Copyright	(c) Colin Woodbury 2015 - 2018 (c) Edward Kmett 2013-2014 (c) Paul Wilson 2012
License	BSD3
Maintainer	Colin Woodbury <colingw@gmail.com>
Safe Haskell	None
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

class AsNumber t where
_Integral :: (AsNumber t, Integral a) => Traversal' t a
nonNull :: Traversal' Value Value
data Primitive
- = StringPrim !Text
- | NumberPrim !Scientific
- | BoolPrim !Bool
- | NullPrim
class AsNumber t => AsPrimitive t where
class AsPrimitive t => AsValue t where
key :: AsValue t => Text -> 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

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 #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' ByteString Scientific # _Double :: Traversal' ByteString Double # _Integer :: Traversal' ByteString Integer #
AsNumber ByteString #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' ByteString Scientific # _Double :: Traversal' ByteString Double # _Integer :: Traversal' ByteString Integer #
AsNumber Scientific #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Scientific Scientific # _Double :: Traversal' Scientific Double # _Integer :: Traversal' Scientific Integer #
AsNumber String #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' String Scientific # _Double :: Traversal' String Double # _Integer :: Traversal' String Integer #
AsNumber Text #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Text Scientific # _Double :: Traversal' Text Double # _Integer :: Traversal' Text Integer #
AsNumber Value #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Value Scientific # _Double :: Traversal' Value Double # _Integer :: Traversal' Value Integer #
AsNumber Text #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Text Scientific # _Double :: Traversal' Text Double # _Integer :: Traversal' Text Integer #
AsNumber Primitive #
Instance details 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 #
Instance details Defined in Lens.Micro.Aeson Methods (==) :: Primitive -> Primitive -> Bool # (/=) :: Primitive -> Primitive -> Bool #
Ord Primitive #
Instance details 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 #
Instance details Defined in Lens.Micro.Aeson Methods showsPrec :: Int -> Primitive -> ShowS # show :: Primitive -> String # showList :: [Primitive] -> ShowS #
Generic Primitive #
Instance details Defined in Lens.Micro.Aeson Associated Types type Rep Primitive :: * -> * # Methods from :: Primitive -> Rep Primitive x # to :: Rep Primitive x -> Primitive #
Hashable Primitive #
Instance details Defined in Lens.Micro.Aeson Methods hashWithSalt :: Int -> Primitive -> Int # hash :: Primitive -> Int #
NFData Primitive #
Instance details Defined in Lens.Micro.Aeson Methods rnf :: Primitive -> () #
AsPrimitive Primitive #
Instance details Defined in Lens.Micro.Aeson Methods _Primitive :: Traversal' Primitive Primitive # _String :: Traversal' Primitive Text # _Bool :: Traversal' Primitive Bool # _Null :: Traversal' Primitive () #
AsNumber Primitive #
Instance details Defined in Lens.Micro.Aeson Methods _Number :: Traversal' Primitive Scientific # _Double :: Traversal' Primitive Double # _Integer :: Traversal' Primitive Integer #
type Rep Primitive #
Instance details Defined in Lens.Micro.Aeson type Rep Primitive = D1 (MetaData "Primitive" "Lens.Micro.Aeson" "microlens-aeson-2.3.0-KfDofWvAst63DwGOgDpqcG" 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 :: * -> *)))

class AsNumber t => AsPrimitive t where #

Traverse into various JSON primitives.

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

Minimal complete definition

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