typeMismatch
    -- gives a much more informative error message.
    parseJSON invalid    =
        prependFailure "parsing Coord failed, "
            (typeMismatch "Object" invalid)

For this common case of only being concerned with a single type of JSON value, the functions withObject, withScientific, etc. are provided. Their use is to be preferred when possible, since they are more terse. Using withObject, we can rewrite the above instance (assuming the same language extension and data type) as:

instance FromJSON Coord where
    parseJSON = withObject "Coord" $ \v -> Coord
        <$> v .: "x"
        <*> v .: "y"

Instead of manually writing your FromJSON instance, there are two options to do it automatically:

  • Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
  • The compiler can provide a default generic implementation for parseJSON.

To use the second, simply add a deriving Generic clause to your datatype and declare a FromJSON instance for your datatype without giving a definition for parseJSON.

For example, the previous example can be simplified to just:

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics

data Coord = Coord { x :: Double, y :: Double } deriving Generic

instance FromJSON Coord

The default implementation will be equivalent to parseJSON = genericParseJSON defaultOptions; if you need different options, you can customize the generic decoding by defining:

customOptions = defaultOptions
                { fieldLabelModifier = map toUpper
                }

instance FromJSON Coord where
    parseJSON = genericParseJSON customOptions

Minimal complete definition

Nothing

Methods

parseJSON :: Value -> Parser a #

default parseJSON :: (Generic a, GFromJSON Zero (Rep a)) => Value -> Parser a #

parseJSONList :: Value -> Parser [a] #

Instances

Instances details
FromJSON Bool # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Char # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Double # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Float # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Int # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Int8 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Int16 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Int32 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Int64 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Integer #

This instance includes a bounds check to prevent maliciously large inputs to fill up the memory of the target system. You can newtype Scientific and provide your own instance using withScientific if you want to allow larger inputs.

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Natural # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Ordering # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Word # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Word8 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Word16 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Word32 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Word64 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON () # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser () #

parseJSONList :: Value -> Parser [()] #

FromJSON Text # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Text # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Void # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Version # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON CTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON IntSet # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Scientific # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON ZonedTime #

Supported string formats:

YYYY-MM-DD HH:MM Z YYYY-MM-DD HH:MM:SS Z YYYY-MM-DD HH:MM:SS.SSS Z

The first space may instead be a T, and the second space is optional. The Z represents UTC. The Z may be replaced with a time zone offset of the form +0000 or -08:00, where the first two digits are hours, the : is optional and the second two digits (also optional) are minutes.

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON LocalTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON TimeOfDay # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON CalendarDiffTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON UTCTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON SystemTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON NominalDiffTime #

This instance includes a bounds check to prevent maliciously large inputs to fill up the memory of the target system. You can newtype Scientific and provide your own instance using withScientific if you want to allow larger inputs.

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON DiffTime #

This instance includes a bounds check to prevent maliciously large inputs to fill up the memory of the target system. You can newtype Scientific and provide your own instance using withScientific if you want to allow larger inputs.

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON DayOfWeek # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Day # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON CalendarDiffDays # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON QuarterOfYear # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Quarter # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Month # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON UUID # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON DotNetTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON Value # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON [a] # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser [a] #

parseJSONList :: Value -> Parser [[a]] #

FromJSON a => FromJSON (Maybe a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, Integral a) => FromJSON (Ratio a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Min a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Min a) #

parseJSONList :: Value -> Parser [Min a] #

FromJSON a => FromJSON (Max a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Max a) #

parseJSONList :: Value -> Parser [Max a] #

FromJSON a => FromJSON (First a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Last a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (WrappedMonoid a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Option a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Identity a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (First a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Last a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Dual a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (NonEmpty a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (IntMap a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON v => FromJSON (Tree v) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Seq a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Seq a) #

parseJSONList :: Value -> Parser [Seq a] #

(Ord a, FromJSON a) => FromJSON (Set a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Set a) #

parseJSONList :: Value -> Parser [Set a] #

FromJSON1 f => FromJSON (Fix f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Fix f) #

parseJSONList :: Value -> Parser [Fix f] #

(FromJSON1 f, Functor f) => FromJSON (Mu f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Mu f) #

parseJSONList :: Value -> Parser [Mu f] #

(FromJSON1 f, Functor f) => FromJSON (Nu f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Nu f) #

parseJSONList :: Value -> Parser [Nu f] #

FromJSON a => FromJSON (DNonEmpty a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (DList a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(Prim a, FromJSON a) => FromJSON (PrimArray a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (SmallArray a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Array a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Maybe a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

(Eq a, Hashable a, FromJSON a) => FromJSON (HashSet a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(Vector Vector a, FromJSON a) => FromJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(Storable a, FromJSON a) => FromJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(Prim a, FromJSON a) => FromJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON a => FromJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSON b) => FromJSON (Either a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Either a b) #

parseJSONList :: Value -> Parser [Either a b] #

(FromJSON a, FromJSON b) => FromJSON (a, b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b) #

parseJSONList :: Value -> Parser [(a, b)] #

HasResolution a => FromJSON (Fixed a) #

This instance includes a bounds check to prevent maliciously large inputs to fill up the memory of the target system. You can newtype Scientific and provide your own instance using withScientific if you want to allow larger inputs.

Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSON (Proxy a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSONKey k, Ord k, FromJSON v) => FromJSON (Map k v) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Map k v) #

parseJSONList :: Value -> Parser [Map k v] #

(FromJSON a, FromJSON b) => FromJSON (Pair a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Pair a b) #

parseJSONList :: Value -> Parser [Pair a b] #

(FromJSON a, FromJSON b) => FromJSON (These a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (These a b) #

parseJSONList :: Value -> Parser [These a b] #

(FromJSON a, FromJSON b) => FromJSON (Either a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Either a b) #

parseJSONList :: Value -> Parser [Either a b] #

(FromJSON a, FromJSON b) => FromJSON (These a b) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (These a b) #

parseJSONList :: Value -> Parser [These a b] #

(FromJSON v, FromJSONKey k, Eq k, Hashable k) => FromJSON (HashMap k v) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSON b, FromJSON c) => FromJSON (a, b, c) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c) #

parseJSONList :: Value -> Parser [(a, b, c)] #

FromJSON a => FromJSON (Const a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Const a b) #

parseJSONList :: Value -> Parser [Const a b] #

FromJSON b => FromJSON (Tagged a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Tagged a b) #

parseJSONList :: Value -> Parser [Tagged a b] #

(FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (These1 f g a) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (These1 f g a) #

parseJSONList :: Value -> Parser [These1 f g a] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSON (a, b, c, d) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d) #

parseJSONList :: Value -> Parser [(a, b, c, d)] #

(FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Product f g a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Product f g a) #

parseJSONList :: Value -> Parser [Product f g a] #

(FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Sum f g a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Sum f g a) #

parseJSONList :: Value -> Parser [Sum f g a] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e) => FromJSON (a, b, c, d, e) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e) #

parseJSONList :: Value -> Parser [(a, b, c, d, e)] #

(FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Compose f g a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (Compose f g a) #

parseJSONList :: Value -> Parser [Compose f g a] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f) => FromJSON (a, b, c, d, e, f) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g) => FromJSON (a, b, c, d, e, f, g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h) => FromJSON (a, b, c, d, e, f, g, h) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i) => FromJSON (a, b, c, d, e, f, g, h, i) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j) => FromJSON (a, b, c, d, e, f, g, h, i, j) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k) => FromJSON (a, b, c, d, e, f, g, h, i, j, k) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j, k) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l) => FromJSON (a, b, c, d, e, f, g, h, i, j, k, l) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m) => FromJSON (a, b, c, d, e, f, g, h, i, j, k, l, m) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m, FromJSON n) => FromJSON (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m, n) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m, FromJSON n, FromJSON o) => FromJSON (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

parseJSON :: Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) #

parseJSONList :: Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] #

fromJSON :: FromJSON a => Value -> Result a #

Convert a value from JSON, failing if the types do not match.

parse :: (a -> Parser b) -> a -> Result b #

Run a Parser.

parseEither :: (a -> Parser b) -> a -> Either String b #

Run a Parser with an Either result type. If the parse fails, the Left payload will contain an error message.

parseMaybe :: (a -> Parser b) -> a -> Maybe b #

Run a Parser with a Maybe result type.

parseFail :: String -> Parser a #

Raise a parsing failure with some custom message.

class ToJSON a where #

A type that can be converted to JSON.

Instances in general must specify toJSON and should (but don't need to) specify toEncoding.

An example type and instance:

-- Allow ourselves to write Text literals.
{-# LANGUAGE OverloadedStrings #-}

data Coord = Coord { x :: Double, y :: Double }

instance ToJSON Coord where
  toJSON (Coord x y) = object ["x" .= x, "y" .= y]

  toEncoding (Coord x y) = pairs ("x" .= x <> "y" .= y)

Instead of manually writing your ToJSON instance, there are two options to do it automatically:

  • Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
  • The compiler can provide a default generic implementation for toJSON.

To use the second, simply add a deriving Generic clause to your datatype and declare a ToJSON instance. If you require nothing other than defaultOptions, it is sufficient to write (and this is the only alternative where the default toJSON implementation is sufficient):

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics

data Coord = Coord { x :: Double, y :: Double } deriving Generic

instance ToJSON Coord where
    toEncoding = genericToEncoding defaultOptions

If on the other hand you wish to customize the generic decoding, you have to implement both methods:

customOptions = defaultOptions
                { fieldLabelModifier = map toUpper
                }

instance ToJSON Coord where
    toJSON     = genericToJSON customOptions
    toEncoding = genericToEncoding customOptions

Previous versions of this library only had the toJSON method. Adding toEncoding had two reasons:

  1. toEncoding is more efficient for the common case that the output of toJSON is directly serialized to a ByteString. Further, expressing either method in terms of the other would be non-optimal.
  2. The choice of defaults allows a smooth transition for existing users: Existing instances that do not define toEncoding still compile and have the correct semantics. This is ensured by making the default implementation of toEncoding use toJSON. This produces correct results, but since it performs an intermediate conversion to a Value, it will be less efficient than directly emitting an Encoding. (this also means that specifying nothing more than instance ToJSON Coord would be sufficient as a generically decoding instance, but there probably exists no good reason to not specify toEncoding in new instances.)

Minimal complete definition

Nothing

Methods

toJSON :: a -> Value #

Convert a Haskell value to a JSON-friendly intermediate type.

default toJSON :: (Generic a, GToJSON' Value Zero (Rep a)) => a -> Value #

toEncoding :: a -> Encoding #

Encode a Haskell value as JSON.

