ArithSeqInfo(..), HsLit(..), Sig, GRHSsAndBinds,
Match, Fake, InPat, OutPat, PolyType,
irrefutablePat, collectPatBinders )
-import RnHsSyn ( RenamedHsExpr(..), RenamedQual(..), RenamedStmt(..) )
-import TcHsSyn ( TcExpr(..), TcQual(..), TcStmt(..), TcIdOcc(..) )
+import RnHsSyn ( RenamedHsExpr(..), RenamedQual(..),
+ RenamedStmt(..), RenamedRecordBinds(..)
+ )
+import TcHsSyn ( TcExpr(..), TcQual(..), TcStmt(..),
+ TcIdOcc(..), TcRecordBinds(..),
+ mkHsTyApp
+ )
import TcMonad
import Inst ( Inst, InstOrigin(..), OverloadedLit(..),
- LIE(..), emptyLIE, plusLIE, newOverloadedLit,
+ LIE(..), emptyLIE, plusLIE, plusLIEs, newOverloadedLit,
newMethod, newMethodWithGivenTy, newDicts )
import TcBinds ( tcBindsAndThen )
import TcEnv ( tcLookupLocalValue, tcLookupGlobalValue, tcLookupClassByKey,
- tcLookupGlobalValueByKey, newMonoIds, tcGetGlobalTyVars )
+ tcLookupGlobalValueByKey, newMonoIds, tcGetGlobalTyVars,
+ tcGlobalOcc
+ )
import TcMatches ( tcMatchesCase, tcMatch )
import TcMonoType ( tcPolyType )
import TcPat ( tcPat )
import TcSimplify ( tcSimplifyAndCheck, tcSimplifyRank2 )
-import TcType ( TcType(..), TcMaybe(..), tcReadTyVar,
- tcInstType, tcInstTcType,
- tcInstTyVar, newTyVarTy, zonkTcTyVars )
+import TcType ( TcType(..), TcMaybe(..),
+ tcInstType, tcInstTcType, tcInstTyVars,
+ newTyVarTy, zonkTcTyVars, zonkTcType )
import TcKind ( TcKind )
import Class ( Class(..), getClassSig )
-import Id ( Id(..), GenId, idType )
-import Kind ( Kind, mkBoxedTypeKind, mkTypeKind )
-import GenSpecEtc ( checkSigTyVars, checkSigTyVarsGivenGlobals, specTy )
+import FieldLabel ( fieldLabelName )
+import Id ( Id(..), GenId, idType, dataConFieldLabels )
+import Kind ( Kind, mkBoxedTypeKind, mkTypeKind, mkArrowKind )
+import GenSpecEtc ( checkSigTyVars, checkSigTyVarsGivenGlobals )
import PrelInfo ( intPrimTy, charPrimTy, doublePrimTy,
floatPrimTy, addrPrimTy, addrTy,
boolTy, charTy, stringTy, mkListTy,
mkTupleTy, mkPrimIoTy )
import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys,
getTyVar_maybe, getFunTy_maybe,
- splitForAllTy, splitRhoTy, splitSigmaTy,
- isTauTy, mkFunTys, tyVarsOfType, getForAllTy_maybe )
+ splitForAllTy, splitRhoTy, splitSigmaTy, splitFunTy,
+ isTauTy, mkFunTys, tyVarsOfType, getForAllTy_maybe,
+ maybeAppDataTyCon
+ )
import TyVar ( GenTyVar, TyVarSet(..), unionTyVarSets, mkTyVarSet )
-import Unify ( unifyTauTy, unifyTauTyList, unifyTauTyLists )
+import Unify ( unifyTauTy, unifyTauTyList, unifyTauTyLists, unifyFunTy )
import Unique ( Unique, cCallableClassKey, cReturnableClassKey,
enumFromClassOpKey, enumFromThenClassOpKey,
enumFromToClassOpKey, enumFromThenToClassOpKey,
monadClassKey, monadZeroClassKey )
import Name ( Name ) -- Instance
+import Outputable ( interpp'SP )
import PprType ( GenType, GenTyVar ) -- Instances
import Maybes ( maybeToBool )
import Pretty
= -- get the Monad and MonadZero classes
-- create type consisting of a fresh monad tyvar
tcAddSrcLoc src_loc $
- tcLookupClassByKey monadClassKey `thenNF_Tc` \ monadClass ->
- tcLookupClassByKey monadZeroClassKey `thenNF_Tc` \ monadZeroClass ->
- let
- (tv,_,_) = getClassSig monadClass
- in
- tcInstTyVar tv `thenNF_Tc` \ m_tyvar ->
