X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcExpr.lhs;h=536a5d33f753e8c03483f06d06a995bf90b9ec58;hb=20d387c481324aed48e8469d3fbf0695b3b2e365;hp=7aecdaaf81061d0ed2b46ca7a47a652039bbfbd0;hpb=3ca33229d4b9c1ed2829318631e73e748154f3ff;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs index 7aecdaa..536a5d3 100644 --- a/ghc/compiler/typecheck/TcExpr.lhs +++ b/ghc/compiler/typecheck/TcExpr.lhs @@ -4,87 +4,74 @@ \section[TcExpr]{Typecheck an expression} \begin{code} -module TcExpr ( tcApp, tcExpr, tcPolyExpr, tcId ) where +module TcExpr ( tcApp, tcExpr, tcMonoExpr, tcPolyExpr, tcId ) where #include "HsVersions.h" import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..), - HsBinds(..), Stmt(..), StmtCtxt(..), - mkMonoBind, nullMonoBinds + MonoBinds(..), StmtCtxt(..), + mkMonoBind, nullMonoBinds ) import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds ) -import TcHsSyn ( TcExpr, TcRecordBinds, - mkHsTyApp, mkHsLet, maybeBoxedPrimType - ) +import TcHsSyn ( TcExpr, TcRecordBinds, mkHsTyApp, mkHsLet ) import TcMonad import BasicTypes ( RecFlag(..) ) -import Inst ( Inst, InstOrigin(..), OverloadedLit(..), - LIE, emptyLIE, unitLIE, consLIE, plusLIE, plusLIEs, - lieToList, listToLIE, tyVarsOfLIE, zonkLIE, +import Inst ( InstOrigin(..), + LIE, emptyLIE, unitLIE, plusLIE, plusLIEs, newOverloadedLit, newMethod, newIPDict, instOverloadedFun, newDicts, newClassDicts, - partitionLIEbyMeth, getIPsOfLIE, instToId, ipToId + getIPsOfLIE, instToId, ipToId ) import TcBinds ( tcBindsAndThen ) -import TcEnv ( tcInstId, - tcLookupValue, tcLookupClassByKey, - tcLookupValueByKey, - tcExtendGlobalTyVars, tcLookupValueMaybe, - tcLookupTyCon, tcLookupDataCon +import TcEnv ( TcTyThing(..), tcInstId, + tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe, + tcLookupTyCon, tcLookupDataCon, tcLookup, + tcExtendGlobalTyVars ) import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts ) -import TcMonoType ( tcHsType, checkSigTyVars, sigCtxt ) -import TcPat ( badFieldCon ) -import TcSimplify ( tcSimplify, tcSimplifyAndCheck ) +import TcMonoType ( tcHsSigType, checkSigTyVars, sigCtxt ) +import TcPat ( badFieldCon, simpleHsLitTy ) +import TcSimplify ( tcSimplifyAndCheck, partitionPredsOfLIE ) +import TcImprove ( tcImprove ) import TcType ( TcType, TcTauType, tcInstTyVars, tcInstTcType, tcSplitRhoTy, - newTyVarTy, newTyVarTy_OpenKind, zonkTcType ) + newTyVarTy, newTyVarTys, zonkTcType ) -import Class ( Class ) -import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType - ) -import Id ( idType, recordSelectorFieldLabel, - isRecordSelector, - Id, mkVanillaId - ) -import DataCon ( dataConFieldLabels, dataConSig, dataConId, +import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon ) +import Id ( idType, recordSelectorFieldLabel, isRecordSelector, mkVanillaId ) +import DataCon ( dataConFieldLabels, dataConSig, dataConStrictMarks, StrictnessMark(..) ) import Name ( Name, getName ) -import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys, - ipName_maybe, - splitFunTy_maybe, splitFunTys, isNotUsgTy, - mkTyConApp, - splitForAllTys, splitRhoTy, +import Type ( mkFunTy, mkAppTy, mkTyVarTys, ipName_maybe, + splitFunTy_maybe, splitFunTys, + mkTyConApp, splitSigmaTy, + splitRhoTy, isTauTy, tyVarsOfType, tyVarsOfTypes, - isForAllTy, splitAlgTyConApp, splitAlgTyConApp_maybe, - boxedTypeKind, mkArrowKind, + isSigmaTy, splitAlgTyConApp, splitAlgTyConApp_maybe, + liftedTypeKind, openTypeKind, mkArrowKind, tidyOpenType ) -import Subst ( mkTopTyVarSubst, substClasses ) -import UsageSPUtils ( unannotTy ) -import VarSet ( emptyVarSet, unionVarSet, elemVarSet, mkVarSet ) -import TyCon ( tyConDataCons ) -import TysPrim ( intPrimTy, charPrimTy, doublePrimTy, - floatPrimTy, addrPrimTy - ) -import TysWiredIn ( boolTy, charTy, stringTy ) -import PrelInfo ( ioTyCon_NAME ) -import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy, - unifyUnboxedTupleTy ) -import Unique ( cCallableClassKey, cReturnableClassKey, - enumFromClassOpKey, enumFromThenClassOpKey, - enumFromToClassOpKey, enumFromThenToClassOpKey, - thenMClassOpKey, failMClassOpKey, returnMClassOpKey +import TyCon ( TyCon, tyConTyVars ) +import Subst ( mkTopTyVarSubst, substClasses, substTy ) +import VarSet ( elemVarSet, mkVarSet ) +import TysWiredIn ( boolTy ) +import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy ) +import PrelNames ( cCallableClassName, + cReturnableClassName, + enumFromName, enumFromThenName, + enumFromToName, enumFromThenToName, + thenMName, failMName, returnMName, ioTyConName ) import Outputable import Maybes ( maybeToBool, mapMaybe ) import ListSetOps ( minusList ) import Util -import CmdLineOpts ( opt_WarnMissingFields ) +import CmdLineOpts +import HscTypes ( TyThing(..) ) \end{code} @@ -97,14 +84,14 @@ import CmdLineOpts ( opt_WarnMissingFields ) \begin{code} tcExpr :: RenamedHsExpr -- Expession to type check -> TcType -- Expected type (could be a polytpye) - -> TcM s (TcExpr, LIE) + -> TcM (TcExpr, LIE) -tcExpr expr ty | isForAllTy ty = -- Polymorphic case - tcPolyExpr expr ty `thenTc` \ (expr', lie, _, _, _) -> - returnTc (expr', lie) +tcExpr expr ty | isSigmaTy ty = -- Polymorphic case + tcPolyExpr expr ty `thenTc` \ (expr', lie, _, _, _) -> + returnTc (expr', lie) - | otherwise = -- Monomorphic case - tcMonoExpr expr ty + | otherwise = -- Monomorphic case + tcMonoExpr expr ty \end{code} @@ -119,7 +106,7 @@ tcExpr expr ty | isForAllTy ty = -- Polymorphic case -- can be a polymorphic one. tcPolyExpr :: RenamedHsExpr -> TcType -- Expected type - -> TcM s (TcExpr, LIE, -- Generalised expr with expected type, and LIE + -> TcM (TcExpr, LIE, -- Generalised expr with expected type, and LIE TcExpr, TcTauType, LIE) -- Same thing, but instantiated; tau-type returned tcPolyExpr arg expected_arg_ty @@ -131,6 +118,7 @@ tcPolyExpr arg expected_arg_ty tcInstTcType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_rho) -> let (sig_theta, sig_tau) = splitRhoTy sig_rho + free_tyvars = tyVarsOfType expected_arg_ty in -- Type-check the arg and unify with expected type tcMonoExpr arg sig_tau `thenTc` \ (arg', lie_arg) -> @@ -146,12 +134,13 @@ tcPolyExpr arg expected_arg_ty -- Conclusion: include the free vars of the expected arg type in the -- list of "free vars" for the signature check. - tcExtendGlobalTyVars (tyVarsOfType expected_arg_ty) $ - tcAddErrCtxtM (sigCtxt sig_msg expected_arg_ty) $ + tcExtendGlobalTyVars free_tyvars $ + tcAddErrCtxtM (sigCtxt sig_msg sig_tyvars sig_theta sig_tau) $ - checkSigTyVars sig_tyvars `thenTc` \ zonked_sig_tyvars -> + checkSigTyVars sig_tyvars free_tyvars `thenTc` \ zonked_sig_tyvars -> newDicts SignatureOrigin sig_theta `thenNF_Tc` \ (sig_dicts, dict_ids) -> + tcImprove (sig_dicts `plusLIE` lie_arg) `thenTc_` -- ToDo: better origin tcSimplifyAndCheck (text "the type signature of an expression") @@ -170,8 +159,7 @@ tcPolyExpr arg expected_arg_ty returnTc ( generalised_arg, free_insts, arg', sig_tau, lie_arg ) where - sig_msg ty = sep [ptext SLIT("In an expression with expected type:"), - nest 4 (ppr ty)] + sig_msg = ptext SLIT("When checking an expression type signature") \end{code} %************************************************************************ @@ -183,7 +171,7 @@ tcPolyExpr arg expected_arg_ty \begin{code} tcMonoExpr :: RenamedHsExpr -- Expession to type check -> TcTauType -- Expected type (could be a type variable) - -> TcM s (TcExpr, LIE) + -> TcM (TcExpr, LIE) tcMonoExpr (HsVar name) res_ty = tcId name `thenNF_Tc` \ (expr', lie, id_ty) -> @@ -209,88 +197,17 @@ tcMonoExpr (HsIPVar name) res_ty %************************************************************************ %* * -\subsection{Literals} -%* * -%************************************************************************ - -Overloaded literals. - -\begin{code} -tcMonoExpr (HsLit (HsInt i)) res_ty - = newOverloadedLit (LiteralOrigin (HsInt i)) - (OverloadedIntegral i) - res_ty `thenNF_Tc` \ stuff -> - returnTc stuff - -tcMonoExpr (HsLit (HsFrac f)) res_ty - = newOverloadedLit (LiteralOrigin (HsFrac f)) - (OverloadedFractional f) - res_ty `thenNF_Tc` \ stuff -> - returnTc