X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcExpr.lhs;h=cb57efdc2868e993e3f00978abc040d958eca901;hb=d75105426df54cf78cf5827ed307a64b51a0f428;hp=65c328c7667aab61797a9e60da19ef0ab76acfb4;hpb=ea659be5faea43df1b2c113d2f22947dff23367e;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs index 65c328c..cb57efd 100644 --- a/ghc/compiler/typecheck/TcExpr.lhs +++ b/ghc/compiler/typecheck/TcExpr.lhs @@ -9,65 +9,58 @@ module TcExpr ( tcApp, tcExpr, tcMonoExpr, tcPolyExpr, tcId ) where #include "HsVersions.h" import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..), - MonoBinds(..), StmtCtxt(..), - mkMonoBind, nullMonoBinds + HsMatchContext(..), HsDoContext(..), mkMonoBind ) import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds ) -import TcHsSyn ( TcExpr, TcRecordBinds, mkHsTyApp, mkHsLet ) +import TcHsSyn ( TcExpr, TcRecordBinds, mkHsLet ) import TcMonad -import BasicTypes ( RecFlag(..) ) - +import BasicTypes ( RecFlag(..), isMarkedStrict ) import Inst ( InstOrigin(..), - LIE, emptyLIE, unitLIE, plusLIE, plusLIEs, + LIE, mkLIE, emptyLIE, unitLIE, plusLIE, plusLIEs, newOverloadedLit, newMethod, newIPDict, - instOverloadedFun, newDicts, newClassDicts, - getIPsOfLIE, instToId, ipToId + newDicts, + instToId, tcInstId ) import TcBinds ( tcBindsAndThen ) -import TcEnv ( TcTyThing(..), tcInstId, - tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe, - tcLookupTyCon, tcLookupDataCon, tcLookup, +import TcEnv ( tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe, + tcLookupTyCon, tcLookupDataCon, tcLookupId, tcExtendGlobalTyVars ) import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts ) -import TcMonoType ( tcHsSigType, checkSigTyVars, sigCtxt ) +import TcMonoType ( tcHsSigType, UserTypeCtxt(..), checkSigTyVars, sigCtxt ) import TcPat ( badFieldCon, simpleHsLitTy ) -import TcSimplify ( tcSimplifyAndCheck, partitionPredsOfLIE ) -import TcImprove ( tcImprove ) -import TcType ( TcType, TcTauType, - tcInstTyVars, - tcInstTcType, tcSplitRhoTy, - newTyVarTy, newTyVarTys, zonkTcType ) - -import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon ) -import Id ( idType, recordSelectorFieldLabel, isRecordSelector, mkVanillaId ) -import DataCon ( dataConFieldLabels, dataConSig, - dataConStrictMarks, StrictnessMark(..) +import TcSimplify ( tcSimplifyCheck, tcSimplifyIPs ) +import TcMType ( tcInstTyVars, tcInstType, + newTyVarTy, newTyVarTys, zonkTcType, + unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy ) -import Name ( Name, getName ) -import Type ( mkFunTy, mkAppTy, mkTyVarTys, ipName_maybe, - splitFunTy_maybe, splitFunTys, - mkTyConApp, splitSigmaTy, - splitRhoTy, +import TcType ( tcSplitFunTys, tcSplitTyConApp, + isQualifiedTy, + mkFunTy, mkAppTy, mkTyConTy, + mkTyConApp, mkClassPred, tcFunArgTy, isTauTy, tyVarsOfType, tyVarsOfTypes, - isSigmaTy, splitAlgTyConApp, splitAlgTyConApp_maybe, - boxedTypeKind, openTypeKind, mkArrowKind, + liftedTypeKind, openTypeKind, mkArrowKind, + tcSplitSigmaTy, tcTyConAppTyCon, tidyOpenType ) -import TyCon ( TyCon, tyConTyVars ) -import Subst ( mkTopTyVarSubst, substClasses, substTy ) -import VarSet ( elemVarSet, mkVarSet ) -import TysWiredIn ( boolTy ) -import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy ) +import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType, fieldLabelTyCon ) +import Id ( idType, recordSelectorFieldLabel, isRecordSelector ) +import DataCon ( dataConFieldLabels, dataConSig, + dataConStrictMarks + ) +import Name ( Name ) +import TyCon ( TyCon, tyConTyVars, isAlgTyCon, tyConDataCons ) +import Subst ( mkTopTyVarSubst, substTheta, substTy ) +import VarSet ( elemVarSet ) +import TysWiredIn ( boolTy, mkListTy, listTyCon ) import PrelNames ( cCallableClassName, cReturnableClassName, - enumFromName, enumFromThenName, + enumFromName, enumFromThenName, enumFromToName, enumFromThenToName, thenMName, failMName, returnMName, ioTyConName ) import Outputable -import Maybes ( maybeToBool, mapMaybe ) import ListSetOps ( minusList ) import Util import CmdLineOpts @@ -86,12 +79,12 @@ tcExpr :: RenamedHsExpr -- Expession to type check -> TcType -- Expected type (could be a polytpye) -> TcM (TcExpr, LIE) -tcExpr expr ty | isSigmaTy ty = -- Polymorphic case - tcPolyExpr expr ty `thenTc` \ (expr', lie, _, _, _) -> - returnTc (expr', lie) +tcExpr expr ty | isQualifiedTy 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} @@ -115,10 +108,9 @@ tcPolyExpr arg expected_arg_ty -- To ensure that the forall'd type variables don't get unified with each -- other or any other types, we make fresh copy of the alleged type - tcInstTcType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_rho) -> + tcInstType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_theta, sig_tau) -> let - (sig_theta, sig_tau) = splitRhoTy sig_rho - free_tyvars = tyVarsOfType expected_arg_ty + free_tvs = tyVarsOfType expected_arg_ty in -- Type-check the arg and unify with expected type tcMonoExpr arg sig_tau `thenTc` \ (arg', lie_arg) -> @@ -134,25 +126,23 @@ 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 free_tyvars $ + tcExtendGlobalTyVars free_tvs $ tcAddErrCtxtM (sigCtxt sig_msg sig_tyvars sig_theta sig_tau) $ - 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 + newDicts SignatureOrigin sig_theta `thenNF_Tc` \ sig_dicts -> + tcSimplifyCheck (text "the type signature of an expression") - (mkVarSet zonked_sig_tyvars) + sig_tyvars sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) -> + checkSigTyVars sig_tyvars free_tvs `thenTc` \ zonked_sig_tyvars -> + let -- This HsLet binds any Insts which came out of the simplification. -- It's a bit out of place here, but using AbsBind involves inventing -- a couple of new names which seems worse. generalised_arg = TyLam zonked_sig_tyvars $ - DictLam dict_ids $ + DictLam (map instToId sig_dicts) $ mkHsLet inst_binds $ arg' in @@ -188,10 +178,7 @@ tcMonoExpr (HsVar name) res_ty \begin{code} tcMonoExpr (HsIPVar name) res_ty - -- ZZ What's the `id' used for here... - = let id = mkVanillaId name res_ty in - tcGetInstLoc (OccurrenceOf id) `thenNF_Tc` \ loc -> - newIPDict name res_ty loc `thenNF_Tc` \ ip -> + = newIPDict (IPOcc name) name res_ty `thenNF_Tc` \ ip -> returnNF_Tc (HsIPVar (instToId ip), unitLIE ip) \end{code} @@ -206,8 +193,8 @@ 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 -tcMonoExpr (NegApp expr neg) res_ty - = tcMonoExpr (HsApp (HsVar neg) expr) res_ty +tcMonoExpr (NegApp expr neg_name) res_ty + = tcMonoExpr (HsApp (HsVar neg_name) expr) res_ty tcMonoExpr (HsLam match) res_ty = tcMatchLambda match res_ty `thenTc` \ (match',lie) -> @@ -271,15 +258,25 @@ arg/result types); unify them with the args/result; and store them for later