{-# LANGUAGE CPP, FlexibleInstances, UndecidableInstances, GeneralizedNewtypeDeriving, ScopedTypeVariables #-} {-| Primitive functions, such as addition on builtin integers. -} module Agda.TypeChecking.Primitive where import Control.Monad import Control.Monad.Error import Data.Map (Map) import qualified Data.Map as Map import Data.Char import Agda.Interaction.Options import Agda.Syntax.Position import Agda.Syntax.Common hiding (Nat) import Agda.Syntax.Internal import Agda.Syntax.Literal import Agda.Syntax.Concrete.Pretty () import Agda.Syntax.Abstract.Name import qualified Agda.Syntax.Concrete.Name as C import Agda.TypeChecking.Monad import Agda.TypeChecking.Monad.Builtin import Agda.TypeChecking.Reduce import Agda.TypeChecking.Substitute import Agda.TypeChecking.Errors import Agda.TypeChecking.Quote (quoteType, quotingKit) import Agda.TypeChecking.Pretty () -- instances only import {-# SOURCE #-} Agda.TypeChecking.Conversion import Agda.TypeChecking.Constraints import Agda.TypeChecking.Level import Agda.Utils.Monad import Agda.Utils.Pretty (pretty) #include "../undefined.h" import Agda.Utils.Impossible -- | Rewrite a literal to constructor form if possible. constructorForm :: Term -> TCM Term constructorForm v = case ignoreSharing v of {- 2012-04-02 changed semantics of DontCare -- Andreas, 2011-10-03, the following line restores IrrelevantLevel DontCare v -> constructorForm v -} Lit (LitInt r n) -> cons primZero primSuc (Lit . LitInt r) n -- Level (Max []) -> primLevelZero -- Level (Max [ClosedLevel n]) -> cons primLevelZero primLevelSuc (Level . Max . (:[]) . ClosedLevel) n _ -> return v where cons pZero pSuc lit n | n == 0 = pZero | n > 0 = do s <- pSuc return $ s `apply` [defaultArg $ lit $ n - 1] | otherwise = return v --------------------------------------------------------------------------- -- * Primitive functions --------------------------------------------------------------------------- data PrimitiveImpl = PrimImpl Type PrimFun -- Haskell type to Agda type newtype Str = Str { unStr :: String } deriving (Eq, Ord) newtype Nat = Nat { unNat :: Integer } deriving (Eq, Ord, Num, Integral, Enum, Real) newtype Lvl = Lvl { unLvl :: Integer } deriving (Eq, Ord) instance Show Lvl where show = show . unLvl instance Show Nat where show = show . unNat class PrimType a where primType :: a -> TCM Type instance (PrimType a, PrimType b) => PrimTerm (a -> b) where primTerm _ = unEl <$> (primType (undefined :: a) --> primType (undefined :: b)) instance PrimTerm a => PrimType a where primType _ = el $ primTerm (undefined :: a) class PrimTerm a where primTerm :: a -> TCM Term instance PrimTerm Integer where primTerm _ = primInteger instance PrimTerm Bool where primTerm _ = primBool instance PrimTerm Char where primTerm _ = primChar instance PrimTerm Double where primTerm _ = primFloat instance PrimTerm Str where primTerm _ = primString instance PrimTerm Nat where primTerm _ = primNat instance PrimTerm Lvl where primTerm _ = primLevel instance PrimTerm QName where primTerm _ = primQName instance PrimTerm Type where primTerm _ = primAgdaType instance PrimTerm a => PrimTerm [a] where primTerm _ = list (primTerm (undefined :: a)) instance PrimTerm a => PrimTerm (IO a) where primTerm _ = io (primTerm (undefined :: a)) -- From Agda term to Haskell value class ToTerm a where toTerm :: TCM (a -> Term) instance ToTerm Integer where toTerm = return $ Lit . LitInt noRange instance ToTerm Nat where toTerm = return $ Lit . LitInt noRange . unNat instance ToTerm Lvl where toTerm = return $ Level . Max . (:[]) . ClosedLevel . unLvl instance ToTerm Double where toTerm = return $ Lit . LitFloat noRange instance ToTerm Char where toTerm = return $ Lit . LitChar noRange instance ToTerm Str where toTerm = return $ Lit . LitString noRange . unStr instance ToTerm QName where toTerm = return $ Lit . LitQName noRange instance ToTerm Bool where toTerm = do true <- primTrue false <- primFalse return $ \b -> if b then true else false instance ToTerm Type where toTerm = snd <$> quotingKit -- | @buildList A ts@ builds a list of type @List A@. Assumes that the terms -- @ts@ all have type @A@. buildList :: TCM ([Term] -> Term) buildList = do nil' <- primNil cons' <- primCons let nil = nil' cons x xs = cons' `apply` [defaultArg x, defaultArg xs] return $ foldr cons nil instance (PrimTerm a, ToTerm a) => ToTerm [a] where toTerm = do mkList <- buildList fromA <- toTerm return $ mkList . map fromA -- From Haskell value to Agda term type FromTermFunction a = Arg Term -> TCM (Reduced (MaybeReduced (Arg Term)) a) class FromTerm a where fromTerm :: TCM (FromTermFunction a) instance FromTerm Integer where fromTerm = fromLiteral $ \l -> case l of LitInt _ n -> Just n _ -> Nothing instance FromTerm Nat where fromTerm = fromLiteral $ \l -> case l of LitInt _ n -> Just $ Nat n _ -> Nothing instance FromTerm Lvl where fromTerm = fromReducedTerm $ \l -> case l of Level (Max [ClosedLevel n]) -> Just $ Lvl n _ -> Nothing instance FromTerm Double where fromTerm = fromLiteral $ \l -> case l of LitFloat _ x -> Just x _ -> Nothing instance FromTerm Char where fromTerm = fromLiteral $ \l -> case l of LitChar _ c -> Just c _ -> Nothing instance FromTerm Str where fromTerm = fromLiteral $ \l -> case l of LitString _ s -> Just $ Str s _ -> Nothing instance FromTerm QName where fromTerm = fromLiteral $ \l -> case l of LitQName _ x -> Just x _ -> Nothing instance FromTerm Bool where fromTerm = do true <- primTrue false <- primFalse fromReducedTerm $ \t -> case t of _ | t === true -> Just True | t === false -> Just False | otherwise -> Nothing where Def x [] === Def y [] = x == y Con x [] === Con y [] = x == y Var n [] === Var m [] = n == m _ === _ = False instance (ToTerm a, FromTerm a) => FromTerm [a] where fromTerm = do nil' <- primNil cons' <- primCons nil <- isCon nil' cons <- isCon cons' toA <- fromTerm fromA <- toTerm return $ mkList nil cons toA fromA where isCon (Lam _ b) = isCon $ absBody b isCon (Con c _) = return c isCon (Shared p) = isCon (derefPtr p) isCon v = do d <- prettyTCM v typeError $ GenericError $ "expected constructor in built-in binding to " ++ show d -- TODO: check this when binding the things mkList nil cons toA fromA t = do b <- reduceB t let t = ignoreBlocking b let arg = Arg (argHiding t) (argRelevance t) case unArg t of Con c [] | c == nil -> return $ YesReduction [] Con c [x,xs] | c == cons -> redBind (toA x) (\x' -> notReduced $ arg $ Con c [ignoreReduced x',xs]) $ \y -> redBind (mkList nil cons toA fromA xs) (fmap $ \xs' -> arg $ Con c [defaultArg $ fromA y, xs']) $ \ys -> redReturn (y : ys) _ -> return $ NoReduction (reduced b) -- | Conceptually: @redBind m f k = either (return . Left . f) k =<< m@ redBind :: TCM (Reduced a a') -> (a -> b) -> (a' -> TCM (Reduced b b')) -> TCM (Reduced b b') redBind ma f k = do r <- ma case r of NoReduction x -> return $ NoReduction $ f x YesReduction y -> k y redReturn :: a -> TCM (Reduced a' a) redReturn = return . YesReduction fromReducedTerm :: (Term -> Maybe a) -> TCM (FromTermFunction a) fromReducedTerm f = return $ \t -> do b <- reduceB t case f $ ignoreSharing $ unArg (ignoreBlocking b) of