\section[TcExpr]{Typecheck an expression}
\begin{code}
-module TcExpr ( tcApp, tcExpr, tcPolyExpr, tcId ) where
+module TcExpr ( tcApp, tcExpr, tcMonoExpr, tcPolyExpr, tcId ) where
#include "HsVersions.h"
import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
- MonoBinds(..), StmtCtxt(..),
- mkMonoBind, nullMonoBinds
+ HsMatchContext(..), mkMonoBind
)
import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds )
-import TcHsSyn ( TcExpr, TcRecordBinds, mkHsTyApp, mkHsLet )
+import TcHsSyn ( TcExpr, TcRecordBinds, mkHsLet )
import TcMonad
import BasicTypes ( RecFlag(..) )
import Inst ( InstOrigin(..),
- LIE, emptyLIE, unitLIE, plusLIE, plusLIEs,
+ LIE, mkLIE, emptyLIE, unitLIE, plusLIE, plusLIEs,
newOverloadedLit, newMethod, newIPDict,
- instOverloadedFun, newDicts, newClassDicts,
- getIPsOfLIE, instToId, ipToId
+ newDicts, newClassDicts,
+ instToId, tcInstId
)
import TcBinds ( tcBindsAndThen )
-import TcEnv ( tcInstId,
- tcLookupValue, tcLookupClass, tcLookupGlobalId,
- tcLookupTyCon, tcLookupDataCon,
- tcExtendGlobalTyVars, tcLookupValueMaybe,
+import TcEnv ( tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe,
+ tcLookupTyCon, tcLookupDataCon, tcLookupId,
+ tcExtendGlobalTyVars, tcLookupSyntaxName
)
import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts )
import TcMonoType ( tcHsSigType, checkSigTyVars, sigCtxt )
import TcPat ( badFieldCon, simpleHsLitTy )
-import TcSimplify ( tcSimplifyAndCheck, partitionPredsOfLIE )
-import TcImprove ( tcImprove )
+import TcSimplify ( tcSimplifyCheck, tcSimplifyIPs )
import TcType ( TcType, TcTauType,
- tcInstTyVars,
- tcInstTcType, tcSplitRhoTy,
+ tcInstTyVars, tcInstType,
newTyVarTy, newTyVarTys, zonkTcType )
import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon )
-import Id ( idType, recordSelectorFieldLabel, isRecordSelector, mkVanillaId )
+import Id ( idType, recordSelectorFieldLabel, isRecordSelector )
import DataCon ( dataConFieldLabels, dataConSig,
dataConStrictMarks, StrictnessMark(..)
)
-import Name ( Name, getName )
-import Type ( mkFunTy, mkAppTy, mkTyVarTys, ipName_maybe,
- splitFunTy_maybe, splitFunTys, isNotUsgTy,
+import Name ( Name )
+import Type ( mkFunTy, mkAppTy, mkTyConTy,
+ splitFunTy_maybe, splitFunTys,
mkTyConApp, splitSigmaTy,
- splitRhoTy,
isTauTy, tyVarsOfType, tyVarsOfTypes,
isSigmaTy, splitAlgTyConApp, splitAlgTyConApp_maybe,
- boxedTypeKind, openTypeKind, mkArrowKind,
+ liftedTypeKind, openTypeKind, mkArrowKind,
tidyOpenType
)
import TyCon ( TyCon, tyConTyVars )
import Subst ( mkTopTyVarSubst, substClasses, substTy )
-import UsageSPUtils ( unannotTy )
-import VarSet ( elemVarSet, mkVarSet )
-import TysWiredIn ( boolTy )
+import VarSet ( elemVarSet )
+import TysWiredIn ( boolTy, mkListTy, listTyCon )
import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy )
-import PrelNames ( cCallableClassKey, cReturnableClassKey,
- enumFromClassOpKey, enumFromThenClassOpKey,
- enumFromToClassOpKey, enumFromThenToClassOpKey,
- thenMClassOpKey, failMClassOpKey, returnMClassOpKey, ioTyConKey
+import PrelNames ( cCallableClassName,
+ cReturnableClassName,
+ enumFromName, enumFromThenName, negateName,
+ enumFromToName, enumFromThenToName,
+ thenMName, failMName, returnMName, ioTyConName
)
import Outputable
import Maybes ( maybeToBool, mapMaybe )
import ListSetOps ( minusList )
import Util
-import CmdLineOpts ( opt_WarnMissingFields )
+import CmdLineOpts
+import HscTypes ( TyThing(..) )
\end{code}
-- 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
- tcInstTcType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_rho) ->
+ tcInstType expected_arg_ty `thenNF_Tc` \ (sig_tyvars, sig_theta, sig_tau) ->
let
- (sig_theta, sig_tau) = splitRhoTy sig_rho
- free_tyvars = tyVarsOfType expected_arg_ty
+ free_tvs = 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 free_tyvars $
+ tcExtendGlobalTyVars free_tvs $
tcAddErrCtxtM (sigCtxt sig_msg sig_tyvars sig_theta sig_tau) $
- 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
+ newDicts SignatureOrigin sig_theta `thenNF_Tc` \ sig_dicts ->
+ tcSimplifyCheck
(text "the type signature of an expression")
- (mkVarSet zonked_sig_tyvars)
+ sig_tyvars
sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->
+ checkSigTyVars sig_tyvars free_tvs `thenTc` \ zonked_sig_tyvars ->
+
let
-- 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.
