{-# LANGUAGE AllowAmbiguousTypes #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE MultiWayIf #-} {-# LANGUAGE PatternSynonyms #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeApplications #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE UndecidableInstances #-} {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-} ----------------------------------------------------------------------------- -- -- (c) The University of Glasgow 2006 -- -- The purpose of this module is to transform an HsExpr into a CoreExpr which -- when evaluated, returns a (Meta.Q Meta.Exp) computation analogous to the -- input HsExpr. We do this in the DsM monad, which supplies access to -- CoreExpr's of the "smart constructors" of the Meta.Exp datatype. -- -- It also defines a bunch of knownKeyNames, in the same way as is done -- in prelude/GHC.Builtin.Names. It's much more convenient to do it here, because -- otherwise we have to recompile GHC.Builtin.Names whenever we add a Name, which is -- a Royal Pain (triggers other recompilation). ----------------------------------------------------------------------------- module GHC.HsToCore.Quote( dsBracket ) where import GHC.Prelude import GHC.Platform import GHC.Driver.Session import GHC.HsToCore.Errors.Types import {-# SOURCE #-} GHC.HsToCore.Expr ( dsExpr ) import GHC.HsToCore.Match.Literal import GHC.HsToCore.Monad import GHC.HsToCore.Binds import qualified Language.Haskell.TH as TH import qualified Language.Haskell.TH.Syntax as TH import GHC.Hs import GHC.Tc.Utils.TcType import GHC.Tc.Types.Evidence import GHC.Core.Class import GHC.Core.DataCon import GHC.Core.TyCon import GHC.Core import GHC.Core.Type( pattern ManyTy, mkFunTy ) import GHC.Core.Make import GHC.Core.Utils import GHC.Builtin.Names import GHC.Builtin.Names.TH import GHC.Builtin.Types import GHC.Unit.Module import GHC.Utils.Outputable import GHC.Utils.Panic import GHC.Utils.Panic.Plain import GHC.Utils.Misc import GHC.Utils.Monad import GHC.Data.Bag import GHC.Data.FastString import GHC.Data.Maybe import GHC.Types.SrcLoc as SrcLoc import GHC.Types.Unique import GHC.Types.Basic import GHC.Types.ForeignCall import GHC.Types.Var import GHC.Types.Id import GHC.Types.SourceText import GHC.Types.Fixity import GHC.Types.TyThing import GHC.Types.Name hiding( varName, tcName ) import GHC.Types.Name.Env import GHC.TypeLits import Data.Kind (Constraint) import qualified GHC.LanguageExtensions as LangExt import Language.Haskell.Syntax.Basic (FieldLabelString(..)) import Data.ByteString ( unpack ) import Control.Monad import Data.List (sort, sortBy) import Data.List.NonEmpty ( NonEmpty(..), toList ) import Data.Function import Control.Monad.Trans.Reader import Control.Monad.Trans.Class import GHC.Types.Name.Reader (RdrName(..)) data MetaWrappers = MetaWrappers { -- Applies its argument to a type argument `m` and dictionary `Quote m` quoteWrapper :: CoreExpr -> CoreExpr -- Apply its argument to a type argument `m` and a dictionary `Monad m` , monadWrapper :: CoreExpr -> CoreExpr -- Apply the container typed variable `m` to the argument type `T` to get `m T`. , metaTy :: Type -> Type -- Information about the wrappers which be printed to be inspected , _debugWrappers :: (HsWrapper, HsWrapper, Type) } -- | Construct the functions which will apply the relevant part of the -- QuoteWrapper to identifiers during desugaring. mkMetaWrappers :: QuoteWrapper -> DsM MetaWrappers mkMetaWrappers q@(QuoteWrapper quote_var_raw m_var) = do let quote_var = Var quote_var_raw -- Get the superclass selector to select the Monad dictionary, going -- to be used to construct the monadWrapper. quote_tc <- dsLookupTyCon quoteClassName monad_tc <- dsLookupTyCon monadClassName let Just cls = tyConClass_maybe quote_tc Just monad_cls = tyConClass_maybe monad_tc -- Quote m -> Monad m monad_sel = classSCSelId cls 0 -- Only used for the defensive assertion that the selector has -- the expected type tyvars = dataConUserTyVarBinders (classDataCon cls) expected_ty = mkInvisForAllTys tyvars $ mkFunTy invisArgConstraintLike ManyTy (mkClassPred cls (mkTyVarTys (binderVars tyvars))) (mkClassPred monad_cls (mkTyVarTys (binderVars tyvars))) massertPpr (idType monad_sel `eqType` expected_ty) (ppr monad_sel $$ ppr expected_ty) let m_ty = Type m_var -- Construct the contents of MetaWrappers quoteWrapper = applyQuoteWrapper q monadWrapper = mkWpEvApps [EvExpr $ mkCoreApps (Var monad_sel) [m_ty, quote_var]] <.> mkWpTyApps [m_var] tyWrapper t = mkAppTy m_var t debug = (quoteWrapper, monadWrapper, m_var) dsHsWrapper quoteWrapper $ \q_f -> do { dsHsWrapper monadWrapper $ \m_f -> do { return (MetaWrappers q_f m_f tyWrapper debug) } } -- Turn A into m A wrapName :: Name -> MetaM Type wrapName n = do t <- lookupType n wrap_fn <- asks metaTy return (wrap_fn t) -- The local state is always the same, calculated from the passed in -- wrapper type MetaM a = ReaderT MetaWrappers DsM a getPlatform :: MetaM Platform getPlatform = targetPlatform <$> getDynFlags ----------------------------------------------------------------------------- dsBracket :: HsBracketTc -> DsM CoreExpr -- See Note [Desugaring Brackets] -- Returns a CoreExpr of type (M TH.Exp) -- The quoted thing is parameterised over Name, even though it has -- been type checked. We don't want all those type decorations! dsBracket (HsBracketTc { hsb_wrap = mb_wrap, hsb_splices = splices, hsb_quote = quote }) = case quote of VarBr _ _ n -> do { MkC e1 <- lookupOccDsM (unLoc n) ; return e1 } ExpBr _ e -> runOverloaded $ do { MkC e1 <- repLE e ; return e1 } PatBr _ p -> runOverloaded $ do { MkC p1 <- repTopP p ; return p1 } TypBr _ t -> runOverloaded $ do { MkC t1 <- repLTy t ; return t1 } DecBrG _ gp -> runOverloaded $ do { MkC ds1 <- repTopDs gp ; return ds1 } DecBrL {} -> panic "dsUntypedBracket: unexpected DecBrL" where Just wrap = mb_wrap -- Not used in VarBr case -- In the overloaded case we have to get given a wrapper, it is just -- the VarBr case that there is no wrapper, because they -- have a simple type. runOverloaded act = do { mw <- mkMetaWrappers wrap ; runReaderT (mapReaderT (dsExtendMetaEnv new_bit) act) mw } new_bit = mkNameEnv [(n, DsSplice (unLoc e)) | PendingTcSplice n e <- splices] {- Note [Desugaring Brackets] ~~~~~~~~~~~~~~~~~~~~~~~~~~ In the old days (pre Dec 2019) quotation brackets used to be monomorphic, ie an expression bracket was of type Q Exp. This made the desugaring process simple as there were no complicated type variables to keep consistent throughout the whole AST. Due to the overloaded quotations proposal a quotation bracket is now of type `Quote m => m Exp` and all the combinators defined in TH.Lib have been generalised to work with any monad implementing a minimal interface. https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst Users can rejoice at the flexibility but now there is some additional complexity in how brackets are desugared as all these polymorphic combinators need their arguments instantiated. > IF YOU ARE MODIFYING THIS MODULE DO NOT USE ANYTHING SPECIFIC TO Q. INSTEAD > USE THE `wrapName` FUNCTION TO APPLY THE `m` TYPE VARIABLE TO A TYPE CONSTRUCTOR. What the arguments should be instantiated to is supplied by the `QuoteWrapper` datatype which is produced by `GHC.Tc.Gen.Splice`. It is a pair of an evidence variable for `Quote m` and a type variable `m`. All the polymorphic combinators in desugaring need to be applied to these two type variables. There are three important functions which do the application. 1. The default is `rep2` which takes a function name of type `Quote m => T` as an argument. 2. `rep2M` takes a function name of type `Monad m => T` as an argument 3. `rep2_nw` takes a function name without any constraints as an argument. These functions then use the information in QuoteWrapper to apply the correct arguments to the functions as the representation is constructed. The `MetaM` monad carries around an environment of three functions which are used in order to wrap the polymorphic combinators and instantiate the arguments to the correct things. 1. quoteWrapper wraps functions of type `forall m . Quote m => T` 2. monadWrapper wraps functions of type `forall m . Monad m => T` 3. metaTy wraps a type in the polymorphic `m` variable of the whole representation. Historical note about the implementation: At the first attempt, I attempted to lie that the type of any quotation was `Quote m => m Exp` and then specialise it by applying a wrapper to pass the `m` and `Quote m` arguments. This approach was simpler to implement but didn't work because of nested splices. For example, you might have a nested splice of a more specific type which fixes the type of the overall quote and so all the combinators used must also be instantiated to that specific type. Therefore you really have to use the contents of the quote wrapper to directly apply the right type to the combinators rather than first generate a polymorphic definition and then just apply the wrapper at the end. -} {- -------------- Examples -------------------- [| \x -> x |] ====> gensym (unpackString "x"#) `bindQ` \ x1::String -> lam (pvar x1) (var x1) [| \x -> $(f [| x |]) |] ====> gensym (unpackString "x"#) `bindQ` \ x1::String -> lam (pvar x1) (f (var x1)) -} ------------------------------------------------------- -- Declarations ------------------------------------------------------- -- Proxy for the phantom type of `Core`. All the generated fragments have -- type something like `Quote m => m Exp` so to keep things simple we represent fragments -- of that type as `M Exp`. data M a repTopP :: LPat GhcRn -> MetaM (Core (M TH.Pat)) repTopP pat = do { ss <- mkGenSyms (collectPatBinders CollNoDictBinders pat) ; pat' <- addBinds ss (repLP pat) ; wrapGenSyms ss pat' } repTopDs :: HsGroup GhcRn -> MetaM (Core (M [TH.Dec])) repTopDs group@(HsGroup { hs_valds = valds , hs_splcds = splcds , hs_tyclds = tyclds , hs_derivds = derivds , hs_fixds = fixds , hs_defds = defds , hs_fords = fords , hs_warnds = warnds , hs_annds = annds , hs_ruleds = ruleds , hs_docs = docs }) = do { let { bndrs = hsScopedTvBinders valds ++ hsGroupBinders group ++ map foExt (hsPatSynSelectors valds) ; instds = tyclds >>= group_instds } ; ss <- mkGenSyms bndrs ; -- Bind all the names mainly to avoid repeated use of explicit strings. -- Thus we get -- do { t :: String <- genSym "T" ; -- return (Data t [] ...more t's... } -- The other important reason is that the output must mention -- only "T", not "Foo:T" where Foo is the current module decls <- addBinds ss ( do { val_ds <- rep_val_binds valds ; _ <- mapM no_splice splcds ; tycl_ds <- mapM repTyClD (tyClGroupTyClDecls tyclds) ; role_ds <- mapM repRoleD (concatMap group_roles tyclds) ; kisig_ds <- mapM repKiSigD (concatMap group_kisigs tyclds) ; inst_ds <- mapM repInstD instds ; deriv_ds <- mapM repStandaloneDerivD derivds ; fix_ds <- mapM repLFixD fixds ; def_ds <- mapM repDefD defds ; for_ds <- mapM repForD fords ; _ <- mapM no_warn (concatMap (wd_warnings . unLoc) warnds) ; ann_ds <- mapM repAnnD annds ; rule_ds <- mapM repRuleD (concatMap (rds_rules . unLoc) ruleds) ; _ <- mapM no_doc docs -- more needed ; return (de_loc $ sort_by_loc $ val_ds ++ catMaybes tycl_ds ++ role_ds ++ kisig_ds ++ (concat fix_ds) ++ def_ds ++ inst_ds ++ rule_ds ++ for_ds ++ ann_ds ++ deriv_ds) }) ; core_list <- repListM decTyConName return decls ; dec_ty <- lookupType decTyConName ; q_decs <- repSequenceM dec_ty core_list ; wrapGenSyms ss q_decs } where no_splice (L loc _) = notHandledL (locA loc) ThSplicesWithinDeclBrackets no_warn :: LWarnDecl GhcRn -> MetaM a no_warn (L loc (Warning _ thing _)) = notHandledL (locA loc) (ThWarningAndDeprecationPragmas thing) no_doc (L loc _) = notHandledL (locA loc) ThHaddockDocumentation hsScopedTvBinders :: HsValBinds GhcRn -> [Name] -- See Note [Scoped type variables in quotes] hsScopedTvBinders binds = concatMap get_scoped_tvs sigs where sigs = case binds of ValBinds _ _ sigs -> sigs XValBindsLR (NValBinds _ sigs) -> sigs get_scoped_tvs :: LSig GhcRn -> [Name] get_scoped_tvs (L _ signature) | TypeSig _ _ sig <- signature = get_scoped_tvs_from_sig (hswc_body sig) | ClassOpSig _ _ _ sig <- signature = get_scoped_tvs_from_sig sig | PatSynSig _ _ sig <- signature = get_scoped_tvs_from_sig sig | otherwise = [] get_scoped_tvs_from_sig :: LHsSigType GhcRn -> [Name] -- Collect both implicit and explicit quantified variables, since -- the types in instance heads, as well as `via` types in DerivingVia, can -- bring implicitly quantified type variables into scope, e.g., -- -- instance Foo [a] where -- m = n @a -- -- See also Note [Scoped type variables in quotes] get_scoped_tvs_from_sig (L _ (HsSig{sig_bndrs = outer_bndrs})) = hsOuterTyVarNames outer_bndrs {- Notes Note [Scoped type variables in quotes] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Quoting declarations with scoped type variables requires some care. Consider: $([d| f :: forall a. a -> a f x = x::a |]) Here, the `forall a` brings `a` into scope over the binding group. This has ramifications when desugaring the quote, as we must ensure that that the desugared code binds `a` with `Language.Haskell.TH.newName` and refers to the bound `a` type variable in the type signature and in the body of `f`. As a result, the call to `newName` must occur before any part of the declaration for `f` is processed. To achieve this, we: (a) Gensym a binding for `a` at the same time as we do one for `f`, collecting the relevant binders with the hsScopedTvBinders family of functions. (b) Use `addBinds` to bring these gensymmed bindings into scope over any part of the code where the type variables scope. In the `f` example, above, that means the type signature and the body of `f`. (c) When processing the `forall`, /don't/ gensym the type variables. We have already brought the type variables into scope in part (b), after all, so gensymming them again would lead to shadowing. We use the rep_ty_sig family of functions for processing types without gensymming the type variables again. (d) Finally, we use wrapGenSyms to generate the Core for these