The default implementation of this method creates an intermediate Value using toJSON. This provides source-level compatibility for people upgrading from older versions of this library, but obviously offers no performance advantage.

To benefit from direct encoding, you must provide an implementation for this method. The easiest way to do so is by having your types implement Generic using the DeriveGeneric extension, and then have GHC generate a method body as follows.

instance ToJSON Coord where
    toEncoding = genericToEncoding defaultOptions

toJSONList :: [a] -> Value #

toEncodingList :: [a] -> Encoding #

Instances

Instances details
ToJSON Bool # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Char # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Double # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Float # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Int # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Int8 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Int16 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Int32 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Int64 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Integer # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Natural # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Ordering # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Word # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Word8 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Word16 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Word32 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Word64 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON () # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: () -> Value #

toEncoding :: () -> Encoding #

toJSONList :: [()] -> Value #

toEncodingList :: [()] -> Encoding #

ToJSON Text # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Text # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Number # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Void # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Version # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON CTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON IntSet # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Scientific # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON ZonedTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON LocalTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON TimeOfDay # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON CalendarDiffTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON UTCTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON SystemTime #

Encoded as number

Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON NominalDiffTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON DiffTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON DayOfWeek # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Day # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON CalendarDiffDays # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON QuarterOfYear # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Quarter # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Month # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON UUID # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON DotNetTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON Value # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON [a] # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: [a] -> Value #

toEncoding :: [a] -> Encoding #

toJSONList :: [[a]] -> Value #

toEncodingList :: [[a]] -> Encoding #

ToJSON a => ToJSON (Maybe a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, Integral a) => ToJSON (Ratio a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Min a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Min a -> Value #

toEncoding :: Min a -> Encoding #

toJSONList :: [Min a] -> Value #

toEncodingList :: [Min a] -> Encoding #

ToJSON a => ToJSON (Max a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Max a -> Value #

toEncoding :: Max a -> Encoding #

toJSONList :: [Max a] -> Value #

toEncodingList :: [Max a] -> Encoding #

ToJSON a => ToJSON (First a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Last a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (WrappedMonoid a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Option a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Identity a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (First a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Last a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Dual a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (NonEmpty a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (IntMap a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON v => ToJSON (Tree v) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Seq a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Seq a -> Value #

toEncoding :: Seq a -> Encoding #

toJSONList :: [Seq a] -> Value #

toEncodingList :: [Seq a] -> Encoding #

ToJSON a => ToJSON (Set a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Set a -> Value #

toEncoding :: Set a -> Encoding #

toJSONList :: [Set a] -> Value #

toEncodingList :: [Set a] -> Encoding #

ToJSON1 f => ToJSON (Fix f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Fix f -> Value #

toEncoding :: Fix f -> Encoding #

toJSONList :: [Fix f] -> Value #

toEncodingList :: [Fix f] -> Encoding #

(ToJSON1 f, Functor f) => ToJSON (Mu f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Mu f -> Value #

toEncoding :: Mu f -> Encoding #

toJSONList :: [Mu f] -> Value #

toEncodingList :: [Mu f] -> Encoding #

(ToJSON1 f, Functor f) => ToJSON (Nu f) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Nu f -> Value #

toEncoding :: Nu f -> Encoding #

toJSONList :: [Nu f] -> Value #

toEncodingList :: [Nu f] -> Encoding #

ToJSON a => ToJSON (DNonEmpty a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (DList a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(Prim a, ToJSON a) => ToJSON (PrimArray a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (SmallArray a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Array a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Maybe a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (HashSet a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(Vector Vector a, ToJSON a) => ToJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(Storable a, ToJSON a) => ToJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(Prim a, ToJSON a) => ToJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON a => ToJSON (Vector a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, ToJSON b) => ToJSON (Either a b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Either a b -> Value #

toEncoding :: Either a b -> Encoding #

toJSONList :: [Either a b] -> Value #

toEncodingList :: [Either a b] -> Encoding #

(ToJSON a, ToJSON b) => ToJSON (a, b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b) -> Value #

toEncoding :: (a, b) -> Encoding #

toJSONList :: [(a, b)] -> Value #

toEncodingList :: [(a, b)] -> Encoding #

HasResolution a => ToJSON (Fixed a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSON (Proxy a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON v, ToJSONKey k) => ToJSON (Map k v) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Map k v -> Value #

toEncoding :: Map k v -> Encoding #

toJSONList :: [Map k v] -> Value #

toEncodingList :: [Map k v] -> Encoding #

(ToJSON a, ToJSON b) => ToJSON (Pair a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Pair a b -> Value #

toEncoding :: Pair a b -> Encoding #

toJSONList :: [Pair a b] -> Value #

toEncodingList :: [Pair a b] -> Encoding #

(ToJSON a, ToJSON b) => ToJSON (These a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: These a b -> Value #

toEncoding :: These a b -> Encoding #

toJSONList :: [These a b] -> Value #

toEncodingList :: [These a b] -> Encoding #

(ToJSON a, ToJSON b) => ToJSON (Either a b) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Either a b -> Value #

toEncoding :: Either a b -> Encoding #

toJSONList :: [Either a b] -> Value #

toEncodingList :: [Either a b] -> Encoding #

(ToJSON a, ToJSON b) => ToJSON (These a b) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: These a b -> Value #

