%
-% (c) The AQUA Project, Glasgow University, 1996
+% (c) The AQUA Project, Glasgow University, 1996-1998
%
\section[TcHsSyn]{Specialisations of the @HsSyn@ syntax for the typechecker}
\begin{code}
module TcHsSyn (
- TcMonoBinds, TcHsBinds, TcPat,
- TcExpr, TcGRHSsAndBinds, TcGRHS, TcMatch,
- TcStmt, TcArithSeqInfo, TcRecordBinds,
- TcHsModule, TcCoreExpr, TcDictBinds,
+ mkHsTyApp, mkHsDictApp, mkHsConApp,
+ mkHsTyLam, mkHsDictLam, mkHsDictLet, mkHsApp,
+ hsLitType, hsPatType, mkHsAppTy, mkSimpleHsAlt,
+ nlHsIntLit, mkVanillaTuplePat,
- TypecheckedHsBinds,
- TypecheckedMonoBinds, TypecheckedPat,
- TypecheckedHsExpr, TypecheckedArithSeqInfo,
- TypecheckedStmt,
- TypecheckedMatch, TypecheckedHsModule,
- TypecheckedGRHSsAndBinds, TypecheckedGRHS,
- TypecheckedRecordBinds, TypecheckedDictBinds,
- mkHsTyApp, mkHsDictApp,
- mkHsTyLam, mkHsDictLam,
+ -- re-exported from TcMonad
+ TcId, TcIdSet, TcDictBinds,
- -- re-exported from TcEnv
- TcIdOcc(..), TcIdBndr, tcIdType, tcIdTyVars, tcInstId,
-
- maybeBoxedPrimType,
-
- zonkTopBinds, zonkBinds, zonkMonoBinds, zonkTcId
+ zonkTopDecls, zonkTopExpr, zonkTopLExpr,
+ zonkId, zonkTopBndrs
) where
#include "HsVersions.h"
-- friends:
import HsSyn -- oodles of it
-import Id ( GenId(..), IdDetails, -- Can meddle modestly with Ids
- DictVar, idType, dataConArgTys,
- Id
- )
-- others:
-import Name ( NamedThing(..) )
-import BasicTypes ( IfaceFlavour, Unused )
-import TcEnv ( tcLookupGlobalValueMaybe, tcExtendGlobalValEnv,
- TcIdOcc(..), TcIdBndr, tcIdType, tcIdTyVars, tcInstId
- )
-
-import TcMonad
-import TcType ( TcType, TcMaybe, TcTyVar, TcBox,
- zonkTcTypeToType, zonkTcTyVarToTyVar, zonkTcType
- )
-import TyCon ( isDataTyCon )
-import Type ( mkTyVarTy, tyVarsOfType, splitAlgTyConApp_maybe, isUnpointedType, Type )
-import TyVar ( TyVar, TyVarEnv, emptyTyVarEnv, growTyVarEnvList, emptyTyVarSet )
-import TysPrim ( voidTy )
-import CoreSyn ( GenCoreExpr )
-import Unique ( Unique ) -- instances
+import Id ( idType, setIdType, Id )
+
+import TcRnMonad
+import Type ( Type )
+import TcType ( TcType, TcTyVar, mkTyVarTy, mkTyConApp, isImmutableTyVar )
+import Kind ( isLiftedTypeKind, liftedTypeKind, isSubKind )
+import qualified Type
+import TcMType ( zonkQuantifiedTyVar, zonkType, zonkTcType, writeMetaTyVar )
+import TysPrim ( charPrimTy, intPrimTy, floatPrimTy,
+ doublePrimTy, addrPrimTy
+ )
+import TysWiredIn ( charTy, stringTy, intTy,
+ mkListTy, mkPArrTy, mkTupleTy, unitTy,
+ voidTy, listTyCon, tupleTyCon )
+import TyCon ( mkPrimTyCon, tyConKind, PrimRep(..) )
+import Kind ( splitKindFunTys )
+import Name ( Name, getOccName, mkInternalName, mkDerivedTyConOcc )
+import Var ( Var, isId, isLocalVar, tyVarKind )
+import VarSet
+import VarEnv
+import BasicTypes ( Boxity(..), IPName(..), ipNameName, mapIPName )
+import Maybes ( orElse )
+import Unique ( Uniquable(..) )
+import SrcLoc ( noSrcLoc, noLoc, Located(..), unLoc )
+import Util ( mapSnd )
import Bag
-import UniqFM
-import Util ( zipEqual )
import Outputable
\end{code}
-Type definitions
-~~~~~~~~~~~~~~~~
-
-The @Tc...@ datatypes are the ones that apply {\em during} type checking.
-All the types in @Tc...@ things have mutable type-variables in them for
-unification.
-
-At the end of type checking we zonk everything to @Typechecked...@ datatypes,
-which have immutable type variables in them.
-
-\begin{code}
-type TcHsBinds s = HsBinds (TcBox s) (TcIdOcc s) (TcPat s)
-type TcMonoBinds s = MonoBinds (TcBox s) (TcIdOcc s) (TcPat s)
-type TcDictBinds s = TcMonoBinds s
-type TcPat s = OutPat (TcBox s) (TcIdOcc s)
-type TcExpr s = HsExpr (TcBox s) (TcIdOcc s) (TcPat s)
-type TcGRHSsAndBinds s = GRHSsAndBinds (TcBox s) (TcIdOcc s) (TcPat s)
-type TcGRHS s = GRHS (TcBox s) (TcIdOcc s) (TcPat s)
-type TcMatch s = Match (TcBox s) (TcIdOcc s) (TcPat s)
-type TcStmt s = Stmt (TcBox s) (TcIdOcc s) (TcPat s)
-type TcArithSeqInfo s = ArithSeqInfo (TcBox s) (TcIdOcc s) (TcPat s)
-type TcRecordBinds s = HsRecordBinds (TcBox s) (TcIdOcc s) (TcPat s)
-type TcHsModule s = HsModule (TcBox s) (TcIdOcc s) (TcPat s)
-
-type TcCoreExpr s = GenCoreExpr (TcIdOcc s) (TcIdOcc s) (TcBox s)
-
-type TypecheckedPat = OutPat Unused Id
-type TypecheckedMonoBinds = MonoBinds Unused Id TypecheckedPat
-type TypecheckedDictBinds = TypecheckedMonoBinds
-type TypecheckedHsBinds = HsBinds Unused Id TypecheckedPat
-type TypecheckedHsExpr = HsExpr Unused Id TypecheckedPat
-type TypecheckedArithSeqInfo = ArithSeqInfo Unused Id TypecheckedPat
-type TypecheckedStmt = Stmt Unused Id TypecheckedPat
-type TypecheckedMatch = Match Unused Id TypecheckedPat
-type TypecheckedGRHSsAndBinds = GRHSsAndBinds Unused Id TypecheckedPat
-type TypecheckedGRHS = GRHS Unused Id TypecheckedPat
-type TypecheckedRecordBinds = HsRecordBinds Unused Id TypecheckedPat
-type TypecheckedHsModule = HsModule Unused Id TypecheckedPat
-\end{code}
-
-\begin{code}
-mkHsTyApp expr [] = expr
-mkHsTyApp expr tys = TyApp expr tys
-
-mkHsDictApp expr [] = expr
-mkHsDictApp expr dict_vars = DictApp expr dict_vars
-
-mkHsTyLam [] expr = expr
-mkHsTyLam tyvars expr = TyLam tyvars expr
-
-mkHsDictLam [] expr = expr
-mkHsDictLam dicts expr = DictLam dicts expr
-\end{code}
-
%************************************************************************
%* *
-\subsection[BackSubst-HsBinds]{Running a substitution over @HsBinds@}
+\subsection[mkFailurePair]{Code for pattern-matching and other failures}
%* *
%************************************************************************
-Some gruesome hackery for desugaring ccalls. It's here because if we put it
-in Type.lhs we get irritating loops, and it's only used by TcInstDcls.lhs and
-DsCCall.lhs.
