From: sof Date: Sun, 18 May 1997 22:52:47 +0000 (+0000) Subject: [project @ 1997-05-18 22:52:47 by sof] X-Git-Tag: Approximately_1000_patches_recorded~625 X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=96781381830a18e7e807a56d2a24c32afa233c83;p=ghc-hetmet.git [project @ 1997-05-18 22:52:47 by sof] new PP; 2.04 updates --- diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs index 2d46c8b..7b53c42 100644 --- a/ghc/compiler/typecheck/TcExpr.lhs +++ b/ghc/compiler/typecheck/TcExpr.lhs @@ -6,12 +6,13 @@ \begin{code} #include "HsVersions.h" -module TcExpr ( tcExpr, tcId ) where +module TcExpr ( tcExpr, tcStmt, tcId ) where IMP_Ubiq() import HsSyn ( HsExpr(..), Stmt(..), DoOrListComp(..), - HsBinds(..), Bind(..), MonoBinds(..), + HsBinds(..), MonoBinds(..), + SYN_IE(RecFlag), nonRecursive, ArithSeqInfo(..), HsLit(..), Sig, GRHSsAndBinds, Match, Fake, InPat, OutPat, HsType, Fixity, pprParendExpr, failureFreePat, collectPatBinders ) @@ -30,7 +31,7 @@ import Inst ( Inst, InstOrigin(..), OverloadedLit(..), import TcBinds ( tcBindsAndThen, checkSigTyVars ) import TcEnv ( tcLookupLocalValue, tcLookupGlobalValue, tcLookupClassByKey, tcLookupGlobalValueByKey, newMonoIds, tcGetGlobalTyVars, - tcExtendGlobalTyVars + tcExtendGlobalTyVars, tcLookupGlobalValueMaybe ) import SpecEnv ( SpecEnv ) import TcMatches ( tcMatchesCase, tcMatch ) @@ -38,23 +39,27 @@ import TcMonoType ( tcHsType ) import TcPat ( tcPat ) import TcSimplify ( tcSimplifyAndCheck, tcSimplifyRank2 ) import TcType ( SYN_IE(TcType), TcMaybe(..), - tcInstId, tcInstType, tcInstSigTcType, - tcInstSigType, tcInstTcType, tcInstTheta, - newTyVarTy, zonkTcTyVars, zonkTcType ) + tcInstId, tcInstType, tcInstSigTcType, tcInstTyVars, + tcInstSigType, tcInstTcType, tcInstTheta, tcSplitRhoTy, + newTyVarTy, newTyVarTys, zonkTcTyVars, zonkTcType ) import TcKind ( TcKind ) import Class ( SYN_IE(Class), classSig ) -import FieldLabel ( fieldLabelName ) -import Id ( idType, dataConFieldLabels, dataConSig, SYN_IE(Id), GenId ) +import FieldLabel ( fieldLabelName, fieldLabelType ) +import Id ( idType, dataConFieldLabels, dataConSig, recordSelectorFieldLabel, + isRecordSelector, + SYN_IE(Id), GenId + ) +import FieldLabel ( FieldLabel ) import Kind ( Kind, mkBoxedTypeKind, mkTypeKind, mkArrowKind ) import Name ( Name{-instance Eq-} ) import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys, mkRhoTy, - getTyVar_maybe, getFunTy_maybe, instantiateTy, + getTyVar_maybe, getFunTy_maybe, instantiateTy, applyTyCon, splitForAllTy, splitRhoTy, splitSigmaTy, splitFunTy, - isTauTy, mkFunTys, tyVarsOfType, getForAllTy_maybe, + isTauTy, mkFunTys, tyVarsOfType, tyVarsOfTypes, getForAllTy_maybe, getAppDataTyCon, maybeAppDataTyCon ) -import TyVar ( GenTyVar, SYN_IE(TyVarSet), unionTyVarSets, mkTyVarSet ) +import TyVar ( GenTyVar, SYN_IE(TyVarSet), unionTyVarSets, elementOfTyVarSet, mkTyVarSet ) import TysPrim ( intPrimTy, charPrimTy, doublePrimTy, floatPrimTy, addrPrimTy, realWorldTy ) @@ -68,10 +73,11 @@ import Unique ( Unique, cCallableClassKey, cReturnableClassKey, enumFromToClassOpKey, enumFromThenToClassOpKey, thenMClassOpKey, zeroClassOpKey, returnMClassOpKey ) -import Outputable ( interpp'SP ) +import Outputable ( speakNth, interpp'SP, Outputable(..) ) import PprType ( GenType, GenTyVar ) -- Instances import Maybes ( maybeToBool ) import Pretty +import ListSetOps ( minusList ) import Util \end{code} @@ -283,9 +289,14 @@ tcExpr (HsSCC label expr) tcExpr (HsLet binds expr) = tcBindsAndThen - HsLet -- The combiner + combiner binds -- Bindings to check - (tcExpr expr) -- Typechecker for the expression + (tc_expr expr) `thenTc` \ ((expr', ty), lie) -> + returnTc (expr', lie, ty) + where + tc_expr expr = tcExpr expr `thenTc` \ (expr', lie, ty) -> + returnTc ((expr',ty), lie) + combiner bind (expr, ty) = (HsLet bind expr, ty) tcExpr in_expr@(HsCase expr matches src_loc) = tcAddSrcLoc src_loc $ @@ -344,49 +355,134 @@ tcExpr (RecordCon (HsVar con) rbinds) -- Con is syntactically constrained to be a data constructor ASSERT( maybeToBool (maybeAppDataTyCon record_ty ) ) - tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> - -- Check that the record bindings match the constructor - tcLookupGlobalValue con `thenNF_Tc` \ con_id -> - checkTc (checkRecordFields rbinds con_id) - (badFieldsCon con rbinds) `thenTc_` + tcLookupGlobalValue con `thenNF_Tc` \ con_id -> + let + bad_fields = badFields rbinds con_id + in + checkTc (null bad_fields) (badFieldsCon con bad_fields) `thenTc_` + + -- Typecheck the record bindings + -- (Do this after checkRecordFields in case there's a field that + -- doesn't match the constructor.) + tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> returnTc (RecordCon con_expr rbinds', con_lie `plusLIE` rbinds_lie, record_ty) --- One small complication in RecordUpd is that we have to generate some --- dictionaries for the data type context, since we are going to --- do some construction. + +-- The main complication with RecordUpd is that we need to explicitly +-- handle the *non-updated* fields. Consider: +-- +-- data T a b = MkT1 { fa :: a, fb :: b } +-- | MkT2 { fa :: a, fc :: Int -> Int } +-- | MkT3 { fd :: a } +-- +-- upd :: T a b -> c -> T a c +-- upd t x = t { fb = x} +-- +-- The type signature on upd is correct (i.e. the result should not be (T a b)) +-- because upd should be equivalent to: +-- +-- upd t x = case t of +-- MkT1 p q -> MkT1 p x +-- MkT2 a b -> MkT2 p b +-- MkT3 d -> error ... -- --- What dictionaries do we need? For the moment we assume that all --- data constructors have the same context, and grab it from the first --- constructor. If they have varying contexts then we'd have to --- union the ones that could participate in the update. +-- So we need to give a completely fresh type to the result record, +-- and then constrain it by the fields that are *not* updated ("p" above). +-- +-- Note that because MkT3 doesn't contain all the fields being updated, +-- its RHS is simply an error, so it doesn't impose any type constraints +-- +-- All this is done in STEP 4 below. tcExpr (RecordUpd record_expr rbinds) - = ASSERT( not (null rbinds) ) - tcAddErrCtxt recordUpdCtxt $ - - tcExpr record_expr `thenTc` \ (record_expr', record_lie, record_ty) -> - tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> + = tcAddErrCtxt