toEncoding :: These a b -> Encoding #

toJSONList :: [These a b] -> Value #

toEncodingList :: [These a b] -> Encoding #

(ToJSON v, ToJSONKey k) => ToJSON (HashMap k v) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, ToJSON b, ToJSON c) => ToJSON (a, b, c) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c) -> Value #

toEncoding :: (a, b, c) -> Encoding #

toJSONList :: [(a, b, c)] -> Value #

toEncodingList :: [(a, b, c)] -> Encoding #

ToJSON a => ToJSON (Const a b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Const a b -> Value #

toEncoding :: Const a b -> Encoding #

toJSONList :: [Const a b] -> Value #

toEncodingList :: [Const a b] -> Encoding #

ToJSON b => ToJSON (Tagged a b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Tagged a b -> Value #

toEncoding :: Tagged a b -> Encoding #

toJSONList :: [Tagged a b] -> Value #

toEncodingList :: [Tagged a b] -> Encoding #

(ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (These1 f g a) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: These1 f g a -> Value #

toEncoding :: These1 f g a -> Encoding #

toJSONList :: [These1 f g a] -> Value #

toEncodingList :: [These1 f g a] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d) => ToJSON (a, b, c, d) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d) -> Value #

toEncoding :: (a, b, c, d) -> Encoding #

toJSONList :: [(a, b, c, d)] -> Value #

toEncodingList :: [(a, b, c, d)] -> Encoding #

(ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (Product f g a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Product f g a -> Value #

toEncoding :: Product f g a -> Encoding #

toJSONList :: [Product f g a] -> Value #

toEncodingList :: [Product f g a] -> Encoding #

(ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (Sum f g a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Sum f g a -> Value #

toEncoding :: Sum f g a -> Encoding #

toJSONList :: [Sum f g a] -> Value #

toEncodingList :: [Sum f g a] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e) => ToJSON (a, b, c, d, e) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e) -> Value #

toEncoding :: (a, b, c, d, e) -> Encoding #

toJSONList :: [(a, b, c, d, e)] -> Value #

toEncodingList :: [(a, b, c, d, e)] -> Encoding #

(ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (Compose f g a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: Compose f g a -> Value #

toEncoding :: Compose f g a -> Encoding #

toJSONList :: [Compose f g a] -> Value #

toEncodingList :: [Compose f g a] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f) => ToJSON (a, b, c, d, e, f) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f) -> Value #

toEncoding :: (a, b, c, d, e, f) -> Encoding #

toJSONList :: [(a, b, c, d, e, f)] -> Value #

toEncodingList :: [(a, b, c, d, e, f)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g) => ToJSON (a, b, c, d, e, f, g) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g) -> Value #

toEncoding :: (a, b, c, d, e, f, g) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h) => ToJSON (a, b, c, d, e, f, g, h) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i) => ToJSON (a, b, c, d, e, f, g, h, i) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j) => ToJSON (a, b, c, d, e, f, g, h, i, j) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j, ToJSON k) => ToJSON (a, b, c, d, e, f, g, h, i, j, k) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j, k) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j, k) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j, ToJSON k, ToJSON l) => ToJSON (a, b, c, d, e, f, g, h, i, j, k, l) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j, k, l) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j, k, l) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j, ToJSON k, ToJSON l, ToJSON m) => ToJSON (a, b, c, d, e, f, g, h, i, j, k, l, m) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j, ToJSON k, ToJSON l, ToJSON m, ToJSON n) => ToJSON (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> Encoding #

(ToJSON a, ToJSON b, ToJSON c, ToJSON d, ToJSON e, ToJSON f, ToJSON g, ToJSON h, ToJSON i, ToJSON j, ToJSON k, ToJSON l, ToJSON m, ToJSON n, ToJSON o) => ToJSON (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSON :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Value #

toEncoding :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Encoding #

toJSONList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> Value #

toEncodingList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> Encoding #

class KeyValue kv where #

A key-value pair for encoding a JSON object.

Methods

(.=) :: ToJSON v => Text -> v -> kv infixr 8 #

Instances

Instances details
KeyValue Pair # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Pair #

KeyValue Object #

Constructs a singleton HashMap. For calling functions that demand an Object for constructing objects. To be used in conjunction with mconcat. Prefer to use object where possible.

Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Object #

KeyValue Series # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

(.=) :: ToJSON v => Text -> v -> Series #

modifyFailure :: (String -> String) -> Parser a -> Parser a #

If the inner Parser failed, modify the failure message using the provided function. This allows you to create more descriptive error messages. For example:

parseJSON (Object o) = modifyFailure
    ("Parsing of the Foo value failed: " ++)
    (Foo <$> o .: "someField")

Since 0.6.2.0

prependFailure :: String -> Parser a -> Parser a #

If the inner Parser failed, prepend the given string to the failure message.

prependFailure s = modifyFailure (s ++)

parserThrowError :: JSONPath -> String -> Parser a #

Throw a parser error with an additional path.

Since: 1.2.1.0

parserCatchError :: Parser a -> (JSONPath -> String -> Parser a) -> Parser a #

A handler function to handle previous errors and return to normal execution.

Since: 1.2.1.0

Keys for maps

class ToJSONKey a where #

Typeclass for types that can be used as the key of a map-like container (like Map or HashMap). For example, since Text has a ToJSONKey instance and Char has a ToJSON instance, we can encode a value of type Map Text Char:

>>> LBC8.putStrLn $ encode $ Map.fromList [("foo" :: Text, 'a')]
{"foo":"a"}

Since Int also has a ToJSONKey instance, we can similarly write:

>>> LBC8.putStrLn $ encode $ Map.fromList [(5 :: Int, 'a')]
{"5":"a"}

JSON documents only accept strings as object keys. For any type from base that has a natural textual representation, it can be expected that its ToJSONKey instance will choose that representation.