- let
- m = mkTyVarTy m_tyvar
- in
- tcDoStmts False m stmts `thenTc` \ ((stmts',monad,mzero), lie, do_ty) ->
+ newTyVarTy monadKind `thenNF_Tc` \ m ->
+ tcDoStmts False m stmts `thenTc` \ ((stmts',monad,mzero), lie, do_ty) ->
-- create dictionaries for monad and possibly monadzero
(if monad then
+ tcLookupClassByKey monadClassKey `thenNF_Tc` \ monadClass ->
newDicts DoOrigin [(monadClass, m)]
else
returnNF_Tc (emptyLIE, [panic "TcExpr: MonadZero dictionary"])
) `thenNF_Tc` \ (m_lie, [m_id]) ->
(if mzero then
+ tcLookupClassByKey monadZeroClassKey `thenNF_Tc` \ monadZeroClass ->
newDicts DoOrigin [(monadZeroClass, m)]
else
returnNF_Tc (emptyLIE, [panic "TcExpr: MonadZero dictionary"])
returnTc (HsDoOut stmts' m_id mz_id src_loc,
lie `plusLIE` m_lie `plusLIE` mz_lie,
do_ty)
+ where
+ monadKind = mkArrowKind mkBoxedTypeKind mkBoxedTypeKind
\end{code}
\begin{code}
= tcExprs exprs `thenTc` \ (exprs', lie, tys) ->
returnTc (ExplicitTuple exprs', lie, mkTupleTy (length tys) tys)
-tcExpr (RecordCon con rbinds)
- = panic "tcExpr:RecordCon"
-tcExpr (RecordUpd exp rbinds)
- = panic "tcExpr:RecordUpd"
+tcExpr (RecordCon (HsVar con) rbinds)
+ = tcGlobalOcc con `thenNF_Tc` \ (con_id, arg_tys, con_rho) ->
+ let
+ (con_theta, con_tau) = splitRhoTy con_rho
+ (_, record_ty) = splitFunTy con_tau
+ con_expr = mkHsTyApp (HsVar (RealId con_id)) arg_tys
+ in
+ -- TEMPORARY ASSERT
+ ASSERT( null con_theta )
+
+ -- Con is syntactically constrained to be a data constructor
+ ASSERT( maybeToBool (maybeAppDataTyCon record_ty ) )
+
+ tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) ->
+
+ checkTc (checkRecordFields rbinds con_id)
+ (badFieldsCon con rbinds) `thenTc_`
+
+ returnTc (RecordCon con_expr rbinds', panic "tcExpr:RecordCon:con_lie???" {-con_lie???-} `plusLIE` rbinds_lie, record_ty)
+
+tcExpr (RecordUpd record_expr rbinds)
+ = tcExpr record_expr `thenTc` \ (record_expr', record_lie, record_ty) ->
+ tcRecordBinds record_ty rbinds `thenTc` \ (rbinds', rbinds_lie) ->
+
+ -- Check that the field names are plausible
+ zonkTcType record_ty `thenNF_Tc` \ record_ty' ->
+ let
+ maybe_tycon_stuff = maybeAppDataTyCon record_ty'
+ Just (tycon, args_tys, data_cons) = maybe_tycon_stuff
+ in
+ checkTc (maybeToBool maybe_tycon_stuff)
+ (panic "TcExpr:Records:mystery error message") `thenTc_`
+ checkTc (any (checkRecordFields rbinds) data_cons)
+ (badFieldsUpd rbinds) `thenTc_`
+ returnTc (RecordUpd record_expr' rbinds', record_lie `plusLIE` rbinds_lie, record_ty)
tcExpr (ArithSeqIn seq@(From expr))
= tcExpr expr `thenTc` \ (expr', lie1, ty) ->
-- Check the tau-type part
tcSetErrCtxt (exprSigCtxt in_expr) $
- specTy SignatureOrigin sigma_sig `thenNF_Tc` \ (sig_tyvars, sig_dicts, sig_tau, _) ->
- unifyTauTy tau_ty sig_tau `thenTc_`
+ tcInstType [] sigma_sig `thenNF_Tc` \ sigma_sig' ->
+ let
+ (sig_tyvars', sig_theta', sig_tau') = splitSigmaTy sigma_sig'
+ in
+ unifyTauTy tau_ty sig_tau' `thenTc_`
-- Check the type variables of the signature
- checkSigTyVars sig_tyvars sig_tau tau_ty `thenTc` \ sig_tyvars' ->
+ checkSigTyVars sig_tyvars' sig_tau' `thenTc_`
-- Check overloading constraints
