Language/Symantic/Type/Unit.hs

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