recordUpdCtxt $ - -- Check that the field names are plausible - zonkTcType record_ty `thenNF_Tc` \ record_ty' -> + -- STEP 1 + -- Figure out the tycon and data cons from the first field name + ASSERT( not (null rbinds) ) + let + ((first_field_name, _, _) : rest) = rbinds + in + tcLookupGlobalValueMaybe first_field_name `thenNF_Tc` \ maybe_sel_id -> + (case maybe_sel_id of + Just sel_id | isRecordSelector sel_id -> returnTc sel_id + other -> failTc (notSelector first_field_name) + ) `thenTc` \ sel_id -> let - (tycon, inst_tys, data_cons) = --trace "TcExpr.getAppDataTyCon" $ - getAppDataTyCon record_ty' - -- The record binds are non-empty (syntax); so at least one field - -- label will have been unified with record_ty by tcRecordBinds; - -- field labels must be of data type; hencd the getAppDataTyCon must succeed. - (tyvars, theta, _, _) = dataConSig (head data_cons) + (_, tau) = splitForAllTy (idType sel_id) + Just (data_ty, _) = getFunTy_maybe tau -- Must succeed since sel_id is a selector + (tycon, _, data_cons) = getAppDataTyCon data_ty + (con_tyvars, theta, _, _, _, _) = dataConSig (head data_cons) in - tcInstTheta (zipEqual "tcExpr:RecordUpd" tyvars inst_tys) theta `thenNF_Tc` \ theta' -> - newDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) -> - checkTc (any (checkRecordFields rbinds) data_cons) + tcInstTyVars con_tyvars `thenNF_Tc` \ (_, result_inst_tys, result_inst_env) -> + + -- STEP 2 + -- Check for bad fields + checkTc (any (null . badFields rbinds) data_cons) (badFieldsUpd rbinds) `thenTc_` - returnTc (RecordUpdOut record_expr' dicts rbinds', + -- STEP 3 + -- Typecheck the update bindings. + -- (Do this after checking for bad fields in case there's a field that + -- doesn't match the constructor.) + let + result_record_ty = applyTyCon tycon result_inst_tys + in + tcRecordBinds result_record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) -> + + -- STEP 4 + -- Use the un-updated fields to find a vector of booleans saying + -- which type arguments must be the same in updatee and result. + -- + -- WARNING: this code assumes that all data_cons in a common tycon + -- have FieldLabels abstracted over the same tyvars. + let + upd_field_lbls = [recordSelectorFieldLabel sel_id | (RealId sel_id, _, _) <- rbinds'] + con_field_lbls_s = map dataConFieldLabels data_cons + + -- A constructor is only relevant to this process if + -- it contains all the fields that are being updated + relevant_field_lbls_s = filter is_relevant con_field_lbls_s + is_relevant con_field_lbls = all (`elem` con_field_lbls) upd_field_lbls + + non_upd_field_lbls = concat relevant_field_lbls_s `minusList` upd_field_lbls + common_tyvars = tyVarsOfTypes (map fieldLabelType non_upd_field_lbls) + + mk_inst_ty (tyvar, result_inst_ty) + | tyvar `elementOfTyVarSet` common_tyvars = returnNF_Tc result_inst_ty -- Same as result type + | otherwise = newTyVarTy mkBoxedTypeKind -- Fresh type + in + mapNF_Tc mk_inst_ty (zip con_tyvars result_inst_tys) `thenNF_Tc` \ inst_tys -> + + -- STEP 5 + -- Typecheck the expression to be updated + tcExpr record_expr `thenTc` \ (record_expr', record_lie, record_ty) -> + unifyTauTy (applyTyCon tycon inst_tys) record_ty `thenTc_` + + + -- STEP 6 + -- Figure out the LIE we need. We have to generate some + -- dictionaries for the data type context, since we are going to + -- do some construction. + -- + -- What dictionaries do we need? For the moment we assume that all + -- data constructors have the same context, and grab it from the first + -- constructor. If they have varying contexts then we'd have to + -- union the ones that could participate in the update. + let + (tyvars, theta, _, _, _, _) = dataConSig (head data_cons) + inst_env = zipEqual "tcExpr:RecordUpd" tyvars result_inst_tys + in + tcInstTheta inst_env theta `thenNF_Tc` \ theta' -> + newDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) -> + + -- Phew! + returnTc (RecordUpdOut record_expr' result_record_ty dicts rbinds', con_lie `plusLIE` record_lie `plusLIE` rbinds_lie, - record_ty) + result_record_ty) + tcExpr (ArithSeqIn seq@(From expr)) = tcExpr expr `thenTc` \ (expr', lie1, ty) -> @@ -608,11 +704,7 @@ tcArg expected_arg_ty arg returnTc (TyLam sig_tyvars (HsLet (mk_binds inst_binds) arg'), free_insts) ) where - - mk_binds [] = EmptyBinds - mk_binds ((inst,rhs):inst_binds) - = (SingleBind (NonRecBind (VarMonoBind inst rhs))) `ThenBinds` - mk_binds inst_binds + mk_binds inst_binds = MonoBind inst_binds [] nonRecursive \end{code} %************************************************************************ @@ -650,17 +742,17 @@ tcId name instantiate_it2 tc_id_occ tyvars rho instantiate_it2 tc_id_occ tyvars rho - | null theta -- Is it overloaded? - = returnNF_Tc (mkHsTyApp (HsVar tc_id_occ) arg_tys, emptyLIE, tau) - - | otherwise -- Yes, it's overloaded - = newMethodWithGivenTy (OccurrenceOf tc_id_occ) + = tcSplitRhoTy rho `thenNF_Tc` \ (theta, tau) -> + if null theta then -- Is it overloaded? + returnNF_Tc (mkHsTyApp (HsVar tc_id_occ) arg_tys, emptyLIE, tau) + else + -- Yes, it's overloaded + newMethodWithGivenTy (OccurrenceOf tc_id_occ) tc_id_occ arg_tys rho `thenNF_Tc` \ (lie1, meth_id) -> instantiate_it meth_id tau `thenNF_Tc` \ (expr, lie2, final_tau) -> returnNF_Tc (expr, lie1 `plusLIE` lie2, final_tau) where - (theta, tau) = splitRhoTy rho arg_tys = mkTyVarTys tyvars \end{code} @@ -674,11 +766,30 @@ tcId name tcDoStmts do_or_lc stmts src_loc = -- get the Monad and MonadZero classes -- create type consisting of a fresh monad tyvar + ASSERT( not (null stmts) ) tcAddSrcLoc src_loc $ newTyVarTy (mkArrowKind mkBoxedTypeKind mkBoxedTypeKind) `thenNF_Tc` \ m -> + let + tc_stmts [] = returnTc (([], error "tc_stmts"), emptyLIE) + tc_stmts (stmt:stmts) = tcStmt tcExpr do_or_lc (mkAppTy m) combine_stmts stmt $ + tc_stmts stmts + + combine_stmts stmt@(ReturnStmt _) (Just ty) ([], _) = ([stmt], ty) + combine_stmts stmt@(ExprStmt e _) (Just ty) ([], _) = ([stmt], ty) + combine_stmts stmt _ ([], _) = panic "Bad last stmt tcDoStmts" + combine_stmts stmt _ (stmts, ty) = (stmt:stmts, ty) + in + tc_stmts stmts `thenTc` \ ((stmts', result_ty), final_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, + -- not only for typechecker efficiency, but also because otherwise during + -- simplification we end up with