{-# LANGUAGE NondecreasingIndentation #-} module Agda.TypeChecking.Rules.Term where import Prelude hiding ( null ) import Control.Monad.Reader import Data.Maybe import Data.Either (partitionEithers, lefts) import Data.Monoid (mappend) import qualified Data.List as List import qualified Data.Map as Map import Agda.Interaction.Options import Agda.Interaction.Highlighting.Generate (disambiguateRecordFields) import qualified Agda.Syntax.Abstract as A import Agda.Syntax.Abstract.Views as A import qualified Agda.Syntax.Info as A import Agda.Syntax.Concrete.Pretty () -- only Pretty instances import Agda.Syntax.Concrete (FieldAssignment'(..), nameFieldA) import qualified Agda.Syntax.Concrete.Name as C import Agda.Syntax.Common import Agda.Syntax.Internal as I import Agda.Syntax.Internal.MetaVars import Agda.Syntax.Position import Agda.Syntax.Literal import Agda.Syntax.Scope.Base ( ThingsInScope, AbstractName , emptyScopeInfo , exportedNamesInScope) import Agda.Syntax.Scope.Monad (getNamedScope) import Agda.Syntax.Translation.InternalToAbstract (reify) import Agda.TypeChecking.CompiledClause import Agda.TypeChecking.Constraints import Agda.TypeChecking.Conversion import Agda.TypeChecking.Coverage.SplitTree import Agda.TypeChecking.Datatypes import Agda.TypeChecking.EtaContract import Agda.TypeChecking.Generalize import Agda.TypeChecking.Implicit import Agda.TypeChecking.Irrelevance import Agda.TypeChecking.IApplyConfluence import Agda.TypeChecking.Level import Agda.TypeChecking.MetaVars import Agda.TypeChecking.Monad import Agda.TypeChecking.Monad.Builtin import Agda.TypeChecking.Patterns.Abstract import Agda.TypeChecking.Positivity.Occurrence import Agda.TypeChecking.Pretty import Agda.TypeChecking.Primitive import Agda.TypeChecking.Quote import Agda.TypeChecking.RecordPatterns import Agda.TypeChecking.Records import Agda.TypeChecking.Reduce import Agda.TypeChecking.Rules.LHS import Agda.TypeChecking.SizedTypes import Agda.TypeChecking.SizedTypes.Solve import Agda.TypeChecking.Sort import Agda.TypeChecking.Substitute import Agda.TypeChecking.Telescope import Agda.TypeChecking.Unquote import Agda.TypeChecking.Warnings import {-# SOURCE #-} Agda.TypeChecking.Empty ( ensureEmptyType ) import {-# SOURCE #-} Agda.TypeChecking.Rules.Def (checkFunDef', useTerPragma) import {-# SOURCE #-} Agda.TypeChecking.Rules.Decl (checkSectionApplication) import {-# SOURCE #-} Agda.TypeChecking.Rules.Application import Agda.Utils.Except (MonadError(catchError, throwError)) import Agda.Utils.Functor import Agda.Utils.Lens import Agda.Utils.List import Agda.Utils.Maybe import Agda.Utils.Monad import Agda.Utils.Null import Agda.Utils.Pretty ( prettyShow ) import qualified Agda.Utils.Pretty as P import Agda.Utils.Size import Agda.Utils.Tuple import Agda.Utils.Impossible --------------------------------------------------------------------------- -- * Types --------------------------------------------------------------------------- -- | Check that an expression is a type. isType :: A.Expr -> Sort -> TCM Type isType = isType' CmpLeq -- | Check that an expression is a type. -- * If @c == CmpEq@, the given sort must be the minimal sort. -- * If @c == CmpLeq@, the given sort may be any bigger sort. isType' :: Comparison -> A.Expr -> Sort -> TCM Type isType' c e s = traceCall (IsTypeCall c e s) $ do v <- checkExpr' c e (sort s) return $ El s v -- | Check that an expression is a type and infer its (minimal) sort. isType_ :: A.Expr -> TCM Type isType_ e = traceCall (IsType_ e) $ do reportResult "tc.term.istype" 15 (\a -> vcat [ "isType_" prettyTCM e , nest 2 $ "returns" prettyTCM a ]) $ do let fallback = isType' CmpEq e =<< do workOnTypes $ newSortMeta case unScope e of A.Fun i (Arg info t) b -> do a <- setArgInfo info . defaultDom <$> isType_ t b <- isType_ b s <- inferFunSort (getSort a) (getSort b) let t' = El s $ Pi a $ NoAbs underscore b noFunctionsIntoSize b t' return t' A.Pi _ tel e | null tel -> isType_ e A.Pi _ tel e -> do (t0, t') <- checkPiTelescope tel $ \ tel -> do t0 <- instantiateFull =<< isType_ e tel <- instantiateFull tel return (t0, telePi tel t0) checkTelePiSort t' noFunctionsIntoSize t0 t' return t' -- Setᵢ A.Set _ n -> do return $ sort (mkType n) -- Propᵢ A.Prop _ n -> do unlessM isPropEnabled $ typeError NeedOptionProp return $ sort (mkProp n) -- Set ℓ A.App i s arg | visible arg, A.Set _ 0 <- unScope s -> do unlessM hasUniversePolymorphism $ genericError "Use --universe-polymorphism to enable level arguments to Set" -- allow NonStrict variables when checking level -- Set : (NonStrict) Level -> Set\omega applyRelevanceToContext NonStrict $ sort . Type <$> checkLevel arg -- Prop ℓ A.App i s arg | visible arg, A.Prop _ 0 <- unScope s -> do unlessM isPropEnabled $ typeError NeedOptionProp unlessM hasUniversePolymorphism $ genericError "Use --universe-polymorphism to enable level arguments to Prop" applyRelevanceToContext NonStrict $ sort . Prop <$> checkLevel arg -- Issue #707: Check an existing interaction point A.QuestionMark minfo ii -> caseMaybeM (lookupInteractionMeta ii) fallback $ \ x -> do -- -- | Just x <- A.metaNumber minfo -> do reportSDoc "tc.ip" 20 $ fsep [ "Rechecking meta " , prettyTCM x , text $ " for interaction point " ++ show ii ] mv <- lookupMeta x let s0 = jMetaType . mvJudgement $ mv -- Andreas, 2016-10-14, issue #2257 -- The meta was created in a context of length @n@. let n = length . envContext . clEnv . miClosRange . mvInfo $ mv (vs, rest) <- splitAt n <$> getContextArgs reportSDoc "tc.ip" 20 $ vcat [ " s0 = " <+> prettyTCM s0 , " vs = " <+> prettyTCM vs , " rest = " <+> prettyTCM rest ] -- We assume the meta variable use here is in an extension of the original context. -- If not we revert to the old buggy behavior of #707 (see test/Succeed/Issue2257b). if (length vs /= n) then fallback else do s1 <- reduce =<< piApplyM s0 vs reportSDoc "tc.ip" 20 $ vcat [ " s1 = " <+> prettyTCM s1 ] reportSDoc "tc.ip" 70 $ vcat [ " s1 = " <+> text (show s1) ] case unEl s1 of Sort s -> return $ El s $ MetaV x $ map Apply vs _ -> __IMPOSSIBLE__ _ -> fallback checkLevel :: NamedArg A.Expr -> TCM Level checkLevel arg = do lvl <- levelType levelView =<< checkNamedArg arg lvl -- | Ensure that a (freshly created) function type does not inhabit 'SizeUniv'. -- Precondition: When @noFunctionsIntoSize t tBlame@ is called, -- we are in the context of @tBlame@ in order to print it correctly. -- Not being in context of @t@ should not matter, as we are only -- checking whether its sort reduces to 'SizeUniv'. noFunctionsIntoSize :: Type -> Type -> TCM () noFunctionsIntoSize t tBlame = do reportSDoc "tc.fun" 20 $ do let El s (Pi dom b) = tBlame sep [ "created function type " <+> prettyTCM tBlame , "with pts rule (" <+> prettyTCM (getSort dom) <+> "," <+> underAbstraction_ b (prettyTCM . getSort) <+> "," <+> prettyTCM s <+> ")" ] s <- reduce $ getSort t when (s == SizeUniv) $ do -- Andreas, 2015-02-14 -- We have constructed a function type in SizeUniv -- which is illegal to prevent issue 1428. typeError $ FunctionTypeInSizeUniv $ unEl tBlame -- | Check that an expression is a type which is equal to a given type. isTypeEqualTo :: A.Expr -> Type -> TCM Type isTypeEqualTo e0 t = scopedExpr e0 >>= \case A.ScopedExpr{} -> __IMPOSSIBLE__ A.Underscore i | A.metaNumber i == Nothing -> return t e -> workOnTypes $ do t' <- isType e (getSort t) t' <$ leqType t t' leqType_ :: Type -> Type -> TCM () leqType_ t t' = workOnTypes $ leqType t t' --------------------------------------------------------------------------- -- * Telescopes --------------------------------------------------------------------------- checkGeneralizeTelescope :: A.GeneralizeTelescope -> ([Maybe Name] -> Telescope -> TCM a) -> TCM a checkGeneralizeTelescope (A.GeneralizeTel vars