#include "HsVersions.h"
import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
- HsBinds(..), MonoBinds(..), Stmt(..), StmtCtxt(..),
- mkMonoBind, nullMonoBinds
+ MonoBinds(..), StmtCtxt(..),
+ mkMonoBind, nullMonoBinds
)
import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds )
-import TcHsSyn ( TcExpr, TcRecordBinds, mkHsConApp,
- mkHsTyApp, mkHsLet
- )
+import TcHsSyn ( TcExpr, TcRecordBinds, mkHsTyApp, mkHsLet )
import TcMonad
import BasicTypes ( RecFlag(..) )
-import Inst ( Inst, InstOrigin(..), OverloadedLit(..),
- LIE, emptyLIE, unitLIE, consLIE, plusLIE, plusLIEs,
- lieToList, listToLIE,
+import Inst ( InstOrigin(..),
+ LIE, emptyLIE, unitLIE, plusLIE, plusLIEs,
newOverloadedLit, newMethod, newIPDict,
instOverloadedFun, newDicts, newClassDicts,
getIPsOfLIE, instToId, ipToId
tcLookupValue, tcLookupClassByKey,
tcLookupValueByKey,
tcExtendGlobalTyVars, tcLookupValueMaybe,
- tcLookupTyCon, tcLookupDataCon
+ tcLookupTyConByKey, tcLookupDataCon
)
import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts )
import TcMonoType ( tcHsSigType, checkSigTyVars, sigCtxt )
-import TcPat ( badFieldCon )
-import TcSimplify ( tcSimplify, tcSimplifyAndCheck, partitionPredsOfLIE )
+import TcPat ( badFieldCon, simpleHsLitTy )
+import TcSimplify ( tcSimplifyAndCheck, partitionPredsOfLIE )
+import TcImprove ( tcImprove )
import TcType ( TcType, TcTauType,
tcInstTyVars,
tcInstTcType, tcSplitRhoTy,
- newTyVarTy, newTyVarTy_OpenKind, zonkTcType )
+ newTyVarTy, newTyVarTys, zonkTcType )
-import Class ( Class )
-import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType
- )
-import Id ( idType, recordSelectorFieldLabel,
- isRecordSelector,
- Id, mkVanillaId
- )
+import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon )
+import Id ( idType, recordSelectorFieldLabel, isRecordSelector, mkVanillaId )
import DataCon ( dataConFieldLabels, dataConSig,
dataConStrictMarks, StrictnessMark(..)
)
import Name ( Name, getName )
-import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys,
- ipName_maybe,
+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, substClasses )
+import TyCon ( TyCon, tyConTyVars )
+import Subst ( mkTopTyVarSubst, substClasses, substTy )
import UsageSPUtils ( unannotTy )
-import VarSet ( emptyVarSet, unionVarSet, elemVarSet, mkVarSet )
-import TyCon ( tyConDataCons )
-import TysPrim ( intPrimTy, charPrimTy, doublePrimTy,
- floatPrimTy, addrPrimTy
- )
-import TysWiredIn ( boolTy, charTy, stringTy )
-import PrelInfo ( ioTyCon_NAME )
-import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy,
- unifyUnboxedTupleTy )
+import VarSet ( elemVarSet, mkVarSet )
+import TysWiredIn ( boolTy )
+import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy )
import Unique ( cCallableClassKey, cReturnableClassKey,
enumFromClassOpKey, enumFromThenClassOpKey,
enumFromToClassOpKey, enumFromThenToClassOpKey,
- thenMClassOpKey, failMClassOpKey, returnMClassOpKey
+ thenMClassOpKey, failMClassOpKey, returnMClassOpKey, ioTyConKey
)
import Outputable
import Maybes ( maybeToBool, mapMaybe )
-> TcType -- Expected type (could be a polytpye)
-> TcM s (TcExpr, LIE)
-tcExpr expr ty | isForAllTy ty = -- Polymorphic case
- tcPolyExpr expr ty `thenTc` \ (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}
checkSigTyVars sig_tyvars free_tyvars `thenTc` \ zonked_sig_tyvars ->
newDicts SignatureOrigin sig_theta `thenNF_Tc` \ (sig_dicts, dict_ids) ->
+ tcImprove (sig_dicts `plusLIE` lie_arg) `thenTc_`
-- ToDo: better origin
tcSimplifyAndCheck
(text "the type signature of an expression")
%************************************************************************
%* *
-\subsection{Literals}
-%* *
-%************************************************************************
-
-Overloaded literals.
