Copyright	(c) Colin Woodbury 2015 (c) Edward Kmett 2013-2014 (c) Paul Wilson 2012
License	BSD3
Maintainer	Colin Woodbury <colingw@gmail.com>
Safe Haskell	Trustworthy
Language	Haskell2010

Lens.Micro.Aeson

Contents

Numbers
Primitive
Objects and Arrays
Decoding

Description

Traversals for Data.Aeson, based on microlens for minimal dependencies.

For basic manipulation of Aeson values, full Prism functionality isn't necessary. Since all Prisms are inherently Traversals, we provide Traversals that mimic the behaviour of the Prisms found in the original Data.Aeson.Lens.

Synopsis

Numbers

class AsNumber t where #

Traverse into various number types.

Methods

_Number :: Traversal' t Scientific #

>>> "[1, \"x\"]" ^? nth 0 . _Number
Just 1.0

>>> "[1, \"x\"]" ^? nth 1 . _Number
Nothing

_Number :: AsPrimitive t => Traversal' t Scientific #

>>> "[1, \"x\"]" ^? nth 0 . _Number
Just 1.0

>>> "[1, \"x\"]" ^? nth 1 . _Number
Nothing

_Double :: Traversal' t Double #

Traversal into an Double over a Value, Primitive or Scientific

>>> "[10.2]" ^? nth 0 . _Double
Just 10.2

_Integer :: Traversal' t Integer #

Traversal into an Integer over a Value, Primitive or Scientific

>>> "[10]" ^? nth 0 . _Integer
Just 10

>>> "[10.5]" ^? nth 0 . _Integer
Just 10

>>> "42" ^? _Integer
Just 42

Instances

AsNumber ByteString #
Methods _Number :: Traversal' ByteString Scientific # _Double :: Traversal' ByteString Double # _Integer :: Traversal' ByteString Integer #
AsNumber ByteString #
Methods _Number :: Traversal' ByteString Scientific # _Double :: Traversal' ByteString Double # _Integer :: Traversal' ByteString Integer #
AsNumber Scientific #
Methods _Number :: Traversal' Scientific Scientific # _Double :: Traversal' Scientific Double # _Integer :: Traversal' Scientific Integer #
AsNumber String #
Methods _Number :: Traversal' String Scientific # _Double :: Traversal' String Double # _Integer :: Traversal' String Integer #
AsNumber Text #
Methods _Number :: Traversal' Text Scientific # _Double :: Traversal' Text Double # _Integer :: Traversal' Text Integer #
AsNumber Value #
Methods _Number :: Traversal' Value Scientific # _Double :: Traversal' Value Double # _Integer :: Traversal' Value Integer #
AsNumber Text #
Methods _Number :: Traversal' Text Scientific # _Double :: Traversal' Text Double # _Integer :: Traversal' Text Integer #
AsNumber Primitive #
Methods _Number :: Traversal' Primitive Scientific # _Double :: Traversal' Primitive Double # _Integer :: Traversal' Primitive Integer #

_Integral :: (AsNumber t, Integral a) => Traversal' t a #

Access Integer Values as Integrals.

>>> "[10]" ^? nth 0 . _Integral
Just 10

>>> "[10.5]" ^? nth 0 . _Integral
Just 10

nonNull :: Traversal' Value Value #

Traversal into non-Null values

>>> "{\"a\": \"xyz\", \"b\": null}" ^? key "a" . nonNull
Just (String "xyz")

>>> "{\"a\": {}, \"b\": null}" ^? key "a" . nonNull
Just (Object (fromList []))