scoped type variables: newName "a" >>= \a -> ... -- process the type signature and body of `f` The relevant places are signposted with references to this Note. Note [Binders and occurrences] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When we desugar [d| data T = MkT |] we want to get Data "T" [] [Con "MkT" []] [] and *not* Data "Foo:T" [] [Con "Foo:MkT" []] [] That is, the new data decl should fit into whatever new module it is asked to fit in. We do *not* clone, though; no need for this: Data "T79" .... But if we see this: data T = MkT foo = reifyDecl T then we must desugar to foo = Data "Foo:T" [] [Con "Foo:MkT" []] [] So in repTopDs we bring the binders into scope with mkGenSyms and addBinds. And we use lookupOcc, rather than lookupBinder in repTyClD and repC. Note [Don't quantify implicit type variables in quotes] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If you're not careful, it's surprisingly easy to take this quoted declaration: [d| id :: a -> a id x = x |] and have Template Haskell turn it into this: id :: forall a. a -> a id x = x Notice that we explicitly quantified the variable `a`! The latter declaration isn't what the user wrote in the first place. Usually, the culprit behind these bugs is taking implicitly quantified type variables (often from the hsib_vars field of HsImplicitBinders) and putting them into a `ForallT` or `ForallC`. Doing so caused #13018 and #13123. -} -- represent associated family instances -- repTyClD :: LTyClDecl GhcRn -> MetaM (Maybe (SrcSpan, Core (M TH.Dec))) repTyClD (L loc (FamDecl { tcdFam = fam })) = liftM Just $ repFamilyDecl (L loc fam) repTyClD (L loc (SynDecl { tcdLName = tc, tcdTyVars = tvs, tcdRhs = rhs })) = do { tc1 <- lookupLOcc tc -- See Note [Binders and occurrences] ; dec <- addQTyVarBinds ReuseBoundNames tvs $ \bndrs -> repSynDecl tc1 bndrs rhs ; return (Just (locA loc, dec)) } repTyClD (L loc (DataDecl { tcdLName = tc , tcdTyVars = tvs , tcdDataDefn = defn })) = do { tc1 <- lookupLOcc tc -- See Note [Binders and occurrences] ; dec <- addQTyVarBinds ReuseBoundNames tvs $ \bndrs -> repDataDefn tc1 (Left bndrs) defn ; return (Just (locA loc, dec)) } repTyClD (L loc (ClassDecl { tcdCtxt = cxt, tcdLName = cls, tcdTyVars = tvs, tcdFDs = fds, tcdSigs = sigs, tcdMeths = meth_binds, tcdATs = ats, tcdATDefs = atds })) = do { cls1 <- lookupLOcc cls -- See Note [Binders and occurrences] ; dec <- addQTyVarBinds FreshNamesOnly tvs $ \bndrs -> do { cxt1 <- repLContext cxt -- See Note [Scoped type variables in quotes] ; (ss, sigs_binds) <- rep_meth_sigs_binds sigs meth_binds ; fds1 <- repLFunDeps fds ; ats1 <- repFamilyDecls ats ; atds1 <- mapM (repAssocTyFamDefaultD . unLoc) atds ; decls1 <- repListM decTyConName return (ats1 ++ atds1 ++ sigs_binds) ; decls2 <- repClass cxt1 cls1 bndrs fds1 decls1 ; wrapGenSyms ss decls2 } ; return $ Just (locA loc, dec) } ------------------------- repRoleD :: LRoleAnnotDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repRoleD (L loc (RoleAnnotDecl _ tycon roles)) = do { tycon1 <- lookupLOcc tycon ; roles1 <- mapM repRole roles ; roles2 <- coreList roleTyConName roles1 ; dec <- repRoleAnnotD tycon1 roles2 ; return (locA loc, dec) } ------------------------- repKiSigD :: LStandaloneKindSig GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repKiSigD (L loc kisig) = case kisig of StandaloneKindSig _ v ki -> do MkC th_v <- lookupLOcc v MkC th_ki <- repHsSigType ki dec <- rep2 kiSigDName [th_v, th_ki] pure (locA loc, dec) ------------------------- repDataDefn :: Core TH.Name -> Either (Core [(M (TH.TyVarBndr ()))]) -- the repTyClD case (Core (Maybe [(M (TH.TyVarBndr ()))]), Core (M TH.Type)) -- the repDataFamInstD case -> HsDataDefn GhcRn -> MetaM (Core (M TH.Dec)) repDataDefn tc opts (HsDataDefn { dd_ctxt = cxt, dd_kindSig = ksig , dd_cons = cons, dd_derivs = mb_derivs }) = do { cxt1 <- repLContext cxt ; derivs1 <- repDerivs mb_derivs ; case cons of NewTypeCon con -> do { con' <- repC con ; ksig' <- repMaybeLTy ksig ; repNewtype cxt1 tc opts ksig' con' derivs1 } DataTypeCons type_data cons -> do { ksig' <- repMaybeLTy ksig ; consL <- mapM repC cons ; cons1 <- coreListM conTyConName consL ; repData type_data cxt1 tc opts ksig' cons1 derivs1 } } repSynDecl :: Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> LHsType GhcRn -> MetaM (Core (M TH.Dec)) repSynDecl tc bndrs ty = do { ty1 <- repLTy ty ; repTySyn tc bndrs ty1 } repFamilyDecl :: LFamilyDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repFamilyDecl decl@(L loc (FamilyDecl { fdInfo = info , fdLName = tc , fdTyVars = tvs , fdResultSig = L _ resultSig , fdInjectivityAnn = injectivity })) = do { tc1 <- lookupLOcc tc -- See Note [Binders and occurrences] ; let resTyVar = case resultSig of TyVarSig _ bndr -> [hsLTyVarName bndr] _ -> [] ; dec <- addQTyVarBinds ReuseBoundNames tvs $ \bndrs -> addSimpleTyVarBinds ReuseBoundNames resTyVar $ case info of ClosedTypeFamily Nothing -> notHandled (ThAbstractClosedTypeFamily decl) ClosedTypeFamily (Just eqns) -> do { eqns1 <- mapM (repTyFamEqn . unLoc) eqns ; eqns2 <- coreListM tySynEqnTyConName eqns1 ; result <- repFamilyResultSig resultSig ; inj <- repInjectivityAnn injectivity ; repClosedFamilyD tc1 bndrs result inj eqns2 } OpenTypeFamily -> do { result <- repFamilyResultSig resultSig ; inj <- repInjectivityAnn injectivity ; repOpenFamilyD tc1 bndrs result inj } DataFamily -> do { kind <- repFamilyResultSigToMaybeKind resultSig ; repDataFamilyD tc1 bndrs kind } ; return (locA loc, dec) } -- | Represent result signature of a type family repFamilyResultSig :: FamilyResultSig GhcRn -> MetaM (Core (M TH.FamilyResultSig)) repFamilyResultSig (NoSig _) = repNoSig repFamilyResultSig (KindSig _ ki) = do { ki' <- repLTy ki ; repKindSig ki' } repFamilyResultSig (TyVarSig _ bndr) = do { bndr' <- repTyVarBndr bndr ; repTyVarSig bndr' } -- | Represent result signature using a Maybe Kind. Used with data families, -- where the result signature can be either missing or a kind but never a named -- result variable. repFamilyResultSigToMaybeKind :: FamilyResultSig GhcRn -> MetaM (Core (Maybe (M TH.Kind))) repFamilyResultSigToMaybeKind (NoSig _) = coreNothingM kindTyConName repFamilyResultSigToMaybeKind (KindSig _ ki) = coreJustM kindTyConName =<< repLTy ki repFamilyResultSigToMaybeKind TyVarSig{} = panic "repFamilyResultSigToMaybeKind: unexpected TyVarSig" -- | Represent injectivity annotation of a type family repInjectivityAnn :: Maybe (LInjectivityAnn GhcRn) -> MetaM (Core (Maybe TH.InjectivityAnn)) repInjectivityAnn Nothing = coreNothing injAnnTyConName repInjectivityAnn (Just (L _ (InjectivityAnn _ lhs rhs))) = do { lhs' <- lookupBinder (unLoc lhs) ; rhs1 <- mapM (lookupBinder . unLoc) rhs ; rhs2 <- coreList nameTyConName rhs1 ; injAnn <- rep2_nw injectivityAnnName [unC lhs', unC rhs2] ; coreJust injAnnTyConName injAnn } repFamilyDecls :: [LFamilyDecl GhcRn] -> MetaM [Core (M TH.Dec)] repFamilyDecls fds = liftM de_loc (mapM repFamilyDecl fds) repAssocTyFamDefaultD :: TyFamDefltDecl GhcRn -> MetaM (Core (M TH.Dec)) repAssocTyFamDefaultD = repTyFamInstD ------------------------- -- represent fundeps -- repLFunDeps :: [LHsFunDep GhcRn] -> MetaM (Core [TH.FunDep]) repLFunDeps fds = repList funDepTyConName repLFunDep fds repLFunDep :: LHsFunDep GhcRn -> MetaM (Core TH.FunDep) repLFunDep (L _ (FunDep _ xs ys)) = do xs' <- repList nameTyConName (lookupBinder . unLoc) xs ys' <- repList nameTyConName (lookupBinder . unLoc) ys repFunDep xs' ys' -- Represent instance declarations -- repInstD :: LInstDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repInstD (L loc (TyFamInstD { tfid_inst = fi_decl })) = do { dec <- repTyFamInstD fi_decl ; return (locA loc, dec) } repInstD (L loc (DataFamInstD { dfid_inst = fi_decl })) = do { dec <- repDataFamInstD fi_decl ; return (locA loc, dec) } repInstD (L loc (ClsInstD { cid_inst = cls_decl })) = do { dec <- repClsInstD cls_decl ; return (locA loc, dec) } repClsInstD :: ClsInstDecl GhcRn -> MetaM (Core (M TH.Dec)) repClsInstD (ClsInstDecl { cid_poly_ty = ty, cid_binds = binds , cid_sigs = sigs, cid_tyfam_insts = ats , cid_datafam_insts = adts , cid_overlap_mode = overlap }) = addSimpleTyVarBinds FreshNamesOnly tvs $ -- We must bring the type variables into scope, so their -- occurrences don't fail, even though the binders don't -- appear in the resulting data structure -- -- But we do NOT bring the binders of 'binds' into scope -- because they are properly regarded as occurrences -- For example, the method names should be bound to -- the selector Ids, not to fresh names (#5410) -- do { cxt1 <- repLContext cxt ; inst_ty1 <- repLTy inst_ty -- See Note [Scoped type variables in quotes] ; (ss, sigs_binds) <- rep_meth_sigs_binds sigs binds ; ats1 <- mapM (repTyFamInstD . unLoc) ats ; adts1 <- mapM (repDataFamInstD . unLoc) adts ; decls1 <- coreListM decTyConName (ats1 ++ adts1 ++ sigs_binds) ; rOver <- repOverlap (fmap unLoc overlap) ; decls2 <- repInst rOver cxt1 inst_ty1 decls1 ; wrapGenSyms ss decls2 } where (tvs, cxt, inst_ty) = splitLHsInstDeclTy ty repStandaloneDerivD :: LDerivDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repStandaloneDerivD (L loc (DerivDecl { deriv_strategy = strat , deriv_type = ty })) = do { dec <- repDerivStrategy strat $ \strat' -> addSimpleTyVarBinds FreshNamesOnly tvs $ do { cxt' <- repLContext cxt ; inst_ty' <- repLTy inst_ty ; repDeriv strat' cxt' inst_ty' } ; return (locA loc, dec) } where (tvs, cxt, inst_ty) = splitLHsInstDeclTy (dropWildCards ty) repTyFamInstD :: TyFamInstDecl GhcRn -> MetaM (Core (M TH.Dec)) repTyFamInstD (TyFamInstDecl { tfid_eqn = eqn }) = do { eqn1 <- repTyFamEqn eqn ; repTySynInst eqn1 } repTyFamEqn :: TyFamInstEqn GhcRn -> MetaM (Core (M TH.TySynEqn)) repTyFamEqn (FamEqn { feqn_tycon = tc_name , feqn_bndrs = outer_bndrs , feqn_pats = tys , feqn_fixity = fixity , feqn_rhs = rhs }) = do { tc <- lookupLOcc tc_name -- See Note [Binders and occurrences] ; addHsOuterFamEqnTyVarBinds outer_bndrs $ \mb_exp_bndrs -> do { tys1 <- case fixity of Prefix -> repTyArgs (repNamedTyCon tc) tys Infix -> do { (HsValArg t1: HsValArg t2: args) <- checkTys tys ; t1' <- repLTy t1 ; t2' <- repLTy t2 ; repTyArgs (repTInfix t1' tc t2') args } ; rhs1 <- repLTy rhs ; repTySynEqn mb_exp_bndrs tys1 rhs1 } } where checkTys :: [LHsTypeArg GhcRn] -> MetaM [LHsTypeArg GhcRn] checkTys tys@(HsValArg _:HsValArg _:_) = return tys checkTys _ = panic "repTyFamEqn:checkTys" repTyArgs :: MetaM (Core (M TH.Type)) -> [LHsTypeArg GhcRn] -> MetaM (Core (M TH.Type)) repTyArgs f [] = f repTyArgs f (HsValArg ty : as) = do { f' <- f ; ty' <- repLTy ty ; repTyArgs (repTapp f' ty') as } repTyArgs f (HsTypeArg _ ki : as) = do { f' <- f ; ki' <- repLTy ki ; repTyArgs (repTappKind f' ki') as } repTyArgs f (HsArgPar _ : as) = repTyArgs f as repDataFamInstD :: DataFamInstDecl GhcRn -> MetaM (Core (M TH.Dec)) repDataFamInstD (DataFamInstDecl { dfid_eqn = FamEqn { feqn_tycon = tc_name , feqn_bndrs = outer_bndrs , feqn_pats = tys , feqn_fixity = fixity , feqn_rhs = defn }}) = do { tc <- lookupLOcc tc_name -- See Note [Binders and occurrences] ; addHsOuterFamEqnTyVarBinds outer_bndrs $ \mb_exp_bndrs -> do { tys1 <- case fixity of Prefix -> repTyArgs (repNamedTyCon tc) tys Infix -> do { (HsValArg t1: HsValArg t2: args) <- checkTys tys ; t1' <- repLTy t1 ; t2' <- repLTy t2 ; repTyArgs (repTInfix t1' tc t2') args } ; repDataDefn tc (Right (mb_exp_bndrs, tys1)) defn } } where checkTys :: [LHsTypeArg GhcRn] -> MetaM [LHsTypeArg GhcRn] checkTys tys@(HsValArg _: HsValArg _: _) = return tys checkTys _ = panic "repDataFamInstD:checkTys" repForD :: LForeignDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repForD (L loc (ForeignImport { fd_name = name, fd_sig_ty = typ , fd_fi = CImport _ (L _ cc) (L _ s) mch cis })) = do MkC name' <- lookupLOcc name MkC typ' <- repHsSigType typ MkC cc' <- repCCallConv cc MkC s' <- repSafety s cis' <- conv_cimportspec cis MkC str <- coreStringLit (mkFastString (static ++ chStr ++ cis')) dec <- rep2 forImpDName [cc', s', str, name', typ'] return (locA loc, dec) where conv_cimportspec (CLabel cls) = notHandled (ThForeignLabel cls) conv_cimportspec (CFunction DynamicTarget) = return "dynamic" conv_cimportspec (CFunction (StaticTarget _ fs _ True)) = return (unpackFS fs) conv_cimportspec (CFunction (StaticTarget _ _ _ False)) = panic "conv_cimportspec: values not supported yet" conv_cimportspec CWrapper = return "wrapper" -- these calling conventions do not support headers and the static keyword raw_cconv = cc == PrimCallConv || cc == JavaScriptCallConv static = case cis of CFunction (StaticTarget _ _ _ _) | not raw_cconv -> "static " _ -> "" chStr = case mch of Just (Header _ h) | not raw_cconv -> unpackFS h ++ " " _ -> "" repForD decl@(L _ ForeignExport{}) = notHandled (ThForeignExport decl) repCCallConv :: CCallConv -> MetaM (Core TH.Callconv) repCCallConv CCallConv = rep2_nw cCallName [] repCCallConv StdCallConv = rep2_nw stdCallName [] repCCallConv CApiConv = rep2_nw cApiCallName [] repCCallConv PrimCallConv = rep2_nw primCallName [] repCCallConv JavaScriptCallConv = rep2_nw javaScriptCallName [] repSafety :: Safety -> MetaM (Core TH.Safety) repSafety PlayRisky = rep2_nw unsafeName [] repSafety PlayInterruptible = rep2_nw interruptibleName [] repSafety PlaySafe = rep2_nw safeName [] repLFixD :: LFixitySig GhcRn -> MetaM [(SrcSpan, Core (M TH.Dec))] repLFixD (L loc fix_sig) = rep_fix_d (locA loc) fix_sig rep_fix_d :: SrcSpan -> FixitySig GhcRn -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_fix_d loc (FixitySig _ names (Fixity _ prec dir)) = do { MkC prec' <- coreIntLit prec ; let rep_fn = case dir of InfixL -> infixLDName InfixR -> infixRDName InfixN -> infixNDName ; let do_one name = do { MkC name' <- lookupLOcc name ; dec <- rep2 rep_fn [prec', name'] ; return (loc,dec) } ; mapM do_one names } repDefD :: LDefaultDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repDefD (L loc (DefaultDecl _ tys)) = do { tys1 <- repLTys tys ; MkC tys2 <- coreListM typeTyConName tys1 ; dec <- rep2 defaultDName [tys2] ; return (locA loc, dec)} repRuleD :: LRuleDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repRuleD (L loc (HsRule { rd_name = n , rd_act = act , rd_tyvs = m_ty_bndrs , rd_tmvs = tm_bndrs , rd_lhs = lhs , rd_rhs = rhs })) = do { let ty_bndrs = fromMaybe [] m_ty_bndrs ; rule <- addHsTyVarBinds FreshNamesOnly ty_bndrs $ \ ex_bndrs -> do { let tm_bndr_names = concatMap ruleBndrNames tm_bndrs ; ss <- mkGenSyms tm_bndr_names ; rule <- addBinds ss $ do { elt_ty <- wrapName tyVarBndrUnitTyConName ; ty_bndrs' <- return $ case m_ty_bndrs of Nothing -> coreNothing' (mkListTy elt_ty) Just _ -> coreJust' (mkListTy elt_ty) ex_bndrs ; tm_bndrs' <- repListM ruleBndrTyConName repRuleBndr tm_bndrs ; n' <- coreStringLit $ unLoc n ; act' <- repPhases act ; lhs' <- repLE lhs ; rhs' <- repLE rhs ; repPragRule n' ty_bndrs' tm_bndrs' lhs' rhs' act' } ; wrapGenSyms ss rule } ; return (locA loc, rule) } ruleBndrNames :: LRuleBndr GhcRn -> [Name] ruleBndrNames (L _ (RuleBndr _ n)) = [unLoc n] ruleBndrNames (L _ (RuleBndrSig _ n sig)) | HsPS { hsps_ext = HsPSRn { hsps_imp_tvs = vars }} <- sig = unLoc n : vars repRuleBndr :: LRuleBndr GhcRn -> MetaM (Core (M TH.RuleBndr)) repRuleBndr (L _ (RuleBndr _ n)) = do { MkC n' <- lookupNBinder n ; rep2 ruleVarName [n'] } repRuleBndr (L _ (RuleBndrSig _ n sig)) = do { MkC n' <- lookupNBinder n ; MkC ty' <- repLTy (hsPatSigType sig) ; rep2 typedRuleVarName [n', ty'] } repAnnD :: LAnnDecl GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) repAnnD (L loc (HsAnnotation _ ann_prov (L _ exp))) = do { target <- repAnnProv ann_prov ; exp' <- repE exp ; dec <- repPragAnn target exp' ; return (locA loc, dec) } repAnnProv :: AnnProvenance GhcRn -> MetaM (Core TH.AnnTarget) repAnnProv (ValueAnnProvenance n) = do { -- An ANN references an identifier bound elsewhere in the module, so -- we must look it up using lookupLOcc (#19377). -- Similarly for TypeAnnProvenance (`ANN type`) below. MkC n' <- lookupLOcc n ; rep2_nw valueAnnotationName [ n' ] } repAnnProv (TypeAnnProvenance n) = do { MkC n' <- lookupLOcc n ; rep2_nw typeAnnotationName [ n' ] } repAnnProv ModuleAnnProvenance = rep2_nw moduleAnnotationName [] ------------------------------------------------------- -- Constructors ------------------------------------------------------- repC :: LConDecl GhcRn -> MetaM (Core (M TH.Con)) repC (L _ (ConDeclH98 { con_name = con , con_forall = False , con_mb_cxt = Nothing , con_args = args })) = repH98DataCon con args repC (L _ (ConDeclH98 { con_name = con , con_forall = is_existential , con_ex_tvs = con_tvs , con_mb_cxt = mcxt , con_args = args })) = addHsTyVarBinds FreshNamesOnly con_tvs $ \ ex_bndrs -> do { c' <- repH98DataCon con args ; ctxt' <- repMbContext mcxt ; if not is_existential && isNothing mcxt then return c' else rep2 forallCName ([unC ex_bndrs, unC ctxt', unC c']) } repC (L _ (ConDeclGADT { con_names = cons , con_bndrs = L _ outer_bndrs , con_mb_cxt = mcxt , con_g_args = args , con_res_ty = res_ty })) | null_outer_imp_tvs && null_outer_exp_tvs -- No implicit or explicit variables , Nothing <- mcxt -- No context -- ==> no need for a forall = repGadtDataCons cons args res_ty | otherwise = addHsOuterSigTyVarBinds outer_bndrs $ \ outer_bndrs' -> -- See Note [Don't quantify implicit type variables in quotes] do { c' <- repGadtDataCons cons args res_ty ; ctxt' <- repMbContext mcxt ; if null_outer_exp_tvs && isNothing mcxt then return c' else rep2 forallCName ([unC outer_bndrs', unC ctxt', unC c']) } where null_outer_imp_tvs = nullOuterImplicit outer_bndrs null_outer_exp_tvs = nullOuterExplicit outer_bndrs repMbContext :: Maybe (LHsContext GhcRn) -> MetaM (Core (M TH.Cxt)) repMbContext Nothing = repContext [] repMbContext (Just (L _ cxt)) = repContext cxt repSrcUnpackedness :: SrcUnpackedness -> MetaM (Core (M TH.SourceUnpackedness)) repSrcUnpackedness SrcUnpack = rep2 sourceUnpackName [] repSrcUnpackedness SrcNoUnpack = rep2 sourceNoUnpackName [] repSrcUnpackedness NoSrcUnpack = rep2 noSourceUnpackednessName [] repSrcStrictness :: SrcStrictness -> MetaM (Core (M TH.SourceStrictness)) repSrcStrictness SrcLazy = rep2 sourceLazyName [] repSrcStrictness SrcStrict = rep2 sourceStrictName [] repSrcStrictness NoSrcStrict = rep2 noSourceStrictnessName [] repBangTy :: LBangType GhcRn -> MetaM (Core (M TH.BangType)) repBangTy ty = do MkC u <- repSrcUnpackedness su' MkC s <- repSrcStrictness ss' MkC b <- rep2 bangName [u, s] MkC t <- repLTy ty' rep2 bangTypeName [b, t] where (su', ss', ty') = case unLoc ty of HsBangTy _ (HsSrcBang _ su ss) ty -> (su, ss, ty) _ -> (NoSrcUnpack, NoSrcStrict, ty) ------------------------------------------------------- -- Deriving clauses ------------------------------------------------------- repDerivs :: HsDeriving GhcRn -> MetaM (Core [M TH.DerivClause]) repDerivs clauses = repListM derivClauseTyConName repDerivClause clauses repDerivClause :: LHsDerivingClause GhcRn -> MetaM (Core (M TH.DerivClause)) repDerivClause (L _ (HsDerivingClause { deriv_clause_strategy = dcs , deriv_clause_tys = dct })) = repDerivStrategy dcs $ \(MkC dcs') -> do MkC dct' <- rep_deriv_clause_tys dct rep2 derivClauseName [dcs',dct'] where rep_deriv_clause_tys :: LDerivClauseTys GhcRn -> MetaM (Core [M TH.Type]) rep_deriv_clause_tys (L _ dct) = case dct of DctSingle _ ty -> rep_deriv_tys [ty] DctMulti _ tys -> rep_deriv_tys tys rep_deriv_tys :: [LHsSigType GhcRn] -> MetaM (Core [M TH.Type]) rep_deriv_tys = repListM typeTyConName repHsSigType rep_meth_sigs_binds :: [LSig GhcRn] -> LHsBinds GhcRn -> MetaM ([GenSymBind], [Core (M TH.Dec)]) -- Represent signatures and methods in class/instance declarations. -- See Note [Scoped type variables in quotes] -- -- Why not use 'repBinds': we have already created symbols for methods in -- 'repTopDs' via 'hsGroupBinders'. However in 'repBinds', we recreate -- these fun_id via 'collectHsValBinders decs', which would lead to the -- instance declarations failing in TH. rep_meth_sigs_binds sigs binds = do { let tvs = concatMap get_scoped_tvs sigs ; ss <- mkGenSyms tvs ; sigs1 <- addBinds ss $ rep_sigs sigs ; binds1 <- addBinds ss $ rep_binds binds ; return (ss, de_loc (sort_by_loc (sigs1 ++ binds1))) } ------------------------------------------------------- -- Signatures in a class decl, or a group of bindings ------------------------------------------------------- rep_sigs :: [LSig GhcRn] -> MetaM [(SrcSpan, Core (M TH.Dec))] -- We silently ignore ones we don't recognise rep_sigs = concatMapM rep_sig rep_sig :: LSig GhcRn -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_sig (L loc (TypeSig _ nms ty)) = mapM (rep_wc_ty_sig sigDName (locA loc) ty) nms rep_sig (L loc (PatSynSig _ nms ty)) = mapM (rep_patsyn_ty_sig (locA loc) ty) nms rep_sig (L loc (ClassOpSig _ is_deflt nms ty)) | is_deflt = mapM (rep_ty_sig defaultSigDName (locA loc) ty) nms | otherwise = mapM (rep_ty_sig sigDName (locA loc) ty) nms rep_sig (L loc (FixSig _ fix_sig)) = rep_fix_d (locA loc) fix_sig rep_sig (L loc (InlineSig _ nm ispec))= rep_inline nm ispec (locA loc) rep_sig (L loc (SpecSig _ nm tys ispec)) = concatMapM (\t -> rep_specialise nm t ispec (locA loc)) tys rep_sig (L loc (SpecInstSig _ ty)) = rep_specialiseInst ty (locA loc) rep_sig (L _ (MinimalSig {})) = notHandled ThMinimalPragmas rep_sig (L _ (SCCFunSig {})) = notHandled ThSCCPragmas rep_sig (L loc (CompleteMatchSig _ cls mty)) = rep_complete_sig cls mty (locA loc) rep_sig d@(L _ (XSig {})) = pprPanic "rep_sig IdSig" (ppr d) -- Desugar the explicit type variable binders in an 'LHsSigType', making -- sure not to gensym them. -- See Note [Scoped type variables in quotes] -- and Note [Don't quantify implicit type variables in quotes] rep_ty_sig_tvs :: [LHsTyVarBndr Specificity GhcRn] -> MetaM (Core [M TH.TyVarBndrSpec]) rep_ty_sig_tvs explicit_tvs = repListM tyVarBndrSpecTyConName repTyVarBndr explicit_tvs -- Desugar the outer type variable binders in an 'LHsSigType', making -- sure not to gensym them. -- See Note [Scoped type variables in quotes] -- and Note [Don't quantify implicit type variables in quotes] rep_ty_sig_outer_tvs :: HsOuterSigTyVarBndrs GhcRn -> MetaM (Core [M TH.TyVarBndrSpec]) rep_ty_sig_outer_tvs (HsOuterImplicit{}) = coreListM tyVarBndrSpecTyConName [] rep_ty_sig_outer_tvs (HsOuterExplicit{hso_bndrs = explicit_tvs}) = rep_ty_sig_tvs explicit_tvs -- Desugar a top-level type signature. Unlike 'repHsSigType', this -- deliberately avoids gensymming the type variables. -- See Note [Scoped type variables in quotes] -- and Note [Don't quantify implicit type variables in quotes] rep_ty_sig :: Name -> SrcSpan -> LHsSigType GhcRn -> LocatedN Name -> MetaM (SrcSpan, Core (M TH.Dec)) rep_ty_sig mk_sig loc sig_ty nm = do { nm1 <- lookupLOcc nm ; ty1 <- rep_ty_sig' sig_ty ; sig <- repProto mk_sig nm1 ty1 ; return (loc, sig) } -- Desugar an 'LHsSigType', making sure not to gensym the type variables at -- the front of the type signature. -- See Note [Scoped type variables in quotes] -- and Note [Don't quantify implicit type variables in quotes] rep_ty_sig' :: LHsSigType GhcRn -> MetaM (Core (M TH.Type)) rep_ty_sig' (L _ (HsSig{sig_bndrs = outer_bndrs, sig_body = body})) | (ctxt, tau) <- splitLHsQualTy body = do { th_explicit_tvs <- rep_ty_sig_outer_tvs outer_bndrs ; th_ctxt <- repLContext ctxt ; th_tau <- repLTy tau ; if nullOuterExplicit outer_bndrs && null (fromMaybeContext ctxt) then return th_tau else repTForall th_explicit_tvs th_ctxt th_tau } rep_patsyn_ty_sig :: SrcSpan -> LHsSigType GhcRn -> LocatedN Name -> MetaM (SrcSpan, Core (M TH.Dec)) -- represents a pattern synonym type signature; -- see Note [Pattern synonym type signatures and Template Haskell] in "GHC.ThToHs" -- -- Don't create the implicit and explicit variables when desugaring signatures, -- see Note [Scoped type variables in quotes] -- and Note [Don't quantify implicit type variables in quotes] rep_patsyn_ty_sig loc sig_ty nm | (univs, reqs, exis, provs, ty) <- splitLHsPatSynTy sig_ty = do { nm1 <- lookupLOcc nm ; th_univs <- rep_ty_sig_tvs univs ; th_exis <- rep_ty_sig_tvs exis ; th_reqs <- repLContext reqs ; th_provs <- repLContext provs ; th_ty <- repLTy ty ; ty1 <- repTForall th_univs th_reqs =<< repTForall th_exis th_provs th_ty ; sig <- repProto patSynSigDName nm1 ty1 ; return (loc, sig) } rep_wc_ty_sig :: Name -> SrcSpan -> LHsSigWcType GhcRn -> LocatedN Name -> MetaM (SrcSpan, Core (M TH.Dec)) rep_wc_ty_sig mk_sig loc sig_ty nm = rep_ty_sig mk_sig loc (hswc_body sig_ty) nm rep_inline :: LocatedN Name -> InlinePragma -- Never defaultInlinePragma -> SrcSpan -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_inline nm ispec loc | Opaque {} <- inl_inline ispec = do { nm1 <- lookupLOcc nm ; opq <- repPragOpaque nm1 ; return [(loc, opq)] } rep_inline nm ispec loc = do { nm1 <- lookupLOcc nm ; inline <- repInline $ inl_inline ispec ; rm <- repRuleMatch $ inl_rule ispec ; phases <- repPhases $ inl_act ispec ; pragma <- repPragInl nm1 inline rm phases ; return [(loc, pragma)] } rep_specialise :: LocatedN Name -> LHsSigType GhcRn -> InlinePragma -> SrcSpan -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_specialise nm ty ispec loc = do { nm1 <- lookupLOcc nm ; ty1 <- repHsSigType ty ; phases <- repPhases $ inl_act ispec ; let inline = inl_inline ispec ; pragma <- if noUserInlineSpec inline then -- SPECIALISE repPragSpec nm1 ty1 phases else -- SPECIALISE INLINE do { inline1 <- repInline inline ; repPragSpecInl nm1 ty1 inline1 phases } ; return [(loc, pragma)] } rep_specialiseInst :: LHsSigType GhcRn -> SrcSpan -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_specialiseInst ty loc = do { ty1 <- repHsSigType ty ; pragma <- repPragSpecInst ty1 ; return [(loc, pragma)] } repInline :: InlineSpec -> MetaM (Core TH.Inline) repInline (NoInline _ ) = dataCon noInlineDataConName -- There is a mismatch between the TH and GHC representation because -- OPAQUE pragmas can't have phase activation annotations (which is -- enforced by the TH API), therefore they are desugared to OpaqueP rather than -- InlineP, see special case in rep_inline. repInline (Opaque _ ) = panic "repInline: Opaque" repInline (Inline _ ) = dataCon inlineDataConName repInline (Inlinable _ ) = dataCon inlinableDataConName repInline NoUserInlinePrag = notHandled ThNoUserInline repRuleMatch :: RuleMatchInfo -> MetaM (Core TH.RuleMatch) repRuleMatch ConLike = dataCon conLikeDataConName repRuleMatch FunLike = dataCon funLikeDataConName repPhases :: Activation -> MetaM (Core TH.Phases) repPhases (ActiveBefore _ i) = do { MkC arg <- coreIntLit i ; dataCon' beforePhaseDataConName [arg] } repPhases (ActiveAfter _ i) = do { MkC arg <- coreIntLit i ; dataCon' fromPhaseDataConName [arg] } repPhases _ = dataCon allPhasesDataConName rep_complete_sig :: Located [LocatedN Name] -> Maybe (LocatedN Name) -> SrcSpan -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_complete_sig (L _ cls) mty loc = do { mty' <- repMaybe nameTyConName lookupLOcc mty ; cls' <- repList nameTyConName lookupLOcc cls ; sig <- repPragComplete cls' mty' ; return [(loc, sig)] } ------------------------------------------------------- -- Types ------------------------------------------------------- class RepTV flag flag' | flag -> flag' where tyVarBndrName :: Name repPlainTV :: Core TH.Name -> flag -> MetaM (Core (M (TH.TyVarBndr flag'))) repKindedTV :: Core TH.Name -> flag -> Core (M TH.Kind) -> MetaM (Core (M (TH.TyVarBndr flag'))) instance RepTV () () where tyVarBndrName = tyVarBndrUnitTyConName repPlainTV (MkC nm) () = rep2 plainTVName [nm] repKindedTV (MkC nm) () (MkC ki) = rep2 kindedTVName [nm, ki] instance RepTV Specificity TH.Specificity where tyVarBndrName = tyVarBndrSpecTyConName repPlainTV (MkC nm) spec = do { (MkC spec') <- rep_flag spec ; rep2 plainInvisTVName [nm, spec'] } repKindedTV (MkC nm) spec (MkC ki) = do { (MkC spec') <- rep_flag spec ; rep2 kindedInvisTVName [nm, spec', ki] } rep_flag :: Specificity -> MetaM (Core TH.Specificity) rep_flag SpecifiedSpec = rep2_nw specifiedSpecName [] rep_flag InferredSpec = rep2_nw inferredSpecName [] addHsOuterFamEqnTyVarBinds :: HsOuterFamEqnTyVarBndrs GhcRn -> (Core (Maybe [M TH.TyVarBndrUnit]) -> MetaM (Core (M a))) -> MetaM (Core (M a)) addHsOuterFamEqnTyVarBinds outer_bndrs thing_inside = do elt_ty <- wrapName tyVarBndrUnitTyConName case outer_bndrs of HsOuterImplicit{hso_ximplicit = imp_tvs} -> addSimpleTyVarBinds ReuseBoundNames imp_tvs $ thing_inside $ coreNothingList elt_ty HsOuterExplicit{hso_bndrs = exp_bndrs} -> addHsTyVarBinds FreshNamesOnly exp_bndrs $ \th_exp_bndrs -> thing_inside $ coreJustList elt_ty th_exp_bndrs addHsOuterSigTyVarBinds :: HsOuterSigTyVarBndrs GhcRn -> (Core [M TH.TyVarBndrSpec] -> MetaM (Core (M a))) -> MetaM (Core (M a)) addHsOuterSigTyVarBinds outer_bndrs thing_inside = case outer_bndrs of HsOuterImplicit{hso_ximplicit = imp_tvs} -> do th_nil <- coreListM tyVarBndrSpecTyConName [] addSimpleTyVarBinds FreshNamesOnly imp_tvs $ thing_inside th_nil HsOuterExplicit{hso_bndrs = exp_bndrs} -> addHsTyVarBinds FreshNamesOnly exp_bndrs thing_inside -- | If a type implicitly quantifies its outermost type variables, return -- 'True' if the list of implicitly bound type variables is empty. If a type -- explicitly quantifies its outermost type variables, always return 'True'. -- -- This is used in various places to determine if a Template Haskell 'Type' -- should be headed by a 'ForallT' or not. nullOuterImplicit :: HsOuterSigTyVarBndrs GhcRn -> Bool nullOuterImplicit (HsOuterImplicit{hso_ximplicit = imp_tvs}) = null imp_tvs nullOuterImplicit (HsOuterExplicit{}) = True -- Vacuously true, as there is no implicit quantification -- | If a type explicitly quantifies its outermost type variables, return -- 'True' if the list of explicitly bound type variables is empty. If a type -- implicitly quantifies its outermost type variables, always return 'True'. -- -- This is used in various places to determine if a Template Haskell 'Type' -- should be headed by a 'ForallT' or not. nullOuterExplicit :: HsOuterSigTyVarBndrs GhcRn -> Bool nullOuterExplicit (HsOuterExplicit{hso_bndrs = exp_bndrs}) = null exp_bndrs nullOuterExplicit (HsOuterImplicit{}) = True -- Vacuously true, as there is no outermost explicit quantification -- Do we want to generate fresh names for type variables -- or reuse the ones that are already in scope? data FreshOrReuse = FreshNamesOnly -- Generate fresh names for all type variables, regardless of existing -- variables in the MetaEnv. -- -- This is the default strategy. | ReuseBoundNames -- Generate fresh names for type variables not in the MetaEnv. -- Where a name is already bound in the MetaEnv, use that existing binding; -- do not create a new one with a fresh name. -- -- This is the strategy used for data/newtype declarations and type family -- instances, so that the nested type variables work right: -- -- class C a where -- type W a b -- instance C (T a) where -- type W (T a) b = blah -- -- The 'a' in the type instance is the one bound by the instance decl -- -- Test cases: TH_reifyExplicitForAllFams T9081 T9199 T10811 mkGenSyms' :: FreshOrReuse -> [Name] -> MetaM [GenSymBind] mkGenSyms' FreshNamesOnly names = mkGenSyms names mkGenSyms' ReuseBoundNames names = -- Make fresh names for the ones that are not already in scope -- This makes things work for associated types do { env <- lift dsGetMetaEnv ; mkGenSyms (filterOut (`elemNameEnv` env) names) } addSimpleTyVarBinds :: FreshOrReuse -> [Name] -- the binders to be added -> MetaM (Core (M a)) -- action in the ext env -> MetaM (Core (M a)) addSimpleTyVarBinds fresh_or_reuse names thing_inside = do { fresh_names <- mkGenSyms' fresh_or_reuse names ; term <- addBinds fresh_names thing_inside ; wrapGenSyms fresh_names term } addHsTyVarBinds :: forall flag flag' a. RepTV flag flag' => FreshOrReuse -> [LHsTyVarBndr flag GhcRn] -- the binders to be added -> (Core [(M (TH.TyVarBndr flag'))] -> MetaM (Core (M a))) -- action in the ext env -> MetaM (Core (M a)) addHsTyVarBinds fresh_or_reuse exp_tvs thing_inside = do { fresh_exp_names <- mkGenSyms' fresh_or_reuse (hsLTyVarNames exp_tvs) ; term <- addBinds fresh_exp_names $ do { kbs <- repListM (tyVarBndrName @flag @flag') repTyVarBndr exp_tvs ; thing_inside kbs } ; wrapGenSyms fresh_exp_names term } addQTyVarBinds :: FreshOrReuse -> LHsQTyVars GhcRn -- the binders to be added -> (Core [(M (TH.TyVarBndr ()))] -> MetaM (Core (M a))) -- action in the ext env -> MetaM (Core (M a)) addQTyVarBinds fresh_or_reuse qtvs thing_inside = let HsQTvs { hsq_ext = imp_tvs , hsq_explicit = exp_tvs } = qtvs in addTyVarBinds fresh_or_reuse exp_tvs imp_tvs thing_inside addTyVarBinds :: RepTV flag flag' => FreshOrReuse -> [LHsTyVarBndr flag GhcRn] -- the binders to be added -> [Name] -> (Core [(M (TH.TyVarBndr flag'))] -> MetaM (Core (M a))) -- action in the ext env -> MetaM (Core (M a)) -- gensym a list of type variables and enter them into the meta environment; -- the computations passed as the second argument is executed in that extended -- meta environment and gets the *new* names on Core-level as an argument addTyVarBinds fresh_or_reuse exp_tvs imp_tvs thing_inside = addSimpleTyVarBinds fresh_or_reuse imp_tvs $ addHsTyVarBinds fresh_or_reuse exp_tvs $ thing_inside -- | Represent a type variable binder repTyVarBndr :: RepTV flag flag' => LHsTyVarBndr flag GhcRn -> MetaM (Core (M (TH.TyVarBndr flag'))) repTyVarBndr (L _ (UserTyVar _ fl (L _ nm)) ) = do { nm' <- lookupBinder nm ; repPlainTV nm' fl } repTyVarBndr (L _ (KindedTyVar _ fl (L _ nm) ki)) = do { nm' <- lookupBinder nm ; ki' <- repLTy ki ; repKindedTV nm' fl ki' } -- represent a type context -- repLContext :: Maybe (LHsContext GhcRn) -> MetaM (Core (M TH.Cxt)) repLContext Nothing = repContext [] repLContext (Just ctxt) = repContext (unLoc ctxt) repContext :: HsContext GhcRn -> MetaM (Core (M TH.Cxt)) repContext ctxt = do preds <- repListM typeTyConName repLTy ctxt repCtxt preds repHsSigType :: LHsSigType GhcRn -> MetaM (Core (M TH.Type)) repHsSigType (L _ (HsSig { sig_bndrs = outer_bndrs, sig_body = body })) | (ctxt, tau) <- splitLHsQualTy body = addHsOuterSigTyVarBinds outer_bndrs $ \ th_outer_bndrs -> do { th_ctxt <- repLContext ctxt ; th_tau <- repLTy tau ; if nullOuterExplicit outer_bndrs && null (fromMaybeContext ctxt) then pure th_tau else repTForall th_outer_bndrs th_ctxt th_tau } -- yield the representation of a list of types repLTys :: [LHsType GhcRn] -> MetaM [Core (M TH.Type)] repLTys tys = mapM repLTy tys -- represent a type repLTy :: LHsType GhcRn -> MetaM (Core (M TH.Type)) repLTy ty = repTy (unLoc ty) -- Desugar a type headed by an invisible forall (e.g., @forall a. a@) or -- a context (e.g., @Show a => a@) into a ForallT from L.H.TH.Syntax. -- In other words, the argument to this function is always an -- @HsForAllTy HsForAllInvis{}@ or @HsQualTy@. -- Types headed by visible foralls (which are desugared to ForallVisT) are -- handled separately in repTy. repForallT :: HsType GhcRn -> MetaM (Core (M TH.Type)) repForallT ty | (tvs, ctxt, tau) <- splitLHsSigmaTyInvis (noLocA ty) = addHsTyVarBinds FreshNamesOnly tvs $ \bndrs -> do { ctxt1 <- repLContext ctxt ; tau1 <- repLTy tau ; repTForall bndrs ctxt1 tau1 -- forall a. C a => {...} } repTy :: HsType GhcRn -> MetaM (Core (M TH.Type)) repTy ty@(HsForAllTy { hst_tele = tele, hst_body = body }) = case tele of HsForAllInvis{} -> repForallT ty HsForAllVis { hsf_vis_bndrs = tvs } -> addHsTyVarBinds FreshNamesOnly tvs $ \bndrs -> do body1 <- repLTy body repTForallVis bndrs body1 repTy ty@(HsQualTy {}) = repForallT ty repTy (HsTyVar _ _ (L _ n)) | n `hasKey` liftedTypeKindTyConKey = repTStar | n `hasKey` constraintKindTyConKey = repTConstraint | n `hasKey` unrestrictedFunTyConKey = repArrowTyCon | n `hasKey` fUNTyConKey = repMulArrowTyCon | isTvOcc occ = do tv1 <- lookupOcc n repTvar tv1 | isDataOcc occ = do tc1 <- lookupOcc n repPromotedDataCon tc1 | n == eqTyConName = repTequality | otherwise = do tc1 <- lookupOcc n repNamedTyCon tc1 where occ = nameOccName n repTy (HsAppTy _ f a) = do f1 <- repLTy f a1 <- repLTy a repTapp f1 a1 repTy (HsAppKindTy _ ty _ ki) = do ty1 <- repLTy ty ki1 <- repLTy ki repTappKind ty1 ki1 repTy (HsFunTy _ w f a) | isUnrestricted w = do f1 <- repLTy f a1 <- repLTy a tcon <- repArrowTyCon repTapps tcon [f1, a1] repTy (HsFunTy _ w f a) = do w1 <- repLTy (arrowToHsType w) f1 <- repLTy f a1 <- repLTy a tcon <- repMulArrowTyCon repTapps tcon [w1, f1, a1] repTy (HsListTy _ t) = do t1 <- repLTy t tcon <- repListTyCon repTapp tcon t1 repTy (HsTupleTy _ HsUnboxedTuple tys) = do tys1 <- repLTys tys tcon <- repUnboxedTupleTyCon (length tys) repTapps tcon tys1 repTy (HsTupleTy _ _ tys) = do tys1 <- repLTys tys tcon <- repTupleTyCon (length tys) repTapps tcon tys1 repTy (HsSumTy _ tys) = do tys1 <- repLTys tys tcon <- repUnboxedSumTyCon (length tys) repTapps tcon tys1 repTy (HsOpTy _ prom ty1 n ty2) = repLTy ((nlHsTyVar prom (unLoc n) `nlHsAppTy` ty1) `nlHsAppTy` ty2) repTy (HsParTy _ t) = repLTy t repTy (HsStarTy _ _) = repTStar repTy (HsKindSig _ t k) = do t1 <- repLTy t k1 <- repLTy k repTSig t1 k1 repTy (HsSpliceTy (HsUntypedSpliceNested n) _) = rep_splice n repTy t@(HsSpliceTy (HsUntypedSpliceTop _ _) _) = pprPanic "repTy: top level splice" (ppr t) repTy (HsExplicitListTy _ _ tys) = do tys1 <- repLTys tys repTPromotedList tys1 repTy (HsExplicitTupleTy _ tys) = do tys1 <- repLTys tys tcon <- repPromotedTupleTyCon (length tys) repTapps tcon tys1 repTy (HsTyLit _ lit) = do lit' <- repTyLit lit repTLit lit' repTy (HsWildCardTy _) = repTWildCard repTy (HsIParamTy _ n t) = do n' <- rep_implicit_param_name (unLoc n) t' <- repLTy t repTImplicitParam n' t' repTy ty = notHandled (ThExoticFormOfType ty) repTyLit :: HsTyLit (GhcPass p) -> MetaM (Core (M TH.TyLit)) repTyLit (HsNumTy _ i) = do platform <- getPlatform rep2 numTyLitName [mkIntegerExpr platform i] repTyLit (HsStrTy _ s) = do { s' <- mkStringExprFS s ; rep2 strTyLitName [s'] } repTyLit (HsCharTy _ c) = do { c' <- return (mkCharExpr c) ; rep2 charTyLitName [c'] } -- | Represent a type wrapped in a Maybe repMaybeLTy :: Maybe (LHsKind GhcRn) -> MetaM (Core (Maybe (M TH.Type))) repMaybeLTy m = do k_ty <- wrapName kindTyConName repMaybeT k_ty repLTy m repRole :: LocatedAn NoEpAnns (Maybe Role) -> MetaM (Core TH.Role) repRole (L _ (Just Nominal)) = rep2_nw nominalRName [] repRole (L _ (Just Representational)) = rep2_nw representationalRName [] repRole (L _ (Just Phantom)) = rep2_nw phantomRName [] repRole (L _ Nothing) = rep2_nw inferRName [] ----------------------------------------------------------------------------- -- Splices ----------------------------------------------------------------------------- -- See Note [How brackets and nested splices are handled] in GHC.Tc.Gen.Splice -- We return a CoreExpr of any old type; the context should know rep_splice :: Name -> MetaM (Core a) rep_splice splice_name = do { mb_val <- lift $ dsLookupMetaEnv splice_name ; case mb_val of Just (DsSplice e) -> do { e' <- lift $ dsExpr e ; return (MkC e') } _ -> pprPanic "HsSplice" (ppr splice_name) } -- Should not happen; statically checked ----------------------------------------------------------------------------- -- Expressions ----------------------------------------------------------------------------- repLEs :: [LHsExpr GhcRn] -> MetaM (Core [(M TH.Exp)]) repLEs es = repListM expTyConName repLE es -- FIXME: some of these panics should be converted into proper error messages -- unless we can make sure that constructs, which are plainly not -- supported in TH already lead to error messages at an earlier stage repLE :: LHsExpr GhcRn -> MetaM (Core (M TH.Exp)) repLE (L loc e) = mapReaderT (putSrcSpanDs (locA loc)) (repE e) repE :: HsExpr GhcRn -> MetaM (Core (M TH.Exp)) repE (HsVar _ (L _ x)) = do { mb_val <- lift $ dsLookupMetaEnv x ; case mb_val of Nothing -> do { str <- lift $ globalVar x ; repVarOrCon x str } Just (DsBound y) -> repVarOrCon x (coreVar y) Just (DsSplice e) -> do { e' <- lift $ dsExpr e ; return (MkC e') } } repE (HsIPVar _ n) = rep_implicit_param_name n >>= repImplicitParamVar repE (HsOverLabel _ _ s) = repOverLabel s repE (HsRecSel _ (FieldOcc x _)) = repE (HsVar noExtField (noLocA x)) -- Remember, we're desugaring renamer output here, so -- HsOverlit can definitely occur repE (HsOverLit _ l) = do { a <- repOverloadedLiteral l; repLit a } repE (HsLit _ l) = do { a <- repLiteral l; repLit a } repE (HsLam _ (MG { mg_alts = (L _ [m]) })) = repLambda m repE e@(HsLam _ (MG { mg_alts = (L _ _) })) = pprPanic "repE: HsLam with multiple alternatives" (ppr e) repE (HsLamCase _ LamCase (MG { mg_alts = (L _ ms) })) = do { ms' <- mapM repMatchTup ms ; core_ms <- coreListM matchTyConName ms' ; repLamCase core_ms } repE (HsLamCase _ LamCases (MG { mg_alts = (L _ ms) })) = do { ms' <- mapM repClauseTup ms ; core_ms <- coreListM matchTyConName ms' ; repLamCases core_ms } repE (HsApp _ x y) = do {a <- repLE x; b <- repLE y; repApp a b} repE (HsAppType _ e _ t) = do { a <- repLE e ; s <- repLTy (hswc_body t) ; repAppType a s } repE (OpApp _ e1 op e2) = do { arg1 <- repLE e1; arg2 <- repLE e2; the_op <- repLE op ; repInfixApp arg1 the_op arg2 } repE (NegApp _ x _) = do a <- repLE x negateVar <- lookupOcc negateName >>= repVar negateVar `repApp` a repE (HsPar _ _ x _) = repLE x repE (SectionL _ x y) = do { a <- repLE x; b <- repLE y; repSectionL a b } repE (SectionR _ x y) = do { a <- repLE x; b <- repLE y; repSectionR a b } repE (HsCase _ e (MG { mg_alts = (L _ ms) })) = do { arg <- repLE e ; ms2 <- mapM repMatchTup ms ; core_ms2 <- coreListM matchTyConName ms2 ; repCaseE arg core_ms2 } repE (HsIf _ x y z) = do a <- repLE x b <- repLE y c <- repLE z repCond a b c repE (HsMultiIf _ alts) = do { (binds, alts') <- liftM unzip $ mapM repLGRHS alts ; expr' <- repMultiIf (nonEmptyCoreList alts') ; wrapGenSyms (concat binds) expr' } repE (HsLet _ _ bs _ e) = do { (ss,ds) <- repBinds bs ; e2 <- addBinds ss (repLE e) ; z <- repLetE ds e2 ; wrapGenSyms ss z } -- FIXME: I haven't got the types here right yet repE e@(HsDo _ ctxt (L _ sts)) | Just maybeModuleName <- case ctxt of { DoExpr m -> Just m; GhciStmtCtxt -> Just Nothing; _ -> Nothing } = do { (ss,zs) <- repLSts sts; e' <- repDoE maybeModuleName (nonEmptyCoreList zs); wrapGenSyms ss e' } | ListComp <- ctxt = do { (ss,zs) <- repLSts sts; e' <- repComp (nonEmptyCoreList zs); wrapGenSyms ss e' } | MDoExpr maybeModuleName <- ctxt = do { (ss,zs) <- repLSts sts; e' <- repMDoE maybeModuleName (nonEmptyCoreList zs); wrapGenSyms ss e' } | otherwise = notHandled (ThMonadComprehensionSyntax e) repE (ExplicitList _ es) = do { xs <- repLEs es; repListExp xs } repE (ExplicitTuple _ es boxity) = let tupArgToCoreExp :: HsTupArg GhcRn -> MetaM (Core (Maybe (M TH.Exp))) tupArgToCoreExp a | (Present _ e) <- a = do { e' <- repLE e ; coreJustM expTyConName e' } | otherwise = coreNothingM expTyConName in do { args <- mapM tupArgToCoreExp es ; expTy <- wrapName expTyConName ; let maybeExpQTy = mkTyConApp maybeTyCon [expTy] listArg = coreList' maybeExpQTy args ; if isBoxed boxity then repTup listArg else repUnboxedTup listArg } repE (ExplicitSum _ alt arity e) = do { e1 <- repLE e ; repUnboxedSum e1 alt arity } repE (RecordCon { rcon_con = c, rcon_flds = flds }) = do { x <- lookupLOcc c; fs <- repFields flds; repRecCon x fs } repE (RecordUpd { rupd_expr = e, rupd_flds = RegularRecUpdFields { recUpdFields = flds } }) = do { x <- repLE e; fs <- repUpdFields flds; repRecUpd x fs } repE e@(RecordUpd { rupd_flds = OverloadedRecUpdFields {} }) = do -- Not possible due to elimination in the renamer. See Note -- [Handling overloaded and rebindable constructs] pprPanic "repE: unexpected overloaded record update" $ ppr e repE (ExprWithTySig _ e wc_ty) = addSimpleTyVarBinds FreshNamesOnly (get_scoped_tvs_from_sig sig_ty) $ do { e1 <- repLE e ; t1 <- rep_ty_sig' sig_ty ; repSigExp e1 t1 } where sig_ty = dropWildCards wc_ty repE (ArithSeq _ _ aseq) = case aseq of From e -> do { ds1 <- repLE e; repFrom ds1 } FromThen e1 e2 -> do ds1 <- repLE e1 ds2 <- repLE e2 repFromThen ds1 ds2 FromTo e1 e2 -> do ds1 <- repLE e1 ds2 <- repLE e2 repFromTo ds1 ds2 FromThenTo e1 e2 e3 -> do ds1 <- repLE e1 ds2 <- repLE e2 ds3 <- repLE e3 repFromThenTo ds1 ds2 ds3 repE (HsTypedSplice n _) = rep_splice n repE (HsUntypedSplice (HsUntypedSpliceNested n) _) = rep_splice n repE e@(HsUntypedSplice (HsUntypedSpliceTop _ _) _) = pprPanic "repE: top level splice" (ppr e) repE (HsStatic _ e) = repLE e >>= rep2 staticEName . (:[]) . unC repE (HsUnboundVar _ uv) = do name <- repRdrName uv repUnboundVar name repE (HsGetField _ e (L _ (DotFieldOcc _ (L _ (FieldLabelString f))))) = do e1 <- repLE e repGetField e1 f repE (HsProjection _ xs) = repProjection (fmap (field_label . unLoc . dfoLabel . unLoc) xs) repE (XExpr (HsExpanded orig_expr ds_expr)) = do { rebindable_on <- lift $ xoptM LangExt.RebindableSyntax ; if rebindable_on -- See Note [Quotation and rebindable syntax] then repE ds_expr else repE orig_expr } repE e@(HsPragE _ (HsPragSCC {}) _) = notHandled (ThCostCentres e) repE e@(HsTypedBracket{}) = notHandled (ThExpressionForm e) repE e@(HsUntypedBracket{}) = notHandled (ThExpressionForm e) repE e@(HsProc{}) = notHandled (ThExpressionForm e) {- Note [Quotation and rebindable syntax] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Consider f = [| (* 3) |] Because of Note [Handling overloaded and rebindable constructs] in GHC.Rename.Expr, the renamer will expand (* 3) to (rightSection (*) 3), regardless of RebindableSyntax. Then, concerning the TH quotation, * If RebindableSyntax is off, we want the TH quote to generate the section (* 3), as the user originally wrote. * If RebindableSyntax is on, we perhaps want the TH quote to generate (rightSection (*) 3), using whatever 'rightSection' is in scope, because (a) RebindableSyntax might not be on in the splicing context (b) Even if it is, 'rightSection' might not be in scope (c) At least in the case of Typed Template Haskell we should never get a type error from the splice. We consult the module-wide RebindableSyntax flag here. We could instead record the choice in HsExpanded, but it seems simpler to consult the flag (again). -} ----------------------------------------------------------------------------- -- Building representations of auxiliary structures like Match, Clause, Stmt, repMatchTup :: LMatch GhcRn (LHsExpr GhcRn) -> MetaM (Core (M TH.Match)) repMatchTup (L _ (Match { m_pats = [p] , m_grhss = GRHSs _ guards wheres })) = do { ss1 <- mkGenSyms (collectPatBinders CollNoDictBinders p) ; addBinds ss1 $ do { ; p1 <- repLP p ; (ss2,ds) <- repBinds wheres ; addBinds ss2 $ do { ; gs <- repGuards guards ; match <- repMatch p1 gs ds ; wrapGenSyms (ss1++ss2) match }}} repMatchTup _ = panic "repMatchTup: case alt with more than one arg" repClauseTup :: LMatch GhcRn (LHsExpr GhcRn) -> MetaM (Core (M TH.Clause)) repClauseTup (L _ (Match { m_pats = ps , m_grhss = GRHSs _ guards wheres })) = do { ss1 <- mkGenSyms (collectPatsBinders CollNoDictBinders ps) ; addBinds ss1 $ do { ps1 <- repLPs ps ; (ss2,ds) <- repBinds wheres ; addBinds ss2 $ do { gs <- repGuards guards ; clause <- repClause ps1 gs ds ; wrapGenSyms (ss1++ss2) clause }}} repGuards :: [LGRHS GhcRn (LHsExpr GhcRn)] -> MetaM (Core (M TH.Body)) repGuards [L _ (GRHS _ [] e)] = do {a <- repLE e; repNormal a } repGuards other = do { zs <- mapM repLGRHS other ; let (xs, ys) = unzip zs ; gd <- repGuarded (nonEmptyCoreList ys) ; wrapGenSyms (concat xs) gd } repLGRHS :: LGRHS GhcRn (LHsExpr GhcRn) -> MetaM ([GenSymBind], (Core (M (TH.Guard, TH.Exp)))) repLGRHS (L _ (GRHS _ [L _ (BodyStmt _ e1 _ _)] e2)) = do { guarded <- repLNormalGE e1 e2 ; return ([], guarded) } repLGRHS (L _ (GRHS _ ss rhs)) = do { (gs, ss') <- repLSts ss ; rhs' <- addBinds gs $ repLE rhs ; guarded <- repPatGE (nonEmptyCoreList ss') rhs' ; return (gs, guarded) } repFields :: HsRecordBinds GhcRn -> MetaM (Core [M TH.FieldExp]) repFields (HsRecFields { rec_flds = flds }) = repListM fieldExpTyConName rep_fld flds where rep_fld :: LHsRecField GhcRn (LHsExpr GhcRn) -> MetaM (Core (M TH.FieldExp)) rep_fld (L _ fld) = do { fn <- lookupOcc (hsRecFieldSel fld) ; e <- repLE (hfbRHS fld) ; repFieldExp fn e } repUpdFields :: [LHsRecUpdField GhcRn GhcRn] -> MetaM (Core [M TH.FieldExp]) repUpdFields = repListM fieldExpTyConName rep_fld where rep_fld :: LHsRecUpdField GhcRn GhcRn -> MetaM (Core (M TH.FieldExp)) rep_fld (L l fld) = case unLoc (hfbLHS fld) of Unambiguous sel_name _ -> do { fn <- lookupLOcc (L l sel_name) ; e <- repLE (hfbRHS fld) ; repFieldExp fn e } Ambiguous{} -> notHandled (ThAmbiguousRecordUpdates fld) ----------------------------------------------------------------------------- -- Representing Stmt's is tricky, especially if bound variables -- shadow each other. Consider: [| do { x <- f 1; x <- f x; g x } |] -- First gensym new names for every variable in any of the patterns. -- both static (x'1 and x'2), and dynamic ((gensym "x") and (gensym "y")) -- if variables didn't shadow, the static gensym wouldn't be necessary -- and we could reuse the original names (x and x). -- -- do { x'1 <- gensym "x" -- ; x'2 <- gensym "x" -- ; doE Nothing -- [ BindSt (pvar x'1) [| f 1 |] -- , BindSt (pvar x'2) [| f x |] -- , NoBindSt [| g x |] -- ] -- } -- The strategy is to translate a whole list of do-bindings by building a -- bigger environment, and a bigger set of meta bindings -- (like: x'1 <- gensym "x" ) and then combining these with the translations -- of the expressions within the Do ----------------------------------------------------------------------------- -- The helper function repSts computes the translation of each sub expression -- and a bunch of prefix bindings denoting the dynamic renaming. repLSts :: [LStmt GhcRn (LHsExpr GhcRn)] -> MetaM ([GenSymBind], [Core (M TH.Stmt)]) repLSts stmts = repSts (map unLoc stmts) repSts :: [Stmt GhcRn (LHsExpr GhcRn)] -> MetaM ([GenSymBind], [Core (M TH.Stmt)]) repSts (BindStmt _ p e : ss) = do { e2 <- repLE e ; ss1 <- mkGenSyms (collectPatBinders CollNoDictBinders p) ; addBinds ss1 $ do { ; p1 <- repLP p; ; (ss2,zs) <- repSts ss ; z <- repBindSt p1 e2 ; return (ss1++ss2, z : zs) }} repSts (LetStmt _ bs : ss) = do { (ss1,ds) <- repBinds bs ; z <- repLetSt ds ; (ss2,zs) <- addBinds ss1 (repSts ss) ; return (ss1++ss2, z : zs) } repSts (BodyStmt _ e _ _ : ss) = do { e2 <- repLE e ; z <- repNoBindSt e2 ; (ss2,zs) <- repSts ss ; return (ss2, z : zs) } repSts (ParStmt _ stmt_blocks _ _ : ss) = do { (ss_s, stmt_blocks1) <- mapAndUnzipM rep_stmt_block stmt_blocks ; let stmt_blocks2 = nonEmptyCoreList stmt_blocks1 ss1 = concat ss_s ; z <- repParSt stmt_blocks2 ; (ss2, zs) <- addBinds ss1 (repSts ss) ; return (ss1++ss2, z : zs) } where rep_stmt_block :: ParStmtBlock GhcRn GhcRn -> MetaM ([GenSymBind], Core [(M TH.Stmt)]) rep_stmt_block (ParStmtBlock _ stmts _ _) = do { (ss1, zs) <- repSts (map unLoc stmts) ; zs1 <- coreListM stmtTyConName zs ; return (ss1, zs1) } repSts [LastStmt _ e _ _] = do { e2 <- repLE e ; z <- repNoBindSt e2 ; return ([], [z]) } repSts (stmt@RecStmt{} : ss) = do { let binders = collectLStmtsBinders CollNoDictBinders (unLoc $ recS_stmts stmt) ; ss1 <- mkGenSyms binders -- Bring all of binders in the recursive group into scope for the -- whole group. ; (ss1_other,rss) <- addBinds ss1 $ repSts (map unLoc (unLoc $ recS_stmts stmt)) ; massert (sort ss1 == sort ss1_other) ; z <- repRecSt (nonEmptyCoreList rss) ; (ss2,zs) <- addBinds ss1 (repSts ss) ; return (ss1++ss2, z : zs) } repSts [] = return ([],[]) repSts other = notHandled (ThExoticStatement other) ----------------------------------------------------------- -- Bindings ----------------------------------------------------------- repBinds :: HsLocalBinds GhcRn -> MetaM ([GenSymBind], Core [(M TH.Dec)]) repBinds (EmptyLocalBinds _) = do { core_list <- coreListM decTyConName [] ; return ([], core_list) } repBinds (HsIPBinds _ (IPBinds _ decs)) = do { ips <- mapM rep_implicit_param_bind decs ; core_list <- coreListM decTyConName (de_loc (sort_by_loc ips)) ; return ([], core_list) } repBinds (HsValBinds _ decs) = do { let { bndrs = hsScopedTvBinders decs ++ collectHsValBinders CollNoDictBinders decs } -- No need to worry about detailed scopes within -- the binding group, because we are talking Names -- here, so we can safely treat it as a mutually -- recursive group -- For hsScopedTvBinders see Note [Scoped type variables in quotes] ; ss <- mkGenSyms bndrs ; prs <- addBinds ss (rep_val_binds decs) ; core_list <- coreListM decTyConName (de_loc (sort_by_loc prs)) ; return (ss, core_list) } rep_implicit_param_bind :: LIPBind GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) rep_implicit_param_bind (L loc (IPBind _ (L _ n) (L _ rhs))) = do { name <- rep_implicit_param_name n ; rhs' <- repE rhs ; ipb <- repImplicitParamBind name rhs' ; return (locA loc, ipb) } rep_implicit_param_name :: HsIPName -> MetaM (Core String) rep_implicit_param_name (HsIPName name) = coreStringLit name rep_val_binds :: HsValBinds GhcRn -> MetaM [(SrcSpan, Core (M TH.Dec))] -- Assumes: all the binders of the binding are already in the meta-env rep_val_binds (XValBindsLR (NValBinds binds sigs)) = do { core1 <- rep_binds (unionManyBags (map snd binds)) ; core2 <- rep_sigs sigs ; return (core1 ++ core2) } rep_val_binds (ValBinds _ _ _) = panic "rep_val_binds: ValBinds" rep_binds :: LHsBinds GhcRn -> MetaM [(SrcSpan, Core (M TH.Dec))] rep_binds = mapM rep_bind . bagToList rep_bind :: LHsBind GhcRn -> MetaM (SrcSpan, Core (M TH.Dec)) -- Assumes: all the binders of the binding are already in the meta-env -- Note GHC treats declarations of a variable (not a pattern) -- e.g. x = g 5 as a Fun MonoBinds. This is indicated by a single match -- with an empty list of patterns rep_bind (L loc (FunBind { fun_id = fn, fun_matches = MG { mg_alts = (L _ [L _ (Match { m_pats = [] , m_grhss = GRHSs _ guards wheres -- For a variable declaration I'm pretty -- sure we always have a FunRhs , m_ctxt = FunRhs { mc_strictness = strictessAnn } } )]) } })) = do { (ss,wherecore) <- repBinds wheres ; guardcore <- addBinds ss (repGuards guards) ; fn' <- lookupNBinder fn ; p <- repPvar fn' >>= case strictessAnn of SrcLazy -> repPtilde SrcStrict -> repPbang NoSrcStrict -> pure ; ans <- repVal p guardcore wherecore ; ans' <- wrapGenSyms ss ans ; return (locA loc, ans') } rep_bind (L loc (FunBind { fun_id = fn , fun_matches = MG { mg_alts = L _ ms } })) = do { ms1 <- mapM repClauseTup ms ; fn' <- lookupNBinder fn ; ans <- repFun fn' (nonEmptyCoreList ms1) ; return (locA loc, ans) } rep_bind (L loc (PatBind { pat_lhs = pat , pat_rhs = GRHSs _ guards wheres })) = do { patcore <- repLP pat ; (ss,wherecore) <- repBinds wheres ; guardcore <- addBinds ss (repGuards guards) ; ans <- repVal patcore guardcore wherecore ; ans' <- wrapGenSyms ss ans ; return (locA loc, ans') } rep_bind (L _ (VarBind { var_id = v, var_rhs = e})) = do { v' <- lookupBinder v ; e2 <- repLE e ; x <- repNormal e2 ; patcore <- repPvar v' ; empty_decls <- coreListM decTyConName [] ; ans <- repVal patcore x empty_decls ; return (srcLocSpan (getSrcLoc v), ans) } rep_bind (L loc (PatSynBind _ (PSB { psb_id = syn , psb_args = args , psb_def = pat , psb_dir = dir }))) = do { syn' <- lookupNBinder syn ; dir' <- repPatSynDir dir ; ss <- mkGenArgSyms args ; patSynD' <- addBinds ss ( do { args' <- repPatSynArgs args ; pat' <- repLP pat ; repPatSynD syn' args' dir' pat' }) ; patSynD'' <- wrapGenArgSyms args ss patSynD' ; return (locA loc, patSynD'') } where mkGenArgSyms :: HsPatSynDetails GhcRn -> MetaM [GenSymBind] -- for Record Pattern Synonyms we want to conflate the selector -- and the pattern-only names in order to provide a nicer TH -- API. Whereas inside GHC, record pattern synonym selectors and -- their pattern-only bound right hand sides have different names, -- we want to treat them the same in TH. This is the reason why we -- need an adjusted mkGenArgSyms in the `RecCon` case below. mkGenArgSyms (PrefixCon _ args) = mkGenSyms (map unLoc args) mkGenArgSyms (InfixCon arg1 arg2) = mkGenSyms [unLoc arg1, unLoc arg2] mkGenArgSyms (RecCon fields) = do { let pats = map (unLoc . recordPatSynPatVar) fields sels = map (foExt . recordPatSynField) fields ; ss <- mkGenSyms sels ; return $ replaceNames (zip sels pats) ss } replaceNames selsPats genSyms = [ (pat, id) | (sel, id) <- genSyms, (sel', pat) <- selsPats , sel == sel' ] wrapGenArgSyms :: HsPatSynDetails GhcRn -> [GenSymBind] -> Core (M TH.Dec) -> MetaM (Core (M TH.Dec)) wrapGenArgSyms (RecCon _) _ dec = return dec wrapGenArgSyms _ ss dec = wrapGenSyms ss dec repPatSynD :: Core TH.Name -> Core (M TH.PatSynArgs) -> Core (M TH.PatSynDir) -> Core (M TH.Pat) -> MetaM (Core (M TH.Dec)) repPatSynD (MkC syn) (MkC args) (MkC dir) (MkC pat) = rep2 patSynDName [syn, args, dir, pat] repPatSynArgs :: HsPatSynDetails GhcRn -> MetaM (Core (M TH.PatSynArgs)) repPatSynArgs (PrefixCon _ args) = do { args' <- repList nameTyConName lookupLOcc args ; repPrefixPatSynArgs args' } repPatSynArgs (InfixCon arg1 arg2) = do { arg1' <- lookupLOcc arg1 ; arg2' <- lookupLOcc arg2 ; repInfixPatSynArgs arg1' arg2' } repPatSynArgs (RecCon fields) = do { sels' <- repList nameTyConName (lookupOcc . foExt) sels ; repRecordPatSynArgs sels' } where sels = map recordPatSynField fields repPrefixPatSynArgs :: Core [TH.Name] -> MetaM (Core (M TH.PatSynArgs)) repPrefixPatSynArgs (MkC nms) = rep2 prefixPatSynName [nms] repInfixPatSynArgs :: Core TH.Name -> Core TH.Name -> MetaM (Core (M TH.PatSynArgs)) repInfixPatSynArgs (MkC nm1) (MkC nm2) = rep2 infixPatSynName [nm1, nm2] repRecordPatSynArgs :: Core [TH.Name] -> MetaM (Core (M TH.PatSynArgs)) repRecordPatSynArgs (MkC sels) = rep2 recordPatSynName [sels] repPatSynDir :: HsPatSynDir GhcRn -> MetaM (Core (M TH.PatSynDir)) repPatSynDir Unidirectional = rep2 unidirPatSynName [] repPatSynDir ImplicitBidirectional = rep2 implBidirPatSynName [] repPatSynDir (ExplicitBidirectional (MG { mg_alts = (L _ clauses) })) = do { clauses' <- mapM repClauseTup clauses ; repExplBidirPatSynDir (nonEmptyCoreList clauses') } repExplBidirPatSynDir :: Core [(M TH.Clause)] -> MetaM (Core (M TH.PatSynDir)) repExplBidirPatSynDir (MkC cls) = rep2 explBidirPatSynName [cls] ----------------------------------------------------------------------------- -- Since everything in a Bind is mutually recursive we need rename all -- all the variables simultaneously. For example: -- [| AndMonoBinds (f x = x + g 2) (g x = f 1 + 2) |] would translate to -- do { f'1 <- gensym "f" -- ; g'2 <- gensym "g" -- ; [ do { x'3 <- gensym "x"; fun f'1 [pvar x'3] [| x + g2 |]}, -- do { x'4 <- gensym "x"; fun g'2 [pvar x'4] [| f 1 + 2 |]} -- ]} -- This requires collecting the bindings (f'1 <- gensym "f"), and the -- environment ( f |-> f'1 ) from each binding, and then unioning them -- together. As we do this we collect GenSymBinds's which represent the renamed -- variables bound by the Bindings. In order not to lose track of these -- representations we build a shadow datatype MB with the same structure as -- MonoBinds, but which has slots for the representations ----------------------------------------------------------------------------- -- GHC allows a more general form of lambda abstraction than specified -- by Haskell 98. In particular it allows guarded lambda's like : -- (\ x | even x -> 0 | odd x -> 1) at the moment we can't represent this in -- Haskell Template's Meta.Exp type so we punt if it isn't a simple thing like -- (\ p1 .. pn -> exp) by causing an error. repLambda :: LMatch GhcRn (LHsExpr GhcRn) -> MetaM (Core (M TH.Exp)) repLambda (L _ (Match { m_pats = ps , m_grhss = GRHSs _ [L _ (GRHS _ [] e)] (EmptyLocalBinds _) } )) = do { let bndrs = collectPatsBinders CollNoDictBinders ps ; ; ss <- mkGenSyms bndrs ; lam <- addBinds ss ( do { xs <- repLPs ps; body <- repLE e; repLam xs body }) ; wrapGenSyms ss lam } repLambda (L _ m) = notHandled (ThGuardedLambdas m) ----------------------------------------------------------------------------- -- Patterns -- repP deals with patterns. It assumes that we have already -- walked over the pattern(s) once to collect the binders, and -- have extended the environment. So every pattern-bound -- variable should already appear in the environment. -- Process a list of patterns repLPs :: [LPat GhcRn] -> MetaM (Core [(M TH.Pat)]) repLPs ps = repListM patTyConName repLP ps repLP :: LPat GhcRn -> MetaM (Core (M TH.Pat)) repLP p = repP (unLoc p) repP :: Pat GhcRn -> MetaM (Core (M TH.Pat)) repP (WildPat _) = repPwild repP (LitPat _ l) = do { l2 <- repLiteral l; repPlit l2 } repP (VarPat _ x) = do { x' <- lookupBinder (unLoc x); repPvar x' } repP (LazyPat _ p) = do { p1 <- repLP p; repPtilde p1 } repP (BangPat _ p) = do { p1 <- repLP p; repPbang p1 } repP (AsPat _ x _ p) = do { x' <- lookupNBinder x; p1 <- repLP p ; repPaspat x' p1 } repP (ParPat _ _ p _) = repLP p repP (ListPat _ ps) = do { qs <- repLPs ps; repPlist qs } repP (TuplePat _ ps boxed) | isBoxed boxed = do { qs <- repLPs ps; repPtup qs } | otherwise = do { qs <- repLPs ps; repPunboxedTup qs } repP (SumPat _ p alt arity) = do { p1 <- repLP p ; repPunboxedSum p1 alt arity } repP (ConPat NoExtField dc details) = do { con_str <- lookupLOcc dc ; case details of PrefixCon tyargs ps -> do { qs <- repLPs ps ; let unwrapTyArg (HsConPatTyArg _ t) = unLoc (hsps_body t) ; ts <- repListM typeTyConName (repTy . unwrapTyArg) tyargs ; repPcon con_str ts qs } RecCon rec -> do { fps <- repListM fieldPatTyConName rep_fld (rec_flds rec) ; repPrec con_str fps } InfixCon p1 p2 -> do { p1' <- repLP p1; p2' <- repLP p2; repPinfix p1' con_str p2' } } where rep_fld :: LHsRecField GhcRn (LPat GhcRn) -> MetaM (Core (M (TH.Name, TH.Pat))) rep_fld (L _ fld) = do { MkC v <- lookupOcc (hsRecFieldSel fld) ; MkC p <- repLP (hfbRHS fld) ; rep2 fieldPatName [v,p] } repP (NPat _ (L _ l) Nothing _) = do { a <- repOverloadedLiteral l ; repPlit a } repP (ViewPat _ e p) = do { e' <- repLE e; p' <- repLP p; repPview e' p' } repP p@(NPat _ (L _ l) (Just _) _) | OverLitRn rebindable _ <- ol_ext l , rebindable = notHandled (ThNegativeOverloadedPatterns p) | HsIntegral i <- ol_val l = do { a <- repOverloadedLiteral l{ol_val = HsIntegral (negateIntegralLit i)} ; repPlit a } | HsFractional i <- ol_val l = do { a <- repOverloadedLiteral l{ol_val = HsFractional (negateFractionalLit i)} ; repPlit a } | otherwise = notHandled (ThExoticPattern p) repP (SigPat _ p t) = do { p' <- repLP p ; t' <- repLTy (hsPatSigType t) ; repPsig p' t' } repP (SplicePat (HsUntypedSpliceNested n) _) = rep_splice n repP p@(SplicePat (HsUntypedSpliceTop _ _) _) = pprPanic "repP: top level splice" (ppr p) repP other = notHandled (ThExoticPattern other) ---------------------------------------------------------- -- Declaration ordering helpers sort_by_loc :: [(SrcSpan, a)] -> [(SrcSpan, a)] sort_by_loc = sortBy (SrcLoc.leftmost_smallest `on` fst) de_loc :: [(a, b)] -> [b] de_loc = map snd ---------------------------------------------------------- -- The meta-environment -- A name/identifier association for fresh names of locally bound entities type GenSymBind = (Name, Id) -- Gensym the string and bind it to the Id -- I.e. (x, x_id) means -- let x_id = gensym "x" in ... -- Generate a fresh name for a locally bound entity mkGenSyms :: [Name] -> MetaM [GenSymBind] -- We can use the existing name. For example: -- [| \x_77 -> x_77 + x_77 |] -- desugars to -- do { x_77 <- genSym "x"; .... } -- We use the same x_77 in the desugared program, but with the type Bndr -- instead of Int -- -- We do make it an Internal name, though (hence localiseName) -- -- Nevertheless, it's monadic because we have to generate nameTy mkGenSyms ns = do { var_ty <- lookupType nameTyConName ; return [ (nm, mkLocalId (localiseName nm) ManyTy var_ty) | nm <- ns] } addBinds :: [GenSymBind] -> MetaM a -> MetaM a -- Add a list of fresh names for locally bound entities to the -- meta environment (which is part of the state carried around -- by the desugarer monad) addBinds bs m = mapReaderT (dsExtendMetaEnv (mkNameEnv [(n,DsBound id) | (n,id) <- bs])) m -- Look up a locally bound name -- lookupNBinder :: LocatedN Name -> MetaM (Core TH.Name) lookupNBinder n = lookupBinder (unLoc n) lookupBinder :: Name -> MetaM (Core TH.Name) lookupBinder = lookupOcc -- Binders are brought into scope before the pattern or what-not is -- desugared. Moreover, in instance declaration the binder of a method -- will be the selector Id and hence a global; so we need the -- globalVar case of lookupOcc -- Look up a name that is either locally bound or a global name -- -- * If it is a global name, generate the "original name" representation (ie, -- the : form) for the associated entity -- lookupLOcc :: GenLocated l Name -> MetaM (Core TH.Name) -- Lookup an occurrence; it can't be a splice. -- Use the in-scope bindings if they exist lookupLOcc n = lookupOcc (unLoc n) lookupOcc :: Name -> MetaM (Core TH.Name) lookupOcc = lift . lookupOccDsM lookupOccDsM :: Name -> DsM (Core TH.Name) lookupOccDsM n = do { mb_val <- dsLookupMetaEnv n ; case mb_val of Nothing -> globalVar n Just (DsBound x) -> return (coreVar x) Just (DsSplice _) -> pprPanic "repE:lookupOcc" (ppr n) } -- Not bound by the meta-env -- Could be top-level; or could be local -- f x = $(g [| x |]) -- Here the x will be local globalVar :: Name -> DsM (Core TH.Name) globalVar n = case nameModule_maybe n of Just m -> globalVarExternal m (getOccName n) Nothing -> globalVarLocal (getUnique n) (getOccName n) globalVarLocal :: Unique -> OccName -> DsM (Core TH.Name) globalVarLocal unique name = do { MkC occ <- occNameLit name ; platform <- targetPlatform <$> getDynFlags ; let uni = mkIntegerExpr platform (toInteger $ getKey unique) ; rep2_nwDsM mkNameLName [occ,uni] } globalVarExternal :: Module -> OccName -> DsM (Core TH.Name) globalVarExternal mod name_occ = do { MkC mod <- coreStringLit name_mod ; MkC pkg <- coreStringLit name_pkg ; MkC occ <- occNameLit name_occ ; if | isDataOcc name_occ -> rep2_nwDsM mkNameG_dName [pkg,mod,occ] | isVarOcc name_occ -> rep2_nwDsM mkNameG_vName [pkg,mod,occ] | isTcOcc name_occ -> rep2_nwDsM mkNameG_tcName [pkg,mod,occ] | Just con_fs <- fieldOcc_maybe name_occ -> do { MkC con <- coreStringLit con_fs ; rep2_nwDsM mkNameG_fldName [pkg,mod,con,occ] } | otherwise -> pprPanic "GHC.HsToCore.Quote.globalVar" (ppr name_occ) } where name_mod = moduleNameFS (moduleName mod) name_pkg = unitFS (moduleUnit mod) lookupType :: Name -- Name of type constructor (e.g. (M TH.Exp)) -> MetaM Type -- The type lookupType tc_name = do { tc <- lift $ dsLookupTyCon tc_name ; return (mkTyConApp tc []) } wrapGenSyms :: [GenSymBind] -> Core (M a) -> MetaM (Core (M a)) -- wrapGenSyms [(nm1,id1), (nm2,id2)] y -- --> bindQ (gensym nm1) (\ id1 -> -- bindQ (gensym nm2 (\ id2 -> -- y)) wrapGenSyms binds body@(MkC b) = do { var_ty <- lookupType nameTyConName ; go var_ty binds } where (_, elt_ty) = tcSplitAppTy (exprType b) -- b :: m a, so we can get the type 'a' by looking at the -- argument type. Need to use `tcSplitAppTy` here as since -- the overloaded quotations patch the type of the expression can -- be something more complicated than just `Q a`. -- See #17839 for when this went wrong with the type `WriterT () m a` go _ [] = return body go var_ty ((name,id) : binds) = do { MkC body' <- go var_ty binds ; lit_str <- occNameLit (occName name) ; gensym_app <- repGensym lit_str ; repBindM var_ty elt_ty gensym_app (MkC (Lam id body')) } occNameLit :: MonadThings m => OccName -> m (Core String) occNameLit name = coreStringLit (occNameFS name) -- %********************************************************************* -- %* * -- Constructing code -- %* * -- %********************************************************************* ----------------------------------------------------------------------------- -- PHANTOM TYPES for consistency. In order to make sure we do this correct -- we invent a new datatype which uses phantom types. newtype Core a = MkC CoreExpr unC :: Core a -> CoreExpr unC (MkC x) = x type family NotM a where NotM (M _) = TypeError ('Text ("rep2_nw must not produce something of overloaded type")) NotM _other = (() :: Constraint) rep2M :: Name -> [CoreExpr] -> MetaM (Core (M a)) rep2 :: Name -> [CoreExpr] -> MetaM (Core (M a)) rep2_nw :: NotM a => Name -> [CoreExpr] -> MetaM (Core a) rep2_nwDsM :: NotM a => Name -> [CoreExpr] -> DsM (Core a) rep2 = rep2X lift (asks quoteWrapper) rep2M = rep2X lift (asks monadWrapper) rep2_nw n xs = lift (rep2_nwDsM n xs) rep2_nwDsM = rep2X id (return id) rep2X :: Monad m => (forall z . DsM z -> m z) -> m (CoreExpr -> CoreExpr) -> Name -> [ CoreExpr ] -> m (Core a) rep2X lift_dsm get_wrap n xs = do { rep_id <- lift_dsm $ dsLookupGlobalId n ; wrap <- get_wrap ; return (MkC $ (foldl' App (wrap (Var rep_id)) xs)) } dataCon' :: Name -> [CoreExpr] -> MetaM (Core a) dataCon' n args = do { id <- lift $ dsLookupDataCon n ; return $ MkC $ mkCoreConApps id args } dataCon :: Name -> MetaM (Core a) dataCon n = dataCon' n [] -- %********************************************************************* -- %* * -- The 'smart constructors' -- %* * -- %********************************************************************* --------------- Patterns ----------------- repPlit :: Core TH.Lit -> MetaM (Core (M TH.Pat)) repPlit (MkC l) = rep2 litPName [l] repPvar :: Core TH.Name -> MetaM (Core (M TH.Pat)) repPvar (MkC s) = rep2 varPName [s] repPtup :: Core [(M TH.Pat)] -> MetaM (Core (M TH.Pat)) repPtup (MkC ps) = rep2 tupPName [ps] repPunboxedTup :: Core [(M TH.Pat)] -> MetaM (Core (M TH.Pat)) repPunboxedTup (MkC ps) = rep2 unboxedTupPName [ps] repPunboxedSum :: Core (M TH.Pat) -> TH.SumAlt -> TH.SumArity -> MetaM (Core (M TH.Pat)) -- Note: not Core TH.SumAlt or Core TH.SumArity; it's easier to be direct here repPunboxedSum (MkC p) alt arity = do { platform <- getPlatform ; rep2 unboxedSumPName [ p , mkIntExprInt platform alt , mkIntExprInt platform arity ] } repPcon :: Core TH.Name -> Core [(M TH.Type)] -> Core [(M TH.Pat)] -> MetaM (Core (M TH.Pat)) repPcon (MkC s) (MkC ts) (MkC ps) = rep2 conPName [s, ts, ps] repPrec :: Core TH.Name -> Core [M (TH.Name, TH.Pat)] -> MetaM (Core (M TH.Pat)) repPrec (MkC c) (MkC rps) = rep2 recPName [c,rps] repPinfix :: Core (M TH.Pat) -> Core TH.Name -> Core (M TH.Pat) -> MetaM (Core (M TH.Pat)) repPinfix (MkC p1) (MkC n) (MkC p2) = rep2 infixPName [p1, n, p2] repPtilde :: Core (M TH.Pat) -> MetaM (Core (M TH.Pat)) repPtilde (MkC p) = rep2 tildePName [p] repPbang :: Core (M TH.Pat) -> MetaM (Core (M TH.Pat)) repPbang (MkC p) = rep2 bangPName [p] repPaspat :: Core TH.Name -> Core (M TH.Pat) -> MetaM (Core (M TH.Pat)) repPaspat (MkC s) (MkC p) = rep2 asPName [s, p] repPwild :: MetaM (Core (M TH.Pat)) repPwild = rep2 wildPName [] repPlist :: Core [(M TH.Pat)] -> MetaM (Core (M TH.Pat)) repPlist (MkC ps) = rep2 listPName [ps] repPview :: Core (M TH.Exp) -> Core (M TH.Pat) -> MetaM (Core (M TH.Pat)) repPview (MkC e) (MkC p) = rep2 viewPName [e,p] repPsig :: Core (M TH.Pat) -> Core (M TH.Type) -> MetaM (Core (M TH.Pat)) repPsig (MkC p) (MkC t) = rep2 sigPName [p, t] --------------- Expressions ----------------- repVarOrCon :: Name -> Core TH.Name -> MetaM (Core (M TH.Exp)) repVarOrCon vc str | isVarNameSpace ns = repVar str -- Both type and term variables (#18740) | otherwise = repCon str where ns = nameNameSpace vc repVar :: Core TH.Name -> MetaM (Core (M TH.Exp)) repVar (MkC s) = rep2 varEName [s] repCon :: Core TH.Name -> MetaM (Core (M TH.Exp)) repCon (MkC s) = rep2 conEName [s] repLit :: Core TH.Lit -> MetaM (Core (M TH.Exp)) repLit (MkC c) = rep2 litEName [c] repApp :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repApp (MkC x) (MkC y) = rep2 appEName [x,y] repAppType :: Core (M TH.Exp) -> Core (M TH.Type) -> MetaM (Core (M TH.Exp)) repAppType (MkC x) (MkC y) = rep2 appTypeEName [x,y] repLam :: Core [(M TH.Pat)] -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repLam (MkC ps) (MkC e) = rep2 lamEName [ps, e] repLamCase :: Core [(M TH.Match)] -> MetaM (Core (M TH.Exp)) repLamCase (MkC ms) = rep2 lamCaseEName [ms] repLamCases :: Core [(M TH.Clause)] -> MetaM (Core (M TH.Exp)) repLamCases (MkC ms) = rep2 lamCasesEName [ms] repTup :: Core [Maybe (M TH.Exp)] -> MetaM (Core (M TH.Exp)) repTup (MkC es) = rep2 tupEName [es] repUnboxedTup :: Core [Maybe (M TH.Exp)] -> MetaM (Core (M TH.Exp)) repUnboxedTup (MkC es) = rep2 unboxedTupEName [es] repUnboxedSum :: Core (M TH.Exp) -> TH.SumAlt -> TH.SumArity -> MetaM (Core (M TH.Exp)) -- Note: not Core TH.SumAlt or Core TH.SumArity; it's easier to be direct here repUnboxedSum (MkC e) alt arity = do { platform <- getPlatform ; rep2 unboxedSumEName [ e , mkIntExprInt platform alt , mkIntExprInt platform arity ] } repCond :: Core (M TH.Exp) -> Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repCond (MkC x) (MkC y) (MkC z) = rep2 condEName [x,y,z] repMultiIf :: Core [M (TH.Guard, TH.Exp)] -> MetaM (Core (M TH.Exp)) repMultiIf (MkC alts) = rep2 multiIfEName [alts] repLetE :: Core [(M TH.Dec)] -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repLetE (MkC ds) (MkC e) = rep2 letEName [ds, e] repCaseE :: Core (M TH.Exp) -> Core [(M TH.Match)] -> MetaM (Core (M TH.Exp)) repCaseE (MkC e) (MkC ms) = rep2 caseEName [e, ms] repDoE :: Maybe ModuleName -> Core [(M TH.Stmt)] -> MetaM (Core (M TH.Exp)) repDoE = repDoBlock doEName repMDoE :: Maybe ModuleName -> Core [(M TH.Stmt)] -> MetaM (Core (M TH.Exp)) repMDoE = repDoBlock mdoEName repDoBlock :: Name -> Maybe ModuleName -> Core [(M TH.Stmt)] -> MetaM (Core (M TH.Exp)) repDoBlock doName maybeModName (MkC ss) = do MkC coreModName <- coreModNameM rep2 doName [coreModName, ss] where coreModNameM :: MetaM (Core (Maybe TH.ModName)) coreModNameM = case maybeModName of Just m -> do MkC s <- coreStringLit (moduleNameFS m) mName <- rep2_nw mkModNameName [s] coreJust modNameTyConName mName _ -> coreNothing modNameTyConName repComp :: Core [(M TH.Stmt)] -> MetaM (Core (M TH.Exp)) repComp (MkC ss) = rep2 compEName [ss] repListExp :: Core [(M TH.Exp)] -> MetaM (Core (M TH.Exp)) repListExp (MkC es) = rep2 listEName [es] repSigExp :: Core (M TH.Exp) -> Core (M TH.Type) -> MetaM (Core (M TH.Exp)) repSigExp (MkC e) (MkC t) = rep2 sigEName [e,t] repRecCon :: Core TH.Name -> Core [M TH.FieldExp]-> MetaM (Core (M TH.Exp)) repRecCon (MkC c) (MkC fs) = rep2 recConEName [c,fs] repRecUpd :: Core (M TH.Exp) -> Core [M TH.FieldExp] -> MetaM (Core (M TH.Exp)) repRecUpd (MkC e) (MkC fs) = rep2 recUpdEName [e,fs] repFieldExp :: Core TH.Name -> Core (M TH.Exp) -> MetaM (Core (M TH.FieldExp)) repFieldExp (MkC n) (MkC x) = rep2 fieldExpName [n,x] repInfixApp :: Core (M TH.Exp) -> Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repInfixApp (MkC x) (MkC y) (MkC z) = rep2 infixAppName [x,y,z] repSectionL :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repSectionL (MkC x) (MkC y) = rep2 sectionLName [x,y] repSectionR :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repSectionR (MkC x) (MkC y) = rep2 sectionRName [x,y] repImplicitParamVar :: Core String -> MetaM (Core (M TH.Exp)) repImplicitParamVar (MkC x) = rep2 implicitParamVarEName [x] ------------ Right hand sides (guarded expressions) ---- repGuarded :: Core [M (TH.Guard, TH.Exp)] -> MetaM (Core (M TH.Body)) repGuarded (MkC pairs) = rep2 guardedBName [pairs] repNormal :: Core (M TH.Exp) -> MetaM (Core (M TH.Body)) repNormal (MkC e) = rep2 normalBName [e] ------------ Guards ---- repLNormalGE :: LHsExpr GhcRn -> LHsExpr GhcRn -> MetaM (Core (M (TH.Guard, TH.Exp))) repLNormalGE g e = do g' <- repLE g e' <- repLE e repNormalGE g' e' repNormalGE :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M (TH.Guard, TH.Exp))) repNormalGE (MkC g) (MkC e) = rep2 normalGEName [g, e] repPatGE :: Core [(M TH.Stmt)] -> Core (M TH.Exp) -> MetaM (Core (M (TH.Guard, TH.Exp))) repPatGE (MkC ss) (MkC e) = rep2 patGEName [ss, e] ------------- Stmts ------------------- repBindSt :: Core (M TH.Pat) -> Core (M TH.Exp) -> MetaM (Core (M TH.Stmt)) repBindSt (MkC p) (MkC e) = rep2 bindSName [p,e] repLetSt :: Core [(M TH.Dec)] -> MetaM (Core (M TH.Stmt)) repLetSt (MkC ds) = rep2 letSName [ds] repNoBindSt :: Core (M TH.Exp) -> MetaM (Core (M TH.Stmt)) repNoBindSt (MkC e) = rep2 noBindSName [e] repParSt :: Core [[(M TH.Stmt)]] -> MetaM (Core (M TH.Stmt)) repParSt (MkC sss) = rep2 parSName [sss] repRecSt :: Core [(M TH.Stmt)] -> MetaM (Core (M TH.Stmt)) repRecSt (MkC ss) = rep2 recSName [ss] -------------- Range (Arithmetic sequences) ----------- repFrom :: Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repFrom (MkC x) = rep2 fromEName [x] repFromThen :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repFromThen (MkC x) (MkC y) = rep2 fromThenEName [x,y] repFromTo :: Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repFromTo (MkC x) (MkC y) = rep2 fromToEName [x,y] repFromThenTo :: Core (M TH.Exp) -> Core (M TH.Exp) -> Core (M TH.Exp) -> MetaM (Core (M TH.Exp)) repFromThenTo (MkC x) (MkC y) (MkC z) = rep2 fromThenToEName [x,y,z] ------------ Match and Clause Tuples ----------- repMatch :: Core (M TH.Pat) -> Core (M TH.Body) -> Core [(M TH.Dec)] -> MetaM (Core (M TH.Match)) repMatch (MkC p) (MkC bod) (MkC ds) = rep2 matchName [p, bod, ds] repClause :: Core [(M TH.Pat)] -> Core (M TH.Body) -> Core [(M TH.Dec)] -> MetaM (Core (M TH.Clause)) repClause (MkC ps) (MkC bod) (MkC ds) = rep2 clauseName [ps, bod, ds] -------------- Dec ----------------------------- repVal :: Core (M TH.Pat) -> Core (M TH.Body) -> Core [(M TH.Dec)] -> MetaM (Core (M TH.Dec)) repVal (MkC p) (MkC b) (MkC ds) = rep2 valDName [p, b, ds] repFun :: Core TH.Name -> Core [(M TH.Clause)] -> MetaM (Core (M TH.Dec)) repFun (MkC nm) (MkC b) = rep2 funDName [nm, b] repData :: Bool -- ^ @True@ for a @type data@ declaration. -- See Note [Type data declarations] in GHC.Rename.Module -> Core (M TH.Cxt) -> Core TH.Name -> Either (Core [(M (TH.TyVarBndr ()))]) (Core (Maybe [(M (TH.TyVarBndr ()))]), Core (M TH.Type)) -> Core (Maybe (M TH.Kind)) -> Core [(M TH.Con)] -> Core [M TH.DerivClause] -> MetaM (Core (M TH.Dec)) repData type_data (MkC cxt) (MkC nm) (Left (MkC tvs)) (MkC ksig) (MkC cons) (MkC derivs) | type_data = rep2 typeDataDName [nm, tvs, ksig, cons] | otherwise = rep2 dataDName [cxt, nm, tvs, ksig, cons, derivs] repData _ (MkC cxt) (MkC _) (Right (MkC mb_bndrs, MkC ty)) (MkC ksig) (MkC cons) (MkC derivs) = rep2 dataInstDName [cxt, mb_bndrs, ty, ksig, cons, derivs] repNewtype :: Core (M TH.Cxt) -> Core TH.Name -> Either (Core [(M (TH.TyVarBndr ()))]) (Core (Maybe [(M (TH.TyVarBndr ()))]), Core (M TH.Type)) -> Core (Maybe (M TH.Kind)) -> Core (M TH.Con) -> Core [M TH.DerivClause] -> MetaM (Core (M TH.Dec)) repNewtype (MkC cxt) (MkC nm) (Left (MkC tvs)) (MkC ksig) (MkC con) (MkC derivs) = rep2 newtypeDName [cxt, nm, tvs, ksig, con, derivs] repNewtype (MkC cxt) (MkC _) (Right (MkC mb_bndrs, MkC ty)) (MkC ksig) (MkC con) (MkC derivs) = rep2 newtypeInstDName [cxt, mb_bndrs, ty, ksig, con, derivs] repTySyn :: Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> Core (M TH.Type) -> MetaM (Core (M TH.Dec)) repTySyn (MkC nm) (MkC tvs) (MkC rhs) = rep2 tySynDName [nm, tvs, rhs] repInst :: Core (Maybe TH.Overlap) -> Core (M TH.Cxt) -> Core (M TH.Type) -> Core [(M TH.Dec)] -> MetaM (Core (M TH.Dec)) repInst (MkC o) (MkC cxt) (MkC ty) (MkC ds) = rep2 instanceWithOverlapDName [o, cxt, ty, ds] repDerivStrategy :: Maybe (LDerivStrategy GhcRn) -> (Core (Maybe (M TH.DerivStrategy)) -> MetaM (Core (M a))) -> MetaM (Core (M a)) repDerivStrategy mds thing_inside = case mds of Nothing -> thing_inside =<< nothing Just ds -> case unLoc ds of StockStrategy _ -> thing_inside =<< just =<< repStockStrategy AnyclassStrategy _ -> thing_inside =<< just =<< repAnyclassStrategy NewtypeStrategy _ -> thing_inside =<< just =<< repNewtypeStrategy ViaStrategy ty -> addSimpleTyVarBinds FreshNamesOnly (get_scoped_tvs_from_sig ty) $ do ty' <- rep_ty_sig' ty via_strat <- repViaStrategy ty' m_via_strat <- just via_strat thing_inside m_via_strat where nothing = coreNothingM derivStrategyTyConName just = coreJustM derivStrategyTyConName repStockStrategy :: MetaM (Core (M TH.DerivStrategy)) repStockStrategy = rep2 stockStrategyName [] repAnyclassStrategy :: MetaM (Core (M TH.DerivStrategy)) repAnyclassStrategy = rep2 anyclassStrategyName [] repNewtypeStrategy :: MetaM (Core (M TH.DerivStrategy)) repNewtypeStrategy = rep2 newtypeStrategyName [] repViaStrategy :: Core (M TH.Type) -> MetaM (Core (M TH.DerivStrategy)) repViaStrategy (MkC t) = rep2 viaStrategyName [t] repOverlap :: Maybe OverlapMode -> MetaM (Core (Maybe TH.Overlap)) repOverlap mb = case mb of Nothing -> nothing Just o -> case o of NoOverlap _ -> nothing Overlappable _ -> just =<< dataCon overlappableDataConName Overlapping _ -> just =<< dataCon overlappingDataConName Overlaps _ -> just =<< dataCon overlapsDataConName Incoherent _ -> just =<< dataCon incoherentDataConName where nothing = coreNothing overlapTyConName just = coreJust overlapTyConName repClass :: Core (M TH.Cxt) -> Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> Core [TH.FunDep] -> Core [(M TH.Dec)] -> MetaM (Core (M TH.Dec)) repClass (MkC cxt) (MkC cls) (MkC tvs) (MkC fds) (MkC ds) = rep2 classDName [cxt, cls, tvs, fds, ds] repDeriv :: Core (Maybe (M TH.DerivStrategy)) -> Core (M TH.Cxt) -> Core (M TH.Type) -> MetaM (Core (M TH.Dec)) repDeriv (MkC ds) (MkC cxt) (MkC ty) = rep2 standaloneDerivWithStrategyDName [ds, cxt, ty] repPragInl :: Core TH.Name -> Core TH.Inline -> Core TH.RuleMatch -> Core TH.Phases -> MetaM (Core (M TH.Dec)) repPragInl (MkC nm) (MkC inline) (MkC rm) (MkC phases) = rep2 pragInlDName [nm, inline, rm, phases] repPragOpaque :: Core TH.Name -> MetaM (Core (M TH.Dec)) repPragOpaque (MkC nm) = rep2 pragOpaqueDName [nm] repPragSpec :: Core TH.Name -> Core (M TH.Type) -> Core TH.Phases -> MetaM (Core (M TH.Dec)) repPragSpec (MkC nm) (MkC ty) (MkC phases) = rep2 pragSpecDName [nm, ty, phases] repPragSpecInl :: Core TH.Name -> Core (M TH.Type) -> Core TH.Inline -> Core TH.Phases -> MetaM (Core (M TH.Dec)) repPragSpecInl (MkC nm) (MkC ty) (MkC inline) (MkC phases) = rep2 pragSpecInlDName [nm, ty, inline, phases] repPragSpecInst :: Core (M TH.Type) -> MetaM (Core (M TH.Dec)) repPragSpecInst (MkC ty) = rep2 pragSpecInstDName [ty] repPragComplete :: Core [TH.Name] -> Core (Maybe TH.Name) -> MetaM (Core (M TH.Dec)) repPragComplete (MkC cls) (MkC mty) = rep2 pragCompleteDName [cls, mty] repPragRule :: Core String -> Core (Maybe [(M (TH.TyVarBndr ()))]) -> Core [(M TH.RuleBndr)] -> Core (M TH.Exp) -> Core (M TH.Exp) -> Core TH.Phases -> MetaM (Core (M TH.Dec)) repPragRule (MkC nm) (MkC ty_bndrs) (MkC tm_bndrs) (MkC lhs) (MkC rhs) (MkC phases) = rep2 pragRuleDName [nm, ty_bndrs, tm_bndrs, lhs, rhs, phases] repPragAnn :: Core TH.AnnTarget -> Core (M TH.Exp) -> MetaM (Core (M TH.Dec)) repPragAnn (MkC targ) (MkC e) = rep2 pragAnnDName [targ, e] repTySynInst :: Core (M TH.TySynEqn) -> MetaM (Core (M TH.Dec)) repTySynInst (MkC eqn) = rep2 tySynInstDName [eqn] repDataFamilyD :: Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> Core (Maybe (M TH.Kind)) -> MetaM (Core (M TH.Dec)) repDataFamilyD (MkC nm) (MkC tvs) (MkC kind) = rep2 dataFamilyDName [nm, tvs, kind] repOpenFamilyD :: Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> Core (M TH.FamilyResultSig) -> Core (Maybe TH.InjectivityAnn) -> MetaM (Core (M TH.Dec)) repOpenFamilyD (MkC nm) (MkC tvs) (MkC result) (MkC inj) = rep2 openTypeFamilyDName [nm, tvs, result, inj] repClosedFamilyD :: Core TH.Name -> Core [(M (TH.TyVarBndr ()))] -> Core (M TH.FamilyResultSig) -> Core (Maybe TH.InjectivityAnn) -> Core [(M TH.TySynEqn)] -> MetaM (Core (M TH.Dec)) repClosedFamilyD (MkC nm) (MkC tvs) (MkC res) (MkC inj) (MkC eqns) = rep2 closedTypeFamilyDName [nm, tvs, res, inj, eqns] repTySynEqn :: Core (Maybe [(M (TH.TyVarBndr ()))]) -> Core (M TH.Type) -> Core (M TH.Type) -> MetaM (Core (M TH.TySynEqn)) repTySynEqn (MkC mb_bndrs) (MkC lhs) (MkC rhs) = rep2 tySynEqnName [mb_bndrs, lhs, rhs] repRoleAnnotD :: Core TH.Name -> Core [TH.Role] -> MetaM (Core (M TH.Dec)) repRoleAnnotD (MkC n) (MkC roles) = rep2 roleAnnotDName [n, roles] repFunDep :: Core [TH.Name] -> Core [TH.Name] -> MetaM (Core TH.FunDep) repFunDep (MkC xs) (MkC ys) = rep2_nw funDepName [xs, ys] repProto :: Name -> Core TH.Name -> Core (M TH.Type) -> MetaM (Core (M TH.Dec)) repProto mk_sig (MkC s) (MkC ty) = rep2 mk_sig [s, ty] repImplicitParamBind :: Core String -> Core (M TH.Exp) -> MetaM (Core (M TH.Dec)) repImplicitParamBind (MkC n) (MkC e) = rep2 implicitParamBindDName [n, e] repCtxt :: Core [(M