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 qualified Data.MonoTraversable as MT
  11 import Data.Proxy
  12
  13 import Language.Symantic.Type.Root
  14 import Language.Symantic.Type.Type0
  15
  16 -- * Type 'Type_Unit'
  17 -- | The @()@ type.
  18 type Type_Unit = Type_Type0 (Proxy ())
  19
  20 pattern Type_Unit :: Type_Unit root ()
  21 pattern Type_Unit  = Type_Type0 Proxy
  22
  23 instance Constraint_Type Eq (Type_Unit root) where
  24         constraint_type _c Type_Type0{} = Just Dict
  25 instance Constraint_Type Ord (Type_Unit root) where
  26         constraint_type _c Type_Type0{} = Just Dict
  27 instance Constraint_Type Monoid (Type_Unit root)
  28 instance Constraint_Type Num (Type_Unit root)
  29 instance Constraint_Type Integral (Type_Unit root)
  30 instance Constraint_Type MT.MonoFunctor (Type_Unit root)
  31 instance -- String_from_Type
  32  String_from_Type (Type_Unit root) where
  33         string_from_type _ = "()"
  34
  35 -- | Inject 'Type_Unit' within a root type.
  36 type_unit :: Lift_Type_Root Type_Unit root => root ()
  37 type_unit = type_type0