>>> "{\"a\": \"xyz\", \"b\": null}" ^? key "b" . nonNull
Nothing

Primitive

data Primitive #

Primitives of Value

Constructors

StringPrim !Text
NumberPrim !Scientific
BoolPrim !Bool
NullPrim

Instances

Eq Primitive #
Methods (==) :: Primitive -> Primitive -> Bool # (/=) :: Primitive -> Primitive -> Bool #
Data Primitive #
Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Primitive -> c Primitive # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Primitive # toConstr :: Primitive -> Constr # dataTypeOf :: Primitive -> DataType # dataCast1 :: Typeable (* -> ) t => (forall d. Data d => c (t d)) -> Maybe (c Primitive) # dataCast2 :: Typeable ( -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Primitive) # gmapT :: (forall b. Data b => b -> b) -> Primitive -> Primitive # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Primitive -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Primitive -> r # gmapQ :: (forall d. Data d => d -> u) -> Primitive -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Primitive -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Primitive -> m Primitive # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Primitive -> m Primitive # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Primitive -> m Primitive #
Ord Primitive #
Methods compare :: Primitive -> Primitive -> Ordering # (<) :: Primitive -> Primitive -> Bool # (<=) :: Primitive -> Primitive -> Bool # (>) :: Primitive -> Primitive -> Bool # (>=) :: Primitive -> Primitive -> Bool # max :: Primitive -> Primitive -> Primitive # min :: Primitive -> Primitive -> Primitive #
Show Primitive #
Methods showsPrec :: Int -> Primitive -> ShowS # show :: Primitive -> String # showList :: [Primitive] -> ShowS #
AsPrimitive Primitive #
Methods _Primitive :: Traversal' Primitive Primitive # _String :: Traversal' Primitive Text # _Bool :: Traversal' Primitive Bool # _Null :: Traversal' Primitive () #
AsNumber Primitive #
Methods _Number :: Traversal' Primitive Scientific # _Double :: Traversal' Primitive Double # _Integer :: Traversal' Primitive Integer #

class AsNumber t => AsPrimitive t where #

Traverse into various JSON primatives.

Methods

_Primitive :: Traversal' t Primitive #

>>> "[1, \"x\", null, true, false]" ^? nth 0 . _Primitive
Just (NumberPrim 1.0)

>>> "[1, \"x\", null, true, false]" ^? nth 1 . _Primitive
Just (StringPrim "x")

>>> "[1, \"x\", null, true, false]" ^? nth 2 . _Primitive
Just NullPrim

>>> "[1, \"x\", null, true, false]" ^? nth 3 . _Primitive
Just (BoolPrim True)

>>> "[1, \"x\", null, true, false]" ^? nth 4 . _Primitive
Just (BoolPrim False)

_Primitive :: AsValue t => Traversal' t Primitive #

>>> "[1, \"x\", null, true, false]" ^? nth 0 . _Primitive
Just (NumberPrim 1.0)

>>> "[1, \"x\", null, true, false]" ^? nth 1 . _Primitive
Just (StringPrim "x")

>>> "[1, \"x\", null, true, false]" ^? nth 2 . _Primitive
Just NullPrim

>>> "[1, \"x\", null, true, false]" ^? nth 3 . _Primitive
Just (BoolPrim True)

>>> "[1, \"x\", null, true, false]" ^? nth 4 . _Primitive
Just (BoolPrim False)

_String :: Traversal' t Text #

>>> "{\"a\": \"xyz\", \"b\": true}" ^? key "a" . _String
Just "xyz"

>>> "{\"a\": \"xyz\", \"b\": true}" ^? key "b" . _String
Nothing

_Bool :: Traversal' t Bool #

>>> "{\"a\": \"xyz\", \"b\": true}" ^? key "b" . _Bool
Just True

>>> "{\"a\": \"xyz\", \"b\": true}" ^? key "a" . _Bool
Nothing

_Null :: Traversal' t () #

>>> "{\"a\": \"xyz\", \"b\": null}" ^? key "b" . _Null
Just ()