+ newDicts SignatureOrigin sig_theta' `thenNF_Tc` \ (sig_dicts, _) ->
tcSimplifyAndCheck
(mkTyVarSet sig_tyvars')
sig_dicts lie `thenTc_`
tcApp_help orig_fun arg_no fun_ty []
= returnTc ([], emptyLIE, fun_ty)
-tcApp_help orig_fun arg_no fun_ty (arg:args)
- | maybeToBool maybe_arrow_ty
- = -- The function's type is A->B
+tcApp_help orig_fun arg_no fun_ty all_args@(arg:args)
+ = -- Expect the function to have type A->B
+ tcAddErrCtxt (tooManyArgsCtxt orig_fun) (
+ unifyFunTy fun_ty
+ ) `thenTc` \ (expected_arg_ty, result_ty) ->
+
+ -- Type check the argument
tcAddErrCtxt (funAppCtxt orig_fun arg_no arg) (
- tcArg expected_arg_ty arg
- ) `thenTc` \ (arg', lie_arg) ->
+ tcArg expected_arg_ty arg
+ ) `thenTc` \ (arg', lie_arg) ->
+ -- Do the other args
tcApp_help orig_fun (arg_no+1) result_ty args `thenTc` \ (args', lie_args, res_ty) ->
- returnTc (arg':args', lie_arg `plusLIE` lie_args, res_ty)
-
- | maybeToBool maybe_tyvar_ty
- = -- The function's type is just a type variable
- tcReadTyVar fun_tyvar `thenNF_Tc` \ maybe_fun_ty ->
- case maybe_fun_ty of
-
- BoundTo new_fun_ty -> -- The tyvar in the corner of the function is bound
- -- to something ... so carry on ....
- tcApp_help orig_fun arg_no new_fun_ty (arg:args)
-
- UnBound -> -- Extra args match against an unbound type
- -- variable as the final result type, so unify the tyvar.
- newTyVarTy mkTypeKind `thenNF_Tc` \ result_ty ->
- tcExprs args `thenTc` \ (args', lie_args, arg_tys) ->
-
- -- Unification can't fail, since we're unifying against a tyvar
- unifyTauTy fun_ty (mkFunTys arg_tys result_ty) `thenTc_`
-
- returnTc (args', lie_args, result_ty)
-
- | otherwise
- = -- Must be an error: a lurking for-all, or (more commonly)
- -- a TyConTy... we've applied the function to too many args
- failTc (tooManyArgs orig_fun)
- where
- maybe_arrow_ty = getFunTy_maybe fun_ty
- Just (expected_arg_ty, result_ty) = maybe_arrow_ty
+ -- Done
+ returnTc (arg':args', lie_arg `plusLIE` lie_args, res_ty)
- maybe_tyvar_ty = getTyVar_maybe fun_ty
- Just fun_tyvar = maybe_tyvar_ty
\end{code}
\begin{code}
let
(expected_tyvars, expected_theta, expected_tau) = splitSigmaTy expected_arg_ty
in
- ASSERT( null expected_theta )
+ ASSERT( null expected_theta ) -- And expected_tyvars are all DontBind things
-- Type-check the arg and unify with expected type
tcExpr arg `thenTc` \ (arg', lie_arg, actual_arg_ty) ->
zonkTcTyVars (tyVarsOfType expected_arg_ty) `thenNF_Tc` \ free_tyvars ->
checkSigTyVarsGivenGlobals
(env_tyvars `unionTyVarSets` free_tyvars)
- expected_tyvars expected_tau actual_arg_ty `thenTc` \ arg_tyvars' ->
+ expected_tyvars expected_tau `thenTc_`
-- Check that there's no overloading involved
- -- Even if there isn't, there may be some Insts which mention the arg_tyvars,
+ -- Even if there isn't, there may be some Insts which mention the expected_tyvars,
-- but which, on simplification, don't actually need a dictionary involving
-- the tyvar. So we have to do a proper simplification right here.
- tcSimplifyRank2 (mkTyVarSet arg_tyvars')
+ tcSimplifyRank2 (mkTyVarSet expected_tyvars)
lie_arg `thenTc` \ (free_insts, inst_binds) ->
-- 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.