tel) k = generalizeTelescope vars (checkTelescope tel) k -- | Type check a (module) telescope. -- Binds the variables defined by the telescope. checkTelescope :: A.Telescope -> (Telescope -> TCM a) -> TCM a checkTelescope = checkTelescope' LamNotPi -- | Type check the telescope of a dependent function type. -- Binds the resurrected variables defined by the telescope. -- The returned telescope is unmodified (not resurrected). checkPiTelescope :: A.Telescope -> (Telescope -> TCM a) -> TCM a checkPiTelescope = checkTelescope' PiNotLam -- | Flag to control resurrection on domains. data LamOrPi = LamNotPi -- ^ We are checking a module telescope. -- We pass into the type world to check the domain type. -- This resurrects the whole context. | PiNotLam -- ^ We are checking a telescope in a Pi-type. -- We stay in the term world, but add resurrected -- domains to the context to check the remaining -- domains and codomain of the Pi-type. deriving (Eq, Show) -- | Type check a telescope. Binds the variables defined by the telescope. checkTelescope' :: LamOrPi -> A.Telescope -> (Telescope -> TCM a) -> TCM a checkTelescope' lamOrPi [] ret = ret EmptyTel checkTelescope' lamOrPi (b : tel) ret = checkTypedBindings lamOrPi b $ \tel1 -> checkTelescope' lamOrPi tel $ \tel2 -> ret $ abstract tel1 tel2 -- | Check a typed binding and extends the context with the bound variables. -- The telescope passed to the continuation is valid in the original context. -- -- Parametrized by a flag wether we check a typed lambda or a Pi. This flag -- is needed for irrelevance. checkTypedBindings :: LamOrPi -> A.TypedBinding -> (Telescope -> TCM a) -> TCM a checkTypedBindings lamOrPi (A.TBind r tac xps e) ret = do let xs = map (updateNamedArg $ A.unBind . A.binderName) xps tac <- traverse (checkTacticAttribute lamOrPi) tac whenJust tac $ \ t -> reportSDoc "tc.term.tactic" 30 $ "Checked tactic attribute:" prettyTCM t -- Andreas, 2011-04-26 irrelevant function arguments may appear -- non-strictly in the codomain type -- 2011-10-04 if flag --experimental-irrelevance is set experimental <- optExperimentalIrrelevance <$> pragmaOptions let cs = map getCohesion xps c = headWithDefault __IMPOSSIBLE__ cs unless (all (c ==) cs) $ __IMPOSSIBLE__ t <- applyCohesionToContext c $ modEnv lamOrPi $ isType_ e -- Jesper, 2019-02-12, Issue #3534: warn if the type of an -- instance argument does not have the right shape unlessNull (filter isInstance xps) $ \ixs -> do (tel, target) <- getOutputTypeName t case target of OutputTypeName{} -> return () OutputTypeVar{} -> return () OutputTypeVisiblePi{} -> warning . InstanceArgWithExplicitArg =<< prettyTCM (A.mkTBind r ixs e) OutputTypeNameNotYetKnown{} -> return () NoOutputTypeName -> warning . InstanceNoOutputTypeName =<< prettyTCM (A.mkTBind r ixs e) let setTac tac EmptyTel = EmptyTel setTac tac (ExtendTel dom tel) = ExtendTel dom{ domTactic = tac } $ setTac (raise 1 tac) <$> tel xs' = map (modMod lamOrPi experimental) xs let tel = setTac tac $ namedBindsToTel xs t addContext (xs', t) $ addTypedPatterns xps (ret tel) where -- if we are checking a typed lambda, we resurrect before we check the -- types, but do not modify the new context entries -- otherwise, if we are checking a pi, we do not resurrect, but -- modify the new context entries modEnv LamNotPi = workOnTypes modEnv _ = id modMod PiNotLam xp = (if xp then mapRelevance irrToNonStrict else id) . (setQuantity topQuantity) modMod _ _ = id checkTypedBindings lamOrPi (A.TLet _ lbs) ret = do checkLetBindings lbs (ret EmptyTel) -- | After a typed binding has been checked, add the patterns it binds addTypedPatterns :: [NamedArg A.Binder] -> TCM a -> TCM a addTypedPatterns xps ret = do let ps = mapMaybe (A.extractPattern . namedArg) xps let lbs = fmap letBinding ps checkLetBindings lbs ret where letBinding :: (A.Pattern, A.BindName) -> A.LetBinding letBinding (p, n) = A.LetPatBind (A.LetRange r) p (A.Var $ A.unBind n) where r = fuseRange p n -- | Check a tactic attribute. Should have type Term → TC ⊤. checkTacticAttribute :: LamOrPi -> A.Expr -> TCM Term checkTacticAttribute LamNotPi e = genericDocError =<< "The @tactic attribute is not allowed here" checkTacticAttribute PiNotLam e = do expectedType <- el primAgdaTerm --> el (primAgdaTCM <#> primLevelZero <@> primUnit) checkExpr e expectedType ifPath :: Type -> TCM a -> TCM a -> TCM a ifPath ty fallback work = do pv <- pathView ty if isPathType pv then work else fallback checkPath :: A.TypedBinding -> A.Expr -> Type -> TCM Term checkPath b@(A.TBind _ _ [x'] typ) body ty = do let x = updateNamedArg (A.unBind . A.binderName) x' info = getArgInfo x PathType s path level typ lhs rhs <- pathView ty interval <- elInf primInterval v <- addContext ([x], interval) $ checkExpr body (El (raise 1 s) (raise 1 (unArg typ) `apply` [argN $ var 0])) iZero <- primIZero iOne <- primIOne let lhs' = subst 0 iZero v rhs' = subst 0 iOne v let t = Lam info $ Abs (namedArgName x) v let btyp i = El s (unArg typ `apply` [argN i]) locallyTC eRange (const noRange) $ blockTerm ty $ traceCall (SetRange $ getRange body) $ do equalTerm (btyp iZero) lhs' (unArg lhs) equalTerm (btyp iOne) rhs' (unArg rhs) return t checkPath b body ty = __IMPOSSIBLE__ --------------------------------------------------------------------------- -- * Lambda abstractions --------------------------------------------------------------------------- -- | Type check a lambda expression. -- "checkLambda bs e ty" means (\ bs -> e) : ty checkLambda :: Comparison -> A.TypedBinding -> A.Expr -> Type -> TCM Term checkLambda cmp (A.TLet _ lbs) body target = checkLetBindings lbs (checkExpr body target) checkLambda cmp b@(A.TBind _ _ xps typ) body target = do reportSDoc "tc.term.lambda" 60 $ vcat [ "checkLambda xs = " <+> prettyA xps , "possiblePath = " <+> text (show (possiblePath, numbinds, unScope typ, info)) ] TelV tel btyp <- telViewUpTo numbinds target if size tel < numbinds || numbinds /= 1 then (if possiblePath then trySeeingIfPath else dontUseTargetType) else useTargetType tel btyp where xs = map (updateNamedArg (A.unBind . A.binderName)) xps numbinds = length xps isUnderscore e = case e of { A.Underscore{} -> True; _ -> False } possiblePath = numbinds == 1 && isUnderscore (unScope typ) && isRelevant info && visible info info = getArgInfo (headWithDefault __IMPOSSIBLE__ xs) trySeeingIfPath = do cubical <- optCubical <$> pragmaOptions reportSLn "tc.term.lambda" 60 $ "trySeeingIfPath for " ++ show xps let postpone' = if cubical then postpone else \ _ _ -> dontUseTargetType ifBlocked target postpone' $ \ _ t -> do ifPath t dontUseTargetType $ if cubical then checkPath b body t else genericError "Option --cubical needed to build a path with a lambda abstraction" postpone m tgt = postponeTypeCheckingProblem_ $ CheckExpr cmp (A.Lam A.exprNoRange (A.DomainFull b) body) tgt dontUseTargetType = do -- Checking λ (xs : argsT) → body : target verboseS "tc.term.lambda" 5 $ tick "lambda-no-target-type" -- First check that argsT is a valid type argsT <- workOnTypes $ isType_ typ let tel = namedBindsToTel xs argsT reportSDoc "tc.term.lambda" 60 $ "dontUseTargetType tel =" <+> pretty tel -- Andreas, 2015-05-28 Issue 1523 -- If argsT is a SizeLt, it must be non-empty to avoid non-termination. -- TODO: do we need to block checkExpr? checkSizeLtSat $ unEl argsT -- Jesper 2019-12-17, #4261: we need to postpone here if -- checking of the record pattern fails; if we try to catch -- higher up the metas created during checking of @argsT@ are -- not available. let postponeOnBlockedPattern m = m `catchIlltypedPatternBlockedOnMeta` \(err , x) -> do reportSDoc "tc.term" 50 $ vcat $ [ "checking record pattern stuck on meta: " <+> text (show x) ] t1 <- addContext (xs, argsT) $ workOnTypes newTypeMeta_ let