{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE TemplateHaskell #-}

module MaybeHelp where

import Control.Lens
import Data.Aeson
import Data.Aeson.TH

data Maybe' a = Just' {__Just' :: a} | Nothing'
    --deriving (Eq, Ord, Show, Read, Generic) --Generic, Flat)
    deriving (Eq, Ord, Show, Read) --Generic, Flat)

--instance ToJSON a => ToJSON (Maybe' a) where
--    toEncoding = genericToEncoding defaultOptions
--
--instance FromJSON a => FromJSON (Maybe' a)

fromJust' :: Maybe' a -> a
fromJust' mx = case mx of
    Just' x -> x
    Nothing' -> error "no fromJust'"

isJust' :: Maybe' a -> Bool
isJust' Just'{} = True
isJust' Nothing' = False

isNothing' :: Maybe' a -> Bool
isNothing' Just'{} = False
isNothing' Nothing' = True

strictify :: Maybe a -> Maybe' a
strictify Nothing = Nothing'
strictify (Just x) = Just' x

toggleJust :: Maybe a -> Maybe ()
toggleJust Nothing = Just ()
toggleJust _ = Nothing

makeLenses ''Maybe'
deriveJSON defaultOptions ''Maybe'