X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcUnify.lhs;h=5fcaea6cf1bc25d61f67f2ea3c50d3096a72ee25;hb=ecd655aaaa4ae495933415ad1ff6f6132ff3967f;hp=39c3cbda27829ba4718e952781f0783be76bda9f;hpb=e0ab62c1879c97b1db44b23150b2e260a9ec48cf;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcUnify.lhs b/compiler/typecheck/TcUnify.lhs index 39c3cbd..5fcaea6 100644 --- a/compiler/typecheck/TcUnify.lhs +++ b/compiler/typecheck/TcUnify.lhs @@ -1,7 +1,9 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % -\section{Type subsumption and unification} + +Type subsumption and unification \begin{code} module TcUnify ( @@ -25,61 +27,29 @@ module TcUnify ( #include "HsVersions.h" -import HsSyn ( HsWrapper(..), idHsWrapper, isIdHsWrapper, (<.>), - mkWpLams, mkWpTyLams, mkWpApps ) -import TypeRep ( Type(..), PredType(..) ) - -import TcMType ( lookupTcTyVar, LookupTyVarResult(..), - tcInstSkolType, tcInstBoxyTyVar, newKindVar, newMetaTyVar, - newBoxyTyVar, newBoxyTyVarTys, readFilledBox, - readMetaTyVar, writeMetaTyVar, newFlexiTyVarTy, - tcInstSkolTyVars, tcInstTyVar, - zonkTcKind, zonkType, zonkTcType, zonkTcTyVarsAndFV, - readKindVar, writeKindVar ) -import TcSimplify ( tcSimplifyCheck ) -import TcEnv ( tcGetGlobalTyVars, findGlobals ) -import TcIface ( checkWiredInTyCon ) +import HsSyn +import TypeRep + +import TcMType +import TcSimplify +import TcEnv +import TcIface import TcRnMonad -- TcType, amongst others -import TcType ( TcKind, TcType, TcTyVar, BoxyTyVar, TcTauType, - BoxySigmaType, BoxyRhoType, BoxyType, - TcTyVarSet, TcThetaType, TcTyVarDetails(..), BoxInfo(..), - SkolemInfo( GenSkol, UnkSkol ), MetaDetails(..), isImmutableTyVar, - pprSkolTvBinding, isTauTy, isTauTyCon, isSigmaTy, - mkFunTy, mkFunTys, mkTyConApp, isMetaTyVar, - tcSplitForAllTys, tcSplitAppTy_maybe, tcSplitFunTys, mkTyVarTys, - tcSplitSigmaTy, tyVarsOfType, mkPhiTy, mkTyVarTy, mkPredTy, - typeKind, mkForAllTys, mkAppTy, isBoxyTyVar, - tcView, exactTyVarsOfType, - tidyOpenType, tidyOpenTyVar, tidyOpenTyVars, - pprType, tidyKind, tidySkolemTyVar, isSkolemTyVar, isSigTyVar, - TvSubst, mkTvSubst, zipTyEnv, zipOpenTvSubst, emptyTvSubst, - substTy, substTheta, - lookupTyVar, extendTvSubst ) -import Type ( Kind, SimpleKind, KindVar, - openTypeKind, liftedTypeKind, unliftedTypeKind, - mkArrowKind, defaultKind, - argTypeKind, isLiftedTypeKind, isUnliftedTypeKind, - isSubKind, pprKind, splitKindFunTys, isSubKindCon, - isOpenTypeKind, isArgTypeKind ) -import TysPrim ( alphaTy, betaTy ) -import Inst ( newDictBndrsO, instCall, instToId ) -import TyCon ( TyCon, tyConArity, tyConTyVars, isSynTyCon ) -import TysWiredIn ( listTyCon ) -import Id ( Id ) -import Var ( Var, varName, tyVarKind, isTcTyVar, tcTyVarDetails ) +import TcType +import Type +import TysPrim +import Inst +import TyCon +import TysWiredIn +import Var import VarSet import VarEnv -import Name ( Name, isSystemName ) -import ErrUtils ( Message ) -import Maybes ( expectJust, isNothing ) -import BasicTypes ( Arity ) -import Util ( notNull, equalLength ) +import Name +import ErrUtils +import Maybes +import BasicTypes +import Util import Outputable - --- Assertion imports -#ifdef DEBUG -import TcType ( isBoxyTy, isFlexi ) -#endif \end{code} %************************************************************************ @@ -95,7 +65,7 @@ tcInfer tc_infer ; res <- tc_infer (mkTyVarTy box) ; res_ty <- readFilledBox box -- Guaranteed filled-in by now ; return (res, res_ty) } -\end{code} +\end{code} %************************************************************************ @@ -148,7 +118,7 @@ subFunTys error_herald n_pats res_ty thing_inside loop n args_so_far res_ty | isSigmaTy res_ty -- Do this before checking n==0, because we -- guarantee to return a BoxyRhoType, not a BoxySigmaType - = do { (gen_fn, (co_fn, res)) <- tcGen res_ty emptyVarSet $ \ res_ty' -> + = do { (gen_fn, (co_fn, res)) <- tcGen res_ty emptyVarSet $ \ _ res_ty' -> loop n args_so_far res_ty' ; return (gen_fn <.