use. \begin{code} -tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty - = -- Get the callable and returnable classes. +tcMonoExpr e0@(HsCCall lbl args may_gc is_casm ignored_fake_result_ty) res_ty + + = getDOptsTc `thenNF_Tc` \ dflags -> + + checkTc (not (is_casm && dopt_HscLang dflags /= HscC)) + (vcat [text "_casm_ is only supported when compiling via C (-fvia-C).", + text "Either compile with -fvia-C, or, better, rewrite your code", + text "to use the foreign function interface. _casm_s are deprecated", + text "and support for them may one day disappear."]) + `thenTc_` + + -- Get the callable and returnable classes. 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)) - [(cCallableClass, [arg_ty])] `thenNF_Tc` \ (arg_dicts, _) -> + = newDicts (CCallOrigin (_UNPK_ lbl) (Just arg)) + [mkClassPred cCallableClass [arg_ty]] `thenNF_Tc` \ arg_dicts -> returnNF_Tc arg_dicts -- Actually a singleton bag result_origin = CCallOrigin (_UNPK_ lbl) Nothing {- Not an arg -} @@ -293,10 +290,10 @@ tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty 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] in @@ -305,9 +302,9 @@ tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty -- Construct the extra insts, which encode the -- 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 (HsCCall lbl args' may_gc is_asm io_result_ty, - foldr plusLIE ccres_dict ccarg_dicts_s `plusLIE` args_lie) + newDicts result_origin [mkClassPred cReturnableClass [result_ty]] `thenNF_Tc` \ ccres_dict -> + returnTc (HsCCall lbl args' may_gc is_casm io_result_ty, + mkLIE (ccres_dict ++ concat ccarg_dicts_s) `plusLIE` args_lie) \end{code} \begin{code} @@ -369,10 +366,10 @@ tcMonoExpr expr@(HsDo do_or_lc stmts src_loc) res_ty \end{code} \begin{code} -tcMonoExpr in_expr@(ExplicitList exprs) res_ty -- Non-empty list +tcMonoExpr in_expr@(ExplicitList _ exprs) res_ty -- Non-empty list = unifyListTy res_ty `thenTc` \ elt_ty -> mapAndUnzipTc (tc_elt elt_ty) exprs `thenTc` \ (exprs', lies) -> - returnTc (ExplicitListOut elt_ty exprs', plusLIEs lies) + returnTc (ExplicitList elt_ty exprs', plusLIEs lies) where tc_elt elt_ty expr = tcAddErrCtxt (listCtxt expr) $ @@ -389,10 +386,10 @@ 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 + (_, record_ty) = tcSplitFunTys con_tau + (tycon, ty_args) = tcSplitTyConApp record_ty in - ASSERT( maybeToBool (splitAlgTyConApp_maybe record_ty ) ) + ASSERT( isAlgTyCon tycon ) unifyTauTy res_ty record_ty `thenTc_` -- Check that the record bindings match the constructor @@ -410,14 +407,11 @@ tcMonoExpr expr@(RecordCon con_name rbinds) res_ty tcRecordBinds tycon ty_args rbinds `thenTc` \ (rbinds', rbinds_lie) -> let - missing_s_fields = missingStrictFields rbinds data_con + (missing_s_fields, missing_fields) = missingFields rbinds data_con in checkTcM (null missing_s_fields) (mapNF_Tc (addErrTc . missingStrictFieldCon con_name) missing_s_fields `thenNF_Tc_` returnNF_Tc ()) `thenNF_Tc_` - let - missing_fields = missingFields rbinds data_con - in doptsTc Opt_WarnMissingFields `thenNF_Tc` \ warn -> checkTcM (not (warn && not (null missing_fields))) (mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_` @@ -474,11 +468,13 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty -- STEP 1 -- Figure out the tycon and data cons from the first field name let - (Just (AnId sel_id) : _) = maybe_sel_ids - (_, _, tau) = splitSigmaTy (idType sel_id) -- Selectors can be overloaded + -- It's OK to use the non-tc splitters here (for a selector) + (Just (AnId sel_id) : _) = maybe_sel_ids + (_, _, tau) = tcSplitSigmaTy (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 + data_ty = tcFunArgTy tau -- Must succeed since sel_id is a selector + tycon = tcTyConAppTyCon data_ty + data_cons = tyConDataCons tycon (con_tyvars, _, _, _, _, _) = dataConSig (head data_cons) in tcInstTyVars con_tyvars `thenNF_Tc` \ (_, result_inst_tys, _) -> @@ -519,7 +515,7 @@ 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 -> @@ -542,13 +538,13 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty let (tyvars, theta, _, _, _, _) = dataConSig (head data_cons) inst_env = mkTopTyVarSubst tyvars result_inst_tys - theta' = substClasses inst_env theta + theta' = substTheta inst_env theta in - newClassDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) -> + newDicts RecordUpdOrigin theta' `thenNF_Tc` \ dicts -> -- Phew! - returnTc (RecordUpdOut record_expr' result_record_ty dicts rbinds', - con_lie `plusLIE` record_lie `plusLIE` rbinds_lie) + returnTc (RecordUpdOut record_expr' record_ty result_record_ty (map instToId dicts) rbinds', + mkLIE dicts `plusLIE` record_lie `plusLIE` rbinds_lie) tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty = unifyListTy res_ty `thenTc` \ elt_ty -> @@ -556,10 +552,10 @@ tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty tcLookupGlobalId enumFromName `thenNF_Tc` \ sel_id -> newMethod (ArithSeqOrigin seq) - sel_id [elt_ty] `thenNF_Tc` \ (lie2, enum_from_id) -> + sel_id [elt_ty] `thenNF_Tc` \ enum_from -> - returnTc (ArithSeqOut (HsVar enum_from_id) (From expr'), - lie1 `plusLIE` lie2) + returnTc (ArithSeqOut (HsVar (instToId enum_from)) (From expr'), + lie1 `plusLIE` unitLIE enum_from) tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ @@ -567,11 +563,11 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_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) -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ enum_from_then -> - returnTc (ArithSeqOut (HsVar enum_from_then_id) - (FromThen expr1' expr2'), - lie1 `plusLIE` lie2 `plusLIE` lie3) + returnTc (ArithSeqOut (HsVar (instToId enum_from_then)) + (FromThen expr1' expr2'), + lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_then) tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ @@ -579,11 +575,11 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_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) -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ enum_from_to -> - returnTc (ArithSeqOut (HsVar enum_from_to_id) + returnTc (ArithSeqOut (HsVar (instToId enum_from_to)) (FromTo expr1' expr2'), - lie1 `plusLIE` lie2 `plusLIE` lie3) + lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_to) tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty = tcAddErrCtxt (arithSeqCtxt in_expr) $ @@ -592,11 +588,11 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty 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) -> + newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ eft -> - returnTc (ArithSeqOut (HsVar eft_id) - (FromThenTo expr1' expr2' expr3'), - lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` lie4) + returnTc (ArithSeqOut (HsVar (instToId eft)) + (FromThenTo