Copyright	(c) Colin Woodbury 2015-2024 (c) Edward Kmett 2013-2014 (c) Paul Wilson 2012
License	BSD3
Maintainer	Colin Woodbury <colin@fosskers.ca>
Safe Haskell	Safe-Inferred
Language	Haskell2010

Lens.Micro.Aeson

Contents

Numbers
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

class AsNumber t where
- _Number :: Traversal' t Scientific
- _Double :: Traversal' t Double
- _Integer :: Traversal' t Integer
_Integral :: (AsNumber t, Integral a) => Traversal' t a
nonNull :: Traversal' Value Value
class AsNumber t => AsValue t where
- _Value :: Traversal' t Value
- _String :: Traversal' t Text
- _Bool :: Traversal' t Bool
- _Null :: Traversal' t ()
- _Object :: Traversal' t (KeyMap Value)
- _Array :: Traversal' t (Vector Value)
key :: AsValue t => Key -> Traversal' t Value
members :: AsValue t => Traversal' t Value
nth :: AsValue t => Int -> Traversal' t Value
values :: AsValue t => Traversal' t Value
class AsJSON t where
- _JSON :: (FromJSON a, ToJSON a) => Traversal' t a

Numbers

class AsNumber t where Source #

Traverse into various number types.

Minimal complete definition

Nothing

Methods

_Number :: Traversal' t Scientific Source #

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

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

default _Number :: AsValue t => Traversal' t Scientific Source #

_Double :: Traversal' t Double Source #

Traversal into an Double over a Value or Scientific

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

_Integer :: Traversal' t Integer Source #

Traversal into an Integer over a Value or Scientific

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

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

>>> "42" ^? _Integer
Just 42

Instances

Instances details

AsNumber Value Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Value Scientific Source # _Double :: Traversal' Value Double Source # _Integer :: Traversal' Value Integer Source #
AsNumber ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' ByteString Scientific Source # _Double :: Traversal' ByteString Double Source # _Integer :: Traversal' ByteString Integer Source #
AsNumber ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' ByteString Scientific Source # _Double :: Traversal' ByteString Double Source # _Integer :: Traversal' ByteString Integer Source #
AsNumber Scientific Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Scientific Scientific Source # _Double :: Traversal' Scientific Double Source # _Integer :: Traversal' Scientific Integer Source #
AsNumber Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Text Scientific Source # _Double :: Traversal' Text Double Source # _Integer :: Traversal' Text Integer Source #
AsNumber Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Text Scientific Source # _Double :: Traversal' Text Double Source # _Integer :: Traversal' Text Integer Source #
AsNumber String Source #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' String Scientific Source # _Double :: Traversal' String Double Source # _Integer :: Traversal' String Integer Source #

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

Access Integer Values as Integrals.

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

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

nonNull :: Traversal' Value Value Source #

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

Objects and Arrays

class AsNumber t => AsValue t where Source #

Traverse into JSON Objects and Arrays.

Minimal complete definition

_Value

Methods

_Value :: Traversal' t Value Source #

Traverse into data that encodes a Value

_String :: Traversal' t Text Source #

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

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

_Bool :: Traversal' t Bool Source #

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

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

_Null :: Traversal' t () Source #

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

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

_Object :: Traversal' t (KeyMap Value) Source #

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

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

_Array :: Traversal' t (Vector Value) Source #

Instances

Instances details

AsValue Value Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' Value Value Source # _String :: Traversal' Value Text Source # _Bool :: Traversal' Value Bool Source # _Null :: Traversal' Value () Source # _Object :: Traversal' Value (KeyMap Value) Source # _Array :: Traversal' Value (Vector Value) Source #
AsValue ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' ByteString Value Source # _String :: Traversal' ByteString Text Source # _Bool :: Traversal' ByteString Bool Source # _Null :: Traversal' ByteString () Source # _Object :: Traversal' ByteString (KeyMap Value) Source # _Array :: Traversal' ByteString (Vector Value) Source #
AsValue ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' ByteString Value Source # _String :: Traversal' ByteString Text Source # _Bool :: Traversal' ByteString Bool Source # _Null :: Traversal' ByteString () Source # _Object :: Traversal' ByteString (KeyMap Value) Source # _Array :: Traversal' ByteString (Vector Value) Source #
AsValue Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' Text Value Source # _String :: Traversal' Text Text Source # _Bool :: Traversal' Text Bool Source # _Null :: Traversal' Text () Source # _Object :: Traversal' Text (KeyMap Value) Source # _Array :: Traversal' Text (Vector Value) Source #
AsValue Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' Text Value Source # _String :: Traversal' Text Text0 Source # _Bool :: Traversal' Text Bool Source # _Null :: Traversal' Text () Source # _Object :: Traversal' Text (KeyMap Value) Source # _Array :: Traversal' Text (Vector Value) Source #
AsValue String Source #
Instance details Defined in Lens.Micro.Aeson Methods _Value :: Traversal' String Value Source # _String :: Traversal' String Text Source # _Bool :: Traversal' String Bool Source # _Null :: Traversal' String () Source # _Object :: Traversal' String (KeyMap Value) Source # _Array :: Traversal' String (Vector Value) Source #

key :: AsValue t => Key -> Traversal' t Value Source #

Like ix, but for Object with Key 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 Source #

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 Source #

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 Source #

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 Source #

Traverse into actual encoded JSON.

Methods

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

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

Instances

Instances details

AsJSON Value Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Value a Source #
AsJSON ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a Source #
AsJSON ByteString Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' ByteString a Source #
AsJSON Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Text a Source #
AsJSON Text Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' Text a Source #
AsJSON String Source #
Instance details Defined in Lens.Micro.Aeson Methods _JSON :: (FromJSON a, ToJSON a) => Traversal' String a Source #