-
+Note: If @hsPatType@ doesn't bear a strong resemblance to @exprType@,
+then something is wrong.
\begin{code}
-maybeBoxedPrimType :: Type -> Maybe (Id, Type)
-maybeBoxedPrimType ty
- = case splitAlgTyConApp_maybe ty of -- Data type,
- Just (tycon, tys_applied, [data_con]) | isDataTyCon tycon -- with exactly one constructor
- -> case (dataConArgTys data_con tys_applied) of
- [data_con_arg_ty] -- Applied to exactly one type,
- | isUnpointedType data_con_arg_ty -- which is primitive
- -> Just (data_con, data_con_arg_ty)
- other_cases -> Nothing
- other_cases -> Nothing
+mkVanillaTuplePat :: [OutPat Id] -> Boxity -> Pat Id
+-- A vanilla tuple pattern simply gets its type from its sub-patterns
+mkVanillaTuplePat pats box
+ = TuplePat pats box (mkTupleTy box (length pats) (map hsPatType pats))
+
+hsPatType :: OutPat Id -> Type
+hsPatType (L _ pat) = pat_type pat
+
+pat_type (ParPat pat) = hsPatType pat
+pat_type (WildPat ty) = ty
+pat_type (VarPat var) = idType var
+pat_type (VarPatOut var _) = idType var
+pat_type (BangPat pat) = hsPatType pat
+pat_type (LazyPat pat) = hsPatType pat
+pat_type (LitPat lit) = hsLitType lit
+pat_type (AsPat var pat) = idType (unLoc var)
+pat_type (ListPat _ ty) = mkListTy ty
+pat_type (PArrPat _ ty) = mkPArrTy ty
+pat_type (TuplePat pats box ty) = ty
+pat_type (ConPatOut _ _ _ _ _ ty) = ty
+pat_type (SigPatOut pat ty) = ty
+pat_type (NPat lit _ _ ty) = ty
+pat_type (NPlusKPat id _ _ _) = idType (unLoc id)
+pat_type (DictPat ds ms) = case (ds ++ ms) of
+ [] -> unitTy
+ [d] -> idType d
+ ds -> mkTupleTy Boxed (length ds) (map idType ds)
+
+
+hsLitType :: HsLit -> TcType
+hsLitType (HsChar c) = charTy
+hsLitType (HsCharPrim c) = charPrimTy
+hsLitType (HsString str) = stringTy
+hsLitType (HsStringPrim s) = addrPrimTy
+hsLitType (HsInt i) = intTy
+hsLitType (HsIntPrim i) = intPrimTy
+hsLitType (HsInteger i ty) = ty
+hsLitType (HsRat _ ty) = ty
+hsLitType (HsFloatPrim f) = floatPrimTy
+hsLitType (HsDoublePrim d) = doublePrimTy
\end{code}
+
%************************************************************************
%* *
\subsection[BackSubst-HsBinds]{Running a substitution over @HsBinds@}
%* *
%************************************************************************
-@zonkTcId@ just works on TcIdOccs. It's used when zonking Method insts.
-
\begin{code}
-zonkTcId :: TcIdOcc s -> NF_TcM s (TcIdOcc s)
-zonkTcId tc_id@(RealId id) = returnNF_Tc tc_id
-zonkTcId (TcId (Id u n ty details prags info))
- = zonkTcType ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (TcId (Id u n ty' details prags info))
+-- zonkId is used *during* typechecking just to zonk the Id's type
+zonkId :: TcId -> TcM TcId
+zonkId id
+ = zonkTcType (idType id) `thenM` \ ty' ->
+ returnM (setIdType id ty')
\end{code}
-This zonking pass runs over the bindings
+The rest of the zonking is done *after* typechecking.
+The main zonking pass runs over the bindings
a) to convert TcTyVars to TyVars etc, dereferencing any bindings etc
b) convert unbound TcTyVar to Void
- c) convert each TcIdBndr to an Id by zonking its type
+ c) convert each TcId to an Id by zonking its type
-We pass an environment around so that
+The type variables are converted by binding mutable tyvars to immutable ones
+and then zonking as normal.
- a) we know which TyVars are unbound
- b) we maintain sharing; eg an Id is zonked at its binding site and they
- all occurrences of that Id point to the common zonked copy
-
-Actually, since this is all in the Tc monad, it's convenient to keep the
-mapping from TcIds to Ids in the GVE of the Tc monad. (Those TcIds
-were previously in the LVE of the Tc monad.)
+The Ids are converted by binding them in the normal Tc envt; that
+way we maintain sharing; eg an Id is zonked at its binding site and they
+all occurrences of that Id point to the common zonked copy
It's all pretty boring stuff, because HsSyn is such a large type, and
the environment manipulation is tiresome.
\begin{code}
-extend_te te tyvars = growTyVarEnvList te [(tyvar, mkTyVarTy tyvar) | tyvar <- tyvars]
-
-zonkIdBndr :: TyVarEnv Type -> TcIdOcc s -> NF_TcM s Id
-zonkIdBndr te (RealId id) = returnNF_Tc id
-zonkIdBndr te (TcId (Id u n ty details prags info))
- = zonkTcTypeToType te ty `thenNF_Tc` \ ty' ->
- returnNF_Tc (Id u n ty' details prags info)
-
-
-zonkIdOcc :: TcIdOcc s -> NF_TcM s Id
-zonkIdOcc (RealId id) = returnNF_Tc id
-zonkIdOcc (TcId id)
- = tcLookupGlobalValueMaybe (getName id) `thenNF_Tc` \ maybe_id' ->
- let
- new_id = case maybe_id' of
- Just id' -> id'
- Nothing -> pprTrace "zonkIdOcc: " (ppr id) $
- Id u n voidTy details prags info
- where
- Id u n _ details prags info = id
- in
- returnNF_Tc new_id
+data ZonkEnv = ZonkEnv (TcType -> TcM Type) -- How to zonk a type
+ (IdEnv Id) -- What variables are in scope
+ -- Maps an Id to its zonked version; both have the same Name
+ -- Is only consulted lazily; hence knot-tying
+
+emptyZonkEnv = ZonkEnv zonkTypeZapping emptyVarEnv
+
+extendZonkEnv :: ZonkEnv -> [Id] -> ZonkEnv
+extendZonkEnv (ZonkEnv zonk_ty env) ids
+ = ZonkEnv zonk_ty (extendVarEnvList env [(id,id) | id <- ids])
+
+extendZonkEnv1 :: ZonkEnv -> Id -> ZonkEnv
+extendZonkEnv1 (ZonkEnv zonk_ty env) id
+ = ZonkEnv zonk_ty (extendVarEnv env id id)
+
+setZonkType :: ZonkEnv -> (TcType -> TcM Type) -> ZonkEnv
+setZonkType (ZonkEnv _ env) zonk_ty = ZonkEnv zonk_ty env
+
+zonkEnvIds :: ZonkEnv -> [Id]
+zonkEnvIds (ZonkEnv _ env) = varEnvElts env
+
+zonkIdOcc :: ZonkEnv -> TcId -> Id
+-- Ids defined in this module should be in the envt;
+-- ignore others. (Actually, data constructors are also
+-- not LocalVars, even when locally defined, but that is fine.)
+-- (Also foreign-imported things aren't currently in the ZonkEnv;
+-- that's ok because they don't need zonking.)
+--
+-- Actually, Template Haskell works in 'chunks' of declarations, and
+-- an earlier chunk won't be in the 'env' that the zonking phase
+-- carries around. Instead it'll be in the tcg_gbl_env, already fully
+-- zonked. There's no point in looking it up there (except for error
+-- checking), and it's not conveniently to hand; hence the simple
+-- 'orElse' case in the LocalVar branch.
+--
+-- Even without template splices, in module Main, the checking of
+-- 'main' is done as a separate chunk.