For data types that lack a natural textual representation, an alternative is provided. The map-like container is represented as a JSON array instead of a JSON object. Each value in the array is an array with exactly two values. The first is the key and the second is the value.

For example, values of type '[Text]' cannot be encoded to a string, so a Map with keys of type '[Text]' is encoded as follows:

>>> LBC8.putStrLn $ encode $ Map.fromList [(["foo","bar","baz" :: Text], 'a')]
[[["foo","bar","baz"],"a"]]

The default implementation of ToJSONKey chooses this method of encoding a key, using the ToJSON instance of the type.

To use your own data type as the key in a map, all that is needed is to write a ToJSONKey (and possibly a FromJSONKey) instance for it. If the type cannot be trivially converted to and from Text, it is recommended that ToJSONKeyValue is used. Since the default implementations of the typeclass methods can build this from a ToJSON instance, there is nothing that needs to be written:

data Foo = Foo { fooAge :: Int, fooName :: Text }
  deriving (Eq,Ord,Generic)
instance ToJSON Foo
instance ToJSONKey Foo

That's it. We can now write:

>>> let m = Map.fromList [(Foo 4 "bar",'a'),(Foo 6 "arg",'b')]
>>> LBC8.putStrLn $ encode m
[[{"fooName":"bar","fooAge":4},"a"],[{"fooName":"arg","fooAge":6},"b"]]

The next case to consider is if we have a type that is a newtype wrapper around Text. The recommended approach is to use generalized newtype deriving:

newtype RecordId = RecordId { getRecordId :: Text }
  deriving (Eq,Ord,ToJSONKey)

Then we may write:

>>> LBC8.putStrLn $ encode $ Map.fromList [(RecordId "abc",'a')]
{"abc":"a"}

Simple sum types are a final case worth considering. Suppose we have:

data Color = Red | Green | Blue
  deriving (Show,Read,Eq,Ord)

It is possible to get the ToJSONKey instance for free as we did with Foo. However, in this case, we have a natural way to go to and from Text that does not require any escape sequences. So ToJSONKeyText can be used instead of ToJSONKeyValue to encode maps as objects instead of arrays of pairs. This instance may be implemented using generics as follows:

instance ToJSONKey Color where
  toJSONKey = genericToJSONKey defaultJSONKeyOptions

Low-level implementations

Expand

The Show instance can be used to help write ToJSONKey:

instance ToJSONKey Color where
  toJSONKey = ToJSONKeyText f g
    where f = Text.pack . show
          g = text . Text.pack . show
          -- text function is from Data.Aeson.Encoding

The situation of needing to turning function a -> Text into a ToJSONKeyFunction is common enough that a special combinator is provided for it. The above instance can be rewritten as:

instance ToJSONKey Color where
  toJSONKey = toJSONKeyText (Text.pack . show)

The performance of the above instance can be improved by not using String as an intermediate step when converting to Text. One option for improving performance would be to use template haskell machinery from the text-show package. However, even with the approach, the Encoding (a wrapper around a bytestring builder) is generated by encoding the Text to a ByteString, an intermediate step that could be avoided. The fastest possible implementation would be:

-- Assuming that OverloadedStrings is enabled
instance ToJSONKey Color where
  toJSONKey = ToJSONKeyText f g
    where f x = case x of {Red -> "Red";Green ->"Green";Blue -> "Blue"}
          g x = case x of {Red -> text "Red";Green -> text "Green";Blue -> text "Blue"}
          -- text function is from Data.Aeson.Encoding

This works because GHC can lift the encoded values out of the case statements, which means that they are only evaluated once. This approach should only be used when there is a serious need to maximize performance.

Minimal complete definition

Nothing

Methods

toJSONKey :: ToJSONKeyFunction a #

Strategy for rendering the key for a map-like container.

toJSONKeyList :: ToJSONKeyFunction [a] #

This is similar in spirit to the showsList method of Show. It makes it possible to give String keys special treatment without using OverlappingInstances. End users should always be able to use the default implementation of this method.

Instances

Instances details
ToJSONKey Bool # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Char # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Double # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Float # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Int # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Int8 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Int16 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Int32 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Int64 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Integer # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Natural # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Word # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Word8 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Word16 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Word32 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Word64 # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Text # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Text # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Version # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Scientific # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey ZonedTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey LocalTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey TimeOfDay # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey UTCTime # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey DayOfWeek # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Day # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey QuarterOfYear # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Quarter # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey Month # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey UUID # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSONKey a, ToJSON a) => ToJSONKey [a] # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey a => ToJSONKey (Identity a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, ToJSON b) => ToJSONKey (a, b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

HasResolution a => ToJSONKey (Fixed a) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, ToJSON b, ToJSON c) => ToJSONKey (a, b, c) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSONKey :: ToJSONKeyFunction (a, b, c) #

toJSONKeyList :: ToJSONKeyFunction [(a, b, c)] #

(ToJSON a, ToJSONKey a) => ToJSONKey (Const a b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

ToJSONKey b => ToJSONKey (Tagged a b) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