e = A.Lam A.exprNoRange (A.DomainFull b) body tgt' = telePi tel t1 w <- postponeTypeCheckingProblem (CheckExpr cmp e tgt') $ isInstantiatedMeta x return (tgt' , w) -- Now check body : ?t₁ -- DONT USE tel for addContext, as it loses NameIds. -- WRONG: v <- addContext tel $ checkExpr body t1 (target0 , w) <- postponeOnBlockedPattern $ addContext (xs, argsT) $ addTypedPatterns xps $ do t1 <- workOnTypes newTypeMeta_ v <- checkExpr' cmp body t1 return (telePi tel t1 , teleLam tel v) -- Do not coerce hidden lambdas if notVisible info || any notVisible xs then do pid <- newProblem_ $ leqType target0 target blockTermOnProblem target w pid else do coerce cmp w target0 target useTargetType tel@(ExtendTel dom (Abs y EmptyTel)) btyp = do verboseS "tc.term.lambda" 5 $ tick "lambda-with-target-type" reportSLn "tc.term.lambda" 60 $ "useTargetType y = " ++ y let [x] = xs unless (sameHiding dom info) $ typeError $ WrongHidingInLambda target -- Andreas, 2011-10-01 ignore relevance in lambda if not explicitly given info <- lambdaModalityCheck dom info -- Andreas, 2015-05-28 Issue 1523 -- Ensure we are not stepping under a possibly non-existing size. -- TODO: do we need to block checkExpr? let a = unDom dom checkSizeLtSat $ unEl a -- We only need to block the final term on the argument type -- comparison. The body will be blocked if necessary. We still want to -- compare the argument types first, so we spawn a new problem for that -- check. (pid, argT) <- newProblem $ isTypeEqualTo typ a -- Andreas, Issue 630: take name from function type if lambda name is "_" v <- lambdaAddContext (namedArg x) y (defaultArgDom info argT) $ addTypedPatterns xps $ checkExpr' cmp body btyp blockTermOnProblem target (Lam info $ Abs (namedArgName x) v) pid useTargetType _ _ = __IMPOSSIBLE__ -- | Check that modality info in lambda is compatible with modality -- coming from the function type. -- If lambda has no user-given modality, copy that of function type. lambdaModalityCheck :: LensModality dom => dom -> ArgInfo -> TCM ArgInfo lambdaModalityCheck dom = lambdaCohesionCheck m <=< lambdaQuantityCheck m <=< lambdaIrrelevanceCheck m where m = getModality dom -- | Check that irrelevance info in lambda is compatible with irrelevance -- coming from the function type. -- If lambda has no user-given relevance, copy that of function type. lambdaIrrelevanceCheck :: LensRelevance dom => dom -> ArgInfo -> TCM ArgInfo lambdaIrrelevanceCheck dom info -- Case: no specific user annotation: use relevance of function type | getRelevance info == defaultRelevance = return $ setRelevance (getRelevance dom) info -- Case: explicit user annotation is taken seriously | otherwise = do let rPi = getRelevance dom -- relevance of function type let rLam = getRelevance info -- relevance of lambda -- Andreas, 2017-01-24, issue #2429 -- we should report an error if we try to check a relevant function -- against an irrelevant function type (subtyping violation) unless (moreRelevant rPi rLam) $ do -- @rLam == Relevant@ is impossible here -- @rLam == Irrelevant@ is impossible here (least relevant) -- this error can only happen if @rLam == NonStrict@ and @rPi == Irrelevant@ unless (rLam == NonStrict) __IMPOSSIBLE__ -- separate tests for separate line nums unless (rPi == Irrelevant) __IMPOSSIBLE__ typeError WrongIrrelevanceInLambda return info -- | Check that quantity info in lambda is compatible with quantity -- coming from the function type. -- If lambda has no user-given quantity, copy that of function type. lambdaQuantityCheck :: LensQuantity dom => dom -> ArgInfo -> TCM ArgInfo lambdaQuantityCheck dom info -- Case: no specific user annotation: use quantity of function type | noUserQuantity info = return $ setQuantity (getQuantity dom) info -- Case: explicit user annotation is taken seriously | otherwise = do let qPi = getQuantity dom -- quantity of function type let qLam = getQuantity info -- quantity of lambda unless (qPi `moreQuantity` qLam) $ do typeError WrongQuantityInLambda return info -- | Check that cohesion info in lambda is compatible with cohesion -- coming from the function type. -- If lambda has no user-given cohesion, copy that of function type. lambdaCohesionCheck :: LensCohesion dom => dom -> ArgInfo -> TCM ArgInfo lambdaCohesionCheck dom info -- Case: no specific user annotation: use cohesion of function type | getCohesion info == defaultCohesion = return $ setCohesion (getCohesion dom) info -- Case: explicit user annotation is taken seriously | otherwise = do let cPi = getCohesion dom -- cohesion of function type let cLam = getCohesion info -- cohesion of lambda unless (cPi `sameCohesion` cLam) $ do -- if there is a cohesion annotation then -- it better match the domain. typeError WrongCohesionInLambda return info lambdaAddContext :: Name -> ArgName -> Dom Type -> TCM a -> TCM a lambdaAddContext x y dom | isNoName x = addContext (y, dom) -- Note: String instance | otherwise = addContext (x, dom) -- Name instance of addContext -- | Checking a lambda whose domain type has already been checked. checkPostponedLambda :: Comparison -> Arg ([WithHiding Name], Maybe Type) -> A.Expr -> Type -> TCM Term checkPostponedLambda cmp args@(Arg _ ([] , _ )) body target = do checkExpr' cmp body target checkPostponedLambda cmp args@(Arg info (WithHiding h x : xs, mt)) body target = do let postpone _ t = postponeTypeCheckingProblem_ $ CheckLambda cmp args body t lamHiding = mappend h $ getHiding info insertHiddenLambdas lamHiding target postpone $ \ t@(El _ (Pi dom b)) -> do -- Andreas, 2011-10-01 ignore relevance in lambda if not explicitly given info' <- setHiding lamHiding <$> lambdaModalityCheck dom info -- We only need to block the final term on the argument type -- comparison. The body will be blocked if necessary. We still want to -- compare the argument types first, so we spawn a new problem for that -- check. mpid <- caseMaybe mt (return Nothing) $ \ ascribedType -> Just <$> do newProblem_ $ leqType (unDom dom) ascribedType -- We type-check the body with the ascribedType given by the user -- to get better error messages. -- Using the type dom from the usage context would be more precise, -- though. -- TODO: quantity let dom' = setRelevance (getRelevance info') . setHiding lamHiding $ maybe dom (dom $>) mt v <- lambdaAddContext x (absName b) dom' $ checkPostponedLambda cmp (Arg info (xs, mt)) body $ absBody b let v' = Lam info' $ Abs (nameToArgName x) v maybe (return v') (blockTermOnProblem t v') mpid -- | Insert hidden lambda until the hiding info of the domain type -- matches the expected hiding info. -- Throws 'WrongHidingInLambda' insertHiddenLambdas :: Hiding -- ^ Expected hiding. -> Type -- ^ Expected to be a function type. -> (MetaId -> Type -> TCM Term) -- ^ Continuation on blocked type. -> (Type -> TCM Term) -- ^ Continuation when expected hiding found. -- The continuation may assume that the @Type@ -- is of the form @(El _ (Pi _ _))@. -> TCM Term -- ^ Term with hidden lambda inserted. insertHiddenLambdas h target postpone ret = do -- If the target type is blocked, we postpone, -- because we do not know if a hidden lambda needs to be inserted. ifBlocked target postpone $ \ _ t -> do case unEl t of Pi dom b -> do let h' = getHiding dom -- Found expected hiding: return function type. if sameHiding h h' then ret t else do -- Found a visible argument but expected a hidden one: -- That's an error, as we cannot insert a visible lambda. if visible h' then typeError $ WrongHidingInLambda target else do -- Otherwise, we found a hidden argument that we can insert. let x = absName b Lam (setOrigin Inserted $ domInfo dom) . Abs x <$> do addContext (x, dom) $ insertHiddenLambdas h (absBody b) postpone ret _ -> typeError . GenericDocError =<< do "Expected " <+> prettyTCM target <+> " to be a function type" -- | @checkAbsurdLambda i h e t@ checks absurd lambda against type @t@. -- Precondition: @e = AbsurdLam i h@ checkAbsurdLambda :: Comparison -> A.ExprInfo -> Hiding -> A.Expr -> Type -> TCM Term checkAbsurdLambda cmp i h e t = localTC (set eQuantity topQuantity) $ do -- Andreas, 2019-10-01: check absurd lambdas in non-erased mode. -- Otherwise, they are not usable in meta-solutions in the term world. -- See test/Succeed/Issue3176.agda for an absurd lambda -- created in types. t <- instantiateFull t ifBlocked t (\ m t' -> postponeTypeCheckingProblem_ $ CheckExpr cmp e t') $ \ _ t' -> do case unEl t' of Pi dom@(Dom{domInfo = info', unDom = a}) b | not (sameHiding h info') -> typeError $ WrongHidingInLambda t' | not (noMetas a) -> postponeTypeCheckingProblem (CheckExpr cmp e t') $ noMetas <$> instantiateFull a | otherwise -> blockTerm t' $ do ensureEmptyType (getRange i) a -- Add helper function top <- currentModule aux <- qualify top <$> freshName_ (getRange i, absurdLambdaName) -- if we are in irrelevant / erased position, the helper function -- is added as irrelevant / erased mod <- asksTC getModality reportSDoc "tc.term.absurd" 10 $ vcat [ ("Adding absurd function" <+> prettyTCM mod) <> prettyTCM aux , nest 2 $ "of type" <+> prettyTCM t' ] addConstant aux $ (\ d -> (defaultDefn (setModality mod info') aux t' d) { defPolarity = [Nonvariant] , defArgOccurrences = [Unused] }) $ emptyFunction { funClauses = [ Clause { clauseLHSRange = getRange e , clauseFullRange = getRange e , clauseTel = telFromList [fmap (absurdPatternName,) dom] , namedClausePats = [Arg info' $ Named (Just $ WithOrigin Inserted $ unranged $ absName b) $ absurdP 0] , clauseBody = Nothing , clauseType = Just $ setModality mod $ defaultArg $ absBody b , clauseCatchall = False , clauseRecursive = Just False , clauseUnreachable = Just True -- absurd clauses are unreachable , clauseEllipsis = NoEllipsis } ] , funCompiled = Just Fail , funSplitTree = Just $ SplittingDone 0 , funMutual = Just [] , funTerminates = Just True } -- Andreas 2012-01-30: since aux is lifted to toplevel -- it needs to be applied to the current telescope (issue 557) tel <- getContextTelescope return $ Def aux $ map Apply $ teleArgs tel _ -> typeError $ ShouldBePi t' -- | @checkExtendedLambda i di qname cs e t@ check pattern matching lambda. -- Precondition: @e = ExtendedLam i di qname cs@ checkExtendedLambda :: Comparison -> A.ExprInfo -> A.DefInfo -> QName -> [A.Clause] -> A.Expr -> Type -> TCM Term checkExtendedLambda cmp i di qname cs e t = localTC (set eQuantity topQuantity) $ do -- Andreas, 2019-10-01: check extended lambdas in non-erased mode. -- Otherwise, they are not usable in meta-solutions in the term world. -- See test/Succeed/Issue{3581}.agda for an extended lambda -- created in a type. -- Andreas, 2016-06-16 issue #2045 -- Try to get rid of unsolved size metas before we -- fix the type of the extended lambda auxiliary function solveSizeConstraints DontDefaultToInfty lamMod <- inFreshModuleIfFreeParams currentModule -- #2883: need a fresh module if refined params t <- instantiateFull t ifBlocked t (\ m t' -> postponeTypeCheckingProblem_ $ CheckExpr cmp e t') $ \ _ t -> do j <- currentOrFreshMutualBlock mod <- asksTC getModality let info = setModality mod defaultArgInfo reportSDoc "tc.term.exlam" 20 $ (text (show $ A.defAbstract di) <+> "extended lambda's implementation \"") <> prettyTCM qname <> "\" has type: " $$ prettyTCM t -- <+> " where clauses: " <+> text (show cs) args <- getContextArgs -- Andreas, Ulf, 2016-02-02: We want to postpone type checking an extended lambda -- in case the lhs checker failed due to insufficient type info for the patterns. -- Issues 480, 1159, 1811. (abstract (A.defAbstract di) $ do -- Andreas, 2013-12-28: add extendedlambda as @Function@, not as @Axiom@; -- otherwise, @addClause@ in @checkFunDef'@ fails (see issue 1009). addConstant qname =<< do useTerPragma $ (defaultDefn info qname t emptyFunction) { defMutual = j } checkFunDef' t info NotDelayed (Just $ ExtLamInfo lamMod empty) Nothing di qname cs whenNothingM (asksTC envMutualBlock) $ -- Andrea 10-03-2018: Should other checks be performed here too? e.g. termination/positivity/.. checkIApplyConfluence_ qname return $ Def qname $ map Apply args) where -- Concrete definitions cannot use information about abstract things. abstract ConcreteDef = inConcreteMode abstract AbstractDef = inAbstractMode -- | Run a computation. -- -- * If successful, that's it, we are done. -- -- * If @IlltypedPattern p a@, @NotADatatype a@ or @CannotEliminateWithPattern p a@ -- is thrown and type @a@ is blocked on some meta @x@, -- reset any changes to the state and pass (the error and) @x@ to the handler. -- -- * If @SplitError (UnificationStuck c tel us vs _)@ is thrown and the unification -- problem @us =?= vs : tel@ is blocked on some meta @x@ pass @x@ to the handler. -- -- * If another error was thrown or the type @a@ is not blocked, reraise the error. -- -- Note that the returned meta might only exists in the state where the error was -- thrown, thus, be an invalid 'MetaId' in the current state. -- catchIlltypedPatternBlockedOnMeta :: TCM a -> ((TCErr, MetaId) -> TCM a) -> TCM a catchIlltypedPatternBlockedOnMeta m handle = do -- Andreas, 2016-07-13, issue 2028. -- Save the state to rollback the changes to the signature. st <- getTC m `catchError` \ err -> do let reraise = throwError err -- Get the blocking meta responsible for the type error. -- If we do not find such a meta or the error should not be handled, -- we reraise the error. x <- maybe reraise return =<< do case err of TypeError s cl -> localTCState $ do putTC s enterClosure cl $ \case IlltypedPattern p a -> isBlocked a SplitError (UnificationStuck c tel us vs _) -> do -- Andreas, 2018-11-23, re issue #3403 -- The following computation of meta-variables and picking -- of the first one, seems a bit brittle. -- I do not understand why there is a single @reduce@ here -- (seems to archieve a bit along @normalize@, but how much??). problem <- reduce =<< instantiateFull (flattenTel tel, us, vs) -- over-approximating the set of metas actually blocking unification return $ firstMeta problem SplitError (NotADatatype aClosure) -> enterClosure aClosure $ \ a -> isBlocked a -- Andrea: TODO look for blocking meta in tClosure and its Sort. -- SplitError (CannotCreateMissingClause _ _ _ tClosure) -> CannotEliminateWithPattern p a -> isBlocked a _ -> return Nothing _ -> return Nothing reportSDoc "tc.postpone" 20 $ vcat $ [ "checking definition blocked on meta: " <+> prettyTCM x ] -- Note that we messed up the state a bit. We might want to unroll these state changes. -- However, they are mostly harmless: -- 1. We created a new mutual block id. -- 2. We added a constant without definition. -- In fact, they are not so harmless, see issue 2028! -- Thus, reset the state! putTC st -- The meta might not be known in the reset state, as it could have been created -- somewhere on the way to the type error. lookupMeta' x >>= \case -- Case: we do not know the meta, so we reraise. Nothing -> reraise -- Case: we know the meta here. -- Andreas, 2018-11-23: I do not understand why @InstV@ is necessarily impossible. -- The reasoning is probably that the state @st@ is more advanced that @s@ -- in which @x@ was blocking, thus metas in @st@ should be more instantiated than -- in @s@. But issue #3403 presents a counterexample, so let's play save and reraise -- Just m | InstV{} <- mvInstantiation m -> __IMPOSSIBLE__ -- It cannot be instantiated yet. Just m | InstV{} <- mvInstantiation m -> reraise -- Case: the meta is frozen (and not an interaction meta). -- Postponing doesn't make sense, so we reraise. Just m | Frozen <- mvFrozen m -> isInteractionMeta x >>= \case Nothing -> reraise -- Remaining cases: the meta is known and can still be instantiated. Just{} -> handle (err, x) Just{} -> handle (err, x) --------------------------------------------------------------------------- -- * Records --------------------------------------------------------------------------- -- | Picks up record field assignments from modules that export a definition -- that has the same name as the missing field. expandModuleAssigns :: [Either A.Assign A.ModuleName] -- ^ Modules and field assignments. -> [C.Name] -- ^ Names of fields of the record type. -> TCM A.Assigns -- ^ Completed field assignments from modules. expandModuleAssigns mfs xs = do let (fs , ms) = partitionEithers mfs -- The fields of the record that have not been given by field assignments @fs@ -- are looked up in the given modules @ms@. fs' <- forM (xs List.