generalised_arg = TyLam zonked_sig_tyvars $
- DictLam dict_ids $
+ DictLam (map instToId sig_dicts) $
mkHsLet inst_binds $
arg'
in
\begin{code}
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 ->
+ = newIPDict (IPOcc name) name res_ty `thenNF_Tc` \ ip ->
returnNF_Tc (HsIPVar (instToId ip), unitLIE ip)
\end{code}
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 (HsVar neg) expr) res_ty
+tcMonoExpr (NegApp expr) res_ty
+ = tcLookupSyntaxName negateName `thenNF_Tc` \ neg ->
+ tcMonoExpr (HsApp (HsVar neg) expr) res_ty
tcMonoExpr (HsLam match) res_ty
= tcMatchLambda match res_ty `thenTc` \ (match',lie) ->
let
new_arg_dict (arg, arg_ty)
= newClassDicts (CCallOrigin (_UNPK_ lbl) (Just arg))
- [(cCallableClass, [arg_ty])] `thenNF_Tc` \ (arg_dicts, _) ->
+ [(cCallableClass, [arg_ty])] `thenNF_Tc` \ arg_dicts ->
returnNF_Tc arg_dicts -- Actually a singleton bag
result_origin = CCallOrigin (_UNPK_ lbl) Nothing {- Not an arg -}
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
- -- type must, however, be boxed since it's an argument to the IO
+ -- The argument types can be unlifted or lifted; the result
+ -- type must, however, be lifted since it's an argument to the IO
-- type constructor.
- newTyVarTy boxedTypeKind `thenNF_Tc` \ result_ty ->
+ newTyVarTy liftedTypeKind `thenNF_Tc` \ result_ty ->
let
io_result_ty = mkTyConApp ioTyCon [result_ty]
in
-- 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 ->
- newClassDicts result_origin [(cReturnableClass, [result_ty])] `thenNF_Tc` \ (ccres_dict, _) ->
+ 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)
+ mkLIE (ccres_dict ++ concat ccarg_dicts_s) `plusLIE` args_lie)
\end{code}
\begin{code}
-- Check that the record bindings match the constructor
-- con_name is syntactically constrained to be a data constructor
- tcLookupDataCon con_name `thenTc` \ (data_con, _, _) ->
+ tcLookupDataCon con_name `thenTc` \ data_con ->
let
bad_fields = badFields rbinds data_con
in
let
missing_fields = missingFields rbinds data_con
in
- checkTcM (not (opt_WarnMissingFields && not (null missing_fields)))
+ doptsTc Opt_WarnMissingFields `thenNF_Tc` \ warn ->
+ checkTcM (not (warn && not (null missing_fields)))
(mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_`
returnNF_Tc ()) `thenNF_Tc_`
-- STEP 1
-- 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) )
- splitSigmaTy (idType sel_id) -- Selectors can be overloaded
+ (Just (AnId sel_id) : _) = maybe_sel_ids
+ (_, _, tau) = 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
mk_inst_ty (tyvar, result_inst_ty)
| tyvar `elemVarSet` common_tyvars = returnNF_Tc result_inst_ty -- Same as result type
- | otherwise = newTyVarTy boxedTypeKind -- Fresh type
+ | otherwise = newTyVarTy liftedTypeKind -- Fresh type
in
mapNF_Tc mk_inst_ty (zip con_tyvars result_inst_tys) `thenNF_Tc` \ inst_tys ->
inst_env = mkTopTyVarSubst tyvars result_inst_tys
theta' = substClasses inst_env theta
in
- newClassDicts RecordUpdOrigin theta' `thenNF_Tc` \ (con_lie, dicts) ->
+ newClassDicts RecordUpdOrigin theta' `thenNF_Tc` \ dicts ->
-- Phew!