+zonkIdOcc (ZonkEnv zonk_ty env) id
+ | isLocalVar id = lookupVarEnv env id `orElse` id
+ | otherwise = id
+
+zonkIdOccs env ids = map (zonkIdOcc env) ids
+
+-- zonkIdBndr is used *after* typechecking to get the Id's type
+-- to its final form. The TyVarEnv give
+zonkIdBndr :: ZonkEnv -> TcId -> TcM Id
+zonkIdBndr env id
+ = zonkTcTypeToType env (idType id) `thenM` \ ty' ->
+ returnM (setIdType id ty')
+
+zonkIdBndrs :: ZonkEnv -> [TcId] -> TcM [Id]
+zonkIdBndrs env ids = mappM (zonkIdBndr env) ids
+
+zonkTopBndrs :: [TcId] -> TcM [Id]
+zonkTopBndrs ids = zonkIdBndrs emptyZonkEnv ids
\end{code}
\begin{code}
-zonkTopBinds :: TcMonoBinds s -> NF_TcM s (TypecheckedMonoBinds, TcEnv s)
-zonkTopBinds binds -- Top level is implicitly recursive
- = fixNF_Tc (\ ~(_, new_ids) ->
- tcExtendGlobalValEnv (bagToList new_ids) $
- zonkMonoBinds emptyTyVarEnv binds `thenNF_Tc` \ (binds', new_ids) ->
- tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc ((binds', env), new_ids)
- ) `thenNF_Tc` \ (stuff, _) ->
- returnNF_Tc stuff
-
-
-zonkBinds :: TyVarEnv Type
- -> TcHsBinds s
- -> NF_TcM s (TypecheckedHsBinds, TcEnv s)
-
-zonkBinds te binds
- = go binds (\ binds' -> tcGetEnv `thenNF_Tc` \ env -> returnNF_Tc (binds', env))
- where
- -- go :: TcHsBinds s -> (TypecheckedHsBinds -> NF_TcM s (TypecheckedHsBinds, TcEnv s))
- -- -> NF_TcM s (TypecheckedHsBinds, TcEnv s)
- go (ThenBinds b1 b2) thing_inside = go b1 $ \ b1' ->
- go b2 $ \ b2' ->
- thing_inside (b1' `ThenBinds` b2')
-
- go EmptyBinds thing_inside = thing_inside EmptyBinds
-
- go (MonoBind bind sigs is_rec) thing_inside
- = ASSERT( null sigs )
- fixNF_Tc (\ ~(_, new_ids) ->
- tcExtendGlobalValEnv (bagToList new_ids) $
- zonkMonoBinds te bind `thenNF_Tc` \ (new_bind, new_ids) ->
- thing_inside (MonoBind new_bind [] is_rec) `thenNF_Tc` \ stuff ->
- returnNF_Tc (stuff, new_ids)
- ) `thenNF_Tc` \ (stuff, _) ->
- returnNF_Tc stuff
-\end{code}
-
-\begin{code}
--------------------------------------------------------------------------
-zonkMonoBinds :: TyVarEnv Type
- -> TcMonoBinds s
- -> NF_TcM s (TypecheckedMonoBinds, Bag Id)
-
-zonkMonoBinds te EmptyMonoBinds = returnNF_Tc (EmptyMonoBinds, emptyBag)
-
-zonkMonoBinds te (AndMonoBinds mbinds1 mbinds2)
- = zonkMonoBinds te mbinds1 `thenNF_Tc` \ (b1', ids1) ->
- zonkMonoBinds te mbinds2 `thenNF_Tc` \ (b2', ids2) ->
- returnNF_Tc (b1' `AndMonoBinds` b2', ids1 `unionBags` ids2)
-
-zonkMonoBinds te (PatMonoBind pat grhss_w_binds locn)
- = zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- zonkGRHSsAndBinds te grhss_w_binds `thenNF_Tc` \ new_grhss_w_binds ->
- returnNF_Tc (PatMonoBind new_pat new_grhss_w_binds locn, ids)
-
-zonkMonoBinds te (VarMonoBind var expr)
- = zonkIdBndr te var `thenNF_Tc` \ new_var ->
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (VarMonoBind new_var new_expr, unitBag new_var)
-
-zonkMonoBinds te (CoreMonoBind var core_expr)
- = zonkIdBndr te var `thenNF_Tc` \ new_var ->
- returnNF_Tc (CoreMonoBind new_var core_expr, unitBag new_var)
-
-zonkMonoBinds te (FunMonoBind var inf ms locn)
- = zonkIdBndr te var `thenNF_Tc` \ new_var ->
- mapNF_Tc (zonkMatch te) ms `thenNF_Tc` \ new_ms ->
- returnNF_Tc (FunMonoBind new_var inf new_ms locn, unitBag new_var)
-
-
-zonkMonoBinds te (AbsBinds tyvars dicts exports val_bind)
- = mapNF_Tc zonkTcTyVarToTyVar tyvars `thenNF_Tc` \ new_tyvars ->
+zonkTopExpr :: HsExpr TcId -> TcM (HsExpr Id)
+zonkTopExpr e = zonkExpr emptyZonkEnv e
+
+zonkTopLExpr :: LHsExpr TcId -> TcM (LHsExpr Id)
+zonkTopLExpr e = zonkLExpr emptyZonkEnv e
+
+zonkTopDecls :: LHsBinds TcId -> [LRuleDecl TcId] -> [LForeignDecl TcId]
+ -> TcM ([Id],
+ Bag (LHsBind Id),
+ [LForeignDecl Id],
+ [LRuleDecl Id])
+zonkTopDecls binds rules fords
+ = do { (env, binds') <- zonkRecMonoBinds emptyZonkEnv binds
+ -- Top level is implicitly recursive
+ ; rules' <- zonkRules env rules
+ ; fords' <- zonkForeignExports env fords
+ ; return (zonkEnvIds env, binds', fords', rules') }
+
+---------------------------------------------
+zonkLocalBinds :: ZonkEnv -> HsLocalBinds TcId -> TcM (ZonkEnv, HsLocalBinds Id)
+zonkLocalBinds env EmptyLocalBinds
+ = return (env, EmptyLocalBinds)
+
+zonkLocalBinds env (HsValBinds binds)
+ = do { (env1, new_binds) <- zonkValBinds env binds
+ ; return (env1, HsValBinds new_binds) }
+
+zonkLocalBinds env (HsIPBinds (IPBinds binds dict_binds))
+ = mappM (wrapLocM zonk_ip_bind) binds `thenM` \ new_binds ->
let
- new_te = extend_te te new_tyvars
+ env1 = extendZonkEnv env [ipNameName n | L _ (IPBind n _) <- new_binds]
in
- mapNF_Tc (zonkIdBndr new_te) dicts `thenNF_Tc` \ new_dicts ->
-
- tcExtendGlobalValEnv new_dicts $
- fixNF_Tc (\ ~(_, _, val_bind_ids) ->
- tcExtendGlobalValEnv (bagToList val_bind_ids) $
- zonkMonoBinds new_te val_bind `thenNF_Tc` \ (new_val_bind, val_bind_ids) ->
- mapNF_Tc (zonkExport new_te) exports `thenNF_Tc` \ new_exports ->
- returnNF_Tc (new_val_bind, new_exports, val_bind_ids)
- ) `thenNF_Tc ` \ (new_val_bind, new_exports, _) ->
- let
- new_globals = listToBag [global | (_, global, local) <- new_exports]
- in
- returnNF_Tc (AbsBinds new_tyvars new_dicts new_exports new_val_bind,
- new_globals)
+ zonkRecMonoBinds env1 dict_binds `thenM` \ (env2, new_dict_binds) ->
+ returnM (env2, HsIPBinds (IPBinds new_binds new_dict_binds))
+ where
+ zonk_ip_bind (IPBind n e)
+ = mapIPNameTc (zonkIdBndr env) n `thenM` \ n' ->
+ zonkLExpr env e `thenM` \ e' ->
+ returnM (IPBind n' e')
+
+
+---------------------------------------------
+zonkValBinds :: ZonkEnv -> HsValBinds TcId -> TcM (ZonkEnv, HsValBinds Id)
+zonkValBinds env bs@(ValBindsIn _ _)
+ = panic "zonkValBinds" -- Not in typechecker output
+zonkValBinds env (ValBindsOut binds sigs)
+ = do { (env1, new_binds) <- go env binds
+ ; return (env1, ValBindsOut new_binds sigs) }
where
- zonkExport te (tyvars, global, local)
- = mapNF_Tc zonkTcTyVarToTyVar tyvars `thenNF_Tc` \ new_tyvars ->
- zonkIdBndr te global `thenNF_Tc` \ new_global ->
- zonkIdOcc local `thenNF_Tc` \ new_local ->
- returnNF_Tc (new_tyvars, new_global, new_local)
+ go env [] = return (env, [])
+ go env ((r,b):bs) = do { (env1, b') <- zonkRecMonoBinds env b
+ ; (env2, bs') <- go env1 bs
+ ; return (env2, (r,b'):bs') }
+
+---------------------------------------------
+zonkRecMonoBinds :: ZonkEnv -> LHsBinds TcId -> TcM (ZonkEnv, LHsBinds Id)
+zonkRecMonoBinds env binds
+ = fixM (\ ~(_, new_binds) -> do
+ { let env1 = extendZonkEnv env (collectHsBindBinders new_binds)
+ ; binds' <- zonkMonoBinds env1 binds
+ ; return (env1, binds') })
+
+---------------------------------------------
+zonkMonoBinds :: ZonkEnv -> LHsBinds TcId -> TcM (LHsBinds Id)
+zonkMonoBinds env binds = mapBagM (wrapLocM (zonk_bind env)) binds
+
+zonk_bind :: ZonkEnv -> HsBind TcId -> TcM (HsBind Id)
+zonk_bind env bind@(PatBind { pat_lhs = pat, pat_rhs = grhss, pat_rhs_ty = ty})
+ = do { (_env, new_pat) <- zonkPat env pat -- Env already extended
+ ; new_grhss <- zonkGRHSs env grhss
+ ; new_ty <- zonkTcTypeToType env ty
+ ; return (bind { pat_lhs = new_pat, pat_rhs = new_grhss, pat_rhs_ty = new_ty }) }
+
+zonk_bind env (VarBind { var_id = var, var_rhs = expr })
+ = zonkIdBndr env var `thenM` \ new_var ->
+ zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (VarBind { var_id = new_var, var_rhs = new_expr })
+
+zonk_bind env bind@(FunBind { fun_id = var, fun_matches = ms, fun_co_fn = co_fn })
