highjson

Haskell: Low boilerplate, easy to use and very fast Haskell JSON serialisation and parsing

Monthly Downloads: 12

Programming language: Haskell

License: MIT License

Tags: Data     Text     JSON     Web    

Latest version: v0.4.0.0

README

highjson

Intro

Hackage: highjson

Low boilerplate, easy to use and very fast Haskell JSON serialisation and parsing without the help of TemplateHaskell or Generics built on top of aeson.

Usage

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE PartialTypeSignatures #-}
import Data.Aeson
import Data.HighJson

import Data.HighJson.Swagger -- optional
import Data.Swagger -- optional

data SomeDummy
   = SomeDummy
   { sd_int :: Int
   , sd_bool :: Bool
   , sd_text :: T.Text
   , sd_either :: Either Bool T.Text
   , sd_maybe :: Maybe Int
   } deriving (Show, Eq)

someDummySpec :: RecordTypeSpec SomeDummy _
someDummySpec =
    recSpec "Some Dummy" Nothing SomeDummy $
    "int" .= sd_int
    :& "bool" .= sd_bool
    :& "text" .= sd_text
    :& "either" .= sd_either
    :& "maybe" .= sd_maybe

instance ToJSON SomeDummy where
    toJSON = jsonSerializer someDummySpec
    toEncoding = jsonEncoder someDummySpec

instance FromJSON SomeDummy where
    parseJSON = jsonParser someDummySpec

instance ToSchema SomeSum where -- optional, generates swagger2 specifications
    declareNamedSchema p = makeDeclareNamedSchema someDummySpec p

test =
    decodeEither "{\"int\": 34, \"text\": \"Teext\", \"bool\": true}"
        == Right (SomeDummy 34 True "Teext" Nothing)

Template haskell

There's also a small shortcut via template haskell (highjson-th):

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE PartialTypeSignatures #-}
{-# LANGUAGE TemplateHaskell #-}
import Data.HighJson
import Data.HighJson.Swagger
import Data.HighJson.TH

data SomeDummy
   = SomeDummy
   { sd_int :: Int
   , sd_bool :: Bool
   , sd_text :: T.Text
   , sd_either :: Either Bool T.Text
   , sd_maybe :: Maybe Int
   } deriving (Show, Eq)

someDummySpec :: RecordTypeSpec SomeDummy _
someDummySpec =
    recSpec "Some Dummy" Nothing SomeDummy $
    "int" .= sd_int
    :& "bool" .= sd_bool
    :& "text" .= sd_text
    :& "either" .= sd_either
    :& "maybe" .= sd_maybe

$(deriveJsonSwagger ''SomeDummy 'someDummySpec)

test =
    decodeEither "{\"int\": 34, \"text\": \"Teext\", \"bool\": true}"
        == Right (SomeDummy 34 True "Teext" Nothing)

Tests

For more usage examples check the tests.

Install

• Using cabal: cabal install highjson
• From Source: git clone https://github.com/agrafix/highjson.git && cd highjson && cabal install

Benchmarks

There are benchmarks in the project and it is expected to be en par or faster than aesons generic instances.