| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Data.Aeson.Quick
Synopsis
- module Data.Aeson
- (.?) :: FromJSON a => Value -> Quick -> Maybe a
- (.!) :: FromJSON a => Value -> Quick -> a
- extract :: FromJSON a => Quick -> Value -> Parser a
- (.%) :: ToJSON a => Quick -> a -> Value
- build :: ToJSON a => Quick -> a -> Either String Value
- data Quick
- parseQuick :: Text -> Either String Quick
- quick :: QuasiQuoter
- jsonlit :: QuasiQuoter
Documentation
aeson-quick is a library for terse marshalling of data to and from aeson's
Value.
It works on the observation that by turning objects into tuples inside
the Value, the type system can be employed to do more of the work.
For example, given the JSON:
{ "name": "bob"
, "age": 29
, "hobbies": [{"name": "tennis"}, {"name": "cooking"}]
}You can write:
extractHobbyist ::Value->Maybe(Value,Int, [Value]) extractHobbyist = (.?"{name,age,hobbies:[{name}]}")
module Data.Aeson
(.?) :: FromJSON a => Value -> Quick -> Maybe a Source #
Extracts instances of FromJSON from a Value
This is a wrapper around extract which does the actual work.
Examples assume FromJSON Foo and FromJSON Bar.
Extract key from object:
>>>value .? "{key}" :: Maybe Foo
Extract list of objects:
>>>value .? "[{key}]" :: Maybe [Foo]
Extract with optional key:
>>>value .? "{key,opt?}" :: Maybe (Foo, Maybe Bar)
(.%) :: ToJSON a => Quick -> a -> Value Source #
Turns data into JSON objects.
This is a wrapper around build which does the actual work.
Build a simple Value:
>>>encode $ "{a}" .% True{\"a\": True}
Build a complex Value:
>>>encode $ "[{a}]" '.%' [True, False]"[{\"a\":true},{\"a\":false}]"
QuasiQuoter for a structure, provides compile time checking ie:
>>>val .! [quick|{foo,bar}|]