\\ map (view nameFieldA) fs) $ \ f -> do -- Get the possible assignments for field f from the modules. pms <- forM ms $ \ m -> do modScope <- getNamedScope m let names :: ThingsInScope AbstractName names = exportedNamesInScope modScope return $ case Map.lookup f names of Just [n] -> Just (m, FieldAssignment f $ killRange $ A.nameToExpr n) _ -> Nothing -- If we have several matching assignments, that's an error. case catMaybes pms of [] -> return Nothing [(_, fa)] -> return (Just fa) mfas -> typeError . GenericDocError =<< do vcat $ [ "Ambiguity: the field" <+> prettyTCM f <+> "appears in the following modules: " ] ++ map (prettyTCM . fst) mfas return (fs ++ catMaybes fs') -- | @checkRecordExpression fs e t@ checks record construction against type @t@. -- Precondition @e = Rec _ fs@. checkRecordExpression :: Comparison -- ^ How do we related the inferred type of the record expression -- to the expected type? Subtype or equal type? -> A.RecordAssigns -- ^ @mfs@: modules and field assignments. -> A.Expr -- ^ Must be @A.Rec _ mfs@. -> Type -- ^ Expected type of record expression. -> TCM Term -- ^ Record value in internal syntax. checkRecordExpression cmp mfs e t = do reportSDoc "tc.term.rec" 10 $ sep [ "checking record expression" , prettyA e ] ifBlocked t (\ _ t -> guessRecordType t) {-else-} $ \ _ t -> do case unEl t of -- Case: We know the type of the record already. Def r es -> do let ~(Just vs) = allApplyElims es reportSDoc "tc.term.rec" 20 $ text $ " r = " ++ prettyShow r reportSDoc "tc.term.rec" 30 $ " xs = " <> do text =<< prettyShow . map unDom <$> getRecordFieldNames r reportSDoc "tc.term.rec" 30 $ " ftel= " <> do prettyTCM =<< getRecordFieldTypes r reportSDoc "tc.term.rec" 30 $ " con = " <> do text =<< prettyShow <$> getRecordConstructor r def <- getRecordDef r let -- Field names (C.Name) with ArgInfo from record type definition. cxs = map argFromDom $ recordFieldNames def -- Just field names. xs = map unArg cxs -- Record constructor. con = killRange $ recConHead def reportSDoc "tc.term.rec" 20 $ vcat [ " xs = " <> return (P.pretty xs) , " ftel= " <> prettyTCM (recTel def) , " con = " <> return (P.pretty con) ] -- Andreas, 2018-09-06, issue #3122. -- Associate the concrete record field names used in the record expression -- to their counterpart in the record type definition. disambiguateRecordFields (map _nameFieldA $ lefts mfs) (map unDom $ recFields def) -- Compute the list of given fields, decorated with the ArgInfo from the record def. -- Andreas, 2019-03-18, issue #3122, also pick up non-visible fields from the modules. fs <- expandModuleAssigns mfs (map unArg cxs) -- Compute a list of metas for the missing visible fields. scope <- getScope let re = getRange e meta x = A.Underscore $ A.MetaInfo re scope Nothing (prettyShow x) -- In @es@ omitted explicit fields are replaced by underscores. -- Omitted implicit or instance fields -- are still left out and inserted later by checkArguments_. es <- insertMissingFields r meta fs cxs args <- checkArguments_ ExpandLast re es (recTel def `apply` vs) >>= \case (elims, remainingTel) | null remainingTel , Just args <- allApplyElims elims -> return args _ -> __IMPOSSIBLE__ -- Don't need to block here! reportSDoc "tc.term.rec" 20 $ text $ "finished record expression" return $ Con con ConORec (map Apply args) _ -> typeError $ ShouldBeRecordType t where -- Case: We don't know the type of the record. guessRecordType t = do let fields = [ x | Left (FieldAssignment x _) <- mfs ] rs <- findPossibleRecords fields case rs of -- If there are no records with the right fields we might as well fail right away. [] -> case fields of [] -> genericError "There are no records in scope" [f] -> genericError $ "There is no known record with the field " ++ prettyShow f _ -> genericError $ "There is no known record with the fields " ++ unwords (map prettyShow fields) -- If there's only one record with the appropriate fields, go with that. [r] -> do def <- getConstInfo r let rt = defType def vs <- newArgsMeta rt target <- reduce $ piApply rt vs s <- case unEl target of Sort s -> return s v -> do reportSDoc "impossible" 10 $ vcat [ "The impossible happened when checking record expression against meta" , "Candidate record type r = " <+> prettyTCM r , "Type of r = " <+> prettyTCM rt , "Ends in (should be sort)= " <+> prettyTCM v , text $ " Raw = " ++ show v ] __IMPOSSIBLE__ let inferred = El s $ Def r $ map Apply vs v <- checkExpr e inferred coerce cmp v inferred t -- Andreas 2012-04-21: OLD CODE, WRONG DIRECTION, I GUESS: -- blockTerm t $ v <$ leqType_ t inferred -- If there are more than one possible record we postpone _:_:_ -> do reportSDoc "tc.term.expr.rec" 10 $ sep [ "Postponing type checking of" , nest 2 $ prettyA e <+> ":" <+> prettyTCM t ] postponeTypeCheckingProblem_ $ CheckExpr cmp e t -- | @checkRecordUpdate cmp ei recexpr fs e t@ -- -- Preconditions: @e = RecUpdate ei recexpr fs@ and @t@ is reduced. -- checkRecordUpdate :: Comparison -- ^ @cmp@ -> A.ExprInfo -- ^ @ei@ -> A.Expr -- ^ @recexpr@ -> A.Assigns -- ^ @fs@ -> A.Expr -- ^ @e = RecUpdate ei recexpr fs@ -> Type -- ^ Reduced. -> TCM Term checkRecordUpdate cmp ei recexpr fs e t = do case unEl t of Def r vs -> do v <- checkExpr' cmp recexpr t name <- freshNoName (getRange recexpr) addLetBinding defaultArgInfo name v t $ do projs <- map argFromDom . recFields <$> getRecordDef r -- Andreas, 2018-09-06, issue #3122. -- Associate the concrete record field names used in the record expression -- to their counterpart in the record type definition. disambiguateRecordFields (map _nameFieldA fs) (map unArg projs) axs <- map argFromDom <$> getRecordFieldNames r let xs = map unArg axs es <- orderFields r (\ _ -> Nothing) axs $ map (\ (FieldAssignment x e) -> (x, Just e)) fs let es' = zipWith (replaceFields name ei) projs es checkExpr' cmp (A.Rec ei [ Left (FieldAssignment x e) | (x, Just e) <- zip xs es' ]) t MetaV _ _ -> do inferred <- inferExpr recexpr >>= reduce . snd case unEl inferred of MetaV _ _ -> postponeTypeCheckingProblem_ $ CheckExpr cmp e t _ -> do v <- checkExpr' cmp e inferred coerce cmp v inferred t _ -> typeError $ ShouldBeRecordType t where replaceFields :: Name -> A.ExprInfo -> Arg A.QName -> Maybe A.Expr -> Maybe A.Expr replaceFields n ei a@(Arg _ p) Nothing | visible a = Just $ A.App (A.defaultAppInfo $ getRange ei) (A.Def p) $ defaultNamedArg $ A.Var n replaceFields _ _ (Arg _ _) Nothing = Nothing replaceFields _ _ _ (Just e) = Just $ e --------------------------------------------------------------------------- -- * Literal --------------------------------------------------------------------------- checkLiteral :: Literal -> Type -> TCM Term checkLiteral lit t = do t' <- litType lit coerce CmpEq (Lit lit) t' t --------------------------------------------------------------------------- -- * Terms --------------------------------------------------------------------------- -- | Remove