silly stuff like + -- then = case d of (t,r) -> t + -- then = then + -- where the second "then" sees that it already exists in the "available" stuff. + -- tcLookupGlobalValueByKey returnMClassOpKey `thenNF_Tc` \ return_sel_id -> tcLookupGlobalValueByKey thenMClassOpKey `thenNF_Tc` \ then_sel_id -> tcLookupGlobalValueByKey zeroClassOpKey `thenNF_Tc` \ zero_sel_id -> @@ -688,88 +799,97 @@ tcDoStmts do_or_lc stmts src_loc (RealId then_sel_id) [m] `thenNF_Tc` \ (then_lie, then_id) -> newMethod DoOrigin (RealId zero_sel_id) [m] `thenNF_Tc` \ (zero_lie, zero_id) -> - let - -- go :: [RenamedStmt] -> TcM s ([TcStmt s], LIE s, TcType s) - - go [stmt@(ReturnStmt exp)] -- Must be last statement - = ASSERT( case do_or_lc of { DoStmt -> False; ListComp -> True } ) - tcSetErrCtxt (stmtCtxt do_or_lc stmt) $ - tcExpr exp `thenTc` \ (exp', exp_lie, exp_ty) -> - returnTc ([ReturnStmt exp'], return_lie `plusLIE` exp_lie, mkAppTy m exp_ty) - - go (stmt@(GuardStmt exp src_loc) : stmts) - = ASSERT( case do_or_lc of { DoStmt -> False; ListComp -> True } ) - tcAddSrcLoc src_loc ( - tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( - tcExpr exp `thenTc` \ (exp', exp_lie, exp_ty) -> - unifyTauTy boolTy exp_ty `thenTc_` - returnTc (GuardStmt exp' src_loc, exp_lie) - )) `thenTc` \ (stmt', stmt_lie) -> - go stmts `thenTc` \ (stmts', stmts_lie, stmts_ty) -> - returnTc (stmt' : stmts', - stmt_lie `plusLIE` stmts_lie `plusLIE` zero_lie, - stmts_ty) - - go (stmt@(ExprStmt exp src_loc) : stmts) - = ASSERT( case do_or_lc of { DoStmt -> True; ListComp -> False } ) - tcAddSrcLoc src_loc ( - tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( - tcExpr exp `thenTc` \ (exp', exp_lie, exp_ty) -> - -- Check that exp has type (m tau) for some tau (doesn't matter what) - newTyVarTy mkTypeKind `thenNF_Tc` \ tau -> - unifyTauTy (mkAppTy m tau) exp_ty `thenTc_` - returnTc (ExprStmt exp' src_loc, exp_lie, exp_ty, exp_ty) - )) `thenTc` \ (stmt', stmt_lie, stmt_ty, result_ty) -> - if null stmts then - -- This is the last statement - returnTc ([stmt'], stmt_lie, result_ty) - else - -- More statments follow - go stmts `thenTc` \ (stmts', stmts_lie, stmts_ty) -> - returnTc (stmt' : stmts', - stmt_lie `plusLIE` stmts_lie `plusLIE` then_lie, - stmts_ty) - - go (stmt@(BindStmt pat exp src_loc) : stmts) - = newMonoIds (collectPatBinders pat) mkBoxedTypeKind $ \ _ -> - tcAddSrcLoc src_loc ( - tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( - tcPat pat `thenTc` \ (pat', pat_lie, pat_ty) -> - tcExpr exp `thenTc` \ (exp', exp_lie, exp_ty) -> - unifyTauTy (mkAppTy m pat_ty) exp_ty `thenTc_` - - -- NB: the environment has been extended with the new binders - -- which the rhs can't "see", but the renamer should have made - -- sure that everything is distinct by now, so there's no problem. - -- Putting the tcExpr before the newMonoIds messes up the nesting - -- of error contexts, so I didn't bother - - returnTc (BindStmt pat' exp' src_loc, pat', pat_lie `plusLIE` exp_lie) - )) `thenTc` \ (stmt', pat', stmt_lie) -> - - go stmts `thenTc` \ (stmts', stmts_lie, stmts_ty) -> - - returnTc (stmt' : stmts', - stmt_lie `plusLIE` stmts_lie `plusLIE` then_lie `plusLIE` - (if failureFreePat pat' then emptyLIE else zero_lie), - stmts_ty) - - go (LetStmt binds : stmts) - = tcBindsAndThen -- No error context, but a binding group is - combine -- rather a large thing for an error context anyway - binds - (go stmts) - where - combine binds' stmts' = LetStmt binds' : stmts' - in + monad_lie = then_lie `plusLIE` return_lie `plusLIE` perhaps_zero_lie + perhaps_zero_lie | all failure_free stmts' = emptyLIE + | otherwise = zero_lie - go stmts `thenTc` \ (stmts', final_lie, result_ty) -> + failure_free (BindStmt pat _ _) = failureFreePat pat + failure_free (GuardStmt _ _) = False + failure_free other_stmt = True + in returnTc (HsDoOut do_or_lc stmts' return_id then_id zero_id result_ty src_loc, - final_lie, + final_lie `plusLIE` monad_lie, result_ty) \end{code} +\begin{code} +tcStmt :: (RenamedHsExpr -> TcM s (TcExpr s, LIE s, TcType s)) -- This is tcExpr + -- The sole, disgusting, reason for this parameter + -- is to get the effect of polymorphic recursion + -- ToDo: rm when booting with Haskell 1.3 + -> DoOrListComp + -> (TcType s -> TcType s) -- Relationship type of pat and rhs in pat <- rhs + -> (TcStmt s -> Maybe (TcType s) -> thing -> thing) + -> RenamedStmt + -> TcM s (thing, LIE s) + -> TcM s (thing, LIE s) + +tcStmt tc_expr do_or_lc m combine stmt@(ReturnStmt exp) do_next + = ASSERT( case do_or_lc of { DoStmt -> False; ListComp -> True } ) + tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( + tc_expr exp `thenTc` \ (exp', exp_lie, exp_ty) -> + returnTc (ReturnStmt exp', exp_lie, m exp_ty) + ) `thenTc` \ (stmt', stmt_lie, stmt_ty) -> + do_next `thenTc` \ (thing', thing_lie) -> + returnTc (combine stmt' (Just stmt_ty) thing', + stmt_lie `plusLIE` thing_lie) + +tcStmt tc_expr do_or_lc m combine stmt@(GuardStmt exp src_loc) do_next + = ASSERT( case do_or_lc of { DoStmt -> False; ListComp -> True } ) + tcAddSrcLoc src_loc ( + tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( + tc_expr exp `thenTc` \ (exp', exp_lie, exp_ty) -> + unifyTauTy boolTy exp_ty `thenTc_` + returnTc (GuardStmt exp' src_loc, exp_lie) + )) `thenTc` \ (stmt', stmt_lie) -> + do_next `thenTc` \ (thing', thing_lie) -> + returnTc (combine stmt' Nothing thing', + stmt_lie `plusLIE` thing_lie) + +tcStmt tc_expr do_or_lc m combine stmt@(ExprStmt exp src_loc) do_next + = ASSERT( case do_or_lc of { DoStmt -> True; ListComp -> False } ) + tcAddSrcLoc src_loc ( + tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( + tc_expr exp `thenTc` \ (exp', exp_lie, exp_ty) -> + -- Check that exp has type (m tau) for some tau (doesn't matter what) + newTyVarTy mkTypeKind `thenNF_Tc` \ tau -> + unifyTauTy (m tau) exp_ty `thenTc_` + returnTc (ExprStmt exp' src_loc, exp_lie, exp_ty) + )) `thenTc` \ (stmt', stmt_lie, stmt_ty) -> + do_next `thenTc` \ (thing', thing_lie) -> + returnTc (combine stmt' (Just stmt_ty) thing', + stmt_lie `plusLIE` thing_lie) + +tcStmt tc_expr do_or_lc m combine stmt@(BindStmt pat exp src_loc) do_next + = newMonoIds (collectPatBinders pat) mkBoxedTypeKind $ \ _ -> + tcAddSrcLoc src_loc ( + tcSetErrCtxt (stmtCtxt do_or_lc stmt) ( + tcPat pat `thenTc` \ (pat', pat_lie, pat_ty) -> + tc_expr exp `thenTc` \ (exp', exp_lie, exp_ty) -> + unifyTauTy (m pat_ty) exp_ty `thenTc_` + + -- NB: the environment has been extended with the new binders + -- which the rhs can't "see", but the renamer should have made + -- sure that everything is distinct by now, so there's no problem. + -- Putting the tcExpr before the newMonoIds messes up the nesting + -- of error contexts, so I didn't bother + + returnTc (BindStmt pat' exp' src_loc, pat_lie `plusLIE` exp_lie) + )) `thenTc` \ (stmt', stmt_lie) -> + do_next `thenTc` \ (thing', thing_lie) -> + returnTc (combine stmt' Nothing thing', + stmt_lie `plusLIE` thing_lie) + +tcStmt tc_expr do_or_lc m combine (LetStmt binds) do_next + = tcBindsAndThen -- No error context, but a binding group is + combine' -- rather a large thing for an error context anyway + binds + do_next + where + combine' binds' thing' = combine (LetStmt binds') Nothing thing' +\end{code} + %************************************************************************ %* * \subsection{Record bindings} @@ -810,6 +930,11 @@ tcRecordBinds expected_record_ty rbinds where do_bind (field_label, rhs, pun_flag) = tcLookupGlobalValue field_label `thenNF_Tc` \ sel_id -> + ASSERT( isRecordSelector sel_id ) + -- This lookup and assertion will surely succeed, because + -- we check that the fields are indeed record selectors + -- before calling tcRecordBinds + tcInstId sel_id `thenNF_Tc` \ (_, _, tau) -> -- Record selectors all have type @@ -823,17 +948,12 @@ tcRecordBinds expected_record_ty rbinds tcArg field_ty rhs `thenTc` \ (rhs', lie) -> returnTc ((RealId sel_id, rhs', pun_flag), lie) -checkRecordFields :: RenamedRecordBinds -> Id -> Bool -- True iff all the fields in - -- RecordBinds are field of the - -- specified constructor -checkRecordFields rbinds data_con - = all ok rbinds - where - data_con_fields = dataConFieldLabels data_con - - ok (field_name, _, _) = any (match (getName field_name)) data_con_fields - - match field_name field_label = field_name == fieldLabelName field_label +badFields rbinds data_con + = [field_name | (field_name, _, _) <- rbinds, + not (field_name `elem` field_names) + ] + where + field_names = map fieldLabelName (dataConFieldLabels data_con) \end{code} %************************************************************************ @@ -860,77 +980,78 @@ Errors and contexts Mini-utils: \begin{code} -pp_nest_hang :: String -> Pretty -> Pretty -pp_nest_hang label stuff = ppNest 2 (ppHang (ppStr label) 4 stuff) +pp_nest_hang :: String -> Doc -> Doc +pp_nest_hang label stuff = nest 2 (hang (text label) 4 stuff) \end{code} Boring and alphabetical: \begin{code} arithSeqCtxt expr sty - = ppHang (ppPStr SLIT("In an arithmetic sequence:")) 4 (ppr sty expr) + = hang (ptext SLIT("In an arithmetic sequence:")) 4 (ppr sty expr) branchCtxt b1 b2 sty - = ppSep [ppPStr SLIT("In the branches of a conditional:"), + = sep [ptext SLIT("In the branches of a conditional:"), pp_nest_hang "`then' branch:" (ppr sty b1), pp_nest_hang "`else' branch:" (ppr sty b2)] caseCtxt expr sty - = ppHang (ppPStr SLIT("In a case expression:")) 4 (ppr sty expr) + = hang (ptext