(ToJSON a, ToJSON b, ToJSON c, ToJSON d) => ToJSONKey (a, b, c, d) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

toJSONKey :: ToJSONKeyFunction (a, b, c, d) #

toJSONKeyList :: ToJSONKeyFunction [(a, b, c, d)] #

data ToJSONKeyFunction a #

Constructors

ToJSONKeyText !(a -> Text) !(a -> Encoding' Text)

key is encoded to string, produces object

ToJSONKeyValue !(a -> Value) !(a -> Encoding)

key is encoded to value, produces array

Instances

Instances details
Contravariant ToJSONKeyFunction # 
Instance details

Defined in Data.Aeson.Types.ToJSON

toJSONKeyText :: (a -> Text) -> ToJSONKeyFunction a #

Helper for creating textual keys.

instance ToJSONKey MyKey where
    toJSONKey = toJSONKeyText myKeyToText
      where
        myKeyToText = Text.pack . show -- or showt from text-show

contramapToJSONKeyFunction :: (b -> a) -> ToJSONKeyFunction a -> ToJSONKeyFunction b #

Contravariant map, as ToJSONKeyFunction is a contravariant functor.

class FromJSONKey a where #

Read the docs for ToJSONKey first. This class is a conversion in the opposite direction. If you have a newtype wrapper around Text, the recommended way to define instances is with generalized newtype deriving:

newtype SomeId = SomeId { getSomeId :: Text }
  deriving (Eq,Ord,Hashable,FromJSONKey)

If you have a sum of nullary constructors, you may use the generic implementation:

data Color = Red | Green | Blue
  deriving Generic

instance FromJSONKey Color where
  fromJSONKey = genericFromJSONKey defaultJSONKeyOptions

Minimal complete definition

Nothing

Methods

fromJSONKey :: FromJSONKeyFunction a #

Strategy for parsing the key of a map-like container.

fromJSONKeyList :: FromJSONKeyFunction [a] #

This is similar in spirit to the readList method of Read. It makes it possible to give String keys special treatment without using OverlappingInstances. End users should always be able to use the default implementation of this method.

Instances

Instances details
FromJSONKey Bool # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Char # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Double # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Float # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Int # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Int8 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Int16 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Int32 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Int64 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Integer # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Natural # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Word # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Word8 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Word16 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Word32 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Word64 # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Text # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Text # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Version # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey ZonedTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey LocalTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey TimeOfDay # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey UTCTime # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey DayOfWeek # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Day # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey QuarterOfYear # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Quarter # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey Month # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey UUID # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSONKey a, FromJSON a) => FromJSONKey [a] # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey a => FromJSONKey (Identity a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSON b) => FromJSONKey (a, b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSON b, FromJSON c) => FromJSONKey (a, b, c) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSONKey a) => FromJSONKey (Const a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

FromJSONKey b => FromJSONKey (Tagged a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

(FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSONKey (a, b, c, d) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

fromJSONKey :: FromJSONKeyFunction (a, b, c, d) #

fromJSONKeyList :: FromJSONKeyFunction [(a, b, c, d)] #

data FromJSONKeyFunction a where #

This type is related to ToJSONKeyFunction. If FromJSONKeyValue is used in the FromJSONKey instance, then ToJSONKeyValue should be used in the ToJSONKey instance. The other three data constructors for this type all correspond to ToJSONKeyText. Strictly speaking, FromJSONKeyTextParser is more powerful than FromJSONKeyText, which is in turn more powerful than FromJSONKeyCoerce. For performance reasons, these exist as three options instead of one.

Constructors

FromJSONKeyCoerce 
FromJSONKeyText 

Fields

FromJSONKeyTextParser 

Fields

FromJSONKeyValue 

Fields

Instances

Instances details
Functor FromJSONKeyFunction #

Only law abiding up to interpretation

Instance details

Defined in Data.Aeson.Types.FromJSON

fromJSONKeyCoerce :: Coercible Text a => FromJSONKeyFunction a #

Construct FromJSONKeyFunction for types coercible from Text. This conversion is still unsafe, as Hashable and Eq instances of a should be compatible with Text i.e. hash values should be equal for wrapped values as well. This property will always be maintained if the Hashable and Eq instances are derived with generalized newtype deriving. compatible with Text i.e. hash values be equal for wrapped values as well.

On pre GHC 7.8 this is unconstrainted function.

coerceFromJSONKeyFunction :: Coercible a b => FromJSONKeyFunction a -> FromJSONKeyFunction b #

Semantically the same as coerceFromJSONKeyFunction = fmap coerce = coerce.

See note on fromJSONKeyCoerce.

mapFromJSONKeyFunction :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b #

Same as fmap. Provided for the consistency with ToJSONKeyFunction.

Generic keys

class GetConName f => GToJSONKey f #

Instances

Instances details
GetConName f => GToJSONKey (f :: k -> Type) # 
Instance details

Defined in Data.Aeson.Types.ToJSON

class (ConstructorNames f, SumFromString f) => GFromJSONKey f #

Instances

Instances details
(ConstructorNames f, SumFromString f) => GFromJSONKey f # 
Instance details

Defined in Data.Aeson.Types.FromJSON

genericFromJSONKey :: forall a. (Generic a, GFromJSONKey (Rep a)) => JSONKeyOptions -> FromJSONKeyFunction a #

fromJSONKey for Generic types. These types must be sums of nullary constructors, whose names will be used as keys for JSON objects.

See also genericToJSONKey.