top layers of scope info of expression and set the scope accordingly -- in the 'TCState'. scopedExpr :: A.Expr -> TCM A.Expr scopedExpr (A.ScopedExpr scope e) = setScope scope >> scopedExpr e scopedExpr e = return e -- | Type check an expression. checkExpr :: A.Expr -> Type -> TCM Term checkExpr = checkExpr' CmpLeq -- Andreas, 2019-10-13, issue #4125: -- For the sake of readable types in interactive program construction, -- avoid unnecessary unfoldings via 'reduce' in the type checker! checkExpr' :: Comparison -> A.Expr -> Type -- ^ Unreduced! -> TCM Term checkExpr' cmp e t = verboseBracket "tc.term.expr.top" 5 "checkExpr" $ reportResult "tc.term.expr.top" 15 (\ v -> vcat [ "checkExpr" fsep [ prettyTCM e, ":", prettyTCM t ] , " returns" prettyTCM v ]) $ traceCall (CheckExprCall cmp e t) $ localScope $ doExpandLast $ unfoldInlined =<< do reportSDoc "tc.term.expr.top" 15 $ "Checking" <+> sep [ fsep [ prettyTCM e, ":", prettyTCM t ] , nest 2 $ "at " <+> (text . prettyShow =<< getCurrentRange) ] reportSDoc "tc.term.expr.top.detailed" 80 $ "Checking" <+> fsep [ prettyTCM e, ":", text (show t) ] tReduced <- reduce t reportSDoc "tc.term.expr.top" 15 $ " --> " <+> prettyTCM tReduced e <- scopedExpr e irrelevantIfProp <- isPropM t >>= \case True -> do let mod = defaultModality { modRelevance = Irrelevant } return $ fmap dontCare . applyModalityToContext mod False -> return id irrelevantIfProp $ tryInsertHiddenLambda e tReduced $ case e of A.ScopedExpr scope e -> __IMPOSSIBLE__ -- setScope scope >> checkExpr e t -- a meta variable without arguments: type check directly for efficiency A.QuestionMark i ii -> checkQuestionMark (newValueMeta' RunMetaOccursCheck) cmp t i ii A.Underscore i -> checkUnderscore cmp t i A.WithApp _ e es -> typeError $ NotImplemented "type checking of with application" -- check |- Set l : t (requires universe polymorphism) A.App i s arg@(Arg ai l) | A.Set _ 0 <- unScope s, visible ai -> ifNotM hasUniversePolymorphism (genericError "Use --universe-polymorphism to enable level arguments to Set") $ {- else -} do -- allow NonStrict variables when checking level -- Set : (NonStrict) Level -> Set\omega n <- applyRelevanceToContext NonStrict $ checkLevel arg -- check that Set (l+1) <= t reportSDoc "tc.univ.poly" 10 $ "checking Set " <+> prettyTCM n <+> "against" <+> prettyTCM t coerce cmp (Sort $ Type n) (sort $ Type $ levelSuc n) t -- check |- Prop l : t (requires universe polymorphism) A.App i s arg@(Arg ai l) | A.Prop _ 0 <- unScope s, visible ai -> ifNotM hasUniversePolymorphism (genericError "Use --universe-polymorphism to enable level arguments to Prop") $ {- else -} do n <- applyRelevanceToContext NonStrict $ checkLevel arg reportSDoc "tc.univ.poly" 10 $ "checking Prop " <+> prettyTCM n <+> "against" <+> prettyTCM t coerce cmp (Sort $ Prop n) (sort $ Type $ levelSuc n) t e0@(A.App i q (Arg ai e)) | A.Quote _ <- unScope q, visible ai -> do let quoted (A.Def x) = return x quoted (A.Macro x) = return x quoted (A.Proj o p) | Just x <- getUnambiguous p = return x quoted (A.Proj o p) = genericError $ "quote: Ambigous name: " ++ prettyShow (unAmbQ p) quoted (A.Con c) | Just x <- getUnambiguous c = return x quoted (A.Con c) = genericError $ "quote: Ambigous name: " ++ prettyShow (unAmbQ c) quoted (A.ScopedExpr _ e) = quoted e quoted _ = genericError "quote: not a defined name" x <- quoted (namedThing e) ty <- qNameType coerce cmp (quoteName x) ty t | A.QuoteTerm _ <- unScope q -> do (et, _) <- inferExpr (namedThing e) doQuoteTerm cmp et t A.Quote{} -> genericError "quote must be applied to a defined name" A.QuoteTerm{} -> genericError "quoteTerm must be applied to a term" A.Unquote{} -> genericError "unquote must be applied to a term" A.AbsurdLam i h -> checkAbsurdLambda cmp i h e t A.ExtendedLam i di qname cs -> checkExtendedLambda cmp i di qname cs e t A.Lam i (A.DomainFull b) e -> checkLambda cmp b e t A.Lam i (A.DomainFree _ x) e0 | isNothing (nameOf $ unArg x) && isNothing (A.binderPattern $ namedArg x) -> checkExpr' cmp (A.Lam i (domainFree (getArgInfo x) $ fmap A.unBind $ namedArg x) e0) t | otherwise -> typeError $ NotImplemented "named arguments in lambdas" A.Lit lit -> checkLiteral lit t A.Let i ds e -> checkLetBindings ds $ checkExpr' cmp e t A.Pi _ tel e | null tel -> checkExpr' cmp e t A.Pi _ tel e -> do (t0, t') <- checkPiTelescope tel $ \ tel -> do t0 <- instantiateFull =<< isType_ e tel <- instantiateFull tel return (t0, telePi tel t0) checkTelePiSort t' noFunctionsIntoSize t0 t' let s = getSort t' v = unEl t' when (s == Inf) $ reportSDoc "tc.term.sort" 20 $ vcat [ text ("reduced to omega:") , nest 2 $ "t =" <+> prettyTCM t' , nest 2 $ "cxt =" <+> (prettyTCM =<< getContextTelescope) ] coerce cmp v (sort s) t A.Generalized s e -> do (_, t') <- generalizeType s $ isType_ e noFunctionsIntoSize t' t' let s = getSort t' v = unEl t' when (s == Inf) $ reportSDoc "tc.term.sort" 20 $ vcat [ text ("reduced to omega:") , nest 2 $ "t =" <+> prettyTCM t' , nest 2 $ "cxt =" <+> (prettyTCM =<< getContextTelescope) ] coerce cmp v (sort s) t A.Fun _ (Arg info a) b -> do a' <- isType_ a let adom = defaultArgDom info a' b' <- isType_ b s <- inferFunSort (getSort a') (getSort b') let v = Pi adom (NoAbs underscore b') noFunctionsIntoSize b' $ El s v coerce cmp v (sort s) t A.Set _ n -> do coerce cmp (Sort $ mkType n) (sort $ mkType $ n + 1) t A.Prop _ n -> do unlessM isPropEnabled $ typeError NeedOptionProp coerce cmp (Sort $ mkProp n) (sort $ mkType $ n + 1) t A.Rec _ fs -> checkRecordExpression cmp fs e t A.RecUpdate ei recexpr fs -> checkRecordUpdate cmp ei recexpr fs e tReduced A.DontCare e -> -- resurrect vars ifM ((Irrelevant ==) <$> asksTC getRelevance) (dontCare <$> do applyRelevanceToContext Irrelevant $ checkExpr' cmp e t) (internalError "DontCare may only appear in irrelevant contexts") A.ETel _ -> __IMPOSSIBLE__ A.Dot{} -> genericError "Invalid dotted expression" -- Application _ | Application hd args <- appView e -> checkApplication cmp hd args e t `catchIlltypedPatternBlockedOnMeta` \ (err, x) -> do -- We could not check the term because the type of some pattern is blocked. -- It has to be blocked on some meta, so we can postpone, -- being sure it will be retried when a meta is solved -- (which might be the blocking meta in which case we actually make progress). reportSDoc "tc.term" 50 $ vcat $ [ "checking pattern got stuck on meta: " <+> text (show x) ] postponeTypeCheckingProblem (CheckExpr cmp e t) $ isInstantiatedMeta x where -- | Call checkExpr with an hidden lambda inserted if appropriate, -- else fallback. tryInsertHiddenLambda :: A.Expr -> Type -- ^ Reduced. -> TCM Term -> TCM Term tryInsertHiddenLambda e tReduced fallback -- Insert hidden lambda if all of the following conditions are met: -- type is a hidden function type, {x : A} -> B or {{x : A}} -> B -- expression is not a lambda with the appropriate hiding yet | Pi (Dom{domInfo = info, unDom = a}) b <- unEl tReduced , let h = getHiding info , notVisible h -- expression is not a matching hidden lambda or question mark , not (hiddenLambdaOrHole h e) = do let proceed = doInsert (setOrigin Inserted info) $ absName b expandHidden <- asksTC envExpandLast -- If we skip the lambda insertion for an introduction, -- we will hit a dead end, so proceed no matter what. if definitelyIntroduction then proceed else -- #3019 and #4170: don't insert implicit lambdas in arguments to existing metas if expandHidden == ReallyDontExpandLast then fallback else do -- Andreas, 2017-01-19, issue #2412: -- We do not want to insert a hidden lambda if A is -- possibly empty type of sizes, as this will produce an error. reduce a >>= isSizeType >>= \case Just (BoundedLt u) -> ifBlocked u (\ _ _ -> fallback) $ \ _ v -> do ifM (checkSizeNeverZero v) proceed fallback `catchError` \_ -> fallback _ -> proceed | otherwise = fallback where re = getRange e rx = caseMaybe (rStart re) noRange $ \ pos -> posToRange pos pos doInsert info y = do x <- C.setNotInScope <$> freshName rx y reportSLn "tc.term.expr.impl" 15 $ "Inserting implicit lambda" checkExpr' cmp (A.Lam (A.ExprRange re) (domainFree info $ A.mkBinder x) e) tReduced hiddenLambdaOrHole h e = case e of A.AbsurdLam _ h' -> sameHiding h h' A.ExtendedLam _ _ _ cls -> any hiddenLHS cls A.Lam _ bind _ -> sameHiding h bind A.QuestionMark{} -> True _ -> False hiddenLHS (A.Clause (A.LHS _ (A.LHSHead _ (a : _))) _ _ _ _) = notVisible a hiddenLHS _ = False -- Things with are definitely introductions, -- thus, cannot be of hidden Pi-type, unless they are hidden lambdas. definitelyIntroduction = case e of A.Lam{} -> True A.AbsurdLam{} -> True A.Lit{} -> True A.Pi{} -> True A.Fun{} -> True A.Set{} -> True A.Prop{} -> True A.Rec{} -> True A.RecUpdate{} -> True A.ScopedExpr{} -> __IMPOSSIBLE__ A.ETel{} -> __IMPOSSIBLE__ _ -> False --------------------------------------------------------------------------- -- * Reflection --------------------------------------------------------------------------- doQuoteTerm :: Comparison -> Term -> Type -> TCM Term doQuoteTerm cmp et t = do et' <- etaContract =<< instantiateFull et case allMetasList et' of [] -> do q <- quoteTerm et' ty <- el primAgdaTerm coerce cmp q ty t metas -> postponeTypeCheckingProblem (DoQuoteTerm cmp et t) $ andM $ map isInstantiatedMeta metas -- | Unquote a TCM computation in a given hole. unquoteM :: A.Expr -> Term -> Type -> TCM () unquoteM tacA hole holeType = do tac <- checkExpr tacA =<< (el primAgdaTerm --> el (primAgdaTCM <#> primLevelZero <@> primUnit)) inFreshModuleIfFreeParams $ unquoteTactic tac hole holeType -- | Run a tactic `tac : Term → TC ⊤` in a hole (second argument) of the type -- given by the third argument. Runs the continuation if successful. unquoteTactic :: Term -> Term -> Type -> TCM () unquoteTactic tac hole goal = do reportSDoc "tc.term.tactic" 40 $ sep [ "Running tactic" <+> prettyTCM tac , nest 2 $ "on" <+> prettyTCM hole <+> ":" <+> prettyTCM goal ] ok <- runUnquoteM $ unquoteTCM tac hole case ok of Left (BlockedOnMeta oldState x) -> do putTC oldState mi <- lookupMeta' x (r, meta) <- case mi of Nothing -> do -- fresh meta: need to block on something else! (noRange,) . firstMeta <$> instantiateFull goal -- Remark: -- Nothing: Nothing to block on, leave it yellow. Alternative: fail. -- Just x: range? Just mi -> return (getRange mi, Just x) setCurrentRange r $ addConstraint (UnquoteTactic meta tac hole goal) Left err -> typeError $ UnquoteFailed err Right _ -> return () --------------------------------------------------------------------------- -- * Meta variables --------------------------------------------------------------------------- -- | Check an interaction point without arguments. checkQuestionMark :: (Comparison -> Type -> TCM (MetaId, Term)) -> Comparison -> Type -- ^ Not reduced! -> A.MetaInfo -> InteractionId -> TCM Term checkQuestionMark new cmp t0 i ii = do reportSDoc "tc.interaction" 20 $ sep [ "Found interaction point" , text . show =<< asksTC (^. lensIsAbstract) , pretty ii , ":" , prettyTCM t0 ] reportSDoc "tc.interaction" 60 $ sep [ "Raw:" , text (show t0) ] checkMeta (newQuestionMark' new ii) cmp t0 i -- Andreas, 2013-05-22 use unreduced type t0! -- | Check an underscore without arguments. checkUnderscore :: Comparison -> Type -> A.MetaInfo -> TCM Term checkUnderscore = checkMeta (newValueMeta RunMetaOccursCheck) -- | Type check a meta variable. checkMeta :: (Comparison -> Type -> TCM (MetaId, Term)) -> Comparison -> Type -> A.MetaInfo -> TCM Term checkMeta newMeta cmp t i = fst <$> checkOrInferMeta newMeta (Just (cmp , t)) i -- | Infer the type of a meta variable. -- If it is a new one, we create a new meta for its type. inferMeta :: (Comparison -> Type -> TCM (MetaId, Term)) -> A.MetaInfo -> TCM (Elims -> Term, Type) inferMeta newMeta i = mapFst applyE <$> checkOrInferMeta newMeta Nothing i -- | Type check a meta variable. -- If its type is not given, we return its type, or a fresh one, if it is a new meta. -- If its type is given, we check that the meta has this type, and we return the same -- type. checkOrInferMeta :: (Comparison -> Type -> TCM (MetaId, Term)) -> Maybe (Comparison , Type) -> A.MetaInfo -> TCM (Term, Type) checkOrInferMeta newMeta mt i = do case A.metaNumber i of Nothing -> do setScope (A.metaScope i) (cmp , t) <- maybe ((CmpEq,) <$> workOnTypes newTypeMeta_) return mt (x, v) <- newMeta cmp t setMetaNameSuggestion x (A.metaNameSuggestion i) return (v, t) -- Rechecking an existing metavariable Just x -> do let v = MetaV x [] reportSDoc "tc.meta.check" 20 $ "checking existing meta " <+> prettyTCM v t' <- metaType x reportSDoc "tc.meta.check" 20 $ nest 2 $ "of type " <+> prettyTCM t' case mt of Nothing -> return (v, t') Just (cmp , t) -> (,t) <$> coerce cmp v t' t -- | Turn a domain-free binding (e.g. lambda) into a domain-full one, -- by inserting an underscore for the missing type. domainFree :: ArgInfo -> A.Binder' A.Name -> A.LamBinding domainFree info x = A.DomainFull $ A.mkTBind r [unnamedArg info $ fmap A.mkBindName x] $ A.Underscore underscoreInfo where r = getRange x underscoreInfo = A.MetaInfo { A.metaRange = r , A.metaScope = emptyScopeInfo , A.metaNumber = Nothing , A.metaNameSuggestion = prettyShow $ A.nameConcrete $ A.binderName x } -- | Check arguments whose value we already know. -- -- This function can be used to check user-supplied parameters -- we have already computed by inference. -- -- Precondition: The type @t@ of the head has enough domains. checkKnownArguments :: [NamedArg A.Expr] -- ^ User-supplied arguments (hidden ones may be missing). -> Args -- ^ Inferred arguments (including hidden ones). -> Type -- ^ Type of the head (must be Pi-type with enough domains). -> TCM (Args, Type) -- ^ Remaining inferred arguments, remaining type. checkKnownArguments [] vs t = return (vs, t) checkKnownArguments (arg : args) vs t = do (vs', t') <- traceCall (SetRange $ getRange arg) $ checkKnownArgument arg vs t checkKnownArguments args vs' t' -- | Check an argument whose value we already know. checkKnownArgument :: NamedArg A.Expr -- ^ User-supplied argument. -> Args -- ^ Inferred arguments (including hidden ones). -> Type -- ^ Type of the head (must be Pi-type with enough domains). -> TCM (Args, Type) -- ^ Remaining inferred arguments, remaining type. checkKnownArgument arg [] _ = genericDocError =<< do "Invalid projection parameter " <+> prettyA arg -- Andreas, 2019-07-22, while #3353: we should use domName, not absName !! -- WAS: -- checkKnownArgument arg@(Arg info e) (Arg _infov v : vs) t = do -- (dom@Dom{domInfo = info',unDom = a}, b) <- mustBePi t -- -- Skip the arguments from vs that do not correspond to e -- if not (sameHiding info info' -- && (visible info || maybe True (absName b ==) (bareNameOf e))) checkKnownArgument arg (Arg _ v : vs) t = do -- Skip the arguments from vs that do not correspond to e (dom@Dom{ unDom = a }, b) <- mustBePi t if not $ fromMaybe __IMPOSSIBLE__ $ fittingNamedArg arg dom -- Continue with the next one then checkKnownArgument arg vs (b `absApp` v) -- Found the right argument else do u <- checkNamedArg arg a equalTerm a u v return (vs, b `absApp` v) -- | Check a single argument. checkNamedArg :: NamedArg A.Expr -> Type -> TCM Term checkNamedArg arg@(Arg info e0) t0 = do let e = namedThing e0 let x = bareNameWithDefault "" e0 traceCall (CheckExprCall CmpLeq e t0) $ do reportSDoc "tc.term.args.named" 15 $ do "Checking named arg" <+> sep [ fsep [ prettyTCM arg, ":", prettyTCM t0 ] ] reportSLn "tc.term.args.named" 75 $ " arg = " ++ show (deepUnscope arg) -- Ulf, 2017-03-24: (#2172) Always treat explicit _ and ? as implicit -- argument (i.e. solve with unification). let checkU = checkMeta (newMetaArg (setHiding Hidden info) x) CmpLeq t0 let checkQ = checkQuestionMark (newInteractionMetaArg (setHiding Hidden info) x) CmpLeq t0 if not $ isHole e then checkExpr e t0 else localScope $ do -- Note: we need localScope here, -- as scopedExpr manipulates the scope in the state. -- However, we may not pull localScope over checkExpr! -- This is why we first test for isHole, and only do -- scope manipulations if we actually handle the checking -- of e here (and not pass it to checkExpr). scopedExpr e >>= \case A.Underscore i -> checkU i A.QuestionMark i ii -> checkQ i ii _ -> __IMPOSSIBLE__ where isHole A.Underscore{} = True isHole A.QuestionMark{} = True isHole (A.ScopedExpr _ e) = isHole e isHole _ = False -- | Infer the type of an expression. Implemented by checking against a meta -- variable. Except for neutrals, for them a polymorphic type is inferred. inferExpr :: A.Expr -> TCM (Term, Type) -- inferExpr e = inferOrCheck e Nothing inferExpr = inferExpr' DontExpandLast inferExpr' :: ExpandHidden -> A.Expr -> TCM (Term, Type) inferExpr' exh e = traceCall (InferExpr e) $ do let Application hd args = appView e reportSDoc "tc.infer" 30 $ vcat [ "inferExpr': appView of " <+> prettyA e , " hd = " <+> prettyA hd , " args = " <+> prettyAs args ] reportSDoc "tc.infer" 60 $ vcat [ text $ " hd (raw) = " ++ show hd ] inferApplication exh hd args e defOrVar :: A.Expr -> Bool defOrVar A.Var{} = True defOrVar A.Def{} = True defOrVar A.Proj{} = True defOrVar (A.ScopedExpr _ e) = defOrVar e defOrVar _ = False -- | Used to check aliases @f = e@. -- Switches off 'ExpandLast' for the checking of top-level application. checkDontExpandLast :: Comparison -> A.Expr -> Type -> TCM Term checkDontExpandLast cmp e t = case e of _ | Application hd args <- appView e, defOrVar hd -> traceCall (CheckExprCall cmp e t) $ localScope $ dontExpandLast $ do checkApplication cmp hd args e t _ -> checkExpr' cmp e t -- note that checkExpr always sets ExpandLast -- | Check whether a de Bruijn index is bound by a module telescope. isModuleFreeVar :: Int -> TCM Bool isModuleFreeVar i = do params <- moduleParamsToApply =<< currentModule return $ any ((== Var i []) . unArg) params -- | Infer the type of an expression, and if it is of the form -- @{tel} -> D vs@ for some datatype @D@ then insert the hidden -- arguments. Otherwise, leave the type polymorphic. inferExprForWith :: A.Expr -> TCM (Term, Type) inferExprForWith e = do reportSDoc "tc.with.infer" 20 $ "inferExprforWith " <+> prettyTCM e reportSLn "tc.with.infer" 80 $ "inferExprforWith " ++ show (deepUnscope e) traceCall (InferExpr e) $ do -- With wants type and term fully instantiated! (v, t) <- instantiateFull =<< inferExpr e v0 <- reduce v -- Andreas 2014-11-06, issue 1342. -- Check that we do not `with` on a module parameter! case v0 of Var i [] -> whenM (isModuleFreeVar i) $ do reportSDoc "tc.with.infer" 80 $ vcat [ text $ "with expression is variable " ++ show i , "current modules = " <+> do text . show =<< currentModule , "current module free vars = " <+> do text . show =<< getCurrentModuleFreeVars , "context size = " <+> do text . show =<< getContextSize , "current context = " <+> do prettyTCM =<< getContextTelescope ] typeError $ WithOnFreeVariable e v0 _ -> return () -- Possibly insert hidden arguments. TelV tel t0 <- telViewUpTo' (-1) (not . visible) t case unEl t0 of Def d vs -> do res <- isDataOrRecordType d case res of Nothing -> return (v, t) Just{} -> do (args, t1) <- implicitArgs (-1) notVisible t return (v `apply` args, t1) _ -> return (v, t) --------------------------------------------------------------------------- -- * Let bindings --------------------------------------------------------------------------- checkLetBindings :: [A.LetBinding] -> TCM a -> TCM a checkLetBindings = foldr (.) id . map checkLetBinding checkLetBinding :: A.LetBinding -> TCM a -> TCM a checkLetBinding b@(A.LetBind i info x t e) ret = traceCall (CheckLetBinding b) $ do t <- isType_ t v <- applyModalityToContext info $ checkDontExpandLast CmpLeq e t addLetBinding info (A.unBind x) v t ret checkLetBinding b@(A.LetPatBind i p e) ret = traceCall (CheckLetBinding b) $ do p <- expandPatternSynonyms p (v, t) <- inferExpr' ExpandLast e let -- construct a type t -> dummy for use in checkLeftHandSide t0 = El (getSort t) $ Pi (defaultDom t) (NoAbs underscore __DUMMY_TYPE__) p0 = Arg defaultArgInfo (Named Nothing p) reportSDoc "tc.term.let.pattern" 10 $ vcat [ "let-binding pattern p at type t" , nest 2 $ vcat [ "p (A) =" <+> prettyA p , "t =" <+> prettyTCM t , "cxtRel=" <+> do pretty =<< asksTC getRelevance , "cxtQnt=" <+> do pretty =<< asksTC getQuantity ] ] fvs <- getContextSize checkLeftHandSide (CheckPattern p EmptyTel t) Nothing [p0] t0 Nothing [] $ \ (LHSResult _ delta0 ps _ _t _ asb _) -> bindAsPatterns asb $ do -- After dropping the free variable patterns there should be a single pattern left. let p = case drop fvs ps of [p] -> namedArg p; _ -> __IMPOSSIBLE__ -- Also strip the context variables from the telescope delta = telFromList $ drop fvs $ telToList delta0 reportSDoc "tc.term.let.pattern" 20 $ nest 2 $ vcat [ "p (I) =" <+> prettyTCM p , "delta =" <+> prettyTCM delta , "cxtRel=" <+> do pretty =<< asksTC getRelevance , "cxtQnt=" <+> do pretty =<< asksTC getQuantity ] reportSDoc "tc.term.let.pattern" 80 $ nest 2 $ vcat [ "p (I) =" <+> (text . show) p ] -- We translate it into a list of projections. fs <- recordPatternToProjections p -- We remove the bindings for the pattern variables from the context. cxt0 <- getContext let (binds, cxt) = splitAt (size delta) cxt0 toDrop = length binds -- We create a substitution for the let-bound variables -- (unfortunately, we cannot refer to x in internal syntax -- so we have to copy v). sigma = map ($ v) fs -- We apply the types of the let bound-variables to this substitution. -- The 0th variable in a context is the last one, so we reverse. -- Further, we need to lower all other de Bruijn indices by -- the size of delta, so we append the identity substitution. sub = parallelS (reverse sigma) updateContext sub (drop toDrop) $ do reportSDoc "tc.term.let.pattern" 20 $ nest 2 $ vcat [ "delta =" <+> prettyTCM delta , "binds =" <+> prettyTCM binds ] let fdelta = flattenTel delta reportSDoc "tc.term.let.pattern" 20 $ nest 2 $ vcat [ "fdelta =" <+> addContext delta (prettyTCM fdelta) ] let tsl = applySubst sub fdelta -- We get a list of types let ts = map unDom tsl -- and relevances. let infos = map domInfo tsl -- We get list of names of the let-bound vars from the context. let xs = map (fst . unDom) (reverse binds) -- We add all the bindings to the context. foldr (uncurry4 addLetBinding) ret $ List.zip4 infos xs sigma ts checkLetBinding (A.LetApply i x modapp copyInfo _adir) ret = do -- Any variables in the context that doesn't belong to the current -- module should go with the new module. -- Example: @f x y = let open M t in u@. -- There are 2 @new@ variables, @x@ and @y@, going into the anonynous module -- @module _ (x : _) (y : _) = M t@. fv <- getCurrentModuleFreeVars n <- getContextSize let new = n - fv reportSLn "tc.term.let.apply" 10 $ "Applying " ++ show modapp ++ " with " ++ show new ++ " free variables" reportSDoc "tc.term.let.apply" 20 $ vcat [ "context =" <+> (prettyTCM =<< getContextTelescope) , "module =" <+> (prettyTCM =<< currentModule) , "fv =" <+> (text $ show fv) ] checkSectionApplication i x modapp copyInfo withAnonymousModule x new ret -- LetOpen and LetDeclaredVariable are only used for highlighting. checkLetBinding A.LetOpen{} ret = ret checkLetBinding (A.LetDeclaredVariable _) ret = ret