+ = wrapLocM (zonkIdBndr env) var `thenM` \ new_var ->
+ zonkCoFn env co_fn `thenM` \ (env1, new_co_fn) ->
+ zonkMatchGroup env1 ms `thenM` \ new_ms ->
+ returnM (bind { fun_id = new_var, fun_matches = new_ms, fun_co_fn = new_co_fn })
+
+zonk_bind env (AbsBinds { abs_tvs = tyvars, abs_dicts = dicts,
+ abs_exports = exports, abs_binds = val_binds })
+ = ASSERT( all isImmutableTyVar tyvars )
+ zonkIdBndrs env dicts `thenM` \ new_dicts ->
+ fixM (\ ~(new_val_binds, _) ->
+ let
+ env1 = extendZonkEnv env new_dicts
+ env2 = extendZonkEnv env1 (collectHsBindBinders new_val_binds)
+ in
+ zonkMonoBinds env2 val_binds `thenM` \ new_val_binds ->
+ mappM (zonkExport env2) exports `thenM` \ new_exports ->
+ returnM (new_val_binds, new_exports)
+ ) `thenM` \ (new_val_bind, new_exports) ->
+ returnM (AbsBinds { abs_tvs = tyvars, abs_dicts = new_dicts,
+ abs_exports = new_exports, abs_binds = new_val_bind })
+ where
+ zonkExport env (tyvars, global, local, prags)
+ = zonkIdBndr env global `thenM` \ new_global ->
+ mapM zonk_prag prags `thenM` \ new_prags ->
+ returnM (tyvars, new_global, zonkIdOcc env local, new_prags)
+ zonk_prag prag@(InlinePrag {}) = return prag
+ zonk_prag (SpecPrag expr ty ds inl) = do { expr' <- zonkExpr env expr
+ ; ty' <- zonkTcTypeToType env ty
+ ; let ds' = zonkIdOccs env ds
+ ; return (SpecPrag expr' ty' ds' inl) }
\end{code}
%************************************************************************
%* *
-\subsection[BackSubst-Match-GRHSs]{Match and GRHSsAndBinds}
+\subsection[BackSubst-Match-GRHSs]{Match and GRHSs}
%* *
%************************************************************************
\begin{code}
-zonkMatch :: TyVarEnv Type
- -> TcMatch s -> NF_TcM s TypecheckedMatch
-
-zonkMatch te (PatMatch pat match)
- = zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- tcExtendGlobalValEnv (bagToList ids) $
- zonkMatch te match `thenNF_Tc` \ new_match ->
- returnNF_Tc (PatMatch new_pat new_match)
-
-zonkMatch te (GRHSMatch grhss_w_binds)
- = zonkGRHSsAndBinds te grhss_w_binds `thenNF_Tc` \ new_grhss_w_binds ->
- returnNF_Tc (GRHSMatch new_grhss_w_binds)
-
-zonkMatch te (SimpleMatch expr)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (SimpleMatch new_expr)
+zonkMatchGroup :: ZonkEnv -> MatchGroup TcId-> TcM (MatchGroup Id)
+zonkMatchGroup env (MatchGroup ms ty)
+ = do { ms' <- mapM (zonkMatch env) ms
+ ; ty' <- zonkTcTypeToType env ty
+ ; return (MatchGroup ms' ty') }
+
+zonkMatch :: ZonkEnv -> LMatch TcId-> TcM (LMatch Id)
+zonkMatch env (L loc (Match pats _ grhss))
+ = do { (env1, new_pats) <- zonkPats env pats
+ ; new_grhss <- zonkGRHSs env1 grhss
+ ; return (L loc (Match new_pats Nothing new_grhss)) }
-------------------------------------------------------------------------
-zonkGRHSsAndBinds :: TyVarEnv Type
- -> TcGRHSsAndBinds s
- -> NF_TcM s TypecheckedGRHSsAndBinds
+zonkGRHSs :: ZonkEnv -> GRHSs TcId -> TcM (GRHSs Id)
-zonkGRHSsAndBinds te (GRHSsAndBindsOut grhss binds ty)
- = zonkBinds te binds `thenNF_Tc` \ (new_binds, new_env) ->
- tcSetEnv new_env $
+zonkGRHSs env (GRHSs grhss binds)
+ = zonkLocalBinds env binds `thenM` \ (new_env, new_binds) ->
let
- zonk_grhs (GRHS guard expr locn)
- = zonkStmts te guard `thenNF_Tc` \ (new_guard, new_env) ->
- tcSetEnv new_env $
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (GRHS new_guard new_expr locn)
+ zonk_grhs (GRHS guarded rhs)
+ = zonkStmts new_env guarded `thenM` \ (env2, new_guarded) ->
+ zonkLExpr env2 rhs `thenM` \ new_rhs ->
+ returnM (GRHS new_guarded new_rhs)
in
- mapNF_Tc zonk_grhs grhss `thenNF_Tc` \ new_grhss ->
- zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (GRHSsAndBindsOut new_grhss new_binds new_ty)
+ mappM (wrapLocM zonk_grhs) grhss `thenM` \ new_grhss ->
+ returnM (GRHSs new_grhss new_binds)
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-zonkExpr :: TyVarEnv Type
- -> TcExpr s -> NF_TcM s TypecheckedHsExpr
-
-zonkExpr te (HsVar id)
- = zonkIdOcc id `thenNF_Tc` \ id' ->
- returnNF_Tc (HsVar id')
-
-zonkExpr te (HsLit _) = panic "zonkExpr te:HsLit"
-
-zonkExpr te (HsLitOut lit ty)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (HsLitOut lit new_ty)
-
-zonkExpr te (HsLam match)
- = zonkMatch te match `thenNF_Tc` \ new_match ->
- returnNF_Tc (HsLam new_match)
-
-zonkExpr te (HsApp e1 e2)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- returnNF_Tc (HsApp new_e1 new_e2)
-
-zonkExpr te (OpApp e1 op fixity e2)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te op `thenNF_Tc` \ new_op ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- returnNF_Tc (OpApp new_e1 new_op fixity new_e2)
-
-zonkExpr te (NegApp _ _) = panic "zonkExpr te:NegApp"
-zonkExpr te (HsPar _) = panic "zonkExpr te:HsPar"
-
-zonkExpr te (SectionL expr op)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkExpr te op `thenNF_Tc` \ new_op ->
- returnNF_Tc (SectionL new_expr new_op)
-
-zonkExpr te (SectionR op expr)
- = zonkExpr te op `thenNF_Tc` \ new_op ->
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (SectionR new_op new_expr)
-
-zonkExpr te (HsCase expr ms src_loc)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- mapNF_Tc (zonkMatch te) ms `thenNF_Tc` \ new_ms ->
- returnNF_Tc (HsCase new_expr new_ms src_loc)
-
-zonkExpr te (HsIf e1 e2 e3 src_loc)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- zonkExpr te e3 `thenNF_Tc` \ new_e3 ->
- returnNF_Tc (HsIf new_e1 new_e2 new_e3 src_loc)
-
-zonkExpr te (HsLet binds expr)
- = zonkBinds te binds `thenNF_Tc` \ (new_binds, new_env) ->
- tcSetEnv new_env $
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (HsLet new_binds new_expr)
-
-zonkExpr te (HsDo _ _ _) = panic "zonkExpr te:HsDo"
-
-zonkExpr te (HsDoOut do_or_lc stmts return_id then_id zero_id ty src_loc)
- = zonkStmts te stmts `thenNF_Tc` \ (new_stmts, _) ->
- zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- zonkIdOcc return_id `thenNF_Tc` \ new_return_id ->
- zonkIdOcc then_id `thenNF_Tc` \ new_then_id ->
- zonkIdOcc zero_id `thenNF_Tc` \ new_zero_id ->
- returnNF_Tc (HsDoOut do_or_lc new_stmts new_return_id new_then_id new_zero_id
- new_ty src_loc)
-
-zonkExpr te (ExplicitList _) = panic "zonkExpr te:ExplicitList"
-
-zonkExpr te (ExplicitListOut ty exprs)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- mapNF_Tc (zonkExpr te) exprs `thenNF_Tc` \ new_exprs ->
- returnNF_Tc (ExplicitListOut new_ty new_exprs)
-
-zonkExpr te (ExplicitTuple exprs)
- = mapNF_Tc (zonkExpr te) exprs `thenNF_Tc` \ new_exprs ->
- returnNF_Tc (ExplicitTuple new_exprs)
-
-zonkExpr te (HsCon con_id tys exprs)
- = mapNF_Tc (zonkTcTypeToType te) tys `thenNF_Tc` \ new_tys ->
- mapNF_Tc (zonkExpr te) exprs `thenNF_Tc` \ new_exprs ->
- returnNF_Tc (HsCon con_id new_tys new_exprs)
-
-zonkExpr te (RecordCon con_id con_expr rbinds)
- = zonkIdOcc con_id `thenNF_Tc` \ new_con_id ->
- zonkExpr te con_expr `thenNF_Tc` \ new_con_expr ->
- zonkRbinds te rbinds `thenNF_Tc` \ new_rbinds ->
- returnNF_Tc (RecordCon new_con_id new_con_expr new_rbinds)
-
-zonkExpr te (RecordUpd _ _) = panic "zonkExpr te:RecordUpd"
-
-zonkExpr te (RecordUpdOut expr ty dicts rbinds)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- mapNF_Tc zonkIdOcc dicts `thenNF_Tc` \ new_dicts ->
- zonkRbinds te rbinds `thenNF_Tc` \ new_rbinds ->
- returnNF_Tc (RecordUpdOut new_expr new_ty new_dicts new_rbinds)
-