-
-\begin{code}
-tcMonoExpr (HsLit (HsInt i)) res_ty
- = newOverloadedLit (LiteralOrigin (HsInt i))
- (OverloadedIntegral i)
- res_ty `thenNF_Tc` \ stuff ->
- returnTc stuff
-
-tcMonoExpr (HsLit (HsFrac f)) res_ty
- = newOverloadedLit (LiteralOrigin (HsFrac f))
- (OverloadedFractional f)
- res_ty `thenNF_Tc` \ stuff ->
- returnTc stuff
-
-
-tcMonoExpr (HsLit lit@(HsLitLit s)) res_ty
- = tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass ->
- newClassDicts (LitLitOrigin (_UNPK_ s))
- [(cCallableClass,[res_ty])] `thenNF_Tc` \ (dicts, _) ->
- returnTc (HsLitOut lit res_ty, dicts)
-\end{code}
-
-Primitive literals:
-
-\begin{code}
-tcMonoExpr (HsLit lit@(HsCharPrim c)) res_ty
- = unifyTauTy res_ty charPrimTy `thenTc_`
- returnTc (HsLitOut lit charPrimTy, emptyLIE)
-
-tcMonoExpr (HsLit lit@(HsStringPrim s)) res_ty
- = unifyTauTy res_ty addrPrimTy `thenTc_`
- returnTc (HsLitOut lit addrPrimTy, emptyLIE)
-
-tcMonoExpr (HsLit lit@(HsIntPrim i)) res_ty
- = unifyTauTy res_ty intPrimTy `thenTc_`
- returnTc (HsLitOut lit intPrimTy, emptyLIE)
-
-tcMonoExpr (HsLit lit@(HsFloatPrim f)) res_ty
- = unifyTauTy res_ty floatPrimTy `thenTc_`
- returnTc (HsLitOut lit floatPrimTy, emptyLIE)
-
-tcMonoExpr (HsLit lit@(HsDoublePrim d)) res_ty
- = unifyTauTy res_ty doublePrimTy `thenTc_`
- returnTc (HsLitOut lit doublePrimTy, emptyLIE)
-\end{code}
-
-Unoverloaded literals:
-
-\begin{code}
-tcMonoExpr (HsLit lit@(HsChar c)) res_ty
- = unifyTauTy res_ty charTy `thenTc_`
- returnTc (HsLitOut lit charTy, emptyLIE)
-
-tcMonoExpr (HsLit lit@(HsString str)) res_ty
- = unifyTauTy res_ty stringTy `thenTc_`
- returnTc (HsLitOut lit stringTy, emptyLIE)
-\end{code}
-
-%************************************************************************
-%* *
\subsection{Other expression forms}
%* *
%************************************************************************
\begin{code}
-tcMonoExpr (HsPar expr) res_ty -- preserve parens so printing needn't guess where they go
- = tcMonoExpr expr res_ty
-
--- 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) ->
= -- 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)
= newClassDicts (CCallOrigin (_UNPK_ lbl) (Just 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_`
= tcAddErrCtxt (listCtxt expr) $
tcMonoExpr expr elt_ty
-tcMonoExpr (ExplicitTuple exprs boxed) res_ty
- = (if boxed
- then unifyTupleTy (length exprs) res_ty
- else unifyUnboxedTupleTy (length exprs) res_ty
- ) `thenTc` \ arg_tys ->
+tcMonoExpr (ExplicitTuple exprs boxity) res_ty
+ = unifyTupleTy boxity (length exprs) res_ty `thenTc` \ arg_tys ->
mapAndUnzipTc (\ (expr, arg_ty) -> tcMonoExpr expr arg_ty)
(exprs `zip` arg_tys) -- we know they're of equal length.
`thenTc` \ (exprs', lies) ->
- returnTc (ExplicitTuple exprs' boxed, plusLIEs lies)
+ returnTc (ExplicitTuple exprs' boxity, plusLIEs lies)
tcMonoExpr expr@(RecordCon con_name rbinds) res_ty
= tcAddErrCtxt (recordConCtxt expr) $
tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
let
(_, record_ty) = splitFunTys con_tau
+ (tycon, ty_args, _) = splitAlgTyConApp record_ty
in
ASSERT( maybeToBool (splitAlgTyConApp_maybe record_ty ) )
unifyTauTy res_ty record_ty `thenTc_`
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
-- 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
= tcSetErrCtxt (exprSigCtxt in_expr) $
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
= tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
tcIPBinds binds `thenTc` \ (binds', types, lie2) ->
partitionPredsOfLIE isBound lie `thenTc` \ (ips, lie', dict_binds) ->
- pprTrace "tcMonoExpr With" (ppr (ips, lie', dict_binds)) $
let expr'' = if nullMonoBinds dict_binds
then expr'
else HsLet (mkMonoBind (revBinds dict_binds) [] NonRecursive)
revBinds b = b
tcIPBinds ((name, expr) : binds)
- = newTyVarTy_OpenKind `thenTc` \ ty ->
+ = newTyVarTy openTypeKind `thenTc` \ ty ->
tcGetSrcLoc `thenTc` \ loc ->
let id = ipToId name ty loc in
tcMonoExpr expr ty `thenTc` \ (expr', lie) ->
= 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}
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 this type
+2. Instantiate its tyvars and unify (T a1 .. an) with expected_ty.
-3. Unify the (T a1 .. an) part with the "expected result type", which
- is passed in. This checks that all the field labels come from the
- same type.
+For each binding field = value
-4. Type check the value using tcArg, passing tau as the expected
- argument type.
+3. Instantiate the field type (from the field label) using the type
+ envt from step 2.
+
+4 Type check the value using tcArg, passing the field type as
+ the expected argument type.
This extends OK when the field types are universally quantified.
-Actually, to save excessive creation of fresh type variables,
-we
\begin{code}
tcRecordBinds
- :: TcType -- Expected type of whole record
+ :: TyCon -- Type constructor for the record
+ -> [TcType] -- Args of this type constructor
-> RenamedRecordBinds
-> TcM s (TcRecordBinds, LIE)
-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
\end{code}
-% =================================================
+%************************************************************************
+%* *
+\subsection{Literals}
+%* *
+%************************************************************************
-Errors and contexts
-~~~~~~~~~~~~~~~~~~~
+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}
+
+
+%************************************************************************
+%* *
+\subsection{Errors and contexts}
+%* *
+%************************************************************************
Mini-utils:
+
\begin{code}
pp_nest_hang :: String -> SDoc -> SDoc
pp_nest_hang lbl stuff = nest 2 (hang (text lbl) 4 stuff)
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
-
badFieldsUpd rbinds
= hang (ptext SLIT("No constructor has all these fields:"))
4 (pprQuotedList fields)
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),
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