- returnTc (RecordUpdOut record_expr' result_record_ty dicts rbinds',
- con_lie `plusLIE` record_lie `plusLIE` rbinds_lie)
+ returnTc (RecordUpdOut record_expr' result_record_ty (map instToId dicts) rbinds',
+ mkLIE dicts `plusLIE` record_lie `plusLIE` rbinds_lie)
tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty
= unifyListTy res_ty `thenTc` \ elt_ty ->
tcMonoExpr expr elt_ty `thenTc` \ (expr', lie1) ->
- tcLookupGlobalId enumFromClassOpName `thenNF_Tc` \ sel_id ->
+ tcLookupGlobalId enumFromName `thenNF_Tc` \ sel_id ->
newMethod (ArithSeqOrigin seq)
- sel_id [elt_ty] `thenNF_Tc` \ (lie2, enum_from_id) ->
+ sel_id [elt_ty] `thenNF_Tc` \ enum_from ->
- returnTc (ArithSeqOut (HsVar enum_from_id) (From expr'),
- lie1 `plusLIE` lie2)
+ returnTc (ArithSeqOut (HsVar (instToId enum_from)) (From expr'),
+ lie1 `plusLIE` unitLIE enum_from)
tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_ty
= tcAddErrCtxt (arithSeqCtxt in_expr) $
unifyListTy res_ty `thenTc` \ elt_ty ->
tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
- tcLookupGlobalId enumFromThenClassOpName `thenNF_Tc` \ sel_id ->
- newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_then_id) ->
+ tcLookupGlobalId enumFromThenName `thenNF_Tc` \ sel_id ->
+ newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ enum_from_then ->
- returnTc (ArithSeqOut (HsVar enum_from_then_id)
- (FromThen expr1' expr2'),
- lie1 `plusLIE` lie2 `plusLIE` lie3)
+ returnTc (ArithSeqOut (HsVar (instToId enum_from_then))
+ (FromThen expr1' expr2'),
+ lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_then)
tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_ty
= tcAddErrCtxt (arithSeqCtxt in_expr) $
unifyListTy res_ty `thenTc` \ elt_ty ->
tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
- tcLookupGlobalId enumFromToClassOpName `thenNF_Tc` \ sel_id ->
- newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie3, enum_from_to_id) ->
+ tcLookupGlobalId enumFromToName `thenNF_Tc` \ sel_id ->
+ newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ enum_from_to ->
- returnTc (ArithSeqOut (HsVar enum_from_to_id)
+ returnTc (ArithSeqOut (HsVar (instToId enum_from_to))
(FromTo expr1' expr2'),
- lie1 `plusLIE` lie2 `plusLIE` lie3)
+ lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_to)
tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty
= tcAddErrCtxt (arithSeqCtxt in_expr) $
tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
tcMonoExpr expr3 elt_ty `thenTc` \ (expr3',lie3) ->
- tcLookupGlobalId enumFromThenToClassOpName `thenNF_Tc` \ sel_id ->
- newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ (lie4, eft_id) ->
+ tcLookupGlobalId enumFromThenToName `thenNF_Tc` \ sel_id ->
+ newMethod (ArithSeqOrigin seq) sel_id [elt_ty] `thenNF_Tc` \ eft ->
- returnTc (ArithSeqOut (HsVar eft_id)
- (FromThenTo expr1' expr2' expr3'),
- lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` lie4)
+ returnTc (ArithSeqOut (HsVar (instToId eft))
+ (FromThenTo expr1' expr2' expr3'),
+ lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` unitLIE eft)
\end{code}
%************************************************************************
-- If everything is ok, return the stuff unchanged, except for
-- the effect of any substutions etc. We simply discard the
- -- result of the tcSimplifyAndCheck (inside tcPolyExpr), except for any default
+ -- result of the tcSimplifyCheck (inside tcPolyExpr), except for any default
-- resolution it may have done, which is recorded in the
-- substitution.
returnTc (expr, lie)
\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'
+ = tcMonoExpr expr res_ty `thenTc` \ (expr', expr_lie) ->
+ mapAndUnzipTc tcIPBind binds `thenTc` \ (pairs, bind_lies) ->
+ tcSimplifyIPs (map fst binds) expr_lie `thenTc` \ (expr_lie', dict_binds) ->
+ let
+ binds' = [(instToId ip, rhs) | (ip,rhs) <- pairs]
+ expr'' = HsLet (mkMonoBind dict_binds [] Recursive) 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}
-tcExpr_id :: RenamedHsExpr
- -> TcM (TcExpr,
- LIE,
- TcType)
-tcExpr_id id_expr
- = case id_expr of
- HsVar name -> tcId name `thenNF_Tc` \ stuff ->
- returnTc stuff
- other -> newTyVarTy openTypeKind `thenNF_Tc` \ id_ty ->
- tcMonoExpr id_expr id_ty `thenTc` \ (id_expr', lie_id) ->
- returnTc (id_expr', lie_id, id_ty)
+ returnTc (HsWith expr'' binds', expr_lie' `plusLIE` plusLIEs bind_lies)
+
+tcIPBind (name, expr)
+ = newTyVarTy openTypeKind `thenTc` \ ty ->
+ tcGetSrcLoc `thenTc` \ loc ->
+ newIPDict (IPBind name) name ty `thenNF_Tc` \ ip ->
+ tcMonoExpr expr ty `thenTc` \ (expr', lie) ->
+ returnTc ((ip, expr'), lie)
\end{code}
%************************************************************************
%* *
%************************************************************************
-Between the renamer and the first invocation of the UsageSP inference,
-identifiers read from interface files will have usage information in
-their types, whereas other identifiers will not. The unannotTy here
-in @tcId@ prevents this information from pointlessly propagating
-further prior to the first usage inference.
-
\begin{code}
tcId :: Name -> NF_TcM (TcExpr, LIE, TcType)
+tcId name -- Look up the Id and instantiate its type
+ = tcLookupId name `thenNF_Tc` \ id ->
+ tcInstId id
+\end{code}
-tcId name
- = -- Look up the Id and instantiate its type
- tcLookup name `thenNF_Tc` \ thing ->
- case thing of
- ATcId tc_id -> instantiate_it (OccurrenceOf tc_id) tc_id (idType tc_id)
- AGlobal (AnId id) -> tcInstId id `thenNF_Tc` \ (tyvars, theta, tau) ->
- instantiate_it2 (OccurrenceOf id) id tyvars theta tau
+Typecheck expression which in most cases will be an Id.
- where
- -- The instantiate_it loop runs round instantiating the Id.
- -- It has to be a loop because we are now prepared to entertain
- -- types like
- -- f:: forall a. Eq a => forall b. Baz b => tau
- -- We want to instantiate this to
- -- f2::tau {f2 = f1 b (Baz b), f1 = f a (Eq a)}
- instantiate_it orig fun ty
- = tcInstTcType ty `thenNF_Tc` \ (tyvars, rho) ->
- tcSplitRhoTy rho `thenNF_Tc` \ (theta, tau) ->
- instantiate_it2 orig fun tyvars theta tau
-
- instantiate_it2 orig fun tyvars theta tau
- = if null theta then -- Is it overloaded?
