Priklad Haskell JSON

Main.hs

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DeriveAnyClass #-}

import Data.Aeson
import GHC.Generics

data Message = Message { uuid :: Int, content :: Int }
  deriving (Generic, FromJSON)

exampleFunction :: Int -> Int -> IO ()
exampleFunction uuid msg = print (uuid, msg)

main :: IO ()
main = do
  let jsdata = "{\"uuid\":10, \"content\":20}"
  case eitherDecode jsdata of
    Left err -> error err
    Right msg -> exampleFunction (uuid msg) (content msg)

tst.cabal

name:                tst
version:             0.1.0.0
license-file:        LICENSE
author:              XXX
maintainer:          YYY
build-type:          Simple
cabal-version:       >=1.10

executable tst
  main-is:             Main.hs
  build-depends:       base, aeson
  default-language:    Haskell2010
  ghc-options:         -Wall -fwarn-incomplete-uni-patterns