Portability	portable
Stability	provisional
Maintainer	Sigbjorn Finne <sof@galois.com>

Text.JSON

Contents

JSON Types
Serialization to and from JSValues
Encoding and Decoding
Wrapper Types
Serialization to and from Strings.

Description

Synopsis

JSON Types

data JSValue Source

JSON values

The type to which we encode Haskell values. There's a set of primitives, and a couple of heterogenous collection types.

Objects:

An object structure is represented as a pair of curly brackets surrounding zero or more name/value pairs (or members). A name is a string. A single colon comes after each name, separating the name from the value. A single comma separates a value from a following name.

Arrays:

An array structure is represented as square brackets surrounding zero or more values (or elements). Elements are separated by commas.

Only valid JSON can be constructed this way

Constructors

JSNull
JSBool !Bool
JSRational Bool !Rational
JSString JSString
JSArray [JSValue]
JSObject (JSObject JSValue)

Instances

Eq JSValue
Ord JSValue
Read JSValue
Show JSValue
Typeable JSValue
JSON JSValue	To ensure we generate valid JSON, we map Haskell types to JSValue internally, then pretty print that.

Serialization to and from JSValues

class JSON a whereSource

The class of types serialisable to and from JSON

Methods

readJSON :: JSValue -> Result aSource

showJSON :: a -> JSValue Source

readJSONs :: JSValue -> Result [a]Source

showJSONs :: [a] -> JSValue Source

Instances

JSON Bool
JSON Char
JSON Double
JSON Float
JSON Int
JSON Int8
JSON Int16
JSON Int32
JSON Int64
JSON Integer
JSON Ordering
JSON Word
JSON Word8
JSON Word16
JSON Word32
JSON Word64
JSON ()
JSON ByteString
JSON ByteString
JSON IntSet
JSON JSString
JSON JSValue	To ensure we generate valid JSON, we map Haskell types to JSValue internally, then pretty print that.
JSON a => JSON [a]
JSON a => JSON (Maybe a)
JSON a => JSON (IntMap a)
(Ord a, JSON a) => JSON (Set a)
JSON a => JSON (JSObject a)
(JSON a, JSON b) => JSON (Either a b)
(JSON a, JSON b) => JSON (a, b)
(Ix i, JSON i, JSON e) => JSON (Array i e)
(Ord a, JSON a, JSON b) => JSON (Map a b)
(JSON a, JSON b, JSON c) => JSON (a, b, c)
(JSON a, JSON b, JSON c, JSON d) => JSON (a, b, c, d)

Encoding and Decoding

data Result a Source

A type for parser results

Constructors

Ok a
Error String

Instances

Monad Result
Functor Result
MonadPlus Result
Applicative Result
Alternative Result
MonadError String Result
Eq a => Eq (Result a)
Show a => Show (Result a)

encode :: JSON a => a -> String Source

Encode a Haskell value into a string, in JSON format.

This is a superset of JSON, as types other than Array and Object are allowed at the top level.

decode :: JSON a => String -> Result aSource

Decode a String representing a JSON value (either an object, array, bool, number, null)

This is a superset of JSON, as types other than Array and Object are allowed at the top level.

encodeStrict :: JSON a => a -> String Source

Encode a value as a String in strict JSON format. This follows the spec, and requires all values at the top level to be wrapped in either an Array or Object. JSON types to be an Array or Object.

decodeStrict :: JSON a => String -> Result aSource

Decode a String representing a strict JSON value. This follows the spec, and requires top level JSON types to be an Array or Object.