X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=8af4e852aff5869f297e8d306d3cd2d4b20c2adb;hb=e32edb4c18349c30c91c6db189ff345840bce322;hp=56ff0e1bca581364956792b3b1b5cb60da3256cd;hpb=485c8034041b7d7f26688c24b88a50a62e3d3229;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs index 56ff0e1..8af4e85 100644 --- a/compiler/typecheck/TcTyClsDecls.lhs +++ b/compiler/typecheck/TcTyClsDecls.lhs @@ -17,6 +17,7 @@ import HsTypes import BasicTypes import HscTypes import BuildTyCl +import TcUnify import TcRnMonad import TcEnv import TcTyDecls @@ -44,7 +45,7 @@ import ListSetOps import Digraph import DynFlags -import Data.List ( partition, elemIndex ) +import Data.List import Control.Monad ( mplus ) \end{code} @@ -241,9 +242,9 @@ tcFamInstDecl (L loc decl) tcAddDeclCtxt decl $ do { -- type families require -ftype-families and can't be in an -- hs-boot file - ; gla_exts <- doptM Opt_TypeFamilies + ; type_families <- doptM Opt_TypeFamilies ; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file? - ; checkTc gla_exts $ badFamInstDecl (tcdLName decl) + ; checkTc type_families $ badFamInstDecl (tcdLName decl) ; checkTc (not is_boot) $ badBootFamInstDeclErr -- perform kind and type checking @@ -267,8 +268,13 @@ tcFamInstDecl1 (decl@TySynonym {tcdLName = L loc tc_name}) ; t_typats <- mappM tcHsKindedType k_typats ; t_rhs <- tcHsKindedType k_rhs - ; -- (3) check that the right-hand side is a tau type - ; unless (isTauTy t_rhs) $ + -- (3) check that + -- - left-hand side contains no type family applications + -- (vanilla synonyms are fine, though) + ; mappM_ checkTyFamFreeness t_typats + + -- - the right-hand side is a tau type + ; unless (isTauTy t_rhs) $ addErr (polyTyErr t_rhs) -- (4) construct representation tycon @@ -299,17 +305,23 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, ; tcTyVarBndrs k_tvs $ \t_tvs -> do { -- turn kinded into proper tyvars ; unbox_strict <- doptM Opt_UnboxStrictFields - -- Check that we don't use GADT syntax for indexed types + -- kind check the type indexes and the context + ; t_typats <- mappM tcHsKindedType k_typats + ; stupid_theta <- tcHsKindedContext k_ctxt + + -- (3) Check that + -- - left-hand side contains no type family applications + -- (vanilla synonyms are fine, though) + ; mappM_ checkTyFamFreeness t_typats + + -- - we don't use GADT syntax for indexed types ; checkTc h98_syntax (badGadtIdxTyDecl tc_name) - -- Check that a newtype has exactly one constructor + -- - a newtype has exactly one constructor ; checkTc (new_or_data == DataType || isSingleton k_cons) $ newtypeConError tc_name (length k_cons) - ; t_typats <- mappM tcHsKindedType k_typats - ; stupid_theta <- tcHsKindedContext k_ctxt - - -- (3) construct representation tycon + -- (4) construct representation tycon ; rep_tc_name <- newFamInstTyConName tc_name loc ; tycon <- fixM (\ tycon -> do { data_cons <- mappM (addLocM (tcConDecl unbox_strict tycon t_tvs)) @@ -336,6 +348,27 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False other -> True +-- Check that a type index does not contain any type family applications +-- +-- * Earlier phases have already checked that there are no foralls in the +-- type; we also cannot have PredTys and NoteTys are being skipped by using +-- the core view. +-- +checkTyFamFreeness :: Type -> TcM () +checkTyFamFreeness ty | Just (tycon, tys) <- splitTyConApp_maybe ty + = if isSynTyCon tycon + then addErr $ tyFamAppInIndexErr ty + else mappM_ checkTyFamFreeness tys + -- splitTyConApp_maybe uses the core view; hence, + -- any synonym tycon must be a family tycon + + | Just (ty1, ty2) <- splitAppTy_maybe ty + = checkTyFamFreeness ty1 >> checkTyFamFreeness ty2 + + | otherwise -- only vars remaining + = return () + + -- Kind checking of indexed types -- - @@ -503,18 +536,15 @@ kcTyClDecl decl@(TyData {}) kcTyClDeclBody decl $ kcDataDecl decl -kcTyClDecl decl@(TyFamily {tcdKind = kind}) - = kcTyClDeclBody decl $ \ tvs' -> - return (decl {tcdTyVars = tvs', - tcdKind = kind `mplus` Just liftedTypeKind}) - -- default result kind is '*' +kcTyClDecl decl@(TyFamily {}) + = kcFamilyDecl [] decl -- the empty list signals a toplevel decl kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs, tcdATs = ats}) = kcTyClDeclBody decl $ \ tvs' -> do { is_boot <- tcIsHsBoot ; ctxt' <- kcHsContext ctxt - ; ats' <- mappM (wrapLocM kcTyClDecl) ats - ; sigs' <- mappM (wrapLocM kc_sig ) sigs + ; ats' <- mappM (wrapLocM (kcFamilyDecl tvs')) ats + ; sigs' <- mappM (wrapLocM kc_sig) sigs ; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs', tcdATs = ats'}) } where @@ -566,11 +596,15 @@ kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) return (ConDecl name expl ex_tvs' ex_ctxt' details' res' Nothing) kc_con_details (PrefixCon btys) - = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') } + = do { btys' <- mappM kc_larg_ty btys + ; return (PrefixCon btys') } kc_con_details (InfixCon bty1 bty2) - = do { bty1' <- kc_larg_ty bty1; bty2' <- kc_larg_ty bty2; return (InfixCon bty1' bty2') } + = do { bty1' <- kc_larg_ty bty1 + ; bty2' <- kc_larg_ty bty2 + ; return (InfixCon bty1' bty2') } kc_con_details (RecCon fields) - = do { fields' <- mappM kc_field fields; return (RecCon fields') } + = do { fields' <- mappM kc_field fields + ; return (RecCon fields') } kc_field (ConDeclField fld bty d) = do { bty' <- kc_larg_ty bty ; return (ConDeclField fld bty' d) } @@ -581,6 +615,25 @@ kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) -- Can't allow an unlifted type for newtypes, because we're effectively -- going to remove the constructor while coercing it to a lifted type. -- And newtypes can't be bang'd + +-- Kind check a family declaration or type family default declaration. +-- +kcFamilyDecl :: [LHsTyVarBndr Name] -- tyvars of enclosing class decl if any + -> TyClDecl Name -> TcM (TyClDecl Name) +kcFamilyDecl classTvs decl@(TyFamily {tcdKind = kind}) + = kcTyClDeclBody decl $ \tvs' -> + do { mapM_ unifyClassParmKinds tvs' + ; return (decl {tcdTyVars = tvs', + tcdKind = kind `mplus` Just liftedTypeKind}) + -- default result kind is '*' + } + where + unifyClassParmKinds (L _ (KindedTyVar n k)) + | Just classParmKind <- lookup n classTyKinds = unifyKind k classParmKind + | otherwise = return () + classTyKinds = [(n, k) | L _ (KindedTyVar n k) <- classTvs] +kcFamilyDecl _ decl@(TySynonym {}) -- type family defaults + = panic "TcTyClsDecls.kcFamilyDecl: not implemented yet" \end{code} @@ -661,7 +714,8 @@ tcTyClDecl1 calc_isrec ; stupid_theta <- tcHsKindedContext ctxt ; want_generic <- doptM Opt_Generics ; unbox_strict <- doptM Opt_UnboxStrictFields - ; gla_exts <- doptM Opt_GlasgowExts + ; empty_data_decls <- doptM Opt_EmptyDataDecls + ; kind_signatures <- doptM Opt_KindSignatures ; gadt_ok <- doptM Opt_GADTs ; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file? @@ -669,14 +723,14 @@ tcTyClDecl1 calc_isrec ; checkTc (gadt_ok || h98_syntax) (badGadtDecl tc_name) -- Check that we don't use kind signatures without Glasgow extensions - ; checkTc (gla_exts || isNothing mb_ksig) (badSigTyDecl tc_name) + ; checkTc (kind_signatures || isNothing mb_ksig) (badSigTyDecl tc_name) -- Check that the stupid theta is empty for a GADT-style declaration ; checkTc (null stupid_theta || h98_syntax) (badStupidTheta tc_name) -- Check that there's at least one condecl, - -- or else we're reading an hs-boot file, or -fglasgow-exts - ; checkTc (not (null cons) || gla_exts || is_boot) + -- or else we're reading an hs-boot file, or -XEmptyDataDecls + ; checkTc (not (null cons) || empty_data_decls || is_boot) (emptyConDeclsErr tc_name) -- Check that a newtype has exactly one constructor @@ -1024,18 +1078,20 @@ checkNewDataCon con ------------------------------- checkValidClass :: Class -> TcM () checkValidClass cls - = do { -- CHECK ARITY 1 FOR HASKELL 1.4 - gla_exts <- doptM Opt_GlasgowExts + = do { constrained_class_methods <- doptM Opt_ConstrainedClassMethods + ; multi_param_type_classes <- doptM Opt_MultiParamTypeClasses + ; fundep_classes <- doptM Opt_FunctionalDependencies -- Check that the class is unary, unless GlaExs ; checkTc (notNull tyvars) (nullaryClassErr cls) - ; checkTc (gla_exts || unary) (classArityErr cls) + ; checkTc (multi_param_type_classes || unary) (classArityErr cls) + ; checkTc (fundep_classes || null fundeps) (classFunDepsErr cls) -- Check the super-classes ; checkValidTheta (ClassSCCtxt (className cls)) theta -- Check the class operations - ; mappM_ (check_op gla_exts) op_stuff + ; mappM_ (check_op constrained_class_methods) op_stuff -- Check that if the class has generic methods, then the -- class has only one parameter. We can't do generic @@ -1043,11 +1099,11 @@ checkValidClass cls ; checkTc (unary || no_generics) (genericMultiParamErr cls) } where - (tyvars, theta, _, op_stuff) = classBigSig cls + (tyvars, fundeps, theta, _, _, op_stuff) = classExtraBigSig cls unary = isSingleton tyvars no_generics = null [() | (_, GenDefMeth) <- op_stuff] - check_op gla_exts (sel_id, dm) + check_op constrained_class_methods (sel_id, dm) = addErrCtxt (classOpCtxt sel_id tau) $ do { checkValidTheta SigmaCtxt (tail theta) -- The 'tail' removes the initial (C a) from the @@ -1075,11 +1131,11 @@ checkValidClass cls op_ty = idType sel_id (_,theta1,tau1) = tcSplitSigmaTy op_ty (_,theta2,tau2) = tcSplitSigmaTy tau1 - (theta,tau) | gla_exts = (theta1 ++ theta2, tau2) - | otherwise = (theta1, mkPhiTy (tail theta1) tau1) + (theta,tau) | constrained_class_methods = (theta1 ++ theta2, tau2) + | otherwise = (theta1, mkPhiTy (tail theta1) tau1) -- Ugh! The function might have a type like -- op :: forall a. C a => forall b. (Eq b, Eq a) => tau2 - -- With -fglasgow-exts, we want to allow this, even though the inner + -- With -XConstrainedClassMethods, we want to allow this, even though the inner -- forall has an (Eq a) constraint. Whereas in general, each constraint -- in the context of a for-all must mention at least one quantified -- type variable. What a mess! @@ -1104,7 +1160,11 @@ nullaryClassErr cls classArityErr cls = vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls), - parens (ptext SLIT("Use -fglasgow-exts to allow multi-parameter classes"))] + parens (ptext SLIT("Use -XMultiParamTypeClasses to allow multi-parameter classes"))] + +classFunDepsErr cls + = vcat [ptext SLIT("Fundeps in class") <+> quotes (ppr cls), + parens (ptext SLIT("Use -XFunctionalDependencies to allow fundeps"))] noClassTyVarErr clas op = sep [ptext SLIT("The class method") <+> quotes (ppr op), @@ -1148,7 +1208,7 @@ badDataConTyCon data_con badGadtDecl tc_name = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -X=GADT to allow GADTs")) ] + , nest 2 (parens $ ptext SLIT("Use -XGADTs to allow GADTs")) ] badStupidTheta tc_name = ptext SLIT("A data type declared in GADT style cannot have a context:") <+> quotes (ppr tc_name) @@ -1176,12 +1236,12 @@ newtypeFieldErr con_name n_flds badSigTyDecl tc_name = vcat [ ptext SLIT("Illegal kind signature") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow kind signatures")) ] + , nest 2 (parens $ ptext SLIT("Use -XKindSignatures to allow kind signatures")) ] badFamInstDecl tc_name = vcat [ ptext SLIT("Illegal family instance for") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -X=TypeFamilies to allow indexed type families")) ] + , nest 2 (parens $ ptext SLIT("Use -XTypeFamilies to allow indexed type families")) ] badGadtIdxTyDecl tc_name = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> @@ -1211,7 +1271,12 @@ polyTyErr ty = hang (ptext SLIT("Illegal polymorphic type in type instance") <> colon) 4 $ ppr ty +tyFamAppInIndexErr ty + = hang (ptext SLIT("Illegal type family application in type instance") <> + colon) 4 $ + ppr ty + emptyConDeclsErr tycon = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"), - nest 2 $ ptext SLIT("(-fglasgow-exts permits this)")] + nest 2 $ ptext SLIT("(-XEmptyDataDecls permits this)")] \end{code}