Text.DeadSimpleJSON

A simple approach for parsing JSON.

To read JSON data use read. To print JSON data use show:

 let jsonData = read "[1,2,4,8,16]" :: JSON
 putStrLn $ show jsonData

You can query json data using ?. Querying implies conversion, therefor you may need to specify the result type:

 let jsonData = read "{\"seven\": 7, \"nine\": [1,2,4,8,16]}"
 print $ (jsonData ? "nine[3]" :: Int)

For tighter control use parse. A more convenient way for creating JSON objects in source code or querying JSON data, is using Template Haskell. See Text.SimpleJSON.TH.

The recommended way for importing this module is importing it qualified, like so:

 import qualified Text.SimpleJSON as JSON
 import Text.SimpleJSON (JSON)

Parsing strings

parse :: String -> Either ParseError JSON

Parse a String for JSON data or return a ParseError.

parse' :: String -> Maybe Value

Parses a top-level JSON object, returning Just a Value or Nothing.

parseM :: Monad m => String -> m Value

Purely Monadic version of parse'.

Basic data types

data Value

A JSON value.

Constructors

String String

A JSON String, represented as ordinary Haskell String.

Number !Integer !Integer

A JSON Number, represented by two Integers in exponontial form. Number n e is the same as {n}e{exp}, that is n * 10 ^ e. This allows for arbitrary precision fixed point rationals. See Convert for easy conversions.

Object (Map String Value)

A JSON Object, represented as Map.

Array (Vector Value)

A JSON Array, represented as Vector of Values.

True

True.

False

False.

Null

Null (void, unit, ()).

Instances

Eq Value

Data Value

Read Value

Show Value

Typeable Value

Convert Value

data JSON

A top-level JSON object.

Merely a wrapper that ensures that no other Values but Array and Object reside at the top-level.

Instances

Eq JSON

Data JSON

Read JSON

Show JSON

Typeable JSON

Querying json data

(?) :: Convert a => JSON -> String -> a

top :: JSON -> Value

Unwraps a top-level JSON object to a Value.

Conversion to and from

class Convert a where

Methods

convert :: Value -> a

convert' :: Value -> Maybe a

toJSON :: a -> Value

Instances

Convert Bool

Convert Double

Convert Float

Convert Int

Convert Int8

Convert Int16

Convert Int32

Convert Int64

Convert Integer

Convert String

Convert Value

Convert a => Convert [a]

(Read a, Integral a) => Convert (Ratio a)

Convert a => Convert (Maybe a)