X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcHsType.lhs;h=6f92e4b4384ba6e9de40b3ae92c6fddd90e6bad7;hp=d90638136c2886f7190137a034f571b4bbf22b33;hb=2423c249f5ca7785d0ec89eb33e72662da7561c1;hpb=1dc5c28c2370cc8254f024c5734f76d7e5827cd6 diff --git a/compiler/typecheck/TcHsType.lhs b/compiler/typecheck/TcHsType.lhs index d906381..6f92e4b 100644 --- a/compiler/typecheck/TcHsType.lhs +++ b/compiler/typecheck/TcHsType.lhs @@ -1,4 +1,5 @@ - +% +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[TcMonoType]{Typechecking user-specified @MonoTypes@} @@ -23,41 +24,26 @@ module TcHsType ( #include "HsVersions.h" -import HsSyn ( HsType(..), LHsType, HsTyVarBndr(..), LHsTyVarBndr, - LHsContext, HsPred(..), LHsPred, HsExplicitForAll(..) ) -import RnHsSyn ( extractHsTyVars ) +import HsSyn +import RnHsSyn import TcRnMonad -import TcEnv ( tcExtendTyVarEnv, tcExtendKindEnvTvs, - tcLookup, tcLookupClass, tcLookupTyCon, - TyThing(..), getInLocalScope, getScopedTyVarBinds, - wrongThingErr - ) -import TcMType ( newKindVar, - zonkTcKindToKind, - tcInstBoxyTyVar, readFilledBox, - checkValidType - ) -import TcUnify ( boxyUnify, unifyFunKind, checkExpectedKind ) -import TcIface ( checkWiredInTyCon ) -import TcType ( Type, PredType(..), ThetaType, BoxySigmaType, - TcType, TcKind, isRigidTy, - UserTypeCtxt(..), pprUserTypeCtxt, - substTyWith, mkTyVarTys, tcEqType, - tcIsTyVarTy, mkFunTy, mkSigmaTy, mkPredTy, - mkTyConApp, mkAppTys, typeKind ) -import Kind ( Kind, isLiftedTypeKind, liftedTypeKind, ubxTupleKind, - openTypeKind, argTypeKind, splitKindFunTys ) -import Var ( TyVar, mkTyVar, tyVarName ) -import TyCon ( TyCon, tyConKind ) -import Class ( Class, classTyCon ) -import Name ( Name, mkInternalName ) -import OccName ( mkOccName, tvName ) +import TcEnv +import TcMType +import TcUnify +import TcIface +import TcType +import {- Kind parts of -} Type +import Var +import TyCon +import Class +import Name +import OccName import NameSet -import PrelNames ( genUnitTyConName ) -import TysWiredIn ( mkListTy, listTyCon, mkPArrTy, parrTyCon, tupleTyCon ) -import BasicTypes ( Boxity(..) ) -import SrcLoc ( Located(..), unLoc, noLoc, getLoc, srcSpanStart ) -import UniqSupply ( uniqsFromSupply ) +import PrelNames +import TysWiredIn +import BasicTypes +import SrcLoc +import UniqSupply import Outputable \end{code} @@ -191,8 +177,7 @@ kcHsSigType ty = kcTypeType ty kcHsLiftedSigType ty = kcLiftedType ty tcHsKindedType :: LHsType Name -> TcM Type - -- Don't do kind checking, nor validity checking, - -- but do hoist for-alls to the top + -- Don't do kind checking, nor validity checking. -- This is used in type and class decls, where kinding is -- done in advance, and validity checking is done later -- [Validity checking done later because of knot-tying issues.] @@ -242,15 +227,27 @@ kcCheckHsType (L span ty) exp_kind -- because checkExpectedKind already mentions -- 'ty' by name in any error message - ; checkExpectedKind ty act_kind exp_kind + ; checkExpectedKind (strip ty) act_kind exp_kind ; return (L span ty') } where - -- Wrap a context around only if we want to - -- show that contexts. Omit invisble ones - -- and ones user's won't grok (HsPred p). - add_ctxt (HsPredTy p) thing = thing - add_ctxt (HsForAllTy Implicit tvs (L _ []) ty) thing = thing - add_ctxt other_ty thing = addErrCtxt (typeCtxt ty) thing + -- Wrap a context around only if we want to show that contexts. + add_ctxt (HsPredTy p) thing = thing + -- Omit invisble ones and ones user's won't grok (HsPred p). + add_ctxt (HsForAllTy _ _ (L _ []) _) thing = thing + -- Omit wrapping if the theta-part is empty + -- Reason: the recursive call to kcLiftedType, in the ForAllTy + -- case of kc_hs_type, will do the wrapping instead + -- and we don't want to duplicate + add_ctxt other_ty thing = addErrCtxt (typeCtxt other_ty) thing + + -- We infer the kind of the type, and then complain if it's + -- not right. But we don't want to complain about + -- (ty) or !