stuff - - -tcMonoExpr (HsLit lit@(HsLitLit s)) res_ty - = tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass -> - newClassDicts (LitLitOrigin (_UNPK_ s)) - [(cCallableClass,[res_ty])] `thenNF_Tc` \ (dicts, _) -> - returnTc (HsLitOut lit res_ty, dicts) -\end{code} - -Primitive literals: - -\begin{code} -tcMonoExpr (HsLit lit@(HsCharPrim c)) res_ty - = unifyTauTy res_ty charPrimTy `thenTc_` - returnTc (HsLitOut lit charPrimTy, emptyLIE) - -tcMonoExpr (HsLit lit@(HsStringPrim s)) res_ty - = unifyTauTy res_ty addrPrimTy `thenTc_` - returnTc (HsLitOut lit addrPrimTy, emptyLIE) - -tcMonoExpr (HsLit lit@(HsIntPrim i)) res_ty - = unifyTauTy res_ty intPrimTy `thenTc_` - returnTc (HsLitOut lit intPrimTy, emptyLIE) - -tcMonoExpr (HsLit lit@(HsFloatPrim f)) res_ty - = unifyTauTy res_ty floatPrimTy `thenTc_` - returnTc (HsLitOut lit floatPrimTy, emptyLIE) - -tcMonoExpr (HsLit lit@(HsDoublePrim d)) res_ty - = unifyTauTy res_ty doublePrimTy `thenTc_` - returnTc (HsLitOut lit doublePrimTy, emptyLIE) -\end{code} - -Unoverloaded literals: - -\begin{code} -tcMonoExpr (HsLit lit@(HsChar c)) res_ty - = unifyTauTy res_ty charTy `thenTc_` - returnTc (HsLitOut lit charTy, emptyLIE) - -tcMonoExpr (HsLit lit@(HsString str)) res_ty - = unifyTauTy res_ty stringTy `thenTc_` - returnTc (HsLitOut lit stringTy, emptyLIE) -\end{code} - -%************************************************************************ -%* * \subsection{Other expression forms} %* * %************************************************************************ \begin{code} -tcMonoExpr (HsPar expr) res_ty -- preserve parens so printing needn't guess where they go - = tcMonoExpr expr res_ty +tcMonoExpr (HsLit lit) res_ty = tcLit lit res_ty +tcMonoExpr (HsOverLit lit) res_ty = newOverloadedLit (LiteralOrigin lit) lit res_ty +tcMonoExpr (HsPar expr) res_ty = tcMonoExpr expr res_ty --- perform the negate *before* overloading the integer, since the case --- of minBound on Ints fails otherwise. Could be done elsewhere, but --- convenient to do it here. - -tcMonoExpr (NegApp (HsLit (HsInt i)) neg) res_ty - = tcMonoExpr (HsLit (HsInt (-i))) res_ty - -tcMonoExpr (NegApp expr neg) res_ty - = tcMonoExpr (HsApp neg expr) res_ty +tcMonoExpr (NegApp expr neg) res_ty + = tcMonoExpr (HsApp (HsVar neg) expr) res_ty tcMonoExpr (HsLam match) res_ty = tcMatchLambda match res_ty `thenTc` \ (match',lie) -> @@ -354,11 +271,11 @@ arg/result types); unify them with the args/result; and store them for later use. \begin{code} -tcMonoExpr (CCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty +tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty = -- Get the callable and returnable classes. - tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass -> - tcLookupClassByKey cReturnableClassKey `thenNF_Tc` \ cReturnableClass -> - tcLookupTyCon ioTyCon_NAME `thenNF_Tc` \ ioTyCon -> + tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass -> + tcLookupClass cReturnableClassName `thenNF_Tc` \ cReturnableClass -> + tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon -> let new_arg_dict (arg, arg_ty) = newClassDicts (CCallOrigin (_UNPK_ lbl) (Just arg)) @@ -373,16 +290,15 @@ tcMonoExpr (CCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty tv_idxs | n_args == 0 = [] | otherwise = [1..n_args] in - mapNF_Tc (\ _ -> newTyVarTy_OpenKind) tv_idxs `thenNF_Tc` \ arg_tys -> + newTyVarTys (length tv_idxs) openTypeKind `thenNF_Tc` \ arg_tys -> tcMonoExprs args arg_tys `thenTc` \ (args', args_lie) -> - -- The argument types can be unboxed or boxed; the result - -- type must, however, be boxed since it's an argument to the IO + -- The argument types can be unlifted or lifted; the result + -- type must, however, be lifted since it's an argument to the IO -- type constructor. - newTyVarTy boxedTypeKind `thenNF_Tc` \ result_ty -> + newTyVarTy liftedTypeKind `thenNF_Tc` \ result_ty -> let io_result_ty = mkTyConApp ioTyCon [result_ty] - [ioDataCon] = tyConDataCons ioTyCon in unifyTauTy res_ty io_result_ty `thenTc_` @@ -390,9 +306,7 @@ tcMonoExpr (CCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty -- constraints on the argument and result types. mapNF_Tc new_arg_dict (zipEqual "tcMonoExpr:CCall" args arg_tys) `thenNF_Tc` \ ccarg_dicts_s -> newClassDicts result_origin [(cReturnableClass, [result_ty])] `thenNF_Tc` \ (ccres_dict, _) -> - returnTc (HsApp (HsVar (dataConId ioDataCon) `TyApp` [result_ty]) - (CCall lbl args' may_gc is_asm result_ty), - -- do the wrapping in the newtype constructor here + returnTc (HsCCall lbl args' may_gc is_asm io_result_ty, foldr plusLIE ccres_dict ccarg_dicts_s `plusLIE` args_lie) \end{code} @@ -464,28 +378,26 @@ tcMonoExpr in_expr@(ExplicitList exprs) res_ty -- Non-empty list = tcAddErrCtxt (listCtxt expr) $ tcMonoExpr expr elt_ty -tcMonoExpr (ExplicitTuple exprs boxed) res_ty - = (if boxed - then unifyTupleTy (length exprs) res_ty - else unifyUnboxedTupleTy (length exprs) res_ty - ) `thenTc` \ arg_tys -> +tcMonoExpr (ExplicitTuple exprs boxity) res_ty + = unifyTupleTy boxity (length exprs) res_ty `thenTc` \ arg_tys -> mapAndUnzipTc (\ (expr, arg_ty) -> tcMonoExpr expr arg_ty) (exprs `zip` arg_tys) -- we know they're of equal length. `thenTc` \ (exprs', lies) -> - returnTc (ExplicitTuple exprs' boxed, plusLIEs lies) + returnTc (ExplicitTuple exprs' boxity, plusLIEs lies) tcMonoExpr expr@(RecordCon con_name rbinds) res_ty = tcAddErrCtxt (recordConCtxt expr) $ tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) -> let (_, record_ty) = splitFunTys con_tau + (tycon, ty_args, _) = splitAlgTyConApp record_ty in - -- Con is syntactically constrained to be a data constructor ASSERT( maybeToBool (splitAlgTyConApp_maybe record_ty ) ) unifyTauTy res_ty record_ty `thenTc_` -- Check that the record bindings match the constructor - tcLookupDataCon con_name `thenTc` \ (data_con, _, _) -> + -- con_name is syntactically constrained to be a data constructor + tcLookupDataCon con_name `thenTc` \ data_con -> let bad_fields = badFields rbinds data_con in @@ -495,7 +407,7 @@ tcMonoExpr expr@(RecordCon con_name rbinds) res_ty else -- Typecheck the record bindings - tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> + tcRecordBinds tycon ty_args rbinds `thenTc` \ (rbinds', rbinds_lie) -> let missing_s_fields = missingStrictFields rbinds data_con @@ -506,7 +418,8 @@ tcMonoExpr expr@(RecordCon con_name rbinds) res_ty let missing_fields = missingFields rbinds data_con in - checkTcM (not (opt_WarnMissingFields && not (null missing_fields))) + doptsTc Opt_WarnMissingFields `thenNF_Tc` \ warn -> + checkTcM (not (warn && not (null missing_fields))) (mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_` returnNF_Tc ()) `thenNF_Tc_` @@ -547,28 +460,26 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty let field_names = [field_name | (field_name, _, _) <- rbinds] in - mapNF_Tc tcLookupValueMaybe field_names `thenNF_Tc` \ maybe_sel_ids -> + mapNF_Tc tcLookupGlobal_maybe field_names `thenNF_Tc` \ maybe_sel_ids -> let - bad_guys = [field_name | (field_name, maybe_sel_id) <- field_names `zip` maybe_sel_ids, - case maybe_sel_id of - Nothing -> True - Just sel_id -> not (isRecordSelector sel_id) + bad_guys = [ addErrTc (notSelector field_name) + | (field_name, maybe_sel_id) <- field_names `zip` maybe_sel_ids, + case maybe_sel_id of + Just (AnId sel_id) -> not (isRecordSelector sel_id) + other -> True ] in - mapNF_Tc (addErrTc . notSelector) bad_guys `thenTc_` - if not (null bad_guys) then - failTc - else + checkTcM (null bad_guys) (listNF_Tc bad_guys `thenNF_Tc_` failTc) `thenTc_` -- STEP 1 -- Figure out the tycon and data cons from the first field name let - (Just sel_id : _) = maybe_sel_ids - (_, tau) = ASSERT( isNotUsgTy (idType sel_id) ) - splitForAllTys (idType sel_id) + (Just (AnId sel_id) : _) = maybe_sel_ids + (_, _, tau) = splitSigmaTy (idType sel_id) -- Selectors can be overloaded + -- when the data type has a context Just (data_ty, _) = splitFunTy_maybe tau -- Must succeed since sel_id is a selector - (tycon, _, data_cons) = splitAlgTyConApp data_ty - (con_tyvars, theta, _, _, _, _) = dataConSig (head data_cons) + (tycon, _, data_cons) = splitAlgTyConApp data_ty + (con_tyvars, _, _, _, _, _) = dataConSig (head data_cons) in tcInstTyVars con_tyvars `thenNF_Tc` \ (_, result_inst_tys, _) -> @@ -586,7 +497,7 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty result_record_ty = mkTyConApp tycon result_inst_tys in unifyTauTy res_ty result_record_ty `thenTc_` - tcRecordBinds result_record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> + tcRecordBinds tycon result_inst_tys rbinds `thenTc` \ (rbinds', rbinds_lie) -> -- STEP 4 -- Use the un-updated fields to find a vector of booleans saying @@ -608,7 +519,7 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty mk_inst_ty (tyvar, result_inst_ty) | tyvar `elemVarSet` common_tyvars = returnNF_Tc result_inst_ty -- Same as result type - | otherwise = newTyVarTy boxedTypeKind -- Fresh type + | otherwise = newTyVarTy liftedTypeKind -- Fresh type in mapNF_Tc mk_inst_ty (zip con_tyvars result_inst_tys) `thenNF_Tc` \ inst_tys -> @@ -643,7 +554,7 @@ tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty = unifyListTy res_ty `thenTc` \ elt_ty -> tcMonoExpr expr elt_ty `thenTc` \ (expr', lie1) -> - tcLookupValueByKey enumFromClassOpKey `thenNF_Tc` \ sel_id -> + tcLookupGlobalId enumFromName `thenNF_Tc` \ sel_id -> newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie2, enum_from_id) -> @@ -652,12 +563,11 @@ tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ - unifyListTy res_ty `thenTc` \ elt_ty -> - tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> - tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> - tcLookupValueByKey enumFromThenClassOpKey `thenNF_Tc` \ sel_id -> - newMethod (ArithSeqOrigin seq) - sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_then_id) -> + unifyListTy res_ty `thenTc` \ elt_ty -> + tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> + tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> + tcLookupGlobalId enumFromThenName `thenNF_Tc` \ sel_id -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_then_id) -> returnTc (ArithSeqOut (HsVar enum_from_then_id) (FromThen expr1' expr2'), @@ -665,12 +575,11 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_ty tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ - unifyListTy res_ty `thenTc` \ elt_ty -> - tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> - tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> - tcLookupValueByKey enumFromToClassOpKey `thenNF_Tc` \ sel_id -> - newMethod (ArithSeqOrigin seq) - sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_to_id) -> + unifyListTy res_ty `thenTc` \ elt_ty -> + tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> + tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> + tcLookupGlobalId enumFromToName `thenNF_Tc` \ sel_id -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_to_id) -> returnTc (ArithSeqOut (HsVar enum_from_to_id) (FromTo expr1' expr2'), @@ -678,13 +587,12 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_ty tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ - unifyListTy res_ty `thenTc` \ elt_ty -> - tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> - tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> - tcMonoExpr expr3 elt_ty `thenTc` \ (expr3',lie3) -> - tcLookupValueByKey enumFromThenToClassOpKey `thenNF_Tc` \ sel_id -> - newMethod (ArithSeqOrigin seq) - sel_id [elt_ty] `thenNF_Tc` \ (lie4, eft_id) -> + unifyListTy res_ty `thenTc` \ elt_ty -> + tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) -> + tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) -> + tcMonoExpr expr3 elt_ty `thenTc` \ (expr3',lie3) -> + tcLookupGlobalId enumFromThenToName `thenNF_Tc` \ sel_id -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie4, eft_id) -> returnTc (ArithSeqOut (HsVar eft_id) (FromThenTo expr1' expr2' expr3'), @@ -700,9 +608,9 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty \begin{code} tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty = tcSetErrCtxt (exprSigCtxt in_expr) $ - tcHsType