Language/Symantic/Type/Var.hs

   1 {-# LANGUAGE FlexibleContexts #-}
   2 {-# LANGUAGE FlexibleInstances #-}
   3 {-# LANGUAGE GADTs #-}
   4 {-# LANGUAGE MultiParamTypeClasses #-}
   5 {-# LANGUAGE PatternSynonyms #-}
   6 {-# LANGUAGE TypeFamilies #-}
   7 {-# LANGUAGE ScopedTypeVariables #-}
   8 {-# LANGUAGE UndecidableInstances #-}
   9 {-# OPTIONS_GHC -fno-warn-missing-methods #-}
  10 {-# OPTIONS_GHC -fno-warn-orphans #-}
  11 -- | Type variable.
  12 module Language.Symantic.Type.Var
  13  ( module Language.Symantic.Type.Var
  14  , module Language.Symantic.Lib.Data.Peano
  15  ) where
  16
  17 import Data.Type.Equality ((:~:)(Refl))
  18 import Language.Symantic.Lib.Data.Peano
  19 import Language.Symantic.Type.Root
  20 import Language.Symantic.Type.Type0
  21 import Language.Symantic.Type.Type1
  22
  23 -- * Type 'Var0'
  24 newtype Var0 = Var0 EPeano
  25 type instance Host0_of EPeano = Var0
  26
  27 -- | Undefined instance required to build errors.
  28 instance Eq Var0
  29 -- | Undefined instance required to build errors.
  30 instance Ord Var0
  31
  32 -- * Type 'Var1'
  33 newtype Var1 a = Var1 EPeano
  34 type instance Host1_of EPeano = Var1
  35
  36 -- * Type 'Type_Var0'
  37 -- | The variable type of kind @*@.
  38 type Type_Var0 = Type_Type0 EPeano
  39
  40 pattern Type_Var0 :: SPeano p -> Type_Var0 root Var0
  41 pattern Type_Var0 p = Type_Type0 (EPeano p)
  42
  43 instance Eq_Type1 (Type_Var0 root) where
  44 instance -- String_from_Type
  45  String_from_Type (Type_Var0 root) where
  46         string_from_type (Type_Type0 (EPeano p)) =
  47                 "t" ++ show (integral_from_peano p::Integer)
  48 instance Constraint_Type Eq (Type_Var0 root) where
  49         constraint_type _c Type_Type0{} = Just Dict
  50
  51 -- | Inject 'Type_Var0' within a root type.
  52 type_var0 :: Lift_Type_Root Type_Var0 root => SPeano p -> root Var0
  53 type_var0 = lift_type_root . Type_Type0 . EPeano
  54
  55 -- * Type 'Type_Var1'
  56 -- | The variable type of kind @* -> *@.
  57 type Type_Var1 = Type_Type1 EPeano
  58 instance Constraint_Type Eq (Type_Var1 root)
  59
  60 pattern Type_Var1 :: SPeano p -> root a -> Type_Var1 root (Var1 a)
  61 pattern Type_Var1 p a = Type_Type1 (EPeano p) a
  62
  63 instance Eq_Type1 (Type_Var1 root) where
  64         eq_type1 (Type_Type1 p1 _) (Type_Type1 p2 _)
  65          | p1 == p2
  66          = Just Refl
  67         eq_type1 _ _ = Nothing
  68 instance -- String_from_Type
  69  String_from_Type root =>
  70  String_from_Type (Type_Var1 root) where
  71         string_from_type (Type_Type1 (EPeano p) a) =
  72                 "t_" ++ show (integral_from_peano p::Integer) ++
  73                 " " ++ string_from_type a
  74
  75 -- | Inject 'Type_Var1' within a root type.
  76 type_var1 :: Lift_Type_Root Type_Var1 root => SPeano p -> root a -> root (Var1 a)
  77 type_var1 p = lift_type_root . Type_Var1 p