%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcExpr]{Typecheck an expression}
#include "HsVersions.h"
import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
- HsBinds(..), Stmt(..), DoOrListComp(..),
- failureFreePat, collectPatBinders
+ HsBinds(..), Stmt(..), StmtCtxt(..),
+ failureFreePat
)
-import RnHsSyn ( RenamedHsExpr,
- RenamedStmt, RenamedRecordBinds
- )
-import TcHsSyn ( TcExpr, TcStmt,
- TcRecordBinds,
+import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds )
+import TcHsSyn ( TcExpr, TcRecordBinds,
mkHsTyApp
)
import BasicTypes ( RecFlag(..) )
import Inst ( Inst, InstOrigin(..), OverloadedLit(..),
- LIE, emptyLIE, plusLIE, plusLIEs, newOverloadedLit,
- newMethod, newMethodWithGivenTy, newDicts )
-import TcBinds ( tcBindsAndThen, checkSigTyVars )
-import TcEnv ( TcIdOcc(..), tcInstId,
+ LIE, emptyLIE, unitLIE, plusLIE, plusLIEs, newOverloadedLit,
+ newMethod, newMethodWithGivenTy, newDicts, instToId )
+import TcBinds ( tcBindsAndThen )
+import TcEnv ( TcIdOcc(..), tcInstId, tidyType,
tcLookupLocalValue, tcLookupGlobalValue, tcLookupClassByKey,
- tcLookupGlobalValueByKey, newMonoIds,
+ tcLookupGlobalValueByKey,
tcExtendGlobalTyVars, tcLookupGlobalValueMaybe,
- tcLookupTyCon
+ tcLookupTyCon, tcLookupDataCon
)
import TcMatches ( tcMatchesCase, tcMatchExpected )
-import TcGRHSs ( tcStmt )
-import TcMonoType ( tcHsType )
-import TcPat ( tcPat, badFieldsCon )
+import TcGRHSs ( tcStmts )
+import TcMonoType ( tcHsTcType, checkSigTyVars, sigCtxt )
+import TcPat ( badFieldCon )
import TcSimplify ( tcSimplifyAndCheck )
import TcType ( TcType, TcTauType, TcMaybe(..),
- tcInstType, tcInstSigTcType, tcInstTyVars,
- tcInstSigType, tcInstTcType, tcInstTheta, tcSplitRhoTy,
- newTyVarTy, newTyVarTys, zonkTcType )
-import TcKind ( TcKind )
+ tcInstTyVars,
+ tcInstTcType, tcSplitRhoTy,
+ newTyVarTy, zonkTcType )
import Class ( Class )
import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType )
-import Id ( idType, dataConFieldLabels, dataConSig, recordSelectorFieldLabel,
+import Id ( idType, recordSelectorFieldLabel,
isRecordSelector,
Id
)
-import Kind ( Kind, mkBoxedTypeKind, mkTypeKind, mkArrowKind )
-import Name ( Name{-instance Eq-} )
+import DataCon ( dataConFieldLabels, dataConSig, dataConId )
+import Name ( Name )
import Type ( mkFunTy, mkAppTy, mkTyVarTy, mkTyVarTys,
splitFunTy_maybe, splitFunTys,
mkTyConApp,
- splitForAllTys, splitRhoTy, splitSigmaTy,
+ splitForAllTys, splitRhoTy,
isTauTy, tyVarsOfType, tyVarsOfTypes,
- isForAllTy, splitAlgTyConApp, splitAlgTyConApp_maybe
- )
-import TyVar ( emptyTyVarEnv, zipTyVarEnv,
- elementOfTyVarSet, mkTyVarSet, tyVarSetToList
+ isForAllTy, splitAlgTyConApp, splitAlgTyConApp_maybe,
+ boxedTypeKind, openTypeKind, mkArrowKind,
+ substFlexiTheta
)
+import VarEnv ( zipVarEnv )
+import VarSet ( elemVarSet, mkVarSet )
import TyCon ( tyConDataCons )
import TysPrim ( intPrimTy, charPrimTy, doublePrimTy,
floatPrimTy, addrPrimTy
)
import TysWiredIn ( boolTy, charTy, stringTy )
import PrelInfo ( ioTyCon_NAME )
-import Unify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy )
-import Unique ( Unique, cCallableClassKey, cReturnableClassKey,
+import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy,
+ unifyUnboxedTupleTy )
+import Unique ( cCallableClassKey, cReturnableClassKey,
enumFromClassOpKey, enumFromThenClassOpKey,
enumFromToClassOpKey, enumFromThenToClassOpKey,
thenMClassOpKey, zeroClassOpKey, returnMClassOpKey
-- 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
- tcInstSigTcType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_rho) ->
+ tcInstTcType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_rho) ->
let
(sig_theta, sig_tau) = splitRhoTy sig_rho
in
-- Type-check the arg and unify with expected type
- tcExtendGlobalTyVars sig_tyvars (
+ tcExtendGlobalTyVars (mkVarSet sig_tyvars) (
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 (tyVarSetToList (tyVarsOfType expected_arg_ty)) $
+ tcExtendGlobalTyVars (tyVarsOfType expected_arg_ty) $
+ tcAddErrCtxtM (sigCtxt (text "an expression") sig_tau) $
+
+ checkSigTyVars sig_tyvars `thenTc` \ zonked_sig_tyvars ->
- checkSigTyVars sig_tyvars sig_tau `thenTc` \ zonked_sig_tyvars ->
newDicts SignatureOrigin sig_theta `thenNF_Tc` \ (sig_dicts, dict_ids) ->
-- ToDo: better origin
-
tcSimplifyAndCheck
(text "tcPolyExpr")
- (mkTyVarSet zonked_sig_tyvars)
- sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->
+ (mkVarSet zonked_sig_tyvars)
+ sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->
let
-- This HsLet binds any Insts which came out of the simplification.
