Lens.Micro.Aeson

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.

Numbers

class AsNumber t where

Traverse into various number types.

Minimal complete definition

Nothing

Methods

_Number :: Traversal' t Scientific

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

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

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

_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 String

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' String Scientific

_Double :: Traversal' String Double

_Integer :: Traversal' String Integer

AsNumber ByteString

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' ByteString Scientific

_Double :: Traversal' ByteString Double

_Integer :: Traversal' ByteString Integer

AsNumber ByteString

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' ByteString Scientific

_Double :: Traversal' ByteString Double

_Integer :: Traversal' ByteString Integer

AsNumber Scientific

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' Scientific Scientific

_Double :: Traversal' Scientific Double

_Integer :: Traversal' Scientific Integer

AsNumber Text

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' Text Scientific

_Double :: Traversal' Text Double

_Integer :: Traversal' Text Integer

AsNumber Value

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' Value Scientific

_Double :: Traversal' Value Double

_Integer :: Traversal' Value Integer

AsNumber Text

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' Text Scientific

_Double :: Traversal' Text Double

_Integer :: Traversal' Text Integer

AsNumber Primitive

Defined in Lens.Micro.Aeson

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

Defined in Lens.Micro.Aeson

Methods

(==) :: Primitive -> Primitive -> Bool

(/=) :: Primitive -> Primitive -> Bool

Ord Primitive

Defined in Lens.Micro.Aeson

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

Defined in Lens.Micro.Aeson

Methods

showsPrec :: Int -> Primitive -> ShowS

show :: Primitive -> String

showList :: [Primitive] -> ShowS

Generic Primitive

Defined in Lens.Micro.Aeson

Associated Types

type Rep Primitive :: Type -> Type

Methods

from :: Primitive -> Rep Primitive x

to :: Rep Primitive x -> Primitive

Hashable Primitive

Defined in Lens.Micro.Aeson

Methods

hashWithSalt :: Int -> Primitive -> Int

hash :: Primitive -> Int

AsPrimitive Primitive

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' Primitive Primitive

_String :: Traversal' Primitive Text

_Bool :: Traversal' Primitive Bool

_Null :: Traversal' Primitive ()

AsNumber Primitive

Defined in Lens.Micro.Aeson

Methods

_Number :: Traversal' Primitive Scientific

_Double :: Traversal' Primitive Double

_Integer :: Traversal' Primitive Integer

type Rep Primitive

Defined in Lens.Micro.Aeson

type Rep Primitive = D1 ('MetaData "Primitive" "Lens.Micro.Aeson" "microlens-aeson-2.4.1-4nJdvERBL3ZIcsdmt6zmwE" 'False) ((C1 ('MetaCons "StringPrim" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Text)) :+: C1 ('MetaCons "NumberPrim" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Scientific))) :+: (C1 ('MetaCons "BoolPrim" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Bool)) :+: C1 ('MetaCons "NullPrim" 'PrefixI 'False) (U1 :: Type -> Type)))

class AsNumber t => AsPrimitive t where

Traverse into various JSON primitives.

Minimal complete definition

Nothing

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)

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

_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 String

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' String Primitive

_String :: Traversal' String Text

_Bool :: Traversal' String Bool

_Null :: Traversal' String ()

AsPrimitive ByteString

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' ByteString Primitive

_String :: Traversal' ByteString Text

_Bool :: Traversal' ByteString Bool

_Null :: Traversal' ByteString ()

AsPrimitive ByteString

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' ByteString Primitive

_String :: Traversal' ByteString Text

_Bool :: Traversal' ByteString Bool

_Null :: Traversal' ByteString ()

AsPrimitive Text

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' Text Primitive

_String :: Traversal' Text Text

_Bool :: Traversal' Text Bool

_Null :: Traversal' Text ()

AsPrimitive Value

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' Value Primitive

_String :: Traversal' Value Text

_Bool :: Traversal' Value Bool

_Null :: Traversal' Value ()

AsPrimitive Text

Defined in Lens.Micro.Aeson

Methods

_Primitive :: Traversal' Text Primitive

_String :: Traversal' Text Text0

_Bool :: Traversal' Text Bool

_Null :: Traversal' Text ()

AsPrimitive Primitive

Defined in Lens.Micro.Aeson

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.

Minimal complete definition

_Value

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 String

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' String Value

_Object :: Traversal' String (HashMap Text Value)

_Array :: Traversal' String (Vector Value)

AsValue ByteString

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' ByteString Value

_Object :: Traversal' ByteString (HashMap Text Value)

_Array :: Traversal' ByteString (Vector Value)

AsValue ByteString

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' ByteString Value

_Object :: Traversal' ByteString (HashMap Text Value)

_Array :: Traversal' ByteString (Vector Value)

AsValue Text

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' Text Value

_Object :: Traversal' Text (HashMap Text Value)

_Array :: Traversal' Text (Vector Value)

AsValue Value

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' Value Value

_Object :: Traversal' Value (HashMap Text Value)

_Array :: Traversal' Value (Vector Value)

AsValue Text

Defined in Lens.Micro.Aeson

Methods

_Value :: Traversal' Text Value

_Object :: Traversal' Text (HashMap Text0 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 String

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' String a

AsJSON ByteString

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a

AsJSON ByteString

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a

AsJSON Text

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' Text a

AsJSON Value

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' Value a

AsJSON Text

Defined in Lens.Micro.Aeson

Methods

_JSON :: (FromJSON a, ToJSON a) => Traversal' Text a