-zonkExpr te (ExprWithTySig _ _) = panic "zonkExpr te:ExprWithTySig"
-zonkExpr te (ArithSeqIn _) = panic "zonkExpr te:ArithSeqIn"
-
-zonkExpr te (ArithSeqOut expr info)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkArithSeq te info `thenNF_Tc` \ new_info ->
- returnNF_Tc (ArithSeqOut new_expr new_info)
-
-zonkExpr te (CCall fun args may_gc is_casm result_ty)
- = mapNF_Tc (zonkExpr te) args `thenNF_Tc` \ new_args ->
- zonkTcTypeToType te result_ty `thenNF_Tc` \ new_result_ty ->
- returnNF_Tc (CCall fun new_args may_gc is_casm new_result_ty)
-
-zonkExpr te (HsSCC label expr)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (HsSCC label new_expr)
-
-zonkExpr te (TyLam tyvars expr)
- = mapNF_Tc zonkTcTyVarToTyVar tyvars `thenNF_Tc` \ new_tyvars ->
- let
- new_te = extend_te te new_tyvars
- in
- zonkExpr new_te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (TyLam new_tyvars new_expr)
+zonkLExprs :: ZonkEnv -> [LHsExpr TcId] -> TcM [LHsExpr Id]
+zonkLExpr :: ZonkEnv -> LHsExpr TcId -> TcM (LHsExpr Id)
+zonkExpr :: ZonkEnv -> HsExpr TcId -> TcM (HsExpr Id)
-zonkExpr te (TyApp expr tys)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- mapNF_Tc (zonkTcTypeToType te) tys `thenNF_Tc` \ new_tys ->
- returnNF_Tc (TyApp new_expr new_tys)
+zonkLExprs env exprs = mappM (zonkLExpr env) exprs
+zonkLExpr env expr = wrapLocM (zonkExpr env) expr
-zonkExpr te (DictLam dicts expr)
- = mapNF_Tc (zonkIdBndr te) dicts `thenNF_Tc` \ new_dicts ->
- tcExtendGlobalValEnv new_dicts $
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (DictLam new_dicts new_expr)
+zonkExpr env (HsVar id)
+ = returnM (HsVar (zonkIdOcc env id))
-zonkExpr te (DictApp expr dicts)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- mapNF_Tc zonkIdOcc dicts `thenNF_Tc` \ new_dicts ->
- returnNF_Tc (DictApp new_expr new_dicts)
+zonkExpr env (HsIPVar id)
+ = returnM (HsIPVar (mapIPName (zonkIdOcc env) id))
+zonkExpr env (HsLit (HsRat f ty))
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsLit (HsRat f new_ty))
+zonkExpr env (HsLit lit)
+ = returnM (HsLit lit)
--------------------------------------------------------------------------
-zonkArithSeq :: TyVarEnv Type
- -> TcArithSeqInfo s -> NF_TcM s TypecheckedArithSeqInfo
+zonkExpr env (HsOverLit lit)
+ = do { lit' <- zonkOverLit env lit
+ ; return (HsOverLit lit') }
-zonkArithSeq te (From e)
- = zonkExpr te e `thenNF_Tc` \ new_e ->
- returnNF_Tc (From new_e)
+zonkExpr env (HsLam matches)
+ = zonkMatchGroup env matches `thenM` \ new_matches ->
+ returnM (HsLam new_matches)
-zonkArithSeq te (FromThen e1 e2)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- returnNF_Tc (FromThen new_e1 new_e2)
+zonkExpr env (HsApp e1 e2)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ returnM (HsApp new_e1 new_e2)
-zonkArithSeq te (FromTo e1 e2)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- returnNF_Tc (FromTo new_e1 new_e2)
+zonkExpr env (HsBracketOut body bs)
+ = mappM zonk_b bs `thenM` \ bs' ->
+ returnM (HsBracketOut body bs')
+ where
+ zonk_b (n,e) = zonkLExpr env e `thenM` \ e' ->
+ returnM (n,e')
+
+zonkExpr env (HsSpliceE s) = WARN( True, ppr s ) -- Should not happen
+ returnM (HsSpliceE s)
+
+zonkExpr env (OpApp e1 op fixity e2)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env op `thenM` \ new_op ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ returnM (OpApp new_e1 new_op fixity new_e2)
+
+zonkExpr env (NegApp expr op)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkExpr env op `thenM` \ new_op ->
+ returnM (NegApp new_expr new_op)
+
+zonkExpr env (HsPar e)
+ = zonkLExpr env e `thenM` \new_e ->
+ returnM (HsPar new_e)
+
+zonkExpr env (SectionL expr op)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkLExpr env op `thenM` \ new_op ->
+ returnM (SectionL new_expr new_op)
+
+zonkExpr env (SectionR op expr)
+ = zonkLExpr env op `thenM` \ new_op ->
+ zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (SectionR new_op new_expr)
+
+zonkExpr env (HsCase expr ms)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkMatchGroup env ms `thenM` \ new_ms ->
+ returnM (HsCase new_expr new_ms)
+
+zonkExpr env (HsIf e1 e2 e3)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ zonkLExpr env e3 `thenM` \ new_e3 ->
+ returnM (HsIf new_e1 new_e2 new_e3)
+
+zonkExpr env (HsLet binds expr)
+ = zonkLocalBinds env binds `thenM` \ (new_env, new_binds) ->
+ zonkLExpr new_env expr `thenM` \ new_expr ->
+ returnM (HsLet new_binds new_expr)
+
+zonkExpr env (HsDo do_or_lc stmts body ty)
+ = zonkStmts env stmts `thenM` \ (new_env, new_stmts) ->
+ zonkLExpr new_env body `thenM` \ new_body ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsDo (zonkDo env do_or_lc)
+ new_stmts new_body new_ty)
+
+zonkExpr env (ExplicitList ty exprs)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkLExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitList new_ty new_exprs)
+
+zonkExpr env (ExplicitPArr ty exprs)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkLExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitPArr new_ty new_exprs)
+
+zonkExpr env (ExplicitTuple exprs boxed)
+ = zonkLExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitTuple new_exprs boxed)
+
+zonkExpr env (RecordCon data_con con_expr rbinds)
+ = zonkExpr env con_expr `thenM` \ new_con_expr ->
+ zonkRbinds env rbinds `thenM` \ new_rbinds ->
+ returnM (RecordCon data_con new_con_expr new_rbinds)
+
+zonkExpr env (RecordUpd expr rbinds in_ty out_ty)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkTcTypeToType env in_ty `thenM` \ new_in_ty ->
+ zonkTcTypeToType env out_ty `thenM` \ new_out_ty ->
+ zonkRbinds env rbinds `thenM` \ new_rbinds ->
+ returnM (RecordUpd new_expr new_rbinds new_in_ty new_out_ty)
+
+zonkExpr env (ExprWithTySigOut e ty)
+ = do { e' <- zonkLExpr env e
+ ; return (ExprWithTySigOut e' ty) }
+
+zonkExpr env (ExprWithTySig _ _) = panic "zonkExpr env:ExprWithTySig"
+
+zonkExpr env (ArithSeq expr info)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkArithSeq env info `thenM` \ new_info ->
+ returnM (ArithSeq new_expr new_info)
+
+zonkExpr env (PArrSeq expr info)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkArithSeq env info `thenM` \ new_info ->
+ returnM (PArrSeq new_expr new_info)
+
+zonkExpr env (HsSCC lbl expr)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (HsSCC lbl new_expr)
+
+-- hdaume: core annotations
+zonkExpr env (HsCoreAnn lbl expr)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (HsCoreAnn lbl new_expr)
+
+zonkExpr env (TyLam tyvars expr)
+ = ASSERT( all isImmutableTyVar tyvars )
+ zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (TyLam tyvars new_expr)
+
+zonkExpr env (TyApp expr tys)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkTcTypeToTypes env tys `thenM` \ new_tys ->
+ returnM (TyApp new_expr new_tys)
+
+zonkExpr env (DictLam dicts expr)
+ = zonkIdBndrs env dicts `thenM` \ new_dicts ->
+ let
+ env1 = extendZonkEnv env new_dicts
+ in
+ zonkLExpr env1 expr `thenM` \ new_expr ->
+ returnM (DictLam new_dicts new_expr)
+
+zonkExpr env (DictApp expr dicts)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (DictApp new_expr (zonkIdOccs env dicts))
+
+-- arrow notation extensions
+zonkExpr env (HsProc pat body)
+ = do { (env1, new_pat) <- zonkPat env pat
+ ; new_body <- zonkCmdTop env1 body
+ ; return (HsProc new_pat new_body) }
+