Just x -> return $ YesReduction x Nothing -> return $ NoReduction (reduced b) fromLiteral :: (Literal -> Maybe a) -> TCM (FromTermFunction a) fromLiteral f = fromReducedTerm $ \t -> case t of Lit lit -> f lit _ -> Nothing -- trustMe : {a : Level} {A : Set a} {x y : A} -> x ≡ y primTrustMe :: TCM PrimitiveImpl primTrustMe = do clo <- commandLineOptions when (optSafe clo) (typeError SafeFlagPrimTrustMe) t <- hPi "a" (el primLevel) $ hPi "A" (return $ sort $ varSort 0) $ hPi "x" (El (varSort 1) <$> varM 0) $ hPi "y" (El (varSort 2) <$> varM 1) $ El (varSort 3) <$> primEquality <#> varM 3 <#> varM 2 <@> varM 1 <@> varM 0 Con rf [] <- ignoreSharing <$> primRefl n <- conPars . theDef <$> getConstInfo rf let refl x | n == 2 = Con rf [Arg Hidden Forced x] | n == 3 = Con rf [] | otherwise = __IMPOSSIBLE__ return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 4 $ \ts -> case ts of [a, t, x, y] -> liftTCM $ do noConstraints $ equalTerm (El (Type $ lvlView $ unArg a) (unArg t)) (unArg x) (unArg y) redReturn (refl $ unArg x) `catchError` \_ -> return (NoReduction $ map notReduced [a, t, x, y]) _ -> __IMPOSSIBLE__ primQNameType :: TCM PrimitiveImpl primQNameType = mkPrimFun1TCM (el primQName --> el primAgdaType) typeOfConst primQNameDefinition :: TCM PrimitiveImpl primQNameDefinition = do let argQName qn = [defaultArg (Lit (LitQName noRange qn))] app mt xs = do t <- mt return $ apply t xs con qn Function{} = app primAgdaDefinitionFunDef (argQName qn) con qn Datatype{} = app primAgdaDefinitionDataDef (argQName qn) con qn Record{} = app primAgdaDefinitionRecordDef (argQName qn) con _ Axiom{} = app primAgdaDefinitionPostulate [] con _ Primitive{} = app primAgdaDefinitionPrimitive [] con _ Constructor{} = app primAgdaDefinitionDataConstructor [] unquoteQName <- fromTerm t <- el primQName --> el primAgdaDefinition return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 1 $ \ts -> case ts of [v] -> liftTCM $ redBind (unquoteQName v) (\v' -> [v']) $ \x -> redReturn =<< con x . theDef =<< getConstInfo x _ -> __IMPOSSIBLE__ primDataConstructors :: TCM PrimitiveImpl primDataConstructors = mkPrimFun1TCM (el primAgdaDataDef --> el (list primQName)) (fmap (dataCons . theDef) . getConstInfo) mkPrimLevelZero :: TCM PrimitiveImpl mkPrimLevelZero = do t <- primType (undefined :: Lvl) return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 0 $ \_ -> redReturn $ Level $ Max [] mkPrimLevelSuc :: TCM PrimitiveImpl mkPrimLevelSuc = do t <- primType (id :: Lvl -> Lvl) return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 1 $ \ ~[a] -> liftTCM $ do l <- levelView $ unArg a redReturn $ Level $ levelSuc l mkPrimLevelMax :: TCM PrimitiveImpl mkPrimLevelMax = do t <- primType (max :: Op Lvl) return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 2 $ \ ~[a, b] -> liftTCM $ do Max as <- levelView $ unArg a Max bs <- levelView $ unArg b redReturn $ Level $ levelMax $ as ++ bs mkPrimFun1TCM :: (FromTerm a, ToTerm b) => TCM Type -> (a -> TCM b) -> TCM PrimitiveImpl mkPrimFun1TCM mt f = do toA <- fromTerm fromB <- toTerm t <- mt return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 1 $ \ts -> case ts of [v] -> liftTCM $ redBind (toA v) (\v' -> [v']) $ \x -> redReturn . fromB =<< f x _ -> __IMPOSSIBLE__ -- Tying the knot mkPrimFun1 :: (PrimType a, PrimType b, FromTerm a, ToTerm b) => (a -> b) -> TCM PrimitiveImpl mkPrimFun1 f = do toA <- fromTerm fromB <- toTerm t <- primType f return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 1 $ \ts -> case ts of [v] -> liftTCM $ redBind (toA v) (\v' -> [v']) $ \x -> redReturn $ fromB $ f x _ -> __IMPOSSIBLE__ mkPrimFun2 :: (PrimType a, PrimType b, PrimType c, FromTerm a, ToTerm a, FromTerm b, ToTerm c) => (a -> b -> c) -> TCM PrimitiveImpl mkPrimFun2 f = do toA <- fromTerm fromA <- toTerm toB <- fromTerm fromC <- toTerm t <- primType f return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 2 $ \ts -> case ts of [v,w] -> liftTCM $ redBind (toA v) (\v' -> [v', notReduced w]) $ \x -> redBind (toB w) (\w' -> [ reduced $ notBlocked $ Arg (argHiding v) (argRelevance v) (fromA x) , w']) $ \y -> redReturn $ fromC $ f x y _ -> __IMPOSSIBLE__ mkPrimFun4 :: ( PrimType a, FromTerm a, ToTerm a , PrimType b, FromTerm b, ToTerm b , PrimType c, FromTerm c, ToTerm c , PrimType d, FromTerm d , PrimType e, ToTerm e) => (a -> b -> c -> d -> e) -> TCM PrimitiveImpl mkPrimFun4 f = do (toA, fromA) <- (,) <$> fromTerm <*> toTerm (toB, fromB) <- (,) <$> fromTerm <*> toTerm (toC, fromC) <- (,) <$> fromTerm <*> toTerm toD <- fromTerm fromE <- toTerm t <- primType f return $ PrimImpl t $ PrimFun __IMPOSSIBLE__ 4 $ \ts -> let argFrom fromX a x = reduced $ notBlocked $ Arg (argHiding a) (argRelevance a) (fromX x) in case ts of [a,b,c,d] -> liftTCM $ redBind (toA a) (\a' -> a' : map notReduced [b,c,d]) $ \x -> redBind (toB b) (\b' -> [argFrom fromA a x, b', notReduced c, notReduced d]) $ \y -> redBind (toC c) (\c' -> [ argFrom fromA a x , argFrom fromB b y , c', notReduced d]) $ \z -> redBind (toD d) (\d' -> [ argFrom fromA a x , argFrom fromB b y , argFrom fromC c z , d']) $ \w -> redReturn $ fromE $ f x y z w _ -> __IMPOSSIBLE__ -- Type combinators infixr 4 --> (-->) :: TCM Type -> TCM Type -> TCM Type a --> b = do a' <- a b' <- b return $ El (getSort a' `sLub` getSort b') $ Pi (Dom NotHidden Relevant a') (NoAbs "_" b') infixr 4 .--> (.-->) :: TCM Type -> TCM Type -> TCM Type a .--> b = do a' <- a b' <- b return $ El (getSort a' `sLub` getSort b') $ Pi (Dom NotHidden Irrelevant a') (NoAbs "_" b') gpi :: Hiding -> Relevance -> String -> TCM Type -> TCM Type -> TCM Type gpi h r name a b = do a <- a x <- freshName_ name b <- addCtx x (Dom h r a) b return $ El (getSort a `dLub` Abs name (getSort b)) (Pi (Dom h r a) (Abs name b)) hPi, nPi :: String -> TCM Type -> TCM Type -> TCM Type hPi = gpi Hidden Relevant nPi = gpi NotHidden Relevant varM :: Int -> TCM Term varM = return . var infixl 9 <@>, <#> gApply :: Hiding -> TCM Term -> TCM Term -> TCM Term gApply h a b = do x <- a y <- b return $ x `apply` [Arg h Relevant y] (<@>),(<#>) :: TCM Term -> TCM Term -> TCM Term (<@>) = gApply NotHidden (<#>) = gApply Hidden list :: TCM Term -> TCM Term list t = primList <@> t io :: TCM Term -> TCM Term io t = primIO <@> t el :: TCM Term -> TCM Type el t = El (mkType 0) <$> t tset :: TCM Type tset = return $ sort (mkType 0) -- | Abbreviation: @argN = 'Arg' 'NotHidden' 'Relevant'@. argN = Arg NotHidden Relevant domN = Dom NotHidden Relevant -- | Abbreviation: @argH = 'Arg' 'Hidden' 'Relevant'@. argH = Arg Hidden Relevant domH = Dom Hidden Relevant --------------------------------------------------------------------------- -- * The actual primitive functions --------------------------------------------------------------------------- type Op a = a -> a -> a type Fun a = a -> a type Rel a = a -> a -> Bool type Pred a = a -> Bool primitiveFunctions :: Map String (TCM PrimitiveImpl) primitiveFunctions = Map.fromList -- Integer functions [ "primIntegerPlus" |-> mkPrimFun2 ((+) :: Op Integer) , "primIntegerMinus" |-> mkPrimFun2 ((-) :: Op Integer) , "primIntegerTimes" |-> mkPrimFun2 ((*) :: Op Integer) , "primIntegerDiv" |-> mkPrimFun2 (div :: Op Integer) -- partial , "primIntegerMod" |-> mkPrimFun2 (mod :: Op Integer) -- partial , "primIntegerEquality" |-> mkPrimFun2 ((==) :: Rel Integer) , "primIntegerLess" |-> mkPrimFun2 ((<) :: Rel Integer) , "primIntegerAbs" |-> mkPrimFun1 (Nat . abs :: Integer -> Nat) , "primNatToInteger" |-> mkPrimFun1 (unNat :: Nat -> Integer) , "primShowInteger" |-> mkPrimFun1 (Str . show :: Integer -> Str) -- Natural number functions , "primNatPlus" |-> mkPrimFun2 ((+) :: Op Nat) , "primNatMinus" |-> mkPrimFun2 ((\x y -> max 0 (x - y)) :: Op Nat) , "primNatTimes" |-> mkPrimFun2 ((*) :: Op Nat) , "primNatDivSucAux" |-> mkPrimFun4 ((\k m n j -> k + div (max 0 $ n + m - j) (m + 1)) :: Nat -> Nat -> Nat -> Nat -> Nat) , "primNatModSucAux" |-> let aux :: Nat -> Nat -> Nat -> Nat -> Nat aux k m n j | n > j = mod (n - j - 1) (m + 1) | otherwise = k + n in mkPrimFun4 aux , "primNatEquality" |-> mkPrimFun2 ((==) :: Rel Nat) , "primNatLess" |-> mkPrimFun2 ((<) :: Rel Nat) , "primLevelZero" |-> mkPrimLevelZero , "primLevelSuc" |-> mkPrimLevelSuc , "primLevelMax" |-> mkPrimLevelMax -- Floating point functions , "primIntegerToFloat" |-> mkPrimFun1 (fromIntegral :: Integer -> Double) , "primFloatPlus" |-> mkPrimFun2 ((+) :: Op Double) , "primFloatMinus" |-> mkPrimFun2 ((-) :: Op Double) , "primFloatTimes" |-> mkPrimFun2 ((*) :: Op Double) , "primFloatDiv" |-> mkPrimFun2 ((/) :: Op Double) , "primFloatLess" |-> mkPrimFun2 ((<) :: Rel Double) , "primRound" |-> mkPrimFun1 (round :: Double -> Integer) , "primFloor" |-> mkPrimFun1 (floor :: Double -> Integer) , "primCeiling" |-> mkPrimFun1 (ceiling :: Double -> Integer) , "primExp" |-> mkPrimFun1 (exp :: Fun Double) , "primLog" |-> mkPrimFun1 (log :: Fun Double) -- partial , "primSin" |-> mkPrimFun1 (sin :: Fun Double) , "primShowFloat" |-> mkPrimFun1 (Str . show :: Double -> Str) -- Character functions , "primCharEquality" |-> mkPrimFun2 ((==) :: Rel Char) , "primIsLower" |-> mkPrimFun1 isLower , "primIsDigit" |-> mkPrimFun1 isDigit , "primIsAlpha" |-> mkPrimFun1 isAlpha , "primIsSpace" |-> mkPrimFun1 isSpace , "primIsAscii" |-> mkPrimFun1 isAscii , "primIsLatin1" |-> mkPrimFun1 isLatin1 , "primIsPrint" |-> mkPrimFun1 isPrint , "primIsHexDigit" |-> mkPrimFun1 isHexDigit , "primToUpper" |-> mkPrimFun1 toUpper , "primToLower" |-> mkPrimFun1 toLower , "primCharToNat" |-> mkPrimFun1 (fromIntegral . fromEnum :: Char -> Nat) , "primNatToChar" |-> mkPrimFun1 (toEnum . fromIntegral :: Nat -> Char) , "primShowChar" |-> mkPrimFun1 (Str . show . pretty . LitChar noRange) -- String functions , "primStringToList" |-> mkPrimFun1 unStr , "primStringFromList" |-> mkPrimFun1 Str , "primStringAppend" |-> mkPrimFun2 (\s1 s2 -> Str $ unStr s1 ++ unStr s2) , "primStringEquality" |-> mkPrimFun2 ((==) :: Rel Str) , "primShowString" |-> mkPrimFun1 (Str . show . pretty . LitString noRange . unStr) -- Reflection , "primQNameType" |-> primQNameType , "primQNameDefinition" |-> primQNameDefinition , "primDataConstructors"|-> primDataConstructors -- Other stuff , "primTrustMe" |-> primTrustMe , "primQNameEquality" |-> mkPrimFun2 ((==) :: Rel QName) ] where (|->) = (,) lookupPrimitiveFunction :: String -> TCM PrimitiveImpl lookupPrimitiveFunction x = case Map.lookup x primitiveFunctions of Just p -> liftTCM p Nothing -> typeError $ NoSuchPrimitiveFunction x lookupPrimitiveFunctionQ :: QName -> TCM (String, PrimitiveImpl) lookupPrimitiveFunctionQ q = do let s = case qnameName q of Name _ x _ _ -> show x PrimImpl t pf <- lookupPrimitiveFunction s return (s, PrimImpl t $ pf { primFunName = q })