TH.Pred)] -> MetaM (Core (M TH.Cxt)) repCtxt (MkC tys) = rep2 cxtName [tys] repH98DataCon :: LocatedN Name -> HsConDeclH98Details GhcRn -> MetaM (Core (M TH.Con)) repH98DataCon con details = do con' <- lookupLOcc con -- See Note [Binders and occurrences] case details of PrefixCon _ ps -> do arg_tys <- repPrefixConArgs ps rep2 normalCName [unC con', unC arg_tys] InfixCon st1 st2 -> do verifyLinearFields [st1, st2] arg1 <- repBangTy (hsScaledThing st1) arg2 <- repBangTy (hsScaledThing st2) rep2 infixCName [unC arg1, unC con', unC arg2] RecCon ips -> do arg_vtys <- repRecConArgs ips rep2 recCName [unC con', unC arg_vtys] repGadtDataCons :: NonEmpty (LocatedN Name) -> HsConDeclGADTDetails GhcRn -> LHsType GhcRn -> MetaM (Core (M TH.Con)) repGadtDataCons cons details res_ty = do cons' <- mapM lookupLOcc cons -- See Note [Binders and occurrences] case details of PrefixConGADT ps -> do arg_tys <- repPrefixConArgs ps res_ty' <- repLTy res_ty rep2 gadtCName [ unC (nonEmptyCoreList' cons'), unC arg_tys, unC res_ty'] RecConGADT ips _ -> do arg_vtys <- repRecConArgs ips res_ty' <- repLTy res_ty rep2 recGadtCName [unC (nonEmptyCoreList' cons'), unC arg_vtys, unC res_ty'] -- TH currently only supports linear constructors. -- We also accept the (->) arrow when -XLinearTypes is off, because this -- denotes a linear field. -- This check is not performed in repRecConArgs, since the GADT record -- syntax currently does not have a way to mark fields as nonlinear. verifyLinearFields :: [HsScaled GhcRn (LHsType GhcRn)] -> MetaM () verifyLinearFields ps = do linear <- lift $ xoptM LangExt.LinearTypes let allGood = all (\st -> case hsMult st of HsUnrestrictedArrow _ -> not linear HsLinearArrow _ -> True _ -> False) ps unless allGood $ notHandled ThNonLinearDataCon -- Desugar the arguments in a data constructor declared with prefix syntax. repPrefixConArgs :: [HsScaled GhcRn (LHsType GhcRn)] -> MetaM (Core [M TH.BangType]) repPrefixConArgs ps = do verifyLinearFields ps repListM bangTypeTyConName repBangTy (map hsScaledThing ps) -- Desugar the arguments in a data constructor declared with record syntax. repRecConArgs :: LocatedL [LConDeclField GhcRn] -> MetaM (Core [M TH.VarBangType]) repRecConArgs ips = do args <- concatMapM rep_ip (unLoc ips) coreListM varBangTypeTyConName args where rep_ip (L _ ip) = mapM (rep_one_ip (cd_fld_type ip)) (cd_fld_names ip) rep_one_ip :: LBangType GhcRn -> LFieldOcc GhcRn -> MetaM (Core (M TH.VarBangType)) rep_one_ip t n = do { MkC v <- lookupOcc (foExt $ unLoc n) ; MkC ty <- repBangTy t ; rep2 varBangTypeName [v,ty] } ------------ Types ------------------- repTForall :: Core [(M (TH.TyVarBndr TH.Specificity))] -> Core (M TH.Cxt) -> Core (M TH.Type) -> MetaM (Core (M TH.Type)) repTForall (MkC tvars) (MkC ctxt) (MkC ty) = rep2 forallTName [tvars, ctxt, ty] repTForallVis :: Core [(M (TH.TyVarBndr ()))] -> Core (M TH.Type) -> MetaM (Core (M TH.Type)) repTForallVis (MkC tvars) (MkC ty) = rep2 forallVisTName [tvars, ty] repTvar :: Core TH.Name -> MetaM (Core (M TH.Type)) repTvar (MkC s) = rep2 varTName [s] repTapp :: Core (M TH.Type) -> Core (M TH.Type) -> MetaM (Core (M TH.Type)) repTapp (MkC t1) (MkC t2) = rep2 appTName [t1, t2] repTappKind :: Core (M TH.Type) -> Core (M TH.Kind) -> MetaM (Core (M TH.Type)) repTappKind (MkC ty) (MkC ki) = rep2 appKindTName [ty,ki] repTapps :: Core (M TH.Type) -> [Core (M TH.Type)] -> MetaM (Core (M TH.Type)) repTapps f [] = return f repTapps f (t:ts) = do { f1 <- repTapp f t; repTapps f1 ts } repTSig :: Core (M TH.Type) -> Core (M TH.Kind) -> MetaM (Core (M TH.Type)) repTSig (MkC ty) (MkC ki) = rep2 sigTName [ty, ki] repTequality :: MetaM (Core (M TH.Type)) repTequality = rep2 equalityTName [] repTPromotedList :: [Core (M TH.Type)] -> MetaM (Core (M TH.Type)) repTPromotedList [] = repPromotedNilTyCon repTPromotedList (t:ts) = do { tcon <- repPromotedConsTyCon ; f <- repTapp tcon t ; t' <- repTPromotedList ts ; repTapp f t' } repTLit :: Core (M TH.TyLit) -> MetaM (Core (M TH.Type)) repTLit (MkC lit) = rep2 litTName [lit] repTWildCard :: MetaM (Core (M TH.Type)) repTWildCard = rep2 wildCardTName [] repTImplicitParam :: Core String -> Core (M TH.Type) -> MetaM (Core (M TH.Type)) repTImplicitParam (MkC n) (MkC e) = rep2 implicitParamTName [n, e] repTStar :: MetaM (Core (M TH.Type)) repTStar = rep2 starKName [] repTConstraint :: MetaM (Core (M TH.Type)) repTConstraint = rep2 constraintKName [] --------- Type constructors -------------- repNamedTyCon :: Core TH.Name -> MetaM (Core (M TH.Type)) repNamedTyCon (MkC s) = rep2 conTName [s] repTInfix :: Core (M TH.Type) -> Core TH.Name -> Core (M TH.Type) -> MetaM (Core (M TH.Type)) repTInfix (MkC t1) (MkC name) (MkC t2) = rep2 infixTName [t1,name,t2] repTupleTyCon :: Int -> MetaM (Core (M TH.Type)) -- Note: not Core Int; it's easier to be direct here repTupleTyCon i = do platform <- getPlatform rep2 tupleTName [mkIntExprInt platform i] repUnboxedTupleTyCon :: Int -> MetaM (Core (M TH.Type)) -- Note: not Core Int; it's easier to be direct here repUnboxedTupleTyCon i = do platform <- getPlatform rep2 unboxedTupleTName [mkIntExprInt platform i] repUnboxedSumTyCon :: TH.SumArity -> MetaM (Core (M TH.Type)) -- Note: not Core TH.SumArity; it's easier to be direct here repUnboxedSumTyCon arity = do platform <- getPlatform rep2 unboxedSumTName [mkIntExprInt platform arity] repArrowTyCon :: MetaM (Core (M TH.Type)) repArrowTyCon = rep2 arrowTName [] repMulArrowTyCon :: MetaM (Core (M TH.Type)) repMulArrowTyCon = rep2 mulArrowTName [] repListTyCon :: MetaM (Core (M TH.Type)) repListTyCon = rep2 listTName [] repPromotedDataCon :: Core TH.Name -> MetaM (Core (M TH.Type)) repPromotedDataCon (MkC s) = rep2 promotedTName [s] repPromotedTupleTyCon :: Int -> MetaM (Core (M TH.Type)) repPromotedTupleTyCon i = do platform <- getPlatform rep2 promotedTupleTName [mkIntExprInt platform i] repPromotedNilTyCon :: MetaM (Core (M TH.Type)) repPromotedNilTyCon = rep2 promotedNilTName [] repPromotedConsTyCon :: MetaM (Core (M TH.Type)) repPromotedConsTyCon = rep2 promotedConsTName [] ---------------------------------------------------------- -- Type family result signature repNoSig :: MetaM (Core (M TH.FamilyResultSig)) repNoSig = rep2 noSigName [] repKindSig :: Core (M TH.Kind) -> MetaM (Core (M TH.FamilyResultSig)) repKindSig (MkC ki) = rep2 kindSigName [ki] repTyVarSig :: Core (M (TH.TyVarBndr ())) -> MetaM (Core (M TH.FamilyResultSig)) repTyVarSig (MkC bndr) = rep2 tyVarSigName [bndr] ---------------------------------------------------------- -- Literals repLiteral :: HsLit GhcRn -> MetaM (Core TH.Lit) repLiteral (HsStringPrim _ bs) = do word8_ty <- lookupType word8TyConName let w8s = unpack bs w8s_expr = map (\w8 -> mkCoreConApps word8DataCon [mkWord8Lit (toInteger w8)]) w8s rep2_nw stringPrimLName [mkListExpr word8_ty w8s_expr] repLiteral lit = do lit' <- case lit of HsIntPrim _ i -> mk_integer i HsWordPrim _ w -> mk_integer w HsInt _ i -> mk_integer (il_value i) HsFloatPrim _ r -> mk_rational r HsDoublePrim _ r -> mk_rational r HsCharPrim _ c -> mk_char c _ -> return lit lit_expr <- lift $ dsLit lit' case mb_lit_name of Just lit_name -> rep2_nw lit_name [lit_expr] Nothing -> notHandled (ThExoticLiteral lit) where mb_lit_name = case lit of HsInteger _ _ _ -> Just integerLName HsInt _ _ -> Just integerLName HsIntPrim _ _ -> Just intPrimLName HsWordPrim _ _ -> Just wordPrimLName HsFloatPrim _ _ -> Just floatPrimLName HsDoublePrim _ _ -> Just doublePrimLName HsChar _ _ -> Just charLName HsCharPrim _ _ -> Just charPrimLName HsString _ _ -> Just stringLName HsRat _ _ _ -> Just rationalLName _ -> Nothing mk_integer :: Integer -> MetaM (HsLit GhcRn) mk_integer i = return $ HsInteger NoSourceText i integerTy mk_rational :: FractionalLit -> MetaM (HsLit GhcRn) mk_rational r = do rat_ty <- lookupType rationalTyConName return $ HsRat noExtField r rat_ty mk_string :: FastString -> MetaM (HsLit GhcRn) mk_string s = return $ HsString NoSourceText s mk_char :: Char -> MetaM (HsLit GhcRn) mk_char c = return $ HsChar NoSourceText c repOverloadedLiteral :: HsOverLit GhcRn -> MetaM (Core TH.Lit) repOverloadedLiteral (OverLit { ol_val = val}) = do { lit <- mk_lit val; repLiteral lit } -- The type Rational will be in the environment, because -- the smart constructor 'TH.Syntax.rationalL' uses it in its type, -- and rationalL is sucked in when any TH stuff is used mk_lit :: OverLitVal -> MetaM (HsLit GhcRn) mk_lit (HsIntegral i) = mk_integer (il_value i) mk_lit (HsFractional f) = mk_rational f mk_lit (HsIsString _ s) = mk_string s repRdrName :: RdrName -> MetaM (Core TH.Name) repRdrName rdr_name = do case rdr_name of Unqual occ -> repNameS =<< occNameLit occ Qual mn occ -> do let name_mod = moduleNameFS mn mod <- coreStringLit name_mod occ <- occNameLit occ repNameQ mod occ Orig m n -> lift $ globalVarExternal m n Exact n -> lift $ globalVar n repNameS :: Core String -> MetaM (Core TH.Name) repNameS (MkC name) = rep2_nw mkNameSName [name] repNameQ :: Core String -> Core String -> MetaM (Core TH.Name) repNameQ (MkC mn) (MkC name) = rep2_nw mkNameQName [mn, name] --------------- Miscellaneous ------------------- repGensym :: Core String -> MetaM (Core (M TH.Name)) repGensym (MkC lit_str) = rep2 newNameName [lit_str] repBindM :: Type -> Type -- a and b -> Core (M a) -> Core (a -> M b) -> MetaM (Core (M b)) repBindM ty_a ty_b (MkC x) (MkC y) = rep2M bindMName [Type ty_a, Type ty_b, x, y] repSequenceM :: Type -> Core [M a] -> MetaM (Core (M [a])) repSequenceM ty_a (MkC list) = rep2M sequenceQName [Type ty_a, list] repUnboundVar :: Core TH.Name -> MetaM (Core (M TH.Exp)) repUnboundVar (MkC name) = rep2 unboundVarEName [name] repOverLabel :: FastString -> MetaM (Core (M TH.Exp)) repOverLabel fs = do MkC s <- coreStringLit fs rep2 labelEName [s] repGetField :: Core (M TH.Exp) -> FastString -> MetaM (Core (M TH.Exp)) repGetField (MkC exp) fs = do MkC s <- coreStringLit fs rep2 getFieldEName [exp,s] repProjection :: NonEmpty FastString -> MetaM (Core (M TH.Exp)) repProjection fs = do ne_tycon <- lift $ dsLookupTyCon nonEmptyTyConName MkC xs <- coreListNonEmpty ne_tycon stringTy <$> mapM coreStringLit fs rep2 projectionEName [xs] ------------ Lists ------------------- -- turn a list of patterns into a single pattern matching a list repList :: Name -> (a -> MetaM (Core b)) -> [a] -> MetaM (Core [b]) repList tc_name f args = do { args1 <- mapM f args ; coreList tc_name args1 } -- Create a list of m a values repListM :: Name -> (a -> MetaM (Core b)) -> [a] -> MetaM (Core [b]) repListM tc_name f args = do { ty <- wrapName tc_name ; args1 <- mapM f args ; return $ coreList' ty args1 } coreListM :: Name -> [Core a] -> MetaM (Core [a]) coreListM tc as = repListM tc return as coreList :: Name -- Of the TyCon of the element type -> [Core a] -> MetaM (Core [a]) coreList tc_name es = do { elt_ty <- lookupType tc_name; return (coreList' elt_ty es) } coreList' :: Type -- The element type -> [Core a] -> Core [a] coreList' elt_ty es = MkC (mkListExpr elt_ty (map unC es )) coreListNonEmpty :: TyCon -- TyCon for NonEmpty -> Type -- Element type -> NonEmpty (Core a) -> Core (NonEmpty a) coreListNonEmpty ne_tc ty (MkC x :| xs) = MkC $ mkCoreConApps (tyConSingleDataCon ne_tc) [Type ty, x, mkListExpr ty (map unC xs)] nonEmptyCoreList :: [Core a] -> Core [a] -- The list must be non-empty so we can get the element type -- Otherwise use coreList nonEmptyCoreList [] = panic "coreList: empty argument" nonEmptyCoreList xs@(MkC x:_) = MkC (mkListExpr (exprType x) (map unC xs)) nonEmptyCoreList' :: NonEmpty (Core a) -> Core [a] nonEmptyCoreList' xs@(MkC x:|_) = MkC (mkListExpr (exprType x) (toList $ fmap unC xs)) coreStringLit :: MonadThings m => FastString -> m (Core String) coreStringLit s = do { z <- mkStringExprFS s; return (MkC z) } ------------------- Maybe ------------------ repMaybe :: Name -> (a -> MetaM (Core b)) -> Maybe a -> MetaM (Core (Maybe b)) repMaybe tc_name f m = do t <- lookupType tc_name repMaybeT t f m repMaybeT :: Type -> (a -> MetaM (Core b)) -> Maybe a -> MetaM (Core (Maybe b)) repMaybeT ty _ Nothing = return $ coreNothing' ty repMaybeT ty f (Just es) = coreJust' ty <$> f es -- | Construct Core expression for Nothing of a given type name coreNothing :: Name -- ^ Name of the TyCon of the element type -> MetaM (Core (Maybe a)) coreNothing tc_name = do { elt_ty <- lookupType tc_name; return (coreNothing' elt_ty) } coreNothingM :: Name -> MetaM (Core (Maybe a)) coreNothingM tc_name = do { elt_ty <- wrapName tc_name; return (coreNothing' elt_ty) } -- | Construct Core expression for Nothing of a given type coreNothing' :: Type -- ^ The element type -> Core (Maybe a) coreNothing' elt_ty = MkC (mkNothingExpr elt_ty) -- | Store given Core expression in a Just of a given type name coreJust :: Name -- ^ Name of the TyCon of the element type -> Core a -> MetaM (Core (Maybe a)) coreJust tc_name es = do { elt_ty <- lookupType tc_name; return (coreJust' elt_ty es) } coreJustM :: Name -> Core a -> MetaM (Core (Maybe a)) coreJustM tc_name es = do { elt_ty <- wrapName tc_name; return (coreJust' elt_ty es) } -- | Store given Core expression in a Just of a given type coreJust' :: Type -- ^ The element type -> Core a -> Core (Maybe a) coreJust' elt_ty es = MkC (mkJustExpr elt_ty (unC es)) ------------------- Maybe Lists ------------------ coreJustList :: Type -> Core [a] -> Core (Maybe [a]) coreJustList elt_ty = coreJust' (mkListTy elt_ty) coreNothingList :: Type -> Core (Maybe [a]) coreNothingList elt_ty = coreNothing' (mkListTy elt_ty) ------------ Literals & Variables ------------------- coreIntLit :: Int -> MetaM (Core Int) coreIntLit i = do platform <- getPlatform return (MkC (mkIntExprInt platform i)) coreVar :: Id -> Core TH.Name -- The Id has type Name coreVar id = MkC (Var id) ----------------- Failure ----------------------- notHandledL :: SrcSpan -> ThRejectionReason -> MetaM a notHandledL loc reason | isGoodSrcSpan loc = mapReaderT (putSrcSpanDs loc) $ notHandled reason | otherwise = notHandled reason notHandled :: ThRejectionReason -> MetaM a notHandled reason = lift $ failWithDs (DsNotYetHandledByTH reason)