X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=8a914556e2ba07d3c2afd369818a9c12183431a5;hb=25f84fa7e4b84c3db5ba745a7881c009b778e0b1;hp=f827117623191e5a9d23f15d4b91dc91f0e1b15e;hpb=cd29742326367b45b9f779088309c652fd42c779;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs index f827117..8a91455 100644 --- a/compiler/typecheck/TcTyClsDecls.lhs +++ b/compiler/typecheck/TcTyClsDecls.lhs @@ -6,6 +6,13 @@ TcTyClsDecls: Typecheck type and class declarations \begin{code} +{-# OPTIONS -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details + module TcTyClsDecls ( tcTyAndClassDecls, tcFamInstDecl ) where @@ -263,27 +270,20 @@ tcFamInstDecl1 (decl@TySynonym {tcdLName = L loc tc_name}) ; -- (1) kind check the right-hand side of the type equation ; k_rhs <- kcCheckHsType (tcdSynRhs decl) resKind - -- we need at least as many type parameters as the family declaration - -- specified + -- we need the exact same number of type parameters as the family + -- declaration ; let famArity = tyConArity family - ; checkTc (length k_typats >= famArity) $ tooFewParmsErr famArity + ; checkTc (length k_typats == famArity) $ + wrongNumberOfParmsErr famArity -- (2) type check type equation ; tcTyVarBndrs k_tvs $ \t_tvs -> do { -- turn kinded into proper tyvars ; t_typats <- mappM tcHsKindedType k_typats ; t_rhs <- tcHsKindedType k_rhs - -- all parameters in excess of the family arity must be variables - ; checkTc (all isTyVarTy $ drop famArity t_typats) $ excessParmVarErr - -- (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) + -- - check the well-formedness of the instance + ; checkValidTypeInst t_typats t_rhs -- (4) construct representation tycon ; rep_tc_name <- newFamInstTyConName tc_name loc @@ -319,7 +319,8 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, -- (3) Check that -- - left-hand side contains no type family applications - -- (vanilla synonyms are fine, though) + -- (vanilla synonyms are fine, though, and we checked for + -- foralls earlier) ; mappM_ checkTyFamFreeness t_typats -- - we don't use GADT syntax for indexed types @@ -337,7 +338,7 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, ; tc_rhs <- case new_or_data of DataType -> return (mkDataTyConRhs data_cons) - NewType -> ASSERT( isSingleton data_cons ) + NewType -> ASSERT( not (null data_cons) ) mkNewTyConRhs rep_tc_name tycon (head data_cons) ; buildAlgTyCon rep_tc_name t_tvs stupid_theta tc_rhs Recursive False h98_syntax (Just (family, t_typats)) @@ -356,27 +357,6 @@ 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 -- - @@ -754,7 +734,7 @@ tcTyClDecl1 calc_isrec else case new_or_data of DataType -> return (mkDataTyConRhs data_cons) NewType -> - ASSERT( isSingleton data_cons ) + ASSERT( not (null data_cons) ) mkNewTyConRhs tc_name tycon (head data_cons) ; buildAlgTyCon tc_name final_tvs stupid_theta tc_rhs is_rec (want_generic && canDoGenerics data_cons) h98_syntax Nothing @@ -1074,14 +1054,14 @@ checkNewDataCon con -- One argument ; checkTc (null eq_spec) (newtypePredError con) -- Return type is (T a b c) - ; checkTc (null ex_tvs && null theta) (newtypeExError con) + ; checkTc (null ex_tvs && null eq_theta && null dict_theta) (newtypeExError con) -- No existentials ; checkTc (not (any isMarkedStrict (dataConStrictMarks con))) (newtypeStrictError con) -- No strictness } where - (_univ_tvs, ex_tvs, eq_spec, theta, arg_tys, _res_ty) = dataConFullSig con + (_univ_tvs, ex_tvs, eq_spec, eq_theta, dict_theta, arg_tys, _res_ty) = dataConFullSig con ------------------------------- checkValidClass :: Class -> TcM () @@ -1117,6 +1097,7 @@ checkValidClass cls -- The 'tail' removes the initial (C a) from the -- class itself, leaving just the method type + ; traceTc (text "class op type" <+> ppr op_ty <+> ppr tau) ; checkValidType (FunSigCtxt op_name) tau -- Check that the type mentions at least one of @@ -1264,8 +1245,9 @@ tooFewParmsErr arity = ptext SLIT("Family instance has too few parameters; expected") <+> ppr arity -excessParmVarErr - = ptext SLIT("Additional instance parameters must be variables") +wrongNumberOfParmsErr exp_arity + = ptext SLIT("Number of parameters must match family declaration; expected") + <+> ppr exp_arity badBootFamInstDeclErr = ptext SLIT("Illegal family instance in hs-boot file") @@ -1278,15 +1260,6 @@ wrongKindOfFamily family = | isAlgTyCon family = ptext SLIT("data type") | otherwise = pprPanic "wrongKindOfFamily" (ppr family) -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("(-XEmptyDataDecls permits this)")]