#include "HsVersions.h"
import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
- HsBinds(..), Stmt(..), StmtCtxt(..)
+ 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, plusLIE, plusLIEs, newOverloadedLit,
- newMethod, instOverloadedFun, newDicts, instToId )
+import Inst ( InstOrigin(..),
+ LIE, emptyLIE, unitLIE, plusLIE, plusLIEs,
+ newOverloadedLit, newMethod, newIPDict,
+ instOverloadedFun, newDicts, newClassDicts,
+ getIPsOfLIE, instToId, ipToId
+ )
import TcBinds ( tcBindsAndThen )
import TcEnv ( tcInstId,
tcLookupValue, tcLookupClassByKey,
tcLookupValueByKey,
tcExtendGlobalTyVars, tcLookupValueMaybe,
- tcLookupTyCon, tcLookupDataCon
+ tcLookupTyConByKey, tcLookupDataCon
)
import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts )
-import TcMonoType ( tcHsType, checkSigTyVars, sigCtxt )
-import TcPat ( badFieldCon )
-import 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
+import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon )
+import Id ( idType, recordSelectorFieldLabel, isRecordSelector, mkVanillaId )
+import DataCon ( dataConFieldLabels, dataConSig,
+ dataConStrictMarks, StrictnessMark(..)
)
-import DataCon ( dataConFieldLabels, dataConSig, dataConId )
-import Name ( Name )
-import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys,
+import Name ( Name, getName )
+import Type ( mkFunTy, mkAppTy, mkTyVarTys, ipName_maybe,
splitFunTy_maybe, splitFunTys, isNotUsgTy,
- mkTyConApp,
- splitForAllTys, splitRhoTy,
+ mkTyConApp, splitSigmaTy,
+ splitRhoTy,
isTauTy, tyVarsOfType, tyVarsOfTypes,
- isForAllTy, splitAlgTyConApp, splitAlgTyConApp_maybe,
- boxedTypeKind, mkArrowKind,
+ isSigmaTy, splitAlgTyConApp, splitAlgTyConApp_maybe,
+ boxedTypeKind, openTypeKind, mkArrowKind,
tidyOpenType
)
-import Subst ( mkTopTyVarSubst, substTheta )
+import TyCon ( TyCon, tyConTyVars )
+import Subst ( mkTopTyVarSubst, substClasses, substTy )
import UsageSPUtils ( unannotTy )
import VarSet ( 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,
+import TysWiredIn ( boolTy )
+import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy )
+import PrelNames ( cCallableClassKey, cReturnableClassKey,
enumFromClassOpKey, enumFromThenClassOpKey,
enumFromToClassOpKey, enumFromThenToClassOpKey,
- thenMClassOpKey, failMClassOpKey, returnMClassOpKey
+ thenMClassOpKey, failMClassOpKey, returnMClassOpKey, ioTyConKey
)
import Outputable
-import Maybes ( maybeToBool )
+import Maybes ( maybeToBool, mapMaybe )
import ListSetOps ( minusList )
import Util
+import CmdLineOpts ( opt_WarnMissingFields )
+
\end{code}
%************************************************************************
-> TcType -- Expected type (could be a polytpye)
-> TcM s (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}
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) ->
-- 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 "tcPolyExpr")
+ (text "the type signature of an expression")
(mkVarSet zonked_sig_tyvars)
sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->
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}
%************************************************************************
\begin{code}
tcMonoExpr :: RenamedHsExpr -- Expession to type check
- -> TcTauType -- Expected type (could be a type variable)
+ -> TcTauType -- Expected type (could be a type variable)
-> TcM s (TcExpr, LIE)
tcMonoExpr (HsVar name) res_ty
returnTc (expr', lie)
\end{code}
-%************************************************************************
-%* *
-\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 ->
- newDicts (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)
+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 ->
+ returnNF_Tc (HsIPVar (instToId ip), unitLIE ip)
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-tcMonoExpr (HsPar expr) res_ty -- preserve parens so printing needn't guess where they go
- = 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 (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 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) ->
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 ->
+ tcLookupTyConByKey ioTyConKey `thenNF_Tc` \ ioTyCon ->
let
new_arg_dict (arg, arg_ty)
- = newDicts (CCallOrigin (_UNPK_ lbl) (Just arg))
- [(cCallableClass, [arg_ty])] `thenNF_Tc` \ (arg_dicts, _) ->
+ = newClassDicts (CCallOrigin (_UNPK_ lbl) (Just arg))
+ [(cCallableClass, [arg_ty])] `thenNF_Tc` \ (arg_dicts, _) ->
returnNF_Tc arg_dicts -- Actually a singleton bag
result_origin = CCallOrigin (_UNPK_ lbl) Nothing {- Not an arg -}
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
newTyVarTy boxedTypeKind `thenNF_Tc` \ result_ty ->
let
io_result_ty = mkTyConApp ioTyCon [result_ty]
- [ioDataCon] = tyConDataCons ioTyCon
in
unifyTauTy res_ty io_result_ty `thenTc_`
-- 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 ->
- newDicts 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
