Language/Symantic/Type/Bool.hs

   1 {-# LANGUAGE FlexibleContexts #-}
   2 {-# LANGUAGE GADTs #-}
   3 {-# LANGUAGE MultiParamTypeClasses #-}
   4 {-# LANGUAGE OverloadedStrings #-}
   5 {-# LANGUAGE ScopedTypeVariables #-}
   6 {-# LANGUAGE TypeFamilies #-}
   7 {-# LANGUAGE TypeOperators #-}
   8 module Language.Symantic.Type.Bool where
   9
  10 import Data.Maybe (isJust)
  11 import Data.Type.Equality ((:~:)(Refl))
  12
  13 import Language.Symantic.Type.Common
  14
  15 -- * Type 'Type_Bool'
  16 -- | The 'Bool' type.
  17 data Type_Bool (root:: * -> *) h where
  18         Type_Bool :: Type_Bool root Bool
  19 type instance Root_of_Type      (Type_Bool root) = root
  20 type instance Error_of_Type ast (Type_Bool root) = No_Error_Type
  21
  22 instance -- Eq_Type
  23  Eq_Type (Type_Bool root) where
  24         eq_type Type_Bool Type_Bool = Just Refl
  25 instance -- Eq
  26  Eq (Type_Bool root h) where
  27         x == y = isJust $ x `eq_type` y
  28 instance -- String_from_Type
  29  String_from_Type (Type_Bool root) where
  30         string_from_type Type_Bool = "Bool"
  31 instance -- Show
  32  Show (Type_Bool root h) where
  33         show = string_from_type
  34 instance Constraint_Type Eq (Type_Bool root) where
  35         constraint_type _c Type_Bool = Just Dict
  36 instance Constraint_Type Ord (Type_Bool root) where
  37         constraint_type _c Type_Bool = Just Dict
  38
  39 -- | Convenient alias to include a 'Type_Bool' within a type.
  40 type_bool :: Type_Root_Lift Type_Bool root => root Bool
  41 type_bool = type_root_lift Type_Bool