poly_ty `thenTc` \ sig_tc_ty -> + tcHsSigType poly_ty `thenTc` \ sig_tc_ty -> - if not (isForAllTy sig_tc_ty) then + if not (isSigmaTy sig_tc_ty) then -- Easy case unifyTauTy sig_tc_ty res_ty `thenTc_` tcMonoExpr expr sig_tc_ty @@ -731,22 +639,29 @@ Implicit Parameter bindings. tcMonoExpr (HsWith expr binds) res_ty = tcMonoExpr expr res_ty `thenTc` \ (expr', lie) -> tcIPBinds binds `thenTc` \ (binds', types, lie2) -> - partitionLIEbyMeth isBound lie `thenTc` \ (ips, lie') -> - zonkLIE ips `thenTc` \ ips' -> - tcSimplify (text "With!") (tyVarsOfLIE ips') ips' `thenTc` \ res@(_, dict_binds, _) -> + partitionPredsOfLIE isBound lie `thenTc` \ (ips, lie', dict_binds) -> let expr'' = if nullMonoBinds dict_binds then expr' - else HsLet (MonoBind dict_binds [] NonRecursive) expr' in - tcCheckIPBinds binds' types ips' `thenTc_` + else HsLet (mkMonoBind (revBinds dict_binds) [] NonRecursive) + expr' + in + tcCheckIPBinds binds' types ips `thenTc_` returnTc (HsWith expr'' binds', lie' `plusLIE` lie2) where isBound p = case ipName_maybe p of Just n -> n `elem` names Nothing -> False names = map fst binds + -- revBinds is used because tcSimplify outputs the bindings + -- out-of-order. it's not a problem elsewhere because these + -- bindings are normally used in a recursive let + -- ZZ probably need to find a better solution + revBinds (b1 `AndMonoBinds` b2) = + (revBinds b2) `AndMonoBinds` (revBinds b1) + revBinds b = b tcIPBinds ((name, expr) : binds) - = newTyVarTy_OpenKind `thenTc` \ ty -> + = newTyVarTy openTypeKind `thenTc` \ ty -> tcGetSrcLoc `thenTc` \ loc -> let id = ipToId name ty loc in tcMonoExpr expr ty `thenTc` \ (expr', lie) -> @@ -774,14 +689,14 @@ Typecheck expression which in most cases will be an Id. \begin{code} tcExpr_id :: RenamedHsExpr - -> TcM s (TcExpr, + -> TcM (TcExpr, LIE, TcType) tcExpr_id id_expr = case id_expr of HsVar name -> tcId name `thenNF_Tc` \ stuff -> returnTc stuff - other -> newTyVarTy_OpenKind `thenNF_Tc` \ id_ty -> + other -> newTyVarTy openTypeKind `thenNF_Tc` \ id_ty -> tcMonoExpr id_expr id_ty `thenTc` \ (id_expr', lie_id) -> returnTc (id_expr', lie_id, id_ty) \end{code} @@ -796,7 +711,7 @@ tcExpr_id id_expr tcApp :: RenamedHsExpr -> [RenamedHsExpr] -- Function and args -> TcType -- Expected result type of application - -> TcM s (TcExpr, [TcExpr], -- Translated fun and args + -> TcM (TcExpr, [TcExpr], -- Translated fun and args LIE) tcApp fun args res_ty @@ -820,7 +735,7 @@ tcApp fun args res_ty -- Check that the result type doesn't have any nested for-alls. -- For example, a "build" on its own is no good; it must be applied to something. checkTc (isTauTy actual_result_ty) - (lurkingRank2Err fun fun_ty) `thenTc_` + (lurkingRank2Err fun actual_result_ty) `thenTc_` returnTc (fun', args', lie_fun `plusLIE` plusLIEs lie_args_s) @@ -846,7 +761,7 @@ checkArgsCtxt fun args expected_res_ty actual_res_ty tidy_env split_fun_ty :: TcType -- The type of the function -> Int -- Number of arguments - -> TcM s ([TcType], -- Function argument types + -> TcM ([TcType], -- Function argument types TcType) -- Function result types split_fun_ty fun_ty 0 @@ -862,7 +777,7 @@ split_fun_ty fun_ty n \begin{code} tcArg :: RenamedHsExpr -- The function (for error messages) -> (RenamedHsExpr, TcType, Int) -- Actual argument and expected arg type - -> TcM s (TcExpr, LIE) -- Resulting argument and LIE + -> TcM (TcExpr, LIE) -- Resulting argument and LIE tcArg the_fun (arg, expected_arg_ty, arg_no) = tcAddErrCtxt (funAppCtxt the_fun arg arg_no) $ @@ -876,26 +791,16 @@ tcArg the_fun (arg, expected_arg_ty, arg_no) %* * %************************************************************************ -Between the renamer and the first invocation of the UsageSP inference, -identifiers read from interface files will have usage information in -their types, whereas other identifiers will not. The unannotTy here -in @tcId@ prevents this information from pointlessly propagating -further prior to the first usage inference. - \begin{code} -tcId :: Name -> NF_TcM s (TcExpr, LIE, TcType) +tcId :: Name -> NF_TcM (TcExpr, LIE, TcType) tcId name = -- Look up the Id and instantiate its type - tcLookupValueMaybe name `thenNF_Tc` \ maybe_local -> - - case maybe_local of - Just tc_id -> instantiate_it (OccurrenceOf tc_id) (HsVar tc_id) (unannotTy (idType tc_id)) - - Nothing -> tcLookupValue name `thenNF_Tc` \ id -> - tcInstId id `thenNF_Tc` \ (tyvars, theta, tau) -> - instantiate_it2 (OccurrenceOf id) (HsVar id) tyvars theta tau - + tcLookup name `thenNF_Tc` \ thing -> + case thing of + ATcId tc_id -> instantiate_it (OccurrenceOf tc_id) tc_id (idType tc_id) + AGlobal (AnId id) -> tcInstId id `thenNF_Tc` \ (tyvars, theta, tau) -> + instantiate_it2 (OccurrenceOf id) id tyvars theta tau where -- The instantiate_it loop runs round instantiating the Id. -- It has to be a loop because we are now prepared to entertain @@ -910,7 +815,7 @@ tcId name instantiate_it2 orig fun tyvars theta tau = if null theta then -- Is it overloaded? - returnNF_Tc (mkHsTyApp fun arg_tys, emptyLIE, tau) + returnNF_Tc (mkHsTyApp (HsVar fun) arg_tys, emptyLIE, tau) else -- Yes, it's overloaded instOverloadedFun orig fun arg_tys theta tau `thenNF_Tc` \ (fun', lie1) -> @@ -934,8 +839,8 @@ tcDoStmts do_or_lc stmts src_loc res_ty ASSERT( not (null stmts) ) tcAddSrcLoc src_loc $ - newTyVarTy (mkArrowKind boxedTypeKind boxedTypeKind) `thenNF_Tc` \ m -> - newTyVarTy boxedTypeKind `thenNF_Tc` \ elt_ty -> + newTyVarTy (mkArrowKind liftedTypeKind liftedTypeKind) `thenNF_Tc` \ m -> + newTyVarTy liftedTypeKind `thenNF_Tc` \ elt_ty -> unifyTauTy res_ty (mkAppTy m elt_ty) `thenTc_` -- If it's a comprehension we're dealing with, @@ -945,7 +850,7 @@ tcDoStmts do_or_lc stmts src_loc res_ty ListComp -> unifyListTy res_ty `thenTc_` returnTc () _ -> returnTc ()) `thenTc_` - tcStmts do_or_lc (mkAppTy m) stmts elt_ty `thenTc` \ (stmts', stmts_lie) -> + tcStmts do_or_lc (mkAppTy m) elt_ty src_loc stmts `thenTc` \ ((stmts', _), stmts_lie) -> -- Build the then and zero methods in case we need them -- It's important that "then" and "return" appear just once in the final LIE, @@ -955,9 +860,9 @@ tcDoStmts do_or_lc stmts src_loc res_ty -- then = then -- where the second "then" sees that it already exists in the "available" stuff. -- - tcLookupValueByKey returnMClassOpKey `thenNF_Tc` \ return_sel_id -> - tcLookupValueByKey thenMClassOpKey `thenNF_Tc` \ then_sel_id -> - tcLookupValueByKey failMClassOpKey `thenNF_Tc` \ fail_sel_id -> + tcLookupGlobalId returnMName `thenNF_Tc` \ return_sel_id -> + tcLookupGlobalId thenMName `thenNF_Tc` \ then_sel_id -> + tcLookupGlobalId failMName `thenNF_Tc` \ fail_sel_id -> newMethod DoOrigin return_sel_id [m] `thenNF_Tc` \ (return_lie, return_id) -> newMethod DoOrigin then_sel_id [m] `thenNF_Tc` \ (then_lie, then_id) -> newMethod DoOrigin fail_sel_id [m] `thenNF_Tc` \ (fail_lie, fail_id) -> @@ -977,54 +882,50 @@ tcDoStmts do_or_lc stmts src_loc res_ty Game plan for record bindings ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -For each binding - field = value -1. look up "field", to find its selector Id, which must have type - forall a1..an. T a1 .. an -> tau - where tau is the type of the field. +1. Find the TyCon for the bindings, from the first field label. -2. Instantiate this type +2. Instantiate its tyvars and unify (T a1 .. an) with expected_ty. -3. Unify the (T a1 .. an) part with the "expected result type", which - is passed in. This checks that all the field labels come from the - same type. +For each binding field = value -4. Type check the value using tcArg, passing tau as the expected - argument type. +3. Instantiate the field type (from the field label) using the type + envt from step 2. + +4 Type check the value using tcArg, passing the field type as + the expected argument type. This extends OK when the field types are universally quantified. -Actually, to save excessive creation of fresh type variables, -we \begin{code} tcRecordBinds - :: TcType -- Expected type of whole record + :: TyCon -- Type constructor for the record + -> [TcType] -- Args of this type