Language/LOL/Symantic/Expr/Bool.hs

   1 {-# LANGUAGE DefaultSignatures #-}
   2 {-# LANGUAGE FlexibleContexts #-}
   3 {-# LANGUAGE FlexibleInstances #-}
   4 {-# LANGUAGE GADTs #-}
   5 {-# LANGUAGE MultiParamTypeClasses #-}
   6 {-# LANGUAGE OverloadedStrings #-}
   7 {-# LANGUAGE Rank2Types #-}
   8 {-# LANGUAGE ScopedTypeVariables #-}
   9 {-# LANGUAGE TypeFamilies #-}
  10 {-# LANGUAGE UndecidableInstances #-}
  11 -- | Expression for 'Bool's.
  12 module Language.LOL.Symantic.Expr.Bool where
  13
  14 import Data.Proxy (Proxy(..))
  15 import Prelude hiding (and, not, or)
  16
  17 import Language.LOL.Symantic.AST
  18 import Language.LOL.Symantic.Type
  19 import Language.LOL.Symantic.Expr.Common
  20 import Language.LOL.Symantic.Expr.Lambda
  21 import Language.LOL.Symantic.Repr.Dup
  22 import Language.LOL.Symantic.Trans.Common
  23
  24 -- * Class 'Sym_Bool'
  25
  26 -- | Symantic.
  27 class Sym_Bool repr where
  28         bool ::      Bool -> repr Bool
  29         not  :: repr Bool -> repr Bool
  30         and  :: repr Bool -> repr Bool -> repr Bool
  31         or   :: repr Bool -> repr Bool -> repr Bool
  32         xor  :: repr Bool -> repr Bool -> repr Bool
  33         xor x y = (x `or` y) `and` not (x `and` y)
  34
  35         default bool :: Trans t repr =>        Bool -> t repr Bool
  36         default not  :: Trans t repr => t repr Bool -> t repr Bool
  37         default and  :: Trans t repr => t repr Bool -> t repr Bool -> t repr Bool
  38         default or   :: Trans t repr => t repr Bool -> t repr Bool -> t repr Bool
  39         bool = trans_lift . bool
  40         not  = trans_map1 not
  41         and  = trans_map2 and
  42         or   = trans_map2 or
  43
  44 instance -- Sym_Bool Dup
  45  ( Sym_Bool r1
  46  , Sym_Bool r2
  47  ) => Sym_Bool (Dup r1 r2) where
  48         bool x = bool x `Dup` bool x
  49         not (x1 `Dup` x2)               = not x1    `Dup` not x2
  50         and (x1 `Dup` x2) (y1 `Dup` y2) = and x1 y1 `Dup` and x2 y2
  51         or  (x1 `Dup` x2) (y1 `Dup` y2) = or  x1 y1 `Dup` or  x2 y2
  52         xor (x1 `Dup` x2) (y1 `Dup` y2) = xor x1 y1 `Dup` xor x2 y2
  53
  54 -- * Type 'Expr_Bool'
  55 -- | Expression.
  56 data Expr_Bool (root:: *)
  57 type instance Root_of_Expr (Expr_Bool root) = root
  58 type instance Type_of_Expr (Expr_Bool root) = Type_Bool
  59 type instance Sym_of_Expr (Expr_Bool root) repr = Sym_Bool repr
  60 type instance Error_of_Expr ast (Expr_Bool root) = Error_Expr_Bool ast
  61
  62 instance -- Expr_from AST Expr_Bool
  63  ( Type_from AST (Type_Root_of_Expr root)
  64  , Expr_from AST root
  65
  66  , Type_Root_Lift Type_Bool (Type_Root_of_Expr root)
  67  , Error_Type_Lift (Error_Type_Fun AST)
  68                    (Error_of_Type AST (Type_Root_of_Expr root))
  69  , Error_Expr_Lift (Error_Expr (Error_of_Type AST (Type_Root_of_Expr root))
  70                                (                   Type_Root_of_Expr root)
  71                                AST)
  72                    (Error_of_Expr AST root)
  73
  74  , Type_Unlift Type_Bool (Type_of_Expr root)
  75
  76  , Root_of_Expr root ~ root
  77
  78  , Implicit_HBool (Is_Last_Expr (Expr_Bool root) root)
  79  ) => Expr_from AST (Expr_Bool root) where
  80         expr_from px_ex ctx ast k =
  81                 case ast of
  82                  AST "bool" asts ->
  83                         case asts of
  84                          [AST ast_bool []] ->
  85                                 case read_safe ast_bool of
  86                                  Left err -> Left $ error_expr px_ex $ Error_Expr_Read err ast
  87                                  Right (i::Bool) ->
  88                                         k type_bool $ Forall_Repr_with_Context $
  89                                                 const $ bool i
  90                          _ -> Left $ error_expr px_ex $
  91                                 Error_Expr_Wrong_number_of_arguments 3 ast
  92                  AST "not" asts -> unary_from  asts not
  93                  AST "and" asts -> binary_from asts and
  94                  AST "or"  asts -> binary_from asts or
  95                  AST "xor" asts -> binary_from asts xor
  96                  _ -> Left $
  97                         case hbool :: HBool (Is_Last_Expr (Expr_Bool root) root) of
