Language/Symantic/Lib/Monad.hs

   1 {-# LANGUAGE UndecidableInstances #-}
   2 {-# OPTIONS_GHC -fno-warn-orphans #-}
   3 -- | Symantic for 'Monad'.
   4 module Language.Symantic.Lib.Monad where
   5
   6 import Control.Monad (Monad)
   7 import qualified Control.Monad as Monad
   8 import Data.Proxy
   9 import Data.Type.Equality ((:~:)(Refl))
  10 import Prelude hiding (Monad(..))
  11
  12 import Language.Symantic.Parsing
  13 import Language.Symantic.Parsing.Grammar
  14 import Language.Symantic.Typing
  15 import Language.Symantic.Compiling
  16 import Language.Symantic.Interpreting
  17 import Language.Symantic.Transforming.Trans
  18 import Language.Symantic.Lib.Applicative (Sym_Applicative)
  19
  20 -- * Class 'Sym_Monad'
  21 class Sym_Applicative term => Sym_Monad term where
  22         return :: Monad m => term a -> term (m a)
  23         (>>=)  :: Monad m => term (m a) -> term (a -> m b) -> term (m b)
  24         join   :: Monad m => term (m (m a)) -> term (m a)
  25         when   :: Applicative f => term Bool -> term (f ()) -> term (f ())
  26
  27         default return :: (Trans t term, Monad m)
  28          => t term a -> t term (m a)
  29         default (>>=) :: (Trans t term, Monad m)
  30          => t term (m a) -> t term (a -> m b) -> t term (m b)
  31         default join :: (Trans t term, Monad m)
  32          => t term (m (m a)) -> t term (m a)
  33         default when :: (Trans t term, Applicative f)
  34          => t term Bool -> t term (f ()) -> t term (f ())
  35
  36         return = trans_map1 return
  37         (>>=)  = trans_map2 (>>=)
  38         join   = trans_map1 join
  39         when   = trans_map2 when
  40
  41 infixl 1 >>=
  42
  43 type instance Sym_of_Iface (Proxy Monad) = Sym_Monad
  44 type instance Consts_of_Iface (Proxy Monad) = Proxy Monad ': Consts_imported_by Monad
  45 type instance Consts_imported_by Monad =
  46  [ Proxy ()
  47  , Proxy Applicative
  48  , Proxy Bool
  49  ]
  50
  51 instance Sym_Monad HostI where
  52         return = Monad.liftM  Monad.return
  53         (>>=)  = Monad.liftM2 (Monad.>>=)
  54         join   = Monad.liftM  Monad.join
  55         when   = Monad.liftM2 Monad.when
  56 instance Sym_Monad TextI where
  57         return = textI1 "return"
  58         (>>=)  = textI_infix ">>=" (infixL 1)
  59         join   = textI1 "join"
  60         when   = textI2 "when"
  61 instance (Sym_Monad r1, Sym_Monad r2) => Sym_Monad (DupI r1 r2) where
  62         return = dupI1 (Proxy @Sym_Monad) return
  63         (>>=)  = dupI2 (Proxy @Sym_Monad) (>>=)
  64         join   = dupI1 (Proxy @Sym_Monad) join
  65         when   = dupI2 (Proxy @Sym_Monad) when
  66
  67 instance
  68  ( Read_TypeNameR Type_Name cs rs
  69  , Inj_Const cs Monad
  70  ) => Read_TypeNameR Type_Name cs (Proxy Monad ': rs) where
  71         read_typenameR _cs (Type_Name "Monad") k = k (ty @Monad)
  72         read_typenameR _rs raw k = read_typenameR (Proxy @rs) raw k
  73 instance Show_Const cs => Show_Const (Proxy Monad ': cs) where
  74         show_const ConstZ{} = "Monad"
  75         show_const (ConstS c) = show_const c
  76
  77 instance Proj_ConC cs (Proxy Monad)
  78 data instance TokenT meta (ts::[*]) (Proxy Monad)
  79  = Token_Term_Monad_return (EToken meta '[Proxy Token_Type]) (EToken meta ts)
  80  | Token_Term_Monad_bind   (EToken meta ts) (EToken meta ts)
  81  | Token_Term_Monad_join   (EToken meta ts)
  82  | Token_Term_Monad_when   (EToken meta ts) (EToken meta ts)
  83 deriving instance (Eq meta, Eq_Token meta ts) => Eq (TokenT meta ts (Proxy Monad))
  84 deriving instance (Show meta, Show_Token meta ts) => Show (TokenT meta ts (Proxy Monad))
  85 instance -- CompileI
  86  ( Read_TypeName Type_Name (Consts_of_Ifaces is)
  87  , Inj_Const (Consts_of_Ifaces is) Monad
  88  , Inj_Const (Consts_of_Ifaces is) (->)
  89  , Inj_Const (Consts_of_Ifaces is) ()
  90  , Inj_Const (Consts_of_Ifaces is) Applicative