(ty) or forall a. ty + -- when the real difficulty is with the 'ty' part. + strip (HsParTy (L _ ty)) = strip ty + strip (HsBangTy _ (L _ ty)) = strip ty + strip (HsForAllTy _ _ _ (L _ ty)) = strip ty + strip ty = ty \end{code} Here comes the main function @@ -326,17 +323,18 @@ kc_hs_type (HsPredTy pred) kc_hs_type (HsForAllTy exp tv_names context ty) = kcHsTyVars tv_names $ \ tv_names' -> - kcHsContext context `thenM` \ ctxt' -> - kcLiftedType ty `thenM` \ ty' -> - -- The body of a forall is usually a type, but in principle - -- there's no reason to prohibit *unlifted* types. - -- In fact, GHC can itself construct a function with an - -- unboxed tuple inside a for-all (via CPR analyis; see - -- typecheck/should_compile/tc170) - -- - -- Still, that's only for internal interfaces, which aren't - -- kind-checked, so we only allow liftedTypeKind here - returnM (HsForAllTy exp tv_names' ctxt' ty', liftedTypeKind) + do { ctxt' <- kcHsContext context + ; ty' <- kcLiftedType ty + -- The body of a forall is usually a type, but in principle + -- there's no reason to prohibit *unlifted* types. + -- In fact, GHC can itself construct a function with an + -- unboxed tuple inside a for-all (via CPR analyis; see + -- typecheck/should_compile/tc170) + -- + -- Still, that's only for internal interfaces, which aren't + -- kind-checked, so we only allow liftedTypeKind here + + ; return (HsForAllTy exp tv_names' ctxt' ty', liftedTypeKind) } kc_hs_type (HsBangTy b ty) = do { (ty', kind) <- kcHsType ty @@ -345,6 +343,10 @@ kc_hs_type (HsBangTy b ty) kc_hs_type ty@(HsSpliceTy _) = failWithTc (ptext SLIT("Unexpected type splice:") <+> ppr ty) +-- remove the doc nodes here, no need to worry about the location since +-- its the same for a doc node and it's child type node +kc_hs_type (HsDocTy ty _) + = kc_hs_type (unLoc ty) --------------------------- kcApps :: TcKind -- Function kind @@ -494,6 +496,8 @@ ds_type full_ty@(HsForAllTy exp tv_names ctxt ty) dsHsType ty `thenM` \ tau -> returnM (mkSigmaTy tyvars theta tau) +ds_type (HsSpliceTy {}) = panic "ds_type: HsSpliceTy" + dsHsTypes arg_tys = mappM dsHsType arg_tys \end{code} @@ -561,8 +565,8 @@ tcLHsConResTy res_ty get_largs (L _ ty) args = get_args ty args get_args (HsAppTy fun arg) args = get_largs fun (arg:args) get_args (HsParTy ty) args = get_largs ty args - get_args (HsOpTy ty1 (L span tc) ty2) args = get_args (HsTyVar tc) (ty1:ty2:args) - get_args ty args = (ty, reverse args) + get_args (HsOpTy ty1 (L span tc) ty2) args = (HsTyVar tc, ty1:ty2:args) + get_args ty args = (ty, args) gadtResCtxt ty = hang (ptext SLIT("In the result type of a data constructor:")) @@ -616,7 +620,8 @@ tcDataKindSig :: Maybe Kind -> TcM [TyVar] -- GADT decls can have a (perhaps partial) kind signature -- e.g. data T :: * -> * -> * where ... -- This function makes up suitable (kinded) type variables for --- the argument kinds, and checks that the result kind is indeed * +-- the argument kinds, and checks that the result kind is indeed *. +-- We use it also to make up argument type variables for for data instances. tcDataKindSig Nothing = return [] tcDataKindSig (Just kind) = do { checkTc (isLiftedTypeKind res_kind) (badKindSig kind) @@ -795,7 +800,6 @@ pprHsSigCtxt ctxt hs_ty = vcat [ ptext SLIT("In") <+> pprUserTypeCtxt ctxt <> co pp_sig (FunSigCtxt n) = pp_n_colon n pp_sig (ConArgCtxt n) = pp_n_colon n pp_sig (ForSigCtxt n) = pp_n_colon n - pp_sig (RuleSigCtxt n) = pp_n_colon n pp_sig other = ppr (unLoc hs_ty) pp_n_colon n = ppr n <+> dcolon <+> ppr (unLoc hs_ty)