- 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) ->
- instantiate_it orig fun' tau `thenNF_Tc` \ (expr, lie2, final_tau) ->
- returnNF_Tc (expr, lie1 `plusLIE` lie2, final_tau)
-
- where
- arg_tys = mkTyVarTys tyvars
+\begin{code}
+tcExpr_id :: RenamedHsExpr -> TcM (TcExpr, LIE, TcType)
+tcExpr_id (HsVar name) = tcId name
+tcExpr_id expr = newTyVarTy openTypeKind `thenNF_Tc` \ id_ty ->
+ tcMonoExpr expr id_ty `thenTc` \ (expr', lie_id) ->
+ returnTc (expr', lie_id, id_ty)
\end{code}
+
%************************************************************************
%* *
\subsection{@tcDoStmts@ typechecks a {\em list} of do statements}
ASSERT( not (null stmts) )
tcAddSrcLoc src_loc $
- newTyVarTy (mkArrowKind boxedTypeKind boxedTypeKind) `thenNF_Tc` \ m ->
- newTyVarTy boxedTypeKind `thenNF_Tc` \ elt_ty ->
- unifyTauTy res_ty (mkAppTy m elt_ty) `thenTc_`
-
-- If it's a comprehension we're dealing with,
-- force it to be a list comprehension.
-- (as of Haskell 98, monad comprehensions are no more.)
(case do_or_lc of
- ListComp -> unifyListTy res_ty `thenTc_` returnTc ()
- _ -> returnTc ()) `thenTc_`
+ ListComp -> unifyListTy res_ty `thenTc` \ elt_ty ->
+ returnNF_Tc (mkTyConTy listTyCon, (mkListTy, elt_ty))
+
+ _ -> newTyVarTy (mkArrowKind liftedTypeKind liftedTypeKind) `thenNF_Tc` \ m_ty ->
+ newTyVarTy liftedTypeKind `thenNF_Tc` \ elt_ty ->
+ unifyTauTy res_ty (mkAppTy m_ty elt_ty) `thenTc_`
+ returnNF_Tc (m_ty, (mkAppTy m_ty, elt_ty))
+ ) `thenNF_Tc` \ (tc_ty, m_ty) ->
- tcStmts do_or_lc (mkAppTy m) stmts elt_ty `thenTc` \ (stmts', stmts_lie) ->
+ tcStmts do_or_lc m_ty stmts `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,
-- then = then
-- where the second "then" sees that it already exists in the "available" stuff.
--
- tcLookupGlobalId returnMClassOpName `thenNF_Tc` \ return_sel_id ->
- tcLookupGlobalId thenMClassOpName `thenNF_Tc` \ then_sel_id ->
- tcLookupGlobalId failMClassOpName `thenNF_Tc` \ fail_sel_id ->
- newMethod DoOrigin return_sel_id [m] `thenNF_Tc` \ (return_lie, return_id) ->
- newMethod DoOrigin then_sel_id [m] `thenNF_Tc` \ (then_lie, then_id) ->
- newMethod DoOrigin fail_sel_id [m] `thenNF_Tc` \ (fail_lie, fail_id) ->
+ tcLookupGlobalId returnMName `thenNF_Tc` \ return_sel_id ->
+ tcLookupGlobalId thenMName `thenNF_Tc` \ then_sel_id ->
+ tcLookupGlobalId failMName `thenNF_Tc` \ fail_sel_id ->
+ newMethod DoOrigin return_sel_id [tc_ty] `thenNF_Tc` \ return_inst ->
+ newMethod DoOrigin then_sel_id [tc_ty] `thenNF_Tc` \ then_inst ->
+ newMethod DoOrigin fail_sel_id [tc_ty] `thenNF_Tc` \ fail_inst ->
let
- monad_lie = then_lie `plusLIE` return_lie `plusLIE` fail_lie
+ monad_lie = mkLIE [return_inst, then_inst, fail_inst]
in
- returnTc (HsDoOut do_or_lc stmts' return_id then_id fail_id res_ty src_loc,
+ returnTc (HsDoOut do_or_lc stmts'
+ (instToId return_inst) (instToId then_inst) (instToId fail_inst)
+ res_ty src_loc,
stmts_lie `plusLIE` monad_lie)
\end{code}
tcLit (HsLitLit s _) res_ty
= tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass ->
newClassDicts (LitLitOrigin (_UNPK_ s))
- [(cCallableClass,[res_ty])] `thenNF_Tc` \ (dicts, _) ->
- returnTc (HsLit (HsLitLit s res_ty), dicts)
+ [(cCallableClass,[res_ty])] `thenNF_Tc` \ dicts ->
+ returnTc (HsLit (HsLitLit s res_ty), mkLIE dicts)
tcLit lit res_ty
= unifyTauTy res_ty (simpleHsLitTy lit) `thenTc_`