  91  , Inj_Const (Consts_of_Ifaces is) Bool
  92  , Proj_Con  (Consts_of_Ifaces is)
  93  , Compile is
  94  ) => CompileI is (Proxy Monad) where
  95         compileI tok ctx k =
  96                 case tok of
  97                  Token_Term_Monad_return tok_ty_m tok_a ->
  98                         -- return :: Monad m => a -> m a
  99                         compile_type tok_ty_m $ \(ty_m::Type (Consts_of_Ifaces is) m) ->
 100                         check_kind
 101                          (At Nothing (SKiType `SKiArrow` SKiType))
 102                          (At (Just tok_ty_m) $ kind_of ty_m) $ \Refl ->
 103                         check_con (At (Just tok_ty_m) (ty @Monad :$ ty_m)) $ \Con ->
 104                         compileO tok_a ctx $ \ty_a (TermO a) ->
 105                         k (ty_m :$ ty_a) $ TermO $
 106                          \c -> return (a c)
 107                  Token_Term_Monad_bind tok_ma tok_a2mb ->
 108                         -- (>>=) :: Monad m => m a -> (a -> m b) -> m b
 109                         compileO tok_ma   ctx $ \ty_ma   (TermO ma) ->
 110                         compileO tok_a2mb ctx $ \ty_a2mb (TermO a2mb) ->
 111                         check_con1 (ty @Monad) (At (Just tok_ma) ty_ma) $ \Refl Con ty_ma_m ty_ma_a ->
 112                         check_type2 (ty @(->)) (At (Just tok_a2mb) ty_a2mb) $ \Refl ty_a2mb_a ty_a2mb_mb ->
 113                         check_type1 ty_ma_m (At (Just tok_a2mb) ty_a2mb_mb) $ \Refl _ty_a2mb_mb_b ->
 114                         check_type
 115                          (At (Just tok_a2mb) ty_a2mb_a)
 116                          (At (Just tok_ma) ty_ma_a) $ \Refl ->
 117                         k ty_a2mb_mb $ TermO $
 118                          \c -> (>>=) (ma c) (a2mb c)
 119                  Token_Term_Monad_join tok_mma ->
 120                         -- join :: Monad m => m (m a) -> m a
 121                         compileO tok_mma ctx $ \ty_mma (TermO mma) ->
 122                         check_con1 (ty @Monad) (At (Just tok_mma) ty_mma) $ \Refl Con ty_mma_m ty_mma_ma ->
 123                         check_type1 ty_mma_m (At (Just tok_mma) ty_mma_ma) $ \Refl _ty_mma_ma_a ->
 124                         k ty_mma_ma $ TermO $
 125                          \c -> join (mma c)
 126                  Token_Term_Monad_when tok_cond tok_ok ->
 127                         -- when :: Applicative f => Bool -> f () -> f ()
 128                         compileO tok_cond ctx $ \ty_cond (TermO cond) ->
 129                         compileO tok_ok   ctx $ \ty_ok   (TermO ok) ->
 130                         check_con1 (ty @Applicative) (At (Just tok_ok) ty_ok) $ \Refl Con _ty_ok_f ty_ok_u ->
 131                         check_type
 132                          (At Nothing (ty @Bool))
 133                          (At (Just tok_cond) ty_cond) $ \Refl ->
 134                         check_type
 135                          (At Nothing (ty @()))
 136                          (At (Just tok_ok) ty_ok_u) $ \Refl ->
 137                         k ty_ok $ TermO $
 138                          \c -> when (cond c) (ok c)
 139 instance -- TokenizeT
 140  Inj_Token meta ts Monad =>
 141  TokenizeT meta ts (Proxy Monad) where
 142         tokenizeT _t = mempty
 143          { tokenizers_infix = tokenizeTMod []
 144                  [ (Term_Name "Nothing",) Term_ProTok
 145                          { term_protok = \meta -> ProTokPi $ \m -> ProTokLam $ \a ->
 146                                 ProTok $ inj_etoken meta $ Token_Term_Monad_return m a
 147                          , term_fixity = infixN5
 148                          }
 149                  , tokenize2 ">>="  (infixL 1) Token_Term_Monad_bind
 150                  , tokenize1 "join" infixN5    Token_Term_Monad_join
 151                  , tokenize2 "when" infixN5    Token_Term_Monad_when
 152                  ]
 153          }
 154 instance Gram_Term_AtomsT meta ts (Proxy Monad) g