>>> "{\"a\": \"xyz\", \"b\": null}" ^? key "a" . _Null
Nothing

Instances

AsPrimitive ByteString #
Methods _Primitive :: Traversal' ByteString Primitive # _String :: Traversal' ByteString Text # _Bool :: Traversal' ByteString Bool # _Null :: Traversal' ByteString () #
AsPrimitive ByteString #
Methods _Primitive :: Traversal' ByteString Primitive # _String :: Traversal' ByteString Text # _Bool :: Traversal' ByteString Bool # _Null :: Traversal' ByteString () #
AsPrimitive String #
Methods _Primitive :: Traversal' String Primitive # _String :: Traversal' String Text # _Bool :: Traversal' String Bool # _Null :: Traversal' String () #
AsPrimitive Text #
Methods _Primitive :: Traversal' Text Primitive # _String :: Traversal' Text Text # _Bool :: Traversal' Text Bool # _Null :: Traversal' Text () #
AsPrimitive Value #
Methods _Primitive :: Traversal' Value Primitive # _String :: Traversal' Value Text # _Bool :: Traversal' Value Bool # _Null :: Traversal' Value () #
AsPrimitive Text #
Methods _Primitive :: Traversal' Text Primitive # _String :: Traversal' Text Text # _Bool :: Traversal' Text Bool # _Null :: Traversal' Text () #
AsPrimitive Primitive #
Methods _Primitive :: Traversal' Primitive Primitive # _String :: Traversal' Primitive Text # _Bool :: Traversal' Primitive Bool # _Null :: Traversal' Primitive () #

Objects and Arrays

class AsPrimitive t => AsValue t where #

Traverse into JSON Objects and Arrays.

Methods

_Value :: Traversal' t Value #

Traverse into data that encodes a Value

_Object :: Traversal' t (HashMap Text Value) #

>>> "{\"a\": {}, \"b\": null}" ^? key "a" . _Object
Just (fromList [])

>>> "{\"a\": {}, \"b\": null}" ^? key "b" . _Object
Nothing

_Array :: Traversal' t (Vector Value) #

Instances

AsValue ByteString #
Methods _Value :: Traversal' ByteString Value # _Object :: Traversal' ByteString (HashMap Text Value) # _Array :: Traversal' ByteString (Vector Value) #
AsValue ByteString #
Methods _Value :: Traversal' ByteString Value # _Object :: Traversal' ByteString (HashMap Text Value) # _Array :: Traversal' ByteString (Vector Value) #
AsValue String #
Methods _Value :: Traversal' String Value # _Object :: Traversal' String (HashMap Text Value) # _Array :: Traversal' String (Vector Value) #
AsValue Text #
Methods _Value :: Traversal' Text Value # _Object :: Traversal' Text (HashMap Text Value) # _Array :: Traversal' Text (Vector Value) #
AsValue Value #
Methods _Value :: Traversal' Value Value # _Object :: Traversal' Value (HashMap Text Value) # _Array :: Traversal' Value (Vector Value) #
AsValue Text #
Methods _Value :: Traversal' Text Value # _Object :: Traversal' Text (HashMap Text Value) # _Array :: Traversal' Text (Vector Value) #

key :: AsValue t => Text -> Traversal' t Value #

Like ix, but for Object with Text indices. This often has better inference than ix when used with OverloadedStrings.

>>> "{\"a\": 100, \"b\": 200}" ^? key "a"
Just (Number 100.0)

>>> "[1,2,3]" ^? key "a"
Nothing

members :: AsValue t => Traversal' t Value #

A Traversal into Object properties

>>> "{\"a\": 4, \"b\": 7}" ^.. members
[Number 4.0,Number 7.0]

>>> "{\"a\": 4, \"b\": 7}" & members . _Number %~ (* 10)
"{\"a\":40,\"b\":70}"

nth :: AsValue t => Int -> Traversal' t Value #

Like ix, but for Arrays with Int indexes

>>> "[1,2,3]" ^? nth 1
Just (Number 2.0)

>>> "{\"a\": 100, \"b\": 200}" ^? nth 1
Nothing

>>> "[1,2,3]" & nth 1 .~ Number 20
"[1,20,3]"

values :: AsValue t => Traversal' t Value #

A Traversal into Array elements

>>> "[1,2,3]" ^.. values
[Number 1.0,Number 2.0,Number 3.0]

>>> "[1,2,3]" & values . _Number %~ (* 10)
"[10,20,30]"

Decoding

class AsJSON t where #

Traverse into actual encoded JSON.

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' t a #

_JSON is a Traversal from something containing JSON to something encoded in that structure.

Instances

AsJSON ByteString #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a #
AsJSON ByteString #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a #
AsJSON String #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' String a #
AsJSON Text #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Text a #
AsJSON Value #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Value a #
AsJSON Text #
Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Text a #