= tcMonoExpr (HsApp neg expr) res_ty
tcMonoExpr (HsLam match) res_ty
- = tcMatchExpected [] res_ty match `thenTc` \ (match',lie) ->
+ = tcMatchExpected match res_ty LambdaBody `thenTc` \ (match',lie) ->
returnTc (HsLam match', lie)
tcMonoExpr (HsApp e1 e2) res_ty = accum e1 [e2]
tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass ->
tcLookupClassByKey cReturnableClassKey `thenNF_Tc` \ cReturnableClass ->
tcLookupTyCon ioTyCon_NAME `thenTc` \ (_,_,ioTyCon) ->
-
let
new_arg_dict (arg, arg_ty)
= newDicts (CCallOrigin (_UNPK_ lbl) (Just arg))
in
-- Arguments
- mapNF_Tc (\ _ -> newTyVarTy mkTypeKind) [1..(length args)] `thenNF_Tc` \ ty_vars ->
- tcMonoExprs args ty_vars `thenTc` \ (args', args_lie) ->
+ mapNF_Tc (\ _ -> newTyVarTy openTypeKind)
+ [1..(length args)] `thenNF_Tc` \ ty_vars ->
+ tcMonoExprs args ty_vars `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
-- type constructor.
- newTyVarTy mkBoxedTypeKind `thenNF_Tc` \ result_ty ->
+ 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_`
mapNF_Tc new_arg_dict (zipEqual "tcMonoExpr:CCall" args ty_vars) `thenNF_Tc` \ ccarg_dicts_s ->
newDicts result_origin [(cReturnableClass, [result_ty])] `thenNF_Tc` \ (ccres_dict, _) ->
- case tyConDataCons ioTyCon of { [ioDataCon] ->
- returnTc (HsApp (HsVar (RealId ioDataCon) `TyApp` [result_ty])
- (CCall lbl args' may_gc is_asm io_result_ty),
+ returnTc (HsApp (HsVar (RealId (dataConId ioDataCon)) `TyApp` [result_ty])
+ (CCall lbl args' may_gc is_asm result_ty),
-- do the wrapping in the newtype constructor here
foldr plusLIE ccres_dict ccarg_dicts_s `plusLIE` args_lie)
- }
\end{code}
\begin{code}
= tcAddErrCtxt (listCtxt expr) $
tcMonoExpr expr elt_ty
-tcMonoExpr (ExplicitTuple exprs) res_ty
- = unifyTupleTy (length exprs) res_ty `thenTc` \ arg_tys ->
+tcMonoExpr (ExplicitTuple exprs boxed) res_ty
+ = (if boxed
+ then unifyTupleTy (length exprs) res_ty
+ else unifyUnboxedTupleTy (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', plusLIEs lies)
+ `thenTc` \ (exprs', lies) ->
+ returnTc (ExplicitTuple exprs' boxed, plusLIEs lies)
-tcMonoExpr (RecordCon con_name _ rbinds) res_ty
- = tcLookupGlobalValue con_name `thenNF_Tc` \ con_id ->
- tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
+tcMonoExpr (RecordCon con_name rbinds) res_ty
+ = tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
let
(_, record_ty) = splitFunTys con_tau
in
unifyTauTy res_ty record_ty `thenTc_`
-- Check that the record bindings match the constructor
+ tcLookupDataCon con_name `thenTc` \ (data_con, _, _) ->
let
- bad_fields = badFields rbinds con_id
+ bad_fields = badFields rbinds data_con
in
- checkTc (null bad_fields) (badFieldsCon con_name bad_fields) `thenTc_`
+ mapNF_Tc (addErrTc . badFieldCon con_name) bad_fields `thenNF_Tc_`
-- 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 (RealId con_id) con_expr rbinds', con_lie `plusLIE` rbinds_lie)
+ returnTc (RecordConOut data_con con_expr rbinds', con_lie `plusLIE` rbinds_lie)
-- The main complication with RecordUpd is that we need to explicitly
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
+ | tyvar `elemVarSet` common_tyvars = returnNF_Tc result_inst_ty -- Same as result type
+ | otherwise = newTyVarTy boxedTypeKind -- Fresh type
in
mapNF_Tc mk_inst_ty (zip con_tyvars result_inst_tys) `thenNF_Tc` \ inst_tys ->
-- union the ones that could participate in the update.