SLIT("In a case expression:")) 4 (ppr sty expr) exprSigCtxt expr sty - = ppHang (ppPStr SLIT("In an expression with a type signature:")) + = hang (ptext SLIT("In an expression with a type signature:")) 4 (ppr sty expr) listCtxt expr sty - = ppHang (ppPStr SLIT("In a list expression:")) 4 (ppr sty expr) + = hang (ptext SLIT("In a list expression:")) 4 (ppr sty expr) predCtxt expr sty - = ppHang (ppPStr SLIT("In a predicate expression:")) 4 (ppr sty expr) + = hang (ptext SLIT("In a predicate expression:")) 4 (ppr sty expr) sectionRAppCtxt expr sty - = ppHang (ppPStr SLIT("In a right section:")) 4 (ppr sty expr) + = hang (ptext SLIT("In a right section:")) 4 (ppr sty expr) sectionLAppCtxt expr sty - = ppHang (ppPStr SLIT("In a left section:")) 4 (ppr sty expr) + = hang (ptext SLIT("In a left section:")) 4 (ppr sty expr) funAppCtxt fun arg_no arg sty - = ppHang (ppCat [ ppPStr SLIT("In the"), speakNth arg_no, ppPStr SLIT("argument of"), - ppr sty fun `ppBeside` ppStr ", namely"]) + = hang (hsep [ ptext SLIT("In the"), speakNth arg_no, ptext SLIT("argument of"), + ppr sty fun <> text ", namely"]) 4 (pprParendExpr sty arg) stmtCtxt ListComp stmt sty - = ppHang (ppPStr SLIT("In a list-comprehension qualifer:")) + = hang (ptext SLIT("In a list-comprehension qualifer:")) 4 (ppr sty stmt) stmtCtxt DoStmt stmt sty - = ppHang (ppPStr SLIT("In a do statement:")) + = hang (ptext SLIT("In a do statement:")) 4 (ppr sty stmt) tooManyArgsCtxt f sty - = ppHang (ppPStr SLIT("Too many arguments in an application of the function")) + = hang (ptext SLIT("Too many arguments in an application of the function")) 4 (ppr sty f) lurkingRank2Err fun fun_ty sty - = ppHang (ppCat [ppPStr SLIT("Illegal use of"), ppr sty fun]) - 4 (ppAboves [ppStr "It is applied to too few arguments,", - ppPStr SLIT("so that the result type has for-alls in it")]) + = hang (hsep [ptext SLIT("Illegal use of"), ppr sty fun]) + 4 (vcat [text "It is applied to too few arguments,", + ptext SLIT("so that the result type has for-alls in it")]) rank2ArgCtxt arg expected_arg_ty sty - = ppHang (ppPStr SLIT("In a polymorphic function argument:")) - 4 (ppSep [ppBeside (ppr sty arg) (ppPStr SLIT(" ::")), + = hang (ptext SLIT("In a polymorphic function argument:")) + 4 (sep [(<>) (ppr sty arg) (ptext SLIT(" ::")), ppr sty expected_arg_ty]) badFieldsUpd rbinds sty - = ppHang (ppPStr SLIT("No constructor has all these fields:")) + = hang (ptext SLIT("No constructor has all these fields:")) 4 (interpp'SP sty fields) where fields = [field | (field, _, _) <- rbinds] -recordUpdCtxt sty = ppPStr SLIT("In a record update construct") +recordUpdCtxt sty = ptext SLIT("In a record update construct") -badFieldsCon con rbinds sty - = ppHang (ppBesides [ppPStr SLIT("Inconsistent constructor:"), ppr sty con]) - 4 (ppBesides [ppPStr SLIT("and fields:"), interpp'SP sty fields]) - where - fields = [field | (field, _, _) <- rbinds] +badFieldsCon con fields sty + = hsep [ptext SLIT("Constructor"), ppr sty con, + ptext SLIT("does not have field(s)"), interpp'SP sty fields] + +notSelector field sty + = hsep [ppr sty field, ptext SLIT("is not a record selector")] \end{code}