Example

Expand
data Color = Red | Green | Blue
  deriving Generic

instance FromJSONKey Color where
  fromJSONKey = genericFromJSONKey defaultJSONKeyOptions

Liftings to unary and binary type constructors

class FromJSON1 f where #

Lifting of the FromJSON class to unary type constructors.

Instead of manually writing your FromJSON1 instance, there are two options to do it automatically:

  • Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
  • The compiler can provide a default generic implementation for liftParseJSON.

To use the second, simply add a deriving Generic1 clause to your datatype and declare a FromJSON1 instance for your datatype without giving a definition for liftParseJSON.

For example:

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics

data Pair a b = Pair { pairFst :: a, pairSnd :: b } deriving Generic1

instance FromJSON a => FromJSON1 (Pair a)

If the default implementation doesn't give exactly the results you want, you can customize the generic decoding with only a tiny amount of effort, using genericLiftParseJSON with your preferred Options:

customOptions = defaultOptions
                { fieldLabelModifier = map toUpper
                }

instance FromJSON a => FromJSON1 (Pair a) where
    liftParseJSON = genericLiftParseJSON customOptions

Minimal complete definition

Nothing

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (f a) #

default liftParseJSON :: (Generic1 f, GFromJSON One (Rep1 f)) => (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (f a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [f a] #

Instances

Instances details
FromJSON1 [] # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [a] #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [[a]] #

FromJSON1 Maybe # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Maybe a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Maybe a] #

FromJSON1 Min # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Min a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Min a] #

FromJSON1 Max # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Max a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Max a] #

FromJSON1 First # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (First a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [First a] #

FromJSON1 Last # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Last a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Last a] #

FromJSON1 WrappedMonoid # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (WrappedMonoid a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [WrappedMonoid a] #

FromJSON1 Option # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Option a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Option a] #

FromJSON1 Identity # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Identity a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Identity a] #

FromJSON1 First # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (First a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [First a] #

FromJSON1 Last # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Last a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Last a] #

FromJSON1 Dual # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Dual a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Dual a] #

FromJSON1 NonEmpty # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (NonEmpty a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [NonEmpty a] #

FromJSON1 IntMap # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (IntMap a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [IntMap a] #

FromJSON1 Tree # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Tree a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Tree a] #

FromJSON1 Seq # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Seq a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Seq a] #

FromJSON1 DNonEmpty #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (DNonEmpty a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [DNonEmpty a] #

FromJSON1 DList # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (DList a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [DList a] #

FromJSON1 Maybe #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Maybe a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Maybe a] #

FromJSON1 Vector # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Vector a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Vector a] #

FromJSON a => FromJSON1 (Either a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Either a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Either a a0] #

FromJSON a => FromJSON1 ((,) a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, a0)] #

FromJSON1 (Proxy :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Proxy a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Proxy a] #

(FromJSONKey k, Ord k) => FromJSON1 (Map k) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Map k a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Map k a] #

FromJSON a => FromJSON1 (Pair a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Pair a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Pair a a0] #

FromJSON a => FromJSON1 (These a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (These a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [These a a0] #

FromJSON a => FromJSON1 (Either a) #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Either a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Either a a0] #

FromJSON a => FromJSON1 (These a) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (These a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [These a a0] #

(FromJSONKey k, Eq k, Hashable k) => FromJSON1 (HashMap k) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (HashMap k a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [HashMap k a] #

(FromJSON a, FromJSON b) => FromJSON1 ((,,) a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, a0)] #

FromJSON a => FromJSON1 (Const a :: Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Const a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Const a a0] #

FromJSON1 (Tagged a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Tagged a a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Tagged a a0] #

(FromJSON1 f, FromJSON1 g) => FromJSON1 (These1 f g) #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (These1 f g a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [These1 f g a] #

(FromJSON a, FromJSON b, FromJSON c) => FromJSON1 ((,,,) a b c) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, a0)] #

(FromJSON1 f, FromJSON1 g) => FromJSON1 (Product f g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Product f g a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Product f g a] #

(FromJSON1 f, FromJSON1 g) => FromJSON1 (Sum f g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Sum f g a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Sum f g a] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSON1 ((,,,,) a b c d) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, a0)] #

(FromJSON1 f, FromJSON1 g) => FromJSON1 (Compose f g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (Compose f g a) #

liftParseJSONList :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser [Compose f g a] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e) => FromJSON1 ((,,,,,) a b c d e) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f) => FromJSON1 ((,,,,,,) a b c d e f) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g) => FromJSON1 ((,,,,,,,) a b c d e f g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h) => FromJSON1 ((,,,,,,,,) a b c d e f g h) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i) => FromJSON1 ((,,,,,,,,,) a b c d e f g h i) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j) => FromJSON1 ((,,,,,,,,,,) a b c d e f g h i j) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k) => FromJSON1 ((,,,,,,,,,,,) a b c d e f g h i j k) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l) => FromJSON1 ((,,,,,,,,,,,,) a b c d e f g h i j k l) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m) => FromJSON1 ((,,,,,,,,,,,,,) a b c d e f g h i j k l m) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m, a0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m, FromJSON n) => FromJSON1 ((,,,,,,,,,,,,,,) a b c d e f g h i j k l m n) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m, n, a0) #

liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, a0)] #

parseJSON1 :: (FromJSON1 f, FromJSON a) => Value -> Parser (f a) #

Lift the standard parseJSON function through the type constructor.

class FromJSON2 f where #

Lifting of the FromJSON class to binary type constructors.

