Language/Symantic/Type/Unit.hs

   1 {-# LANGUAGE FlexibleContexts #-}
   2 {-# LANGUAGE FlexibleInstances #-}
   3 {-# LANGUAGE MultiParamTypeClasses #-}
   4 {-# LANGUAGE PatternSynonyms #-}
   5 {-# LANGUAGE ScopedTypeVariables #-}
   6 {-# LANGUAGE TypeFamilies #-}
   7 {-# OPTIONS_GHC -fno-warn-orphans #-}
   8 module Language.Symantic.Type.Unit where
   9
  10 import Data.Proxy
  11 import Language.Symantic.Type.Root
  12 import Language.Symantic.Type.Type0
  13
  14
  15 -- * Type 'Type_Unit'
  16 -- | The @()@ type.
  17 type Type_Unit = Type_Type0 (Proxy ())
  18
  19 pattern Type_Unit :: Type_Unit root ()
  20 pattern Type_Unit  = Type_Type0 Proxy
  21
  22 instance Constraint_Type Eq (Type_Unit root) where
  23         constraint_type _c Type_Type0{} = Just Dict
  24 instance Constraint_Type Ord (Type_Unit root) where
  25         constraint_type _c Type_Type0{} = Just Dict
  26 instance Constraint_Type Monoid (Type_Unit root)
  27 instance -- String_from_Type
  28  String_from_Type (Type_Unit root) where
  29         string_from_type _ = "()"
  30
  31 -- | Inject 'Type_Unit' within a root type.
  32 type_unit :: Lift_Type_Root Type_Unit root => root ()
  33 type_unit = type_type0