+ 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)
\end{code}
\begin{code}
-tcMonoExpr (HsSCC label expr) res_ty
+tcMonoExpr (HsSCC lbl expr) res_ty
= tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
- returnTc (HsSCC label expr', lie)
+ returnTc (HsSCC lbl expr', lie)
tcMonoExpr (HsLet binds expr) res_ty
= tcBindsAndThen
where
tc_expr = tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
returnTc (expr', lie)
- combiner is_rec bind expr = HsLet (MonoBind bind [] is_rec) expr
+ combiner is_rec bind expr = HsLet (mkMonoBind bind [] is_rec) expr
tcMonoExpr in_expr@(HsCase scrut matches src_loc) res_ty
= tcAddSrcLoc src_loc $
= 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 (RecordCon con_name rbinds) res_ty
- = tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
+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
+ -- con_name is syntactically constrained to be a data constructor
tcLookupDataCon con_name `thenTc` \ (data_con, _, _) ->
let
bad_fields = badFields rbinds data_con
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
+ 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
+ checkTcM (not (opt_WarnMissingFields && not (null missing_fields)))
+ (mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_`
+ returnNF_Tc ()) `thenNF_Tc_`
returnTc (RecordConOut data_con con_expr rbinds', con_lie `plusLIE` rbinds_lie)
-
-- The main complication with RecordUpd is that we need to explicitly
-- handle the *non-updated* fields. Consider:
--
--
-- All this is done in STEP 4 below.
-tcMonoExpr (RecordUpd record_expr rbinds) res_ty
- = tcAddErrCtxt recordUpdCtxt $
+tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty
+ = tcAddErrCtxt (recordUpdCtxt expr) $
-- STEP 0
-- Check that the field names are really field names
-- 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)
+ (_, _, tau) = ASSERT( isNotUsgTy (idType sel_id) )
+ 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, _) ->
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
let
(tyvars, theta, _, _, _, _) = dataConSig (head data_cons)
inst_env = mkTopTyVarSubst tyvars result_inst_tys
- theta' = substTheta inst_env theta
+ theta' = substClasses inst_env theta
in
- newDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) ->
+ newClassDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) ->
-- Phew!
returnTc (RecordUpdOut record_expr' result_record_ty dicts rbinds',
\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
returnTc (expr, lie)
\end{code}
+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.
\begin{code}
= 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}
-- 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)
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))
+ Just tc_id -> instantiate_it (OccurrenceOf tc_id) 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
+ instantiate_it2 (OccurrenceOf id) id tyvars theta tau
where
-- The instantiate_it loop runs round instantiating the Id.
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) ->
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 its tyvars and unify (T a1 .. an) with expected_ty.
-2. Instantiate this type
+For each binding field = value
-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.
+3. Instantiate the field type (from the field label) using the type
+ envt from step 2.
-4. Type check the value using tcArg, passing tau as the expected
- argument type.
+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)
-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)
+ = tcLookupValue 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
]
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) ]
+ 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)
+
\end{code}
%************************************************************************
\end{code}
-% =================================================
+%************************************************************************
+%* *
+\subsection{Literals}
+%* *
+%************************************************************************
+
+Overloaded literals.
+
+\begin{code}
+tcLit :: HsLit -> TcType -> TcM s (TcExpr, LIE)
+tcLit (HsLitLit s _) res_ty
+ = tcLookupClassByKey cCallableClassKey `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 label stuff = nest 2 (hang (text label) 4 stuff)
+pp_nest_hang lbl stuff = nest 2 (hang (text lbl) 4 stuff)
\end{code}
Boring and alphabetical:
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:"))
where
fields = [field | (field, _, _) <- rbinds]
-recordUpdCtxt = ptext SLIT("In a record update construct")
+recordUpdCtxt expr = ptext SLIT("In the record update:") <+> ppr expr
+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),
+ ptext SLIT("does not have the required strict field"), quotes (ppr field)]
+missingFieldCon :: Name -> Name -> SDoc
+missingFieldCon con field
+ = hsep [ptext SLIT("Field") <+> quotes (ppr field),
+ ptext SLIT("is not initialised")]
\end{code}