Language/Symantic/Type/Tuple.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.Tuple where
   9
  10 import Data.Proxy
  11 import Data.Type.Equality ((:~:)(Refl))
  12 import Language.Symantic.Type.Root
  13 import Language.Symantic.Type.Type0
  14 import Language.Symantic.Type.Type1
  15 import Language.Symantic.Type.Type2
  16
  17 -- * Type 'Type_Tuple2'
  18 -- | The @(,)@ type.
  19 type Type_Tuple2 = Type_Type2 (Proxy (,))
  20
  21 pattern Type_Tuple2
  22  :: root a -> root b
  23  -> Type_Tuple2 root ((,) a b)
  24 pattern Type_Tuple2 a b
  25  = Type_Type2 Proxy a b
  26
  27 instance Unlift_Type1 Type_Tuple2 where
  28         unlift_type1 (Type_Type2 px a b) k =
  29                 k ( Type_Type1 (Proxy::Proxy ((,) a)) b
  30                   , Lift_Type1 (\(Type_Type1 _ b') -> Type_Type2 px a b')
  31                   )
  32 instance
  33  Constraint_Type Eq root =>
  34  Constraint_Type Eq (Type_Tuple2 root) where
  35         constraint_type c (Type_Type2 _ a b)
  36          | Just Dict <- constraint_type c a
  37          , Just Dict <- constraint_type c b
  38          = Just Dict
  39         constraint_type _c _ = Nothing
  40 instance
  41  Constraint_Type Ord root =>
  42  Constraint_Type Ord (Type_Tuple2 root) where
  43         constraint_type c (Type_Type2 _ a b)
  44          | Just Dict <- constraint_type c a
  45          , Just Dict <- constraint_type c b
  46          = Just Dict
  47         constraint_type _c _ = Nothing
  48 instance Constraint_Type1 Functor (Type_Tuple2 root) where
  49         constraint_type1 _c Type_Type2{} = Just Dict
  50 instance
  51  Constraint_Type Monoid root =>
  52  Constraint_Type1 Applicative (Type_Tuple2 root) where
  53         constraint_type1 _c (Type_Type2 _ a _b)
  54          | Just Dict <- constraint_type (Proxy::Proxy Monoid) a
  55          = Just Dict
  56         constraint_type1 _c _ = Nothing
  57 instance Constraint_Type1 Foldable (Type_Tuple2 root) where
  58         constraint_type1 _c Type_Type2{} = Just Dict
  59 instance Constraint_Type1 Traversable (Type_Tuple2 root) where
  60         constraint_type1 _c Type_Type2{} = Just Dict
  61 instance
  62  Constraint_Type Monoid root =>
  63  Constraint_Type Monoid (Type_Tuple2 root) where
  64         constraint_type c (Type_Type2 _ a b)
  65          | Just Dict <- constraint_type c a
  66          , Just Dict <- constraint_type c b
  67          = Just Dict
  68         constraint_type _c _ = Nothing
  69 instance -- Eq_Type
  70  Eq_Type root =>
  71  Eq_Type (Type_Tuple2 root) where
  72         eq_type (Type_Type2 _px1 a1 b1) (Type_Type2 _px2 a2 b2)
  73          | Just Refl <- a1 `eq_type` a2
  74          , Just Refl <- b1 `eq_type` b2
  75          = Just Refl
  76         eq_type _ _ = Nothing
  77 instance -- Eq_Type1
  78  Eq_Type root =>
  79  Eq_Type1 (Type_Tuple2 root) where
  80         eq_type1 (Type_Type2 _px1 a1 _b1) (Type_Type2 _px2 a2 _b2)
  81          | Just Refl <- a1 `eq_type` a2
  82          = Just Refl
  83         eq_type1 _ _ = Nothing
  84 instance -- String_from_Type
  85  String_from_Type root =>
  86  String_from_Type (Type_Tuple2 root) where
  87         string_from_type (Type_Type2 _ a b) =
  88                 "("  ++ string_from_type a ++
  89                 ", " ++ string_from_type b ++ ")"
  90
  91 -- | Inject 'Type_Tuple2' within a root type.
  92 type_tuple2
  93  :: forall root h_a h_b.
  94  Lift_Type_Root Type_Tuple2 root
  95  => root h_a
  96  -> root h_b
  97  -> root (h_a, h_b)
  98 type_tuple2 a b = lift_type_root
  99          (Type_Tuple2 a b
 100          ::Type_Tuple2 root (h_a, h_b))