constructor -> RenamedRecordBinds - -> TcM s (TcRecordBinds, LIE) + -> TcM (TcRecordBinds, LIE) -tcRecordBinds expected_record_ty rbinds +tcRecordBinds tycon ty_args rbinds = mapAndUnzipTc do_bind rbinds `thenTc` \ (rbinds', lies) -> returnTc (rbinds', plusLIEs lies) where - do_bind (field_label, rhs, pun_flag) - = tcLookupValue field_label `thenNF_Tc` \ sel_id -> + tenv = mkTopTyVarSubst (tyConTyVars tycon) ty_args + + do_bind (field_lbl_name, rhs, pun_flag) + = tcLookupGlobalId field_lbl_name `thenNF_Tc` \ sel_id -> + let + field_lbl = recordSelectorFieldLabel sel_id + field_ty = substTy tenv (fieldLabelType field_lbl) + in ASSERT( isRecordSelector sel_id ) -- This lookup and assertion will surely succeed, because -- we check that the fields are indeed record selectors -- before calling tcRecordBinds + ASSERT2( fieldLabelTyCon field_lbl == tycon, ppr field_lbl ) + -- The caller of tcRecordBinds has already checked + -- that all the fields come from the same type - tcInstId sel_id `thenNF_Tc` \ (_, _, tau) -> + tcPolyExpr rhs field_ty `thenTc` \ (rhs', lie, _, _, _) -> - -- Record selectors all have type - -- forall a1..an. T a1 .. an -> tau - ASSERT( maybeToBool (splitFunTy_maybe tau) ) - let - -- Selector must have type RecordType -> FieldType - Just (record_ty, field_ty) = splitFunTy_maybe tau - in - unifyTauTy expected_record_ty record_ty `thenTc_` - tcPolyExpr rhs field_ty `thenTc` \ (rhs', lie, _, _, _) -> returnTc ((sel_id, rhs', pun_flag), lie) badFields rbinds data_con @@ -1072,7 +973,7 @@ missingFields rbinds data_con %************************************************************************ \begin{code} -tcMonoExprs :: [RenamedHsExpr] -> [TcType] -> TcM s ([TcExpr], LIE) +tcMonoExprs :: [RenamedHsExpr] -> [TcType] -> TcM ([TcExpr], LIE) tcMonoExprs [] [] = returnTc ([], emptyLIE) tcMonoExprs (expr:exprs) (ty:tys) @@ -1082,12 +983,36 @@ tcMonoExprs (expr:exprs) (ty:tys) \end{code} -% ================================================= +%************************************************************************ +%* * +\subsection{Literals} +%* * +%************************************************************************ + +Overloaded literals. + +\begin{code} +tcLit :: HsLit -> TcType -> TcM (TcExpr, LIE) +tcLit (HsLitLit s _) res_ty + = tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass -> + newClassDicts (LitLitOrigin (_UNPK_ s)) + [(cCallableClass,[res_ty])] `thenNF_Tc` \ (dicts, _) -> + returnTc (HsLit (HsLitLit s res_ty), dicts) + +tcLit lit res_ty + = unifyTauTy res_ty (simpleHsLitTy lit) `thenTc_` + returnTc (HsLit lit, emptyLIE) +\end{code} + -Errors and contexts -~~~~~~~~~~~~~~~~~~~ +%************************************************************************ +%* * +\subsection{Errors and contexts} +%* * +%************************************************************************ Mini-utils: + \begin{code} pp_nest_hang :: String -> SDoc -> SDoc pp_nest_hang lbl stuff = nest 2 (hang (text lbl) 4 stuff) @@ -1141,10 +1066,7 @@ appCtxt fun args lurkingRank2Err fun fun_ty = hang (hsep [ptext SLIT("Illegal use of"), quotes (ppr fun)]) 4 (vcat [ptext SLIT("It is applied to too few arguments"), - ptext SLIT("so that the result type has for-alls in it")]) - -rank2ArgCtxt arg expected_arg_ty - = ptext SLIT("In a polymorphic function argument:") <+> ppr arg + ptext SLIT("so that the result type has for-alls in it:") <+> ppr fun_ty]) badFieldsUpd rbinds = hang (ptext SLIT("No constructor has all these fields:")) @@ -1158,15 +1080,6 @@ recordConCtxt expr = ptext SLIT("In the record construction:") <+> ppr expr notSelector field = hsep [quotes (ppr field), ptext SLIT("is not a record selector")] -illegalCcallTyErr isArg ty - = hang (hsep [ptext SLIT("Unacceptable"), arg_or_res, ptext SLIT("type in _ccall_ or _casm_:")]) - 4 (hsep [ppr ty]) - where - arg_or_res - | isArg = ptext SLIT("argument") - | otherwise = ptext SLIT("result") - - missingStrictFieldCon :: Name -> Name -> SDoc missingStrictFieldCon con field = hsep [ptext SLIT("Constructor") <+> quotes (ppr con),