{-# LANGUAGE GADTs #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeOperators #-}

module Cases(
    bool, maybe', either', op, gadtOp
) where

import Test.HUnit
import Data.Derive.IsDataCon

makeIsDataCon ''Bool

bool :: Test
bool = TestList [
        TestCase (assertEqual "is False False" (isFalse False) True)
        , TestCase (assertEqual "is True True" (isTrue True) True)
        , TestCase (assertEqual "is False not True" (isFalse True) False)
        , TestCase (assertEqual "is True not False" (isTrue False) False)
    ]

makeIsDataCon ''Maybe

maybe' :: Test
maybe' = TestList [
         TestCase (assertEqual "Nothing is Nothing" (isNothing Nothing) True)
       , TestCase (assertEqual "Nothing is Nothing" (isJust (Just ())) True)
       , TestCase (assertEqual "Nothing is not Just" (isNothing (Just ())) False)
       , TestCase (assertEqual "Just is not Nothing" (isJust Nothing) False)]

makeIsDataCon ''Either

either' :: Test
either' = TestList [
         TestCase (assertEqual "Left is Left" (isLeft (Left ())) True)
       , TestCase (assertEqual "Right is Right" (isRight (Right ())) True)
       , TestCase (assertEqual "Left is not Right" (isLeft (Right ())) False)
       , TestCase (assertEqual "Right is not Left" (isRight (Left ())) False)]

data (:-:) a b = (:-:) a b | (:=) a b
makeIsDataCon ''(:-:)

op :: Test
op = TestList [
         TestCase (assertEqual "isColonMinusColon is isColonMinusColon" (isColonMinusColon ((:-:) () ())) True)
       , TestCase (assertEqual "isColonEqual is isColonEqual" (isColonEqual ( () := ())) True)
       , TestCase (assertEqual "isColonMinusColon is not isColonEqual" (isColonMinusColon ((:=) () ())) False)
       , TestCase (assertEqual "isColonEqual is not isColonMinusColon" (isColonEqual (() :-: ())) False)]


data Gadt a b where
    (:*:), (:=:)  :: a -> b -> Gadt a b

makeIsDataCon ''Gadt

gadtOp :: Test
gadtOp = TestList [
         TestCase (assertEqual "isColonStarColon is isColonStarColon" (isColonStarColon ((:*:) () ())) True)
       , TestCase (assertEqual "isColonEqualColon is isColonEqualColon" (isColonEqualColon ( () :=: ())) True)
       , TestCase (assertEqual "isColonStarColon is not isColonEqual" (isColonStarColon ((:=:) () ())) False)
       , TestCase (assertEqual "isColonEqualColon is not isColonStarColon" (isColonEqualColon (() :*: ())) False)]