expr1' expr2' expr3'), + lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` unitLIE eft) \end{code} %************************************************************************ @@ -607,10 +603,10 @@ 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) $ - tcHsSigType poly_ty `thenTc` \ sig_tc_ty -> + = tcHsSigType ExprSigCtxt poly_ty `thenTc` \ sig_tc_ty -> - if not (isSigmaTy sig_tc_ty) then + tcAddErrCtxt (exprSigCtxt in_expr) $ + if not (isQualifiedTy sig_tc_ty) then -- Easy case unifyTauTy sig_tc_ty res_ty `thenTc_` tcMonoExpr expr sig_tc_ty @@ -627,7 +623,7 @@ tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty -- If everything is ok, return the stuff unchanged, except for -- the effect of any substutions etc. We simply discard the - -- result of the tcSimplifyAndCheck (inside tcPolyExpr), except for any default + -- result of the tcSimplifyCheck (inside tcPolyExpr), except for any default -- resolution it may have done, which is recorded in the -- substitution. returnTc (expr, lie) @@ -637,68 +633,24 @@ Implicit Parameter bindings. \begin{code} tcMonoExpr (HsWith expr binds) res_ty - = tcMonoExpr expr res_ty `thenTc` \ (expr', lie) -> - tcIPBinds binds `thenTc` \ (binds', types, lie2) -> - partitionPredsOfLIE isBound lie `thenTc` \ (ips, lie', dict_binds) -> - let expr'' = if nullMonoBinds dict_binds - then expr' - 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 openTypeKind `thenTc` \ ty -> - tcGetSrcLoc `thenTc` \ loc -> - let id = ipToId name ty loc in - tcMonoExpr expr ty `thenTc` \ (expr', lie) -> - zonkTcType ty `thenTc` \ ty' -> - tcIPBinds binds `thenTc` \ (binds', types, lie2) -> - returnTc ((id, expr') : binds', ty : types, lie `plusLIE` lie2) -tcIPBinds [] = returnTc ([], [], emptyLIE) - -tcCheckIPBinds binds types ips - = foldrTc tcCheckIPBind (getIPsOfLIE ips) (zip binds types) - --- ZZ how do we use the loc? -tcCheckIPBind bt@((v, _), t1) ((n, t2) : ips) | getName v == n - = unifyTauTy t1 t2 `thenTc_` - tcCheckIPBind bt ips `thenTc` \ ips' -> - returnTc ips' -tcCheckIPBind bt (ip : ips) - = tcCheckIPBind bt ips `thenTc` \ ips' -> - returnTc (ip : ips') -tcCheckIPBind bt [] - = returnTc [] -\end{code} - -Typecheck expression which in most cases will be an Id. + = tcMonoExpr expr res_ty `thenTc` \ (expr', expr_lie) -> + mapAndUnzipTc tcIPBind binds `thenTc` \ (pairs, bind_lies) -> -\begin{code} -tcExpr_id :: RenamedHsExpr - -> TcM (TcExpr, - LIE, - TcType) -tcExpr_id id_expr - = case id_expr of - HsVar name -> tcId name `thenNF_Tc` \ stuff -> - returnTc stuff - other -> newTyVarTy openTypeKind `thenNF_Tc` \ id_ty -> - tcMonoExpr id_expr id_ty `thenTc` \ (id_expr', lie_id) -> - returnTc (id_expr', lie_id, id_ty) + -- If the binding binds ?x = E, we must now + -- discharge any ?x constraints in expr_lie + tcSimplifyIPs (map fst pairs) expr_lie `thenTc` \ (expr_lie', dict_binds) -> + let + binds' = [(instToId ip, rhs) | (ip,rhs) <- pairs] + expr'' = HsLet (mkMonoBind dict_binds [] Recursive) expr' + in + returnTc (HsWith expr'' binds', expr_lie' `plusLIE` plusLIEs bind_lies) + +tcIPBind (name, expr) + = newTyVarTy openTypeKind `thenTc` \ ty -> + tcGetSrcLoc `thenTc` \ loc -> + newIPDict (IPBind name) name ty `thenNF_Tc` \ ip -> + tcMonoExpr expr ty `thenTc` \ (expr', lie) -> + returnTc ((ip, expr'), lie) \end{code} %************************************************************************ @@ -749,8 +701,8 @@ checkArgsCtxt fun args expected_res_ty actual_res_ty tidy_env let (env1, exp_ty'') = tidyOpenType tidy_env exp_ty' (env2, act_ty'') = tidyOpenType env1 act_ty' - (exp_args, _) = splitFunTys exp_ty'' - (act_args, _) = splitFunTys act_ty'' + (exp_args, _) = tcSplitFunTys exp_ty'' + (act_args, _) = tcSplitFunTys act_ty'' message | length exp_args < length act_args = wrongArgsCtxt "too few" fun args | length exp_args > length act_args = wrongArgsCtxt "too many" fun args @@ -793,39 +745,22 @@ tcArg the_fun (arg, expected_arg_ty, arg_no) \begin{code} tcId :: Name -> NF_TcM (TcExpr, LIE, TcType) +tcId name -- Look up the Id and instantiate its type + = tcLookupId name `thenNF_Tc` \ id -> + tcInstId id +\end{code} -tcId name - = -- Look up the Id and instantiate its type - 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 - -- types like - -- f:: forall a. Eq a => forall b. Baz b => tau - -- We want to instantiate this to - -- f2::tau {f2 = f1 b (Baz b), f1 = f a (Eq a)} - instantiate_it orig fun ty - = tcInstTcType ty `thenNF_Tc` \ (tyvars, rho) -> - tcSplitRhoTy rho `thenNF_Tc` \ (theta, tau) -> - instantiate_it2 orig fun tyvars theta tau - - instantiate_it2 orig fun tyvars theta tau - = if null theta then -- Is it overloaded? - 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) -> - instantiate_it orig fun' tau `thenNF_Tc` \ (expr, lie2, final_tau) -> - returnNF_Tc (expr, lie1 `plusLIE` lie2, final_tau) - - where - arg_tys = mkTyVarTys tyvars +Typecheck expression which in most cases will be an Id. + +\begin{code} +tcExpr_id :: RenamedHsExpr -> TcM (TcExpr, LIE, TcType) +tcExpr_id (HsVar name) = tcId name +tcExpr_id expr = newTyVarTy openTypeKind `thenNF_Tc` \ id_ty -> + tcMonoExpr expr id_ty `thenTc` \ (expr', lie_id) -> + returnTc (expr', lie_id, id_ty) \end{code} + %************************************************************************ %* * \subsection{@tcDoStmts@ typechecks a {\em list} of do statements} @@ -839,18 +774,20 @@ 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 -> - unifyTauTy res_ty (mkAppTy m elt_ty) `thenTc_` - -- If it's a comprehension we're dealing with, -- force it to be a list comprehension. -- (as of Haskell 98, monad comprehensions are no more.) (case do_or_lc of - ListComp -> unifyListTy res_ty `thenTc_` returnTc () - _ -> returnTc ()) `thenTc_` + ListComp -> unifyListTy res_ty `thenTc` \ elt_ty -> + returnNF_Tc (mkTyConTy listTyCon, (mkListTy, elt_ty)) - tcStmts do_or_lc (mkAppTy m) elt_ty src_loc stmts `thenTc` \ ((stmts', _), stmts_lie) -> + _ -> newTyVarTy (mkArrowKind liftedTypeKind liftedTypeKind) `thenNF_Tc` \ m_ty -> + newTyVarTy liftedTypeKind `thenNF_Tc` \ elt_ty -> + unifyTauTy res_ty (mkAppTy m_ty elt_ty) `thenTc_` + returnNF_Tc (m_ty, (mkAppTy m_ty, elt_ty)) + ) `thenNF_Tc` \ (tc_ty, m_ty) -> + + tcStmts (DoCtxt do_or_lc) m_ty 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, @@ -863,13 +800,15 @@ tcDoStmts do_or_lc stmts src_loc res_ty 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) -> + newMethod DoOrigin return_sel_id [tc_ty] `thenNF_Tc` \ return_inst -> + newMethod DoOrigin then_sel_id [tc_ty] `thenNF_Tc` \ then_inst -> + newMethod DoOrigin fail_sel_id [tc_ty] `thenNF_Tc` \ fail_inst -> let - monad_lie = then_lie `plusLIE` return_lie `plusLIE` fail_lie + monad_lie = mkLIE [return_inst, then_inst, fail_inst] in - returnTc (HsDoOut do_or_lc stmts' return_id then_id fail_id res_ty src_loc, + returnTc (HsDoOut do_or_lc stmts' + (instToId return_inst) (instToId then_inst) (instToId fail_inst) + res_ty src_loc, stmts_lie `plusLIE` monad_lie) \end{code} @@ -935,35 +874,32 @@ badFields rbinds data_con where field_names = map fieldLabelName (dataConFieldLabels data_con) -missingStrictFields rbinds data_con - = [ fn | fn <- strict_field_names, - not (fn `elem` field_names_used) - ] - where - field_names_used = [ field_name | (field_name, _, _) <- rbinds ] - strict_field_names = mapMaybe isStrict field_info - - isStrict (fl, MarkedStrict) = Just (fieldLabelName fl) - isStrict _ = Nothing - - field_info = zip (dataConFieldLabels data_con) - (dataConStrictMarks data_con) - missingFields rbinds data_con - = [ fn | fn <- non_strict_field_names, not (fn `elem` field_names_used) ] + | null field_labels = ([], []) -- Not declared as a record; + -- But C{} is still valid + | otherwise + = (missing_strict_fields, other_missing_fields) where - field_names_used = [ field_name | (field_name, _, _) <- rbinds ] - - -- missing strict fields have already been flagged as - -- being so, so leave them out here. - non_strict_field_names = mapMaybe isn'tStrict field_info - - isn'tStrict (fl, MarkedStrict) = Nothing - isn'tStrict (fl, _) = Just (fieldLabelName fl) - - field_info = zip (dataConFieldLabels data_con) - (dataConStrictMarks data_con) + missing_strict_fields + = [ fl | (fl, str) <- field_info, + isMarkedStrict str, + not (fieldLabelName fl `elem` field_names_used) + ] + other_missing_fields + = [ fl | (fl, str) <- field_info, + not (isMarkedStrict str), + not (fieldLabelName fl `elem` field_names_used) + ] + field_names_used = [ field_name | (field_name, _, _) <- rbinds ] + field_labels = dataConFieldLabels data_con + + field_info = zipEqual "missingFields" + field_labels + (drop (length ex_theta) (dataConStrictMarks data_con)) + -- The 'drop' is because dataConStrictMarks + -- includes the existential dictionaries + (_, _, _, ex_theta, _, _) = dataConSig data_con \end{code} %************************************************************************ @@ -995,9 +931,9 @@ Overloaded literals. 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) + newDicts (LitLitOrigin (_UNPK_ s)) + [mkClassPred cCallableClass [res_ty]] `thenNF_Tc` \ dicts -> + returnTc (HsLit (HsLitLit s res_ty), mkLIE dicts) tcLit lit res_ty = unifyTauTy res_ty (simpleHsLitTy lit) `thenTc_` @@ -1013,11 +949,6 @@ tcLit lit res_ty Mini-utils: -\begin{code} -pp_nest_hang :: String -> SDoc -> SDoc -pp_nest_hang lbl stuff = nest 2 (hang (text lbl) 4 stuff) -\end{code} - Boring and alphabetical: \begin{code} arithSeqCtxt expr @@ -1080,12 +1011,12 @@ recordConCtxt expr = ptext SLIT("In the record construction:") <+> ppr expr notSelector field = hsep [quotes (ppr field), ptext SLIT("is not a record selector")] -missingStrictFieldCon :: Name -> Name -> SDoc +missingStrictFieldCon :: Name -> FieldLabel -> SDoc missingStrictFieldCon con field = hsep [ptext SLIT("Constructor") <+> quotes (ppr con), ptext SLIT("does not have the required strict field"), quotes (ppr field)] -missingFieldCon :: Name -> Name -> SDoc +missingFieldCon :: Name -> FieldLabel -> SDoc missingFieldCon con field = hsep [ptext SLIT("Field") <+> quotes (ppr field), ptext SLIT("is not initialised")]