+zonkExpr env (HsArrApp e1 e2 ty ho rl)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsArrApp new_e1 new_e2 new_ty ho rl)
+
+zonkExpr env (HsArrForm op fixity args)
+ = zonkLExpr env op `thenM` \ new_op ->
+ mappM (zonkCmdTop env) args `thenM` \ new_args ->
+ returnM (HsArrForm new_op fixity new_args)
+
+zonkExpr env (HsCoerce co_fn expr)
+ = zonkCoFn env co_fn `thenM` \ (env1, new_co_fn) ->
+ zonkExpr env1 expr `thenM` \ new_expr ->
+ return (HsCoerce new_co_fn new_expr)
+
+zonkExpr env other = pprPanic "zonkExpr" (ppr other)
+
+zonkCmdTop :: ZonkEnv -> LHsCmdTop TcId -> TcM (LHsCmdTop Id)
+zonkCmdTop env cmd = wrapLocM (zonk_cmd_top env) cmd
+
+zonk_cmd_top env (HsCmdTop cmd stack_tys ty ids)
+ = zonkLExpr env cmd `thenM` \ new_cmd ->
+ zonkTcTypeToTypes env stack_tys `thenM` \ new_stack_tys ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ mapSndM (zonkExpr env) ids `thenM` \ new_ids ->
+ returnM (HsCmdTop new_cmd new_stack_tys new_ty new_ids)
+
+-------------------------------------------------------------------------
+zonkCoFn :: ZonkEnv -> ExprCoFn -> TcM (ZonkEnv, ExprCoFn)
+zonkCoFn env CoHole = return (env, CoHole)
+zonkCoFn env (CoCompose c1 c2) = do { (env1, c1') <- zonkCoFn env c1
+ ; (env2, c2') <- zonkCoFn env1 c2
+ ; return (env2, CoCompose c1' c2') }
+zonkCoFn env (CoLams ids c) = do { ids' <- zonkIdBndrs env ids
+ ; let env1 = extendZonkEnv env ids'
+ ; (env2, c') <- zonkCoFn env1 c
+ ; return (env2, CoLams ids' c') }
+zonkCoFn env (CoTyLams tvs c) = ASSERT( all isImmutableTyVar tvs )
+ do { (env1, c') <- zonkCoFn env c
+ ; return (env1, CoTyLams tvs c') }
+zonkCoFn env (CoApps c ids) = do { (env1, c') <- zonkCoFn env c
+ ; return (env1, CoApps c' (zonkIdOccs env ids)) }
+zonkCoFn env (CoTyApps c tys) = do { tys' <- zonkTcTypeToTypes env tys
+ ; (env1, c') <- zonkCoFn env c
+ ; return (env1, CoTyApps c' tys') }
+zonkCoFn env (CoLet bs c) = do { (env1, bs') <- zonkRecMonoBinds env bs
+ ; (env2, c') <- zonkCoFn env1 c
+ ; return (env2, CoLet bs' c') }
-zonkArithSeq te (FromThenTo e1 e2 e3)
- = zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- zonkExpr te e3 `thenNF_Tc` \ new_e3 ->
- returnNF_Tc (FromThenTo new_e1 new_e2 new_e3)
-------------------------------------------------------------------------
-zonkStmts :: TyVarEnv Type
- -> [TcStmt s] -> NF_TcM s ([TypecheckedStmt], TcEnv s)
+zonkDo :: ZonkEnv -> HsStmtContext Name -> HsStmtContext Name
+-- Only used for 'do', so the only Ids are in a MDoExpr table
+zonkDo env (MDoExpr tbl) = MDoExpr (mapSnd (zonkIdOcc env) tbl)
+zonkDo env do_or_lc = do_or_lc
-zonkStmts te [] = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc ([], env)
+-------------------------------------------------------------------------
+zonkOverLit :: ZonkEnv -> HsOverLit TcId -> TcM (HsOverLit Id)
+zonkOverLit env (HsIntegral i e)
+ = do { e' <- zonkExpr env e; return (HsIntegral i e') }
+zonkOverLit env (HsFractional r e)
+ = do { e' <- zonkExpr env e; return (HsFractional r e') }
-zonkStmts te [ReturnStmt expr]
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc ([ReturnStmt new_expr], env)
+-------------------------------------------------------------------------
+zonkArithSeq :: ZonkEnv -> ArithSeqInfo TcId -> TcM (ArithSeqInfo Id)
+
+zonkArithSeq env (From e)
+ = zonkLExpr env e `thenM` \ new_e ->
+ returnM (From new_e)
+
+zonkArithSeq env (FromThen e1 e2)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ returnM (FromThen new_e1 new_e2)
+
+zonkArithSeq env (FromTo e1 e2)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ returnM (FromTo new_e1 new_e2)
-zonkStmts te (ExprStmt expr locn : stmts)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkStmts te stmts `thenNF_Tc` \ (new_stmts, new_env) ->
- returnNF_Tc (ExprStmt new_expr locn : new_stmts, new_env)
+zonkArithSeq env (FromThenTo e1 e2 e3)
+ = zonkLExpr env e1 `thenM` \ new_e1 ->
+ zonkLExpr env e2 `thenM` \ new_e2 ->
+ zonkLExpr env e3 `thenM` \ new_e3 ->
+ returnM (FromThenTo new_e1 new_e2 new_e3)
-zonkStmts te (GuardStmt expr locn : stmts)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkStmts te stmts `thenNF_Tc` \ (new_stmts, new_env) ->
- returnNF_Tc (GuardStmt new_expr locn : new_stmts, new_env)
-zonkStmts te (LetStmt binds : stmts)
- = zonkBinds te binds `thenNF_Tc` \ (new_binds, new_env) ->
- tcSetEnv new_env $
- zonkStmts te stmts `thenNF_Tc` \ (new_stmts, new_env2) ->
- returnNF_Tc (LetStmt new_binds : new_stmts, new_env2)
+-------------------------------------------------------------------------
+zonkStmts :: ZonkEnv -> [LStmt TcId] -> TcM (ZonkEnv, [LStmt Id])
+zonkStmts env [] = return (env, [])
+zonkStmts env (s:ss) = do { (env1, s') <- wrapLocSndM (zonkStmt env) s
+ ; (env2, ss') <- zonkStmts env1 ss
+ ; return (env2, s' : ss') }
+
+zonkStmt :: ZonkEnv -> Stmt TcId -> TcM (ZonkEnv, Stmt Id)
+zonkStmt env (ParStmt stmts_w_bndrs)
+ = mappM zonk_branch stmts_w_bndrs `thenM` \ new_stmts_w_bndrs ->
+ let
+ new_binders = concat (map snd new_stmts_w_bndrs)
+ env1 = extendZonkEnv env new_binders
+ in
+ return (env1, ParStmt new_stmts_w_bndrs)
+ where
+ zonk_branch (stmts, bndrs) = zonkStmts env stmts `thenM` \ (env1, new_stmts) ->
+ returnM (new_stmts, zonkIdOccs env1 bndrs)
+
+zonkStmt env (RecStmt segStmts lvs rvs rets binds)
+ = zonkIdBndrs env rvs `thenM` \ new_rvs ->
+ let
+ env1 = extendZonkEnv env new_rvs
+ in
+ zonkStmts env1 segStmts `thenM` \ (env2, new_segStmts) ->
+ -- Zonk the ret-expressions in an envt that
+ -- has the polymorphic bindings in the envt
+ mapM (zonkExpr env2) rets `thenM` \ new_rets ->
+ let
+ new_lvs = zonkIdOccs env2 lvs
+ env3 = extendZonkEnv env new_lvs -- Only the lvs are needed
+ in
+ zonkRecMonoBinds env3 binds `thenM` \ (env4, new_binds) ->
+ returnM (env4, RecStmt new_segStmts new_lvs new_rvs new_rets new_binds)
+
+zonkStmt env (ExprStmt expr then_op ty)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ zonkExpr env then_op `thenM` \ new_then ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (env, ExprStmt new_expr new_then new_ty)
-zonkStmts te (BindStmt pat expr locn : stmts)
- = zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- tcExtendGlobalValEnv (bagToList ids) $
- zonkStmts te stmts `thenNF_Tc` \ (new_stmts, new_env) ->
- returnNF_Tc (BindStmt new_pat new_expr locn : new_stmts, new_env)
+zonkStmt env (LetStmt binds)
+ = zonkLocalBinds env binds `thenM` \ (env1, new_binds) ->
+ returnM (env1, LetStmt new_binds)
+zonkStmt env (BindStmt pat expr bind_op fail_op)
+ = do { new_expr <- zonkLExpr env expr
+ ; (env1, new_pat) <- zonkPat env pat
+ ; new_bind <- zonkExpr env bind_op
+ ; new_fail <- zonkExpr env fail_op
+ ; return (env1, BindStmt new_pat new_expr new_bind new_fail) }
-------------------------------------------------------------------------
-zonkRbinds :: TyVarEnv Type
- -> TcRecordBinds s -> NF_TcM s TypecheckedRecordBinds
+zonkRbinds :: ZonkEnv -> HsRecordBinds TcId -> TcM (HsRecordBinds Id)
-zonkRbinds te rbinds
- = mapNF_Tc zonk_rbind rbinds
+zonkRbinds env rbinds
+ = mappM zonk_rbind rbinds
where
- zonk_rbind (field, expr, pun)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- zonkIdOcc field `thenNF_Tc` \ new_field ->
- returnNF_Tc (new_field, new_expr, pun)
+ zonk_rbind (field, expr)
+ = zonkLExpr env expr `thenM` \ new_expr ->
+ returnM (fmap (zonkIdOcc env) field, new_expr)
+
