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 | Haskell98 |
Lens.Micro.Aeson
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.
- 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
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
_Integral :: (AsNumber t, Integral a) => Traversal' t a #
Access Integer Value
s 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
Primitives of Value
Constructors
StringPrim !Text | |
NumberPrim !Scientific | |
BoolPrim !Bool | |
NullPrim |
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
Objects and Arrays
class AsPrimitive t => AsValue t where #
Traverse into JSON Objects and Arrays.
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
Traverse into actual encoded JSON.
Methods
_JSON :: (FromJSON a, ToJSON a) => Traversal' t a #