let
(tyvars, theta, _, _, _, _) = dataConSig (head data_cons)
- inst_env = zipTyVarEnv tyvars result_inst_tys
+ inst_env = zipVarEnv tyvars result_inst_tys
+ theta' = substFlexiTheta inst_env theta
in
- tcInstTheta inst_env theta `thenNF_Tc` \ theta' ->
newDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) ->
-- Phew!
\begin{code}
tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty
= tcSetErrCtxt (exprSigCtxt in_expr) $
- tcHsType poly_ty `thenTc` \ sig_ty ->
- tcInstSigType sig_ty `thenNF_Tc` \ sig_tc_ty ->
+ tcHsTcType poly_ty `thenTc` \ sig_tc_ty ->
if not (isForAllTy sig_tc_ty) then
-- Easy case
= case id_expr of
HsVar name -> tcId name `thenNF_Tc` \ stuff ->
returnTc stuff
- other -> newTyVarTy mkTypeKind `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}
-- If an error happens we try to figure out whether the
-- function has been given too many or too few arguments,
-- and say so
-checkArgsCtxt fun args expected_res_ty actual_res_ty
+checkArgsCtxt fun args expected_res_ty actual_res_ty tidy_env
= zonkTcType expected_res_ty `thenNF_Tc` \ exp_ty' ->
zonkTcType actual_res_ty `thenNF_Tc` \ act_ty' ->
let
- (exp_args, _) = splitFunTys exp_ty'
- (act_args, _) = splitFunTys act_ty'
+ (env1, exp_ty'') = tidyType tidy_env exp_ty'
+ (env2, act_ty'') = tidyType env1 act_ty'
+ (exp_args, _) = splitFunTys exp_ty''
+ (act_args, _) = splitFunTys 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
| otherwise = appCtxt fun args
in
- returnNF_Tc message
+ returnNF_Tc (env2, message)
split_fun_ty :: TcType s -- The type of the function
case maybe_local of
Just tc_id -> instantiate_it (TcId tc_id) (idType tc_id)
- Nothing -> tcLookupGlobalValue name `thenNF_Tc` \ id ->
- tcInstType emptyTyVarEnv (idType id) `thenNF_Tc` \ inst_ty ->
- let
- (tyvars, rho) = splitForAllTys inst_ty
- in
- instantiate_it2 (RealId id) tyvars rho
+ Nothing -> tcLookupGlobalValue name `thenNF_Tc` \ id ->
+ tcInstId id `thenNF_Tc` \ (tyvars, theta, tau) ->
+ instantiate_it2 (RealId id) tyvars theta tau
where
-- The instantiate_it loop runs round instantiating the Id.
-- f2::tau {f2 = f1 b (Baz b), f1 = f a (Eq a)}
instantiate_it tc_id_occ ty
= tcInstTcType ty `thenNF_Tc` \ (tyvars, rho) ->
- instantiate_it2 tc_id_occ tyvars rho
+ tcSplitRhoTy rho `thenNF_Tc` \ (theta, tau) ->
+ instantiate_it2 tc_id_occ tyvars theta tau
- instantiate_it2 tc_id_occ tyvars rho
- = tcSplitRhoTy rho `thenNF_Tc` \ (theta, tau) ->
- if null theta then -- Is it overloaded?
+ instantiate_it2 tc_id_occ tyvars 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 theta tau `thenNF_Tc` \ (lie1, meth_id) ->
- instantiate_it meth_id tau `thenNF_Tc` \ (expr, lie2, final_tau) ->
- returnNF_Tc (expr, lie1 `plusLIE` lie2, final_tau)
+ tc_id_occ arg_tys theta tau `thenNF_Tc` \ inst ->
+ instantiate_it (instToId inst) tau `thenNF_Tc` \ (expr, lie2, final_tau) ->
+ returnNF_Tc (expr, unitLIE inst `plusLIE` lie2, final_tau)
where
arg_tys = mkTyVarTys tyvars
-- 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 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) ->
- unifyTauTy res_ty result_ty `thenTc_`
+ newTyVarTy (mkArrowKind boxedTypeKind boxedTypeKind) `thenNF_Tc` \ m ->
+ newTyVarTy boxedTypeKind `thenNF_Tc` \ elt_ty ->
+ unifyTauTy res_ty (mkAppTy m elt_ty) `thenTc_`
+
+ tcStmts do_or_lc (mkAppTy m) stmts elt_ty `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,
failure_free other_stmt = True
in
returnTc (HsDoOut do_or_lc stmts' return_id then_id zero_id res_ty src_loc,
- final_lie `plusLIE` monad_lie)
-
+ stmts_lie `plusLIE` monad_lie)
\end{code}
4 (quotes (ppr arg))
wrongArgsCtxt too_many_or_few fun args
- = hang (ptext SLIT("Probable cause:") <+> ppr fun
+ = hang (ptext SLIT("Probable cause:") <+> quotes (ppr fun)
<+> ptext SLIT("is applied to") <+> text too_many_or_few
<+> ptext SLIT("arguments in the call"))
4 (parens (ppr the_app))
projects / ghc-hetmet.git / blobdiff