Language/Symantic/Type/Map.hs

   1 {-# LANGUAGE FlexibleContexts #-}
   2 {-# LANGUAGE GADTs #-}
   3 {-# LANGUAGE MultiParamTypeClasses #-}
   4 {-# LANGUAGE OverloadedStrings #-}
   5 {-# LANGUAGE ScopedTypeVariables #-}
   6 {-# LANGUAGE TypeFamilies #-}
   7 module Language.Symantic.Type.Map where
   8
   9 import Data.Map.Strict as Map
  10 import Data.Maybe (isJust)
  11 import Data.Type.Equality ((:~:)(Refl))
  12
  13 import Language.Symantic.Type.Common
  14 import Language.Symantic.Type.Fun
  15 import Language.Symantic.Type.Bool
  16 import Language.Symantic.Type.Var
  17
  18 -- * Type 'Type_Map'
  19 -- | The 'Map' type.
  20 data Type_Map root h where
  21         Type_Map :: Ord h_k
  22                  => root h_k
  23                  -> root h_a
  24                  -> Type_Map root (Map h_k h_a)
  25
  26 type instance Root_of_Type      (Type_Map root) = root
  27 type instance Error_of_Type ast (Type_Map root) = No_Error_Type
  28
  29 instance -- Type_Eq
  30  Type_Eq root =>
  31  Type_Eq (Type_Map root) where
  32         type_eq (Type_Map k1 a1) (Type_Map k2 a2)
  33          | Just Refl <- k1 `type_eq` k2
  34          , Just Refl <- a1 `type_eq` a2
  35          = Just Refl
  36         type_eq _ _ = Nothing
  37 instance -- Eq
  38  Type_Eq root =>
  39  Eq (Type_Map root h) where
  40         x == y = isJust $ type_eq x y
  41 instance -- String_from_Type
  42  String_from_Type root =>
  43  String_from_Type (Type_Map root) where
  44         string_from_type (Type_Map k a) =
  45                 "Map (" ++ string_from_type k ++ ")"
  46                  ++ " (" ++ string_from_type a ++ ")"
  47 instance -- Show
  48  String_from_Type root =>
  49  Show (Type_Map root h) where
  50         show = string_from_type
  51
  52 -- | Convenient alias to include a 'Type_Map' within a type.
  53 type_map
  54  :: (Type_Root_Lift Type_Map root, Ord h_k)
  55  => root h_k
  56  -> root h_a
  57  -> root (Map h_k h_a)
  58 type_map k a = type_root_lift (Type_Map k a)
  59
  60 -- * Type 'Type_Fun_Bool_Map'
  61 -- | Convenient alias.
  62 type Type_Fun_Bool_Map lam
  63  = Type_Root (Type_Alt Type_Var
  64              (Type_Alt (Type_Fun lam)
  65              (Type_Alt Type_Bool
  66                        Type_Map)))