- returnTc (TyLam arg_tyvars' (HsLet (mk_binds inst_binds) arg'), free_insts)
+ returnTc (TyLam expected_tyvars (HsLet (mk_binds inst_binds) arg'), free_insts)
)
where
tcId :: Name -> TcM s (TcExpr s, LIE s, TcType s)
tcId name
= -- Look up the Id and instantiate its type
- (tcLookupLocalValue name `thenNF_Tc` \ maybe_local ->
- case maybe_local of
- Just tc_id -> tcInstTcType [] (idType tc_id) `thenNF_Tc` \ ty ->
- returnNF_Tc (TcId tc_id, ty)
-
- Nothing -> tcLookupGlobalValue name `thenNF_Tc` \ id ->
- tcInstType [] (idType id) `thenNF_Tc` \ ty ->
- returnNF_Tc (RealId id, ty)
- ) `thenNF_Tc` \ (tc_id_occ, ty) ->
- let
- (tyvars, rho) = splitForAllTy ty
- (theta,tau) = splitRhoTy rho
- arg_tys = mkTyVarTys tyvars
- in
+ tcLookupLocalValue name `thenNF_Tc` \ maybe_local ->
+
+ (case maybe_local of
+ Just tc_id -> let
+ (tyvars, rho) = splitForAllTy (idType tc_id)
+ in
+ tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', arg_tys', tenv) ->
+ tcInstTcType tenv rho `thenNF_Tc` \ rho' ->
+ returnNF_Tc (TcId tc_id, arg_tys', rho')
+
+ Nothing -> tcGlobalOcc name `thenNF_Tc` \ (id, arg_tys, rho) ->
+ returnNF_Tc (RealId id, arg_tys, rho)
+
+ ) `thenNF_Tc` \ (tc_id_occ, arg_tys, rho) ->
+
-- Is it overloaded?
- case theta of
- [] -> -- Not overloaded, so just make a type application
- returnTc (TyApp (HsVar tc_id_occ) arg_tys, emptyLIE, tau)
-
- _ -> -- Overloaded, so make a Method inst
- newMethodWithGivenTy (OccurrenceOf tc_id_occ)
- tc_id_occ arg_tys rho `thenNF_Tc` \ (lie, meth_id) ->
- returnTc (HsVar meth_id, lie, tau)
+ case splitRhoTy rho of
+ ([], tau) -> -- Not overloaded, so just make a type application
+ returnTc (mkHsTyApp (HsVar tc_id_occ) arg_tys, emptyLIE, tau)
+
+ (theta, tau) -> -- Overloaded, so make a Method inst
+ newMethodWithGivenTy (OccurrenceOf tc_id_occ)
+ tc_id_occ arg_tys rho `thenNF_Tc` \ (lie, meth_id) ->
+ returnTc (HsVar meth_id, lie, tau)
\end{code}
\end{code}
+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.
+
+2. Instantiate this type
+
+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.
+
+4. Type check the value using tcArg, passing tau 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 s -- Expected type of whole record
+ -> RenamedRecordBinds
+ -> TcM s (TcRecordBinds s, LIE s)
+
+tcRecordBinds expected_record_ty rbinds
+ = mapAndUnzipTc do_bind rbinds `thenTc` \ (rbinds', lies) ->
+ returnTc (rbinds', plusLIEs lies)
+ where
+ do_bind (field_label, rhs, pun_flag)
+ = tcGlobalOcc field_label `thenNF_Tc` \ (sel_id, _, tau) ->
+
+ -- Record selectors all have type
+ -- forall a1..an. T a1 .. an -> tau
+ ASSERT( maybeToBool (getFunTy_maybe tau) )
+ let
+ -- Selector must have type RecordType -> FieldType
+ Just (record_ty, field_ty) = getFunTy_maybe tau
+ in
+ unifyTauTy expected_record_ty record_ty `thenTc_`
+ 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 field_name) data_con_fields
+
+ match field_name field_label = field_name == fieldLabelName field_label
+\end{code}
+
%************************************************************************
%* *
\subsection{@tcExprs@ typechecks a {\em list} of expressions}
= ppHang (ppStr "In a do statement:")
4 (ppr sty stmt)
-tooManyArgs f sty
+tooManyArgsCtxt f sty
= ppHang (ppStr "Too many arguments in an application of the function")
4 (ppr sty f)
= ppHang (ppStr "In a polymorphic function argument:")
4 (ppSep [ppBeside (ppr sty arg) (ppStr " ::"),
ppr sty expected_arg_ty])
-\end{code}
+badFieldsUpd rbinds sty
+ = ppHang (ppStr "In a record update construct, no constructor has all these fields:")
+ 4 (interpp'SP sty fields)
+ where
+ fields = [field | (field, _, _) <- rbinds]
+
+badFieldsCon con rbinds sty
+ = ppHang (ppBesides [ppStr "Inconsistent constructor:", ppr sty con])
+ 4 (ppBesides [ppStr "and fields:", interpp'SP sty fields])
+ where
+ fields = [field | (field, _, _) <- rbinds]
+\end{code}
projects / ghc-hetmet.git / blobdiff