> co_fn, res) } @@ -669,7 +639,7 @@ tc_sub1 sub_ctxt act_sty (TyVarTy tv) exp_ib exp_sty exp_ty tc_sub1 sub_ctxt act_sty act_ty exp_ib exp_sty exp_ty | not exp_ib, -- SKOL does not apply if exp_ty is inside a box isSigmaTy exp_ty - = do { (gen_fn, co_fn) <- tcGen exp_ty act_tvs $ \ body_exp_ty -> + = do { (gen_fn, co_fn) <- tcGen exp_ty act_tvs $ \ _ body_exp_ty -> tc_sub sub_ctxt act_sty act_ty False body_exp_ty body_exp_ty ; return (gen_fn <.> co_fn) } where @@ -774,7 +744,7 @@ tcGen :: BoxySigmaType -- expected_ty -> TcTyVarSet -- Extra tyvars that the universally -- quantified tyvars of expected_ty -- must not be unified - -> (BoxyRhoType -> TcM result) -- spec_ty + -> ([TcTyVar] -> BoxyRhoType -> TcM result) -> TcM (HsWrapper, result) -- The expression has type: spec_ty -> expected_ty @@ -784,22 +754,21 @@ tcGen expected_ty extra_tvs thing_inside -- We expect expected_ty to be a forall -- mention the *instantiated* tyvar names, so that we get a -- good error message "Rigid variable 'a' is bound by (forall a. a->a)" -- Hence the tiresome but innocuous fixM - ((forall_tvs, theta, rho_ty), skol_info) <- fixM (\ ~(_, skol_info) -> + ((tvs', theta', rho'), skol_info) <- fixM (\ ~(_, skol_info) -> do { (forall_tvs, theta, rho_ty) <- tcInstSkolType skol_info expected_ty - ; span <- getSrcSpanM - ; let skol_info = GenSkol forall_tvs (mkPhiTy theta rho_ty) span + -- Get loation from monad, not from expected_ty + ; let skol_info = GenSkol forall_tvs (mkPhiTy theta rho_ty) ; return ((forall_tvs, theta, rho_ty), skol_info) }) #ifdef DEBUG ; traceTc (text "tcGen" <+> vcat [text "extra_tvs" <+> ppr extra_tvs, text "expected_ty" <+> ppr expected_ty, - text "inst ty" <+> ppr forall_tvs <+> ppr theta <+> ppr rho_ty, - text "free_tvs" <+> ppr free_tvs, - text "forall_tvs" <+> ppr forall_tvs]) + text "inst ty" <+> ppr tvs' <+> ppr theta' <+> ppr rho', + text "free_tvs" <+> ppr free_tvs]) #endif -- Type-check the arg and unify with poly type - ; (result, lie) <- getLIE (thing_inside rho_ty) + ; (result, lie) <- getLIE (thing_inside tvs' rho') -- Check that the "forall_tvs" havn't been constrained -- The interesting bit here is that we must include the free variables @@ -812,20 +781,20 @@ tcGen expected_ty extra_tvs thing_inside -- We expect expected_ty to be a forall -- Conclusion: include the free vars of the expected_ty in the -- list of "free vars" for the signature check. - ; dicts <- newDictBndrsO (SigOrigin skol_info) theta - ; inst_binds <- tcSimplifyCheck sig_msg forall_tvs dicts lie + ; loc <- getInstLoc (SigOrigin skol_info) + ; dicts <- newDictBndrs loc theta' + ; inst_binds <- tcSimplifyCheck loc tvs' dicts lie - ; checkSigTyVarsWrt free_tvs forall_tvs + ; checkSigTyVarsWrt free_tvs tvs' ; traceTc (text "tcGen:done") ; let -- The WpLet binds any Insts which came out of the simplification. dict_ids = map instToId dicts - co_fn = mkWpTyLams forall_tvs <.> mkWpLams dict_ids <.> WpLet inst_binds + co_fn = mkWpTyLams tvs' <.> mkWpLams dict_ids <.> WpLet inst_binds ; returnM (co_fn, result) } where free_tvs = tyVarsOfType expected_ty `unionVarSet` extra_tvs - sig_msg = ptext SLIT("expected type of an expression") \end{code} @@ -996,6 +965,7 @@ u_tys outer nb1 orig_ty1 ty1 nb2 orig_ty2 ty2 go _ ty1@(ForAllTy _ _) ty2@(ForAllTy _ _) | length tvs1 == length tvs2 = do { tvs <- tcInstSkolTyVars UnkSkol tvs1 -- Not a helpful SkolemInfo + -- Get location from monad, not from tvs1 ; let tys = mkTyVarTys tvs in_scope = mkInScopeSet (mkVarSet tvs) subst1 = mkTvSubst in_scope (zipTyEnv tvs1 tys) @@ -1262,7 +1232,7 @@ uUnfilledVars outer swapped tv1 (MetaTv info1 ref1) tv2 (MetaTv info2 ref2) k1_sub_k2 = k1 `isSubKind` k2 k2_sub_k1 = k2 `isSubKind` k1 - nicer_to_update_tv1 = isSystemName (varName tv1) + nicer_to_update_tv1 = isSystemName (Var.varName tv1) -- Try to update sys-y type variables in preference to ones -- gotten (say) by instantiating a polymorphic function with -- a user-written type sig