+-------------------------------------------------------------------------
+mapIPNameTc :: (a -> TcM b) -> IPName a -> TcM (IPName b)
+mapIPNameTc f (Dupable n) = f n `thenM` \ r -> returnM (Dupable r)
+mapIPNameTc f (Linear n) = f n `thenM` \ r -> returnM (Linear r)
\end{code}
+
%************************************************************************
%* *
\subsection[BackSubst-Pats]{Patterns}
%************************************************************************
\begin{code}
-zonkPat :: TyVarEnv Type
- -> TcPat s -> NF_TcM s (TypecheckedPat, Bag Id)
-
-zonkPat te (WildPat ty)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (WildPat new_ty, emptyBag)
-
-zonkPat te (VarPat v)
- = zonkIdBndr te v `thenNF_Tc` \ new_v ->
- returnNF_Tc (VarPat new_v, unitBag new_v)
-
-zonkPat te (LazyPat pat)
- = zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- returnNF_Tc (LazyPat new_pat, ids)
-
-zonkPat te (AsPat n pat)
- = zonkIdBndr te n `thenNF_Tc` \ new_n ->
- zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- returnNF_Tc (AsPat new_n new_pat, new_n `consBag` ids)
-
-zonkPat te (ConPat n ty pats)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- zonkPats te pats `thenNF_Tc` \ (new_pats, ids) ->
- returnNF_Tc (ConPat n new_ty new_pats, ids)
-
-zonkPat te (ConOpPat pat1 op pat2 ty)
- = zonkPat te pat1 `thenNF_Tc` \ (new_pat1, ids1) ->
- zonkPat te pat2 `thenNF_Tc` \ (new_pat2, ids2) ->
- zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (ConOpPat new_pat1 op new_pat2 new_ty, ids1 `unionBags` ids2)
-
-zonkPat te (ListPat ty pats)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- zonkPats te pats `thenNF_Tc` \ (new_pats, ids) ->
- returnNF_Tc (ListPat new_ty new_pats, ids)
-
-zonkPat te (TuplePat pats)
- = zonkPats te pats `thenNF_Tc` \ (new_pats, ids) ->
- returnNF_Tc (TuplePat new_pats, ids)
-
-zonkPat te (RecPat n ty rpats)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- mapAndUnzipNF_Tc zonk_rpat rpats `thenNF_Tc` \ (new_rpats, ids_s) ->
- returnNF_Tc (RecPat n new_ty new_rpats, unionManyBags ids_s)
+zonkPat :: ZonkEnv -> OutPat TcId -> TcM (ZonkEnv, OutPat Id)
+-- Extend the environment as we go, because it's possible for one
+-- pattern to bind something that is used in another (inside or
+-- to the right)
+zonkPat env pat = wrapLocSndM (zonk_pat env) pat
+
+zonk_pat env (ParPat p)
+ = do { (env', p') <- zonkPat env p
+ ; return (env', ParPat p') }
+
+zonk_pat env (WildPat ty)
+ = do { ty' <- zonkTcTypeToType env ty
+ ; return (env, WildPat ty') }
+
+zonk_pat env (VarPat v)
+ = do { v' <- zonkIdBndr env v
+ ; return (extendZonkEnv1 env v', VarPat v') }
+
+zonk_pat env (VarPatOut v binds)
+ = do { v' <- zonkIdBndr env v
+ ; (env', binds') <- zonkRecMonoBinds (extendZonkEnv1 env v') binds
+ ; returnM (env', VarPatOut v' binds') }
+
+zonk_pat env (LazyPat pat)
+ = do { (env', pat') <- zonkPat env pat
+ ; return (env', LazyPat pat') }
+
+zonk_pat env (BangPat pat)
+ = do { (env', pat') <- zonkPat env pat
+ ; return (env', BangPat pat') }
+
+zonk_pat env (AsPat (L loc v) pat)
+ = do { v' <- zonkIdBndr env v
+ ; (env', pat') <- zonkPat (extendZonkEnv1 env v') pat
+ ; return (env', AsPat (L loc v') pat') }
+
+zonk_pat env (ListPat pats ty)
+ = do { ty' <- zonkTcTypeToType env ty
+ ; (env', pats') <- zonkPats env pats
+ ; return (env', ListPat pats' ty') }
+
+zonk_pat env (PArrPat pats ty)
+ = do { ty' <- zonkTcTypeToType env ty
+ ; (env', pats') <- zonkPats env pats
+ ; return (env', PArrPat pats' ty') }
+
+zonk_pat env (TuplePat pats boxed ty)
+ = do { ty' <- zonkTcTypeToType env ty
+ ; (env', pats') <- zonkPats env pats
+ ; return (env', TuplePat pats' boxed ty') }
+
+zonk_pat env (ConPatOut n tvs dicts binds stuff ty)
+ = ASSERT( all isImmutableTyVar tvs )
+ do { new_ty <- zonkTcTypeToType env ty
+ ; new_dicts <- zonkIdBndrs env dicts
+ ; let env1 = extendZonkEnv env new_dicts
+ ; (env2, new_binds) <- zonkRecMonoBinds env1 binds
+ ; (env', new_stuff) <- zonkConStuff env2 stuff
+ ; returnM (env', ConPatOut n tvs new_dicts new_binds new_stuff new_ty) }
+
+zonk_pat env (LitPat lit) = return (env, LitPat lit)
+
+zonk_pat env (SigPatOut pat ty)
+ = do { ty' <- zonkTcTypeToType env ty
+ ; (env', pat') <- zonkPat env pat
+ ; return (env', SigPatOut pat' ty') }
+
+zonk_pat env (NPat lit mb_neg eq_expr ty)
+ = do { lit' <- zonkOverLit env lit
+ ; mb_neg' <- case mb_neg of
+ Nothing -> return Nothing
+ Just neg -> do { neg' <- zonkExpr env neg
+ ; return (Just neg') }
+ ; eq_expr' <- zonkExpr env eq_expr
+ ; ty' <- zonkTcTypeToType env ty
+ ; return (env, NPat lit' mb_neg' eq_expr' ty') }
+
+zonk_pat env (NPlusKPat (L loc n) lit e1 e2)
+ = do { n' <- zonkIdBndr env n
+ ; lit' <- zonkOverLit env lit
+ ; e1' <- zonkExpr env e1
+ ; e2' <- zonkExpr env e2
+ ; return (extendZonkEnv1 env n', NPlusKPat (L loc n') lit' e1' e2') }
+
+zonk_pat env (DictPat ds ms)
+ = do { ds' <- zonkIdBndrs env ds
+ ; ms' <- zonkIdBndrs env ms
+ ; return (extendZonkEnv env (ds' ++ ms'), DictPat ds' ms') }
+
+---------------------------
+zonkConStuff env (PrefixCon pats)
+ = do { (env', pats') <- zonkPats env pats
+ ; return (env', PrefixCon pats') }
+
+zonkConStuff env (InfixCon p1 p2)
+ = do { (env1, p1') <- zonkPat env p1
+ ; (env', p2') <- zonkPat env1 p2
+ ; return (env', InfixCon p1' p2') }
+
+zonkConStuff env (RecCon rpats)
+ = do { (env', pats') <- zonkPats env pats
+ ; returnM (env', RecCon (fields `zip` pats')) }
+ where
+ (fields, pats) = unzip rpats
+
+---------------------------
+zonkPats env [] = return (env, [])
+zonkPats env (pat:pats) = do { (env1, pat') <- zonkPat env pat
+ ; (env', pats') <- zonkPats env1 pats
+ ; return (env', pat':pats') }
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[BackSubst-Foreign]{Foreign exports}
+%* *
+%************************************************************************
+
+
+\begin{code}
+zonkForeignExports :: ZonkEnv -> [LForeignDecl TcId] -> TcM [LForeignDecl Id]
+zonkForeignExports env ls = mappM (wrapLocM (zonkForeignExport env)) ls
+
+zonkForeignExport :: ZonkEnv -> ForeignDecl TcId -> TcM (ForeignDecl Id)
+zonkForeignExport env (ForeignExport i hs_ty spec isDeprec) =
+ returnM (ForeignExport (fmap (zonkIdOcc env) i) undefined spec isDeprec)
+zonkForeignExport env for_imp
+ = returnM for_imp -- Foreign imports don't need zonking
+\end{code}
+
+\begin{code}
+zonkRules :: ZonkEnv -> [LRuleDecl TcId] -> TcM [LRuleDecl Id]
+zonkRules env rs = mappM (wrapLocM (zonkRule env)) rs
+
+zonkRule :: ZonkEnv -> RuleDecl TcId -> TcM (RuleDecl Id)
+zonkRule env (HsRule name act (vars::[RuleBndr TcId]) lhs rhs)
+ = mappM zonk_bndr vars `thenM` \ new_bndrs ->
+ newMutVar emptyVarSet `thenM` \ unbound_tv_set ->
+ let
+ env_rhs = extendZonkEnv env [id | b <- new_bndrs, let id = unLoc b, isId id]
+ -- Type variables don't need an envt
+ -- They are bound through the mutable mechanism
+
+ env_lhs = setZonkType env_rhs (zonkTypeCollecting unbound_tv_set)
+ -- We need to gather the type variables mentioned on the LHS so we can
+ -- quantify over them. Example:
+ -- data T a = C
+ --
+ -- foo :: T a -> Int
+ -- foo C = 1
+ --
+ -- {-# RULES "myrule" foo C = 1 #-}
+ --
+ -- After type checking the LHS becomes (foo a (C a))
+ -- and we do not want to zap the unbound tyvar 'a' to (), because
+ -- that limits the applicability of the rule. Instead, we
+ -- want to quantify over it!