  98                          HTrue  -> error_expr px_ex $ Error_Expr_Unsupported ast
  99                          HFalse -> error_expr px_ex $ Error_Expr_Unsupported_here ast
 100                 where
 101                 unary_from asts
 102                  (op::forall repr. Sym_Bool repr
 103                     => repr Bool -> repr Bool) =
 104                         case asts of
 105                          [ast_x] ->
 106                                 expr_from (Proxy::Proxy root) ctx ast_x $
 107                                  \(ty_x::Type_Root_of_Expr root h_x) (Forall_Repr_with_Context x) ->
 108                                         case type_unlift $ unType_Root ty_x of
 109                                          Just (Type_Bool::Type_Bool (Type_Root_of_Expr root) h_x) ->
 110                                                 k ty_x $ Forall_Repr_with_Context (op . x)
 111                                          _ -> Left $ error_expr px_ex $
 112                                                 Error_Expr_Argument_mismatch
 113                                                  (Exists_Type type_bool)
 114                                                  (Exists_Type ty_x) ast
 115                          _ -> Left $ error_expr px_ex $
 116                                 Error_Expr_Wrong_number_of_arguments 1 ast
 117                 binary_from asts
 118                  (op::forall repr. Sym_Bool repr
 119                     => repr Bool -> repr Bool -> repr Bool) =
 120                         case asts of
 121                          [ast_x, ast_y] ->
 122                                 expr_from (Proxy::Proxy root) ctx ast_x $
 123                                  \(ty_x::Type_Root_of_Expr root h_x) (Forall_Repr_with_Context x) ->
 124                                 expr_from (Proxy::Proxy root) ctx ast_y $
 125                                  \(ty_y::Type_Root_of_Expr root h_y) (Forall_Repr_with_Context y) ->
 126                                         case type_unlift $ unType_Root ty_x of
 127                                          Just (Type_Bool::Type_Bool (Type_Root_of_Expr root) h_x) ->
 128                                                 case type_unlift $ unType_Root ty_y of
 129                                                  Just (Type_Bool::Type_Bool (Type_Root_of_Expr root) h_y) ->
 130                                                         k ty_x $ Forall_Repr_with_Context $
 131                                                          \c -> x c `op` y c
 132                                                  Nothing -> Left $ error_expr px_ex $
 133                                                         Error_Expr_Argument_mismatch
 134                                                          (Exists_Type type_bool)
 135                                                          (Exists_Type ty_y) ast
 136                                          Nothing -> Left $ error_expr px_ex $
 137                                                 Error_Expr_Argument_mismatch
 138                                                  (Exists_Type type_bool)
 139                                                  (Exists_Type ty_x) ast
 140                          _ -> Left $ error_expr px_ex $
 141                                 Error_Expr_Wrong_number_of_arguments 2 ast
 142
 143 -- ** Type 'Expr_Lambda_Bool'
 144 -- | Convenient alias.
 145 type Expr_Lambda_Bool lam = Expr_Root (Expr_Alt (Expr_Lambda lam) Expr_Bool)
 146
 147 expr_lambda_bool_from
 148  :: forall lam ast.
 149  Expr_from ast (Expr_Lambda_Bool lam)
 150  => Proxy lam
 151  -> ast
 152  -> Either (Error_of_Expr ast (Expr_Lambda_Bool lam))
 153            (Exists_Type_and_Repr (Type_Root_of_Expr (Expr_Lambda_Bool lam))
 154                                  (Forall_Repr (Expr_Lambda_Bool lam)))
 155 expr_lambda_bool_from _px_lam ast =
 156         expr_from
 157          (Proxy::Proxy (Expr_Lambda_Bool lam))
 158          Context_Empty ast $ \ty (Forall_Repr_with_Context repr) ->
 159                 Right $ Exists_Type_and_Repr ty $
 160                         Forall_Repr $ repr Context_Empty
 161
 162 -- * Type 'Error_Expr_Bool'
 163 data Error_Expr_Bool ast
 164  =   Error_Expr_Bool
 165  deriving (Eq, Show)