Automatically derivable JSON marshallers in the spirit of Haskell's aeson.

Please note, that while tests suggest that the encoders and decoders perform reasonably well, this library has not been optimized in terms of performance.

Getting started with encoding and decoding is very easy:

module README

import JSON.Derive

%language ElabReflection

data MonsterClass = Imp | Goblin | Orc | Dragon

%runElab derive "MonsterClass" [Show,Eq,ToJSON,FromJSON]

record Villain where
  constructor MkVillain
  name    : String
  hp      : Nat
  class   : MonsterClass
  cronies : List Villain

%runElab derive "Villain" [Show,Eq,ToJSON,FromJSON]

gorgar : Villain
gorgar = MkVillain "Gorgar" 2000 Dragon [MkVillain "Igor" 10 Imp []]

You can give this a try at the REPL:

pack repl docs/src/README.md

README> :exec putStrLn $ encode gorgar
README> :exec printLn $ (decode {a = Villain} (encode gorgar))

More examples can be found in the tutorial.

Besides base, the following dependencies are needed to support the automatic deriving of interface implementations:

• elab-util
• parser-json

In addition, the test suit requires the following:

• pretty-show
• hedgehog

It is nowadays recommended to use a package manager such as pack for installing and managing your Idris2 dependencies.

Personally, I don't think the versatility of using different JSON representations and thus having to go via Encoder, Value, or Object interfaces is worth the hassle. I therefore added a second library, which uses just the JSON representation from the parser-json package.