Instead of manually writing your FromJSON2 instance, Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time.

Minimal complete definition

liftParseJSON2

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (f a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [f a b] #

Instances

Instances details
FromJSON2 Either # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Either a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Either a b] #

FromJSON2 (,) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (a, b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [(a, b)] #

FromJSON2 Pair #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Pair a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Pair a b] #

FromJSON2 These #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (These a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [These a b] #

FromJSON2 Either #

Since: 1.5.3.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Either a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Either a b] #

FromJSON2 These #

Since: 1.5.1.0

Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (These a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [These a b] #

FromJSON a => FromJSON2 ((,,) a) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (a, a0, b) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [(a, a0, b)] #

FromJSON2 (Const :: Type -> Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Const a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Const a b] #

FromJSON2 (Tagged :: Type -> Type -> Type) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Tagged a b) #

liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Tagged a b] #

(FromJSON a, FromJSON b) => FromJSON2 ((,,,) a b) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c) => FromJSON2 ((,,,,) a b c) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSON2 ((,,,,,) a b c d) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e) => FromJSON2 ((,,,,,,) a b c d e) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f) => FromJSON2 ((,,,,,,,) a b c d e f) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g) => FromJSON2 ((,,,,,,,,) a b c d e f g) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h) => FromJSON2 ((,,,,,,,,,) a b c d e f g h) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i) => FromJSON2 ((,,,,,,,,,,) a b c d e f g h i) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j) => FromJSON2 ((,,,,,,,,,,,) a b c d e f g h i j) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k) => FromJSON2 ((,,,,,,,,,,,,) a b c d e f g h i j k) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l) => FromJSON2 ((,,,,,,,,,,,,,) a b c d e f g h i j k l) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, a0, b0)] #

(FromJSON a, FromJSON b, FromJSON c, FromJSON d, FromJSON e, FromJSON f, FromJSON g, FromJSON h, FromJSON i, FromJSON j, FromJSON k, FromJSON l, FromJSON m) => FromJSON2 ((,,,,,,,,,,,,,,) a b c d e f g h i j k l m) # 
Instance details

Defined in Data.Aeson.Types.FromJSON

Methods

liftParseJSON2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser (a, b, c, d, e, f, g, h, i, j, k, l, m, a0, b0) #

liftParseJSONList2 :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> (Value -> Parser b0) -> (Value -> Parser [b0]) -> Value -> Parser [(a, b, c, d, e, f, g, h, i, j, k, l, m, a0, b0)] #

parseJSON2 :: (FromJSON2 f, FromJSON a, FromJSON b) => Value -> Parser (f a b) #

Lift the standard parseJSON function through the type constructor.

class ToJSON1 f where #

Lifting of the ToJSON class to unary type constructors.

Instead of manually writing your ToJSON1 instance, there are two options to do it automatically:

  • Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
  • The compiler can provide a default generic implementation for toJSON1.

To use the second, simply add a deriving Generic1 clause to your datatype and declare a ToJSON1 instance for your datatype without giving definitions for liftToJSON or liftToEncoding.

For example:

{-# LANGUAGE DeriveGeneric #-}

import GHC.Generics

data Pair a b = Pair { pairFst :: a, pairSnd :: b } deriving Generic1

instance ToJSON a => ToJSON1 (Pair a)

If the default implementation doesn't give exactly the results you want, you can customize the generic encoding with only a tiny amount of effort, using genericLiftToJSON and genericLiftToEncoding with your preferred Options:

customOptions = defaultOptions
                { fieldLabelModifier = map toUpper
                }

instance ToJSON a => ToJSON1 (Pair a) where
    liftToJSON     = genericLiftToJSON customOptions
    liftToEncoding = genericLiftToEncoding customOptions

See also ToJSON.

Minimal complete definition

Nothing

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> f a -> Value #

default liftToJSON :: (Generic1 f, GToJSON' Value One (Rep1 f)) => (a -> Value) -> ([a] -> Value) -> f a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [f a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> f a -> Encoding #

default liftToEncoding :: (Generic1 f, GToJSON' Encoding One (Rep1 f)) => (a -> Encoding) -> ([a] -> Encoding) -> f a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [f a] -> Encoding #

Instances

Instances details
ToJSON1 [] # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> [a] -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [[a]] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> [a] -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [[a]] -> Encoding #

ToJSON1 Maybe # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Maybe a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Maybe a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Maybe a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Maybe a] -> Encoding #

ToJSON1 Min # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Min a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Min a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Min a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Min a] -> Encoding #

ToJSON1 Max # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Max a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Max a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Max a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Max a] -> Encoding #

ToJSON1 First # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> First a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [First a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> First a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [First a] -> Encoding #

ToJSON1 Last # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Last a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Last a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Last a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Last a] -> Encoding #

ToJSON1 WrappedMonoid # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> WrappedMonoid a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [WrappedMonoid a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> WrappedMonoid a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [WrappedMonoid a] -> Encoding #

ToJSON1 Option # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Option a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Option a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Option a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Option a] -> Encoding #

ToJSON1 Identity # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> Identity a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Identity a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Identity a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Identity a] -> Encoding #

ToJSON1 First # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) -> First a -> Value #

liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [First a] -> Value #

liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> First a -> Encoding #

liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [First a] -> Encoding #

ToJSON1 Last # 
Instance details

Defined in Data.Aeson.Types.ToJSON

Methods

liftToJSON :: (a -> Value) -> ([a] -> Value) ->