+ --
+ -- It's easiest to find the free tyvars here. Attempts to do so earlier
+ -- are tiresome, because (a) the data type is big and (b) finding the
+ -- free type vars of an expression is necessarily monadic operation.
+ -- (consider /\a -> f @ b, where b is side-effected to a)
+ in
+ zonkLExpr env_lhs lhs `thenM` \ new_lhs ->
+ zonkLExpr env_rhs rhs `thenM` \ new_rhs ->
+
+ readMutVar unbound_tv_set `thenM` \ unbound_tvs ->
+ let
+ final_bndrs :: [Located Var]
+ final_bndrs = map noLoc (varSetElems unbound_tvs) ++ new_bndrs
+ in
+ returnM (HsRule name act (map RuleBndr final_bndrs) new_lhs new_rhs)
+ -- I hate this map RuleBndr stuff
where
- zonk_rpat (f, pat, pun)
- = zonkPat te pat `thenNF_Tc` \ (new_pat, ids) ->
- returnNF_Tc ((f, new_pat, pun), ids)
-
-zonkPat te (LitPat lit ty)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (LitPat lit new_ty, emptyBag)
-
-zonkPat te (NPat lit ty expr)
- = zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (NPat lit new_ty new_expr, emptyBag)
-
-zonkPat te (NPlusKPat n k ty e1 e2)
- = zonkIdBndr te n `thenNF_Tc` \ new_n ->
- zonkTcTypeToType te ty `thenNF_Tc` \ new_ty ->
- zonkExpr te e1 `thenNF_Tc` \ new_e1 ->
- zonkExpr te e2 `thenNF_Tc` \ new_e2 ->
- returnNF_Tc (NPlusKPat new_n k new_ty new_e1 new_e2, unitBag new_n)
-
-zonkPat te (DictPat ds ms)
- = mapNF_Tc (zonkIdBndr te) ds `thenNF_Tc` \ new_ds ->
- mapNF_Tc (zonkIdBndr te) ms `thenNF_Tc` \ new_ms ->
- returnNF_Tc (DictPat new_ds new_ms,
- listToBag new_ds `unionBags` listToBag new_ms)
-
-
-zonkPats te []
- = returnNF_Tc ([], emptyBag)
-zonkPats te (pat:pats)
- = zonkPat te pat `thenNF_Tc` \ (pat', ids1) ->
- zonkPats te pats `thenNF_Tc` \ (pats', ids2) ->
- returnNF_Tc (pat':pats', ids1 `unionBags` ids2)
+ zonk_bndr (RuleBndr v)
+ | isId (unLoc v) = wrapLocM (zonkIdBndr env) v
+ | otherwise = ASSERT( isImmutableTyVar (unLoc v) )
+ return v
\end{code}
+%************************************************************************
+%* *
+\subsection[BackSubst-Foreign]{Foreign exports}
+%* *
+%************************************************************************
+
+\begin{code}
+zonkTcTypeToType :: ZonkEnv -> TcType -> TcM Type
+zonkTcTypeToType (ZonkEnv zonk_ty _) ty = zonk_ty ty
+
+zonkTcTypeToTypes :: ZonkEnv -> [TcType] -> TcM [Type]
+zonkTcTypeToTypes env tys = mapM (zonkTcTypeToType env) tys
+
+zonkTypeCollecting :: TcRef TyVarSet -> TcType -> TcM Type
+-- This variant collects unbound type variables in a mutable variable
+zonkTypeCollecting unbound_tv_set
+ = zonkType zonk_unbound_tyvar
+ where
+ zonk_unbound_tyvar tv
+ = zonkQuantifiedTyVar tv `thenM` \ tv' ->
+ readMutVar unbound_tv_set `thenM` \ tv_set ->
+ writeMutVar unbound_tv_set (extendVarSet tv_set tv') `thenM_`
+ return (mkTyVarTy tv')
+
+zonkTypeZapping :: TcType -> TcM Type
+-- This variant is used for everything except the LHS of rules
+-- It zaps unbound type variables to (), or some other arbitrary type
+zonkTypeZapping ty
+ = zonkType zonk_unbound_tyvar ty
+ where
+ -- Zonk a mutable but unbound type variable to an arbitrary type
+ -- We know it's unbound even though we don't carry an environment,
+ -- because at the binding site for a type variable we bind the
+ -- mutable tyvar to a fresh immutable one. So the mutable store
+ -- plays the role of an environment. If we come across a mutable
+ -- type variable that isn't so bound, it must be completely free.
+ zonk_unbound_tyvar tv = do { writeMetaTyVar tv ty; return ty }
+ where
+ ty = mkArbitraryType tv
+
+
+-- When the type checker finds a type variable with no binding,
+-- which means it can be instantiated with an arbitrary type, it
+-- usually instantiates it to Void. Eg.
+--
+-- length []
+-- ===>
+-- length Void (Nil Void)
+--
+-- But in really obscure programs, the type variable might have
+-- a kind other than *, so we need to invent a suitably-kinded type.
+--
+-- This commit uses
+-- Void for kind *
+-- List for kind *->*
+-- Tuple for kind *->...*->*
+--
+-- which deals with most cases. (Previously, it only dealt with
+-- kind *.)
+--
+-- In the other cases, it just makes up a TyCon with a suitable
+-- kind. If this gets into an interface file, anyone reading that
+-- file won't understand it. This is fixable (by making the client
+-- of the interface file make up a TyCon too) but it is tiresome and
+-- never happens, so I am leaving it
+
+mkArbitraryType :: TcTyVar -> Type
+-- Make up an arbitrary type whose kind is the same as the tyvar.
+-- We'll use this to instantiate the (unbound) tyvar.
+mkArbitraryType tv
+ | liftedTypeKind `isSubKind` kind = voidTy -- The vastly common case
+ | otherwise = mkTyConApp tycon []
+ where
+ kind = tyVarKind tv
+ (args,res) = splitKindFunTys kind
+
+ tycon | kind == tyConKind listTyCon -- *->*
+ = listTyCon -- No tuples this size
+
+ | all isLiftedTypeKind args && isLiftedTypeKind res
+ = tupleTyCon Boxed (length args) -- *-> ... ->*->*
+
+ | otherwise
+ = pprTrace "Urk! Inventing strangely-kinded void TyCon:" (ppr tc_name $$ ppr kind) $
+ mkPrimTyCon tc_name kind 0 [] VoidRep
+ -- Same name as the tyvar, apart from making it start with a colon (sigh)
+ -- I dread to think what will happen if this gets out into an
+ -- interface file. Catastrophe likely. Major sigh.
+
+ tc_name = mkInternalName (getUnique tv) (mkDerivedTyConOcc (getOccName tv)) noSrcLoc
+\end{code}
projects / ghc-hetmet.git / blobdiff