%
-% (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}
checker.
\begin{code}
-#include "HsVersions.h"
-
module TcHsSyn (
- SYN_IE(TcMonoBinds), SYN_IE(TcHsBinds), SYN_IE(TcPat),
- SYN_IE(TcExpr), SYN_IE(TcGRHSsAndBinds), SYN_IE(TcGRHS), SYN_IE(TcMatch),
- SYN_IE(TcStmt), SYN_IE(TcArithSeqInfo), SYN_IE(TcRecordBinds),
- SYN_IE(TcHsModule), SYN_IE(TcCoreExpr), SYN_IE(TcDictBinds),
+ TcMonoBinds, TcHsBinds, TcPat,
+ TcExpr, TcGRHSs, TcGRHS, TcMatch,
+ TcStmt, TcArithSeqInfo, TcRecordBinds,
+ TcHsModule, TcDictBinds,
+ TcForeignDecl,
+ TcCmd, TcCmdTop,
- SYN_IE(TypecheckedHsBinds),
- SYN_IE(TypecheckedMonoBinds), SYN_IE(TypecheckedPat),
- SYN_IE(TypecheckedHsExpr), SYN_IE(TypecheckedArithSeqInfo),
- SYN_IE(TypecheckedStmt),
- SYN_IE(TypecheckedMatch), SYN_IE(TypecheckedHsModule),
- SYN_IE(TypecheckedGRHSsAndBinds), SYN_IE(TypecheckedGRHS),
- SYN_IE(TypecheckedRecordBinds), SYN_IE(TypecheckedDictBinds),
-
- mkHsTyApp, mkHsDictApp,
- mkHsTyLam, mkHsDictLam,
- tcIdType, tcIdTyVars,
-
- zonkTopBinds, zonkBinds, zonkMonoBinds
+ TypecheckedHsBinds, TypecheckedRuleDecl,
+ TypecheckedMonoBinds, TypecheckedPat,
+ TypecheckedHsExpr, TypecheckedArithSeqInfo,
+ TypecheckedStmt, TypecheckedForeignDecl,
+ TypecheckedMatch, TypecheckedHsModule,
+ TypecheckedGRHSs, TypecheckedGRHS,
+ TypecheckedRecordBinds, TypecheckedDictBinds,
+ TypecheckedMatchContext, TypecheckedCoreBind,
+ TypecheckedHsCmd, TypecheckedHsCmdTop,
+
+ mkHsTyApp, mkHsDictApp, mkHsConApp,
+ mkHsTyLam, mkHsDictLam, mkHsLet,
+ hsLitType, hsPatType,
+
+ -- Coercions
+ Coercion, ExprCoFn, PatCoFn,
+ (<$>), (<.>), mkCoercion,
+ idCoercion, isIdCoercion,
+
+ -- re-exported from TcMonad
+ TcId, TcIdSet,
+
+ zonkTopBinds, zonkTopDecls, zonkTopExpr,
+ zonkId, zonkTopBndrs
) where
-IMP_Ubiq(){-uitous-}
+#include "HsVersions.h"
-- friends:
import HsSyn -- oodles of it
-import Id ( GenId(..), IdDetails, -- Can meddle modestly with Ids
- SYN_IE(DictVar), idType,
- SYN_IE(Id)
- )
-- others:
-import Name ( Name{--O only-}, NamedThing(..) )
-import BasicTypes ( IfaceFlavour )
-import TcEnv ( tcLookupGlobalValueMaybe, tcExtendGlobalValEnv )
-import TcMonad
-import TcType ( TcIdOcc(..), SYN_IE(TcIdBndr), SYN_IE(TcType), TcMaybe, SYN_IE(TcTyVar),
- zonkTcTypeToType, zonkTcTyVarToTyVar
- )
-import Usage ( SYