json-0.9.1: Support for serialising Haskell to and from JSON

Copyright(c) Galois Inc. 2007-2009
LicenseBSD3
MaintainerSigbjorn Finne <sof@galois.com>
Stabilityprovisional
Portabilityportable
Safe HaskellSafe
LanguageHaskell98

Text.JSON

Contents

Description

 

Synopsis

JSON Types

data JSValue #

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

Instances

Eq JSValue # 

Methods

(==) :: JSValue -> JSValue -> Bool #

(/=) :: JSValue -> JSValue -> Bool #

Ord JSValue # 
Read JSValue # 
Show 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 where #

The class of types serialisable to and from JSON

Minimal complete definition

readJSON, showJSON

Methods

readJSON :: JSValue -> Result a #

showJSON :: a -> JSValue #

readJSONs :: JSValue -> Result [a] #

showJSONs :: [a] -> JSValue #

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 () # 

Methods

readJSON :: JSValue -> Result () #

showJSON :: () -> JSValue #

readJSONs :: JSValue -> Result [()] #

showJSONs :: [()] -> JSValue #

JSON ByteString # 
JSON ByteString # 
JSON IntSet # 
JSON Text # 
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] # 

Methods

readJSON :: JSValue -> Result [a] #

showJSON :: [a] -> JSValue #

readJSONs :: JSValue -> Result [[a]] #

showJSONs :: [[a]] -> JSValue #

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) # 

Methods

readJSON :: JSValue -> Result (a, b) #

showJSON :: (a, b) -> JSValue #

readJSONs :: JSValue -> Result [(a, b)] #

showJSONs :: [(a, b)] -> JSValue #

(Ix i, JSON i, JSON e) => JSON (Array i e) # 

Methods

readJSON :: JSValue -> Result (Array i e) #

showJSON :: Array i e -> JSValue #

readJSONs :: JSValue -> Result [Array i e] #

showJSONs :: [Array i e] -> JSValue #

(Ord a, JSON a, JSON b) => JSON (Map a b) # 

Methods

readJSON :: JSValue -> Result (Map a b) #

showJSON :: Map a b -> JSValue #

readJSONs :: JSValue -> Result [Map a b] #

showJSONs :: [Map a b] -> JSValue #

(JSON a, JSON b, JSON c) => JSON (a, b, c) # 

Methods

readJSON :: JSValue -> Result (a, b, c) #

showJSON :: (a, b, c) -> JSValue #

readJSONs :: JSValue -> Result [(a, b, c)] #

showJSONs :: [(a, b, c)] -> JSValue #

(JSON a, JSON b, JSON c, JSON d) => JSON (a, b, c, d) # 

Methods

readJSON :: JSValue -> Result (a, b, c, d) #

showJSON :: (a, b, c, d) -> JSValue #

readJSONs :: JSValue -> Result [(a, b, c, d)] #

showJSONs :: [(a, b, c, d)] -> JSValue #

Encoding and Decoding

data Result a #

A type for parser results

Constructors

Ok a 
Error String 

Instances

Monad Result # 

Methods

(>>=) :: Result a -> (a -> Result b) -> Result b #

(>>) :: Result a -> Result b -> Result b #

return :: a -> Result a #

fail :: String -> Result a #

Functor Result # 

Methods

fmap :: (a -> b) -> Result a -> Result b #

(<$) :: a -> Result b -> Result a #

Applicative Result # 

Methods

pure :: a -> Result a #

(<*>) :: Result (a -> b) -> Result a -> Result b #

(*>) :: Result a -> Result b -> Result b #

(<*) :: Result a -> Result b -> Result a #

Alternative Result # 

Methods

empty :: Result a #

(<|>) :: Result a -> Result a -> Result a #

some :: Result a -> Result [a] #

many :: Result a -> Result [a] #

MonadPlus Result # 

Methods

mzero :: Result a #

mplus :: Result a -> Result a -> Result a #

Eq a => Eq (Result a) # 

Methods

(==) :: Result a -> Result a -> Bool #

(/=) :: Result a -> Result a -> Bool #

Show a => Show (Result a) # 

Methods

showsPrec :: Int -> Result a -> ShowS #

show :: Result a -> String #

showList :: [Result a] -> ShowS #

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

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 a #

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 #

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 a #

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

Wrapper Types

toJSString :: String -> JSString #

Turn a Haskell string into a JSON string.

data JSObject e #

As can association lists

Instances

Eq e => Eq (JSObject e) # 

Methods

(==) :: JSObject e -> JSObject e -> Bool #

(/=) :: JSObject e -> JSObject e -> Bool #

Ord e => Ord (JSObject e) # 

Methods

compare :: JSObject e -> JSObject e -> Ordering #

(<) :: JSObject e -> JSObject e -> Bool #

(<=) :: JSObject e -> JSObject e -> Bool #

(>) :: JSObject e -> JSObject e -> Bool #

(>=) :: JSObject e -> JSObject e -> Bool #

max :: JSObject e -> JSObject e -> JSObject e #

min :: JSObject e -> JSObject e -> JSObject e #

Read e => Read (JSObject e) # 
Show e => Show (JSObject e) # 

Methods

showsPrec :: Int -> JSObject e -> ShowS #

show :: JSObject e -> String #

showList :: [JSObject e] -> ShowS #

JSON a => JSON (JSObject a) # 

toJSObject :: [(String, a)] -> JSObject a #

Make JSON object out of an association list.

fromJSObject :: JSObject e -> [(String, e)] #

resultToEither :: Result a -> Either String a #

Map Results to Eithers

Serialization to and from Strings.

Reading JSON

readJSNull :: GetJSON JSValue #

Read the JSON null type

readJSBool :: GetJSON JSValue #

Read the JSON Bool type

readJSString :: GetJSON JSValue #

Read the JSON String type

readJSRational :: GetJSON Rational #

Read an Integer or Double in JSON format, returning a Rational

readJSArray :: GetJSON JSValue #

Read a list in JSON format

readJSObject :: GetJSON JSValue #

Read an object in JSON format

readJSValue :: GetJSON JSValue #

Read one of several possible JS types

Writing JSON

showJSNull :: ShowS #

Write the JSON null type

showJSBool :: Bool -> ShowS #

Write the JSON Bool type

showJSArray :: [JSValue] -> ShowS #

Show a list in JSON format

showJSRational :: Rational -> ShowS #

Show a Rational in JSON format

showJSObject :: JSObject JSValue -> ShowS #

Show an association list in JSON format

showJSValue :: JSValue -> ShowS #

Show JSON values

Instance helpers

valFromObj :: JSON a => String -> JSObject JSValue -> Result a #

Pull a value out of a JSON object.

class JSKey a where #

Haskell types that can be used as keys in JSON objects.

Minimal complete definition

toJSKey, fromJSKey

Methods

toJSKey :: a -> String #

fromJSKey :: String -> Maybe a #

encJSDict :: (JSKey a, JSON b) => [(a, b)] -> JSValue #

Encode an association list as JSObject value.

decJSDict :: (JSKey a, JSON b) => String -> JSValue -> Result [(a, b)] #

Decode a JSObject value into an association list.