{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE PatternSynonyms #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Language.Symantic.Type.Unit where

import qualified Data.MonoTraversable as MT
import Data.Proxy

import Language.Symantic.Type.Root
import Language.Symantic.Type.Type0

-- * Type 'Type_Unit'
-- | The @()@ type.
type Type_Unit = Type_Type0 (Proxy ())

pattern Type_Unit :: Type_Unit root ()
pattern Type_Unit  = Type_Type0 Proxy

instance Constraint_Type Eq (Type_Unit root) where
	constraint_type _c Type_Type0{} = Just Dict
instance Constraint_Type Ord (Type_Unit root) where
	constraint_type _c Type_Type0{} = Just Dict
instance Constraint_Type Monoid (Type_Unit root)
instance Constraint_Type Num (Type_Unit root)
instance Constraint_Type Integral (Type_Unit root)
instance Constraint_Type MT.MonoFunctor (Type_Unit root)
instance -- String_from_Type
 String_from_Type (Type_Unit root) where
	string_from_type _ = "()"

-- | Inject 'Type_Unit' within a root type.
type_unit :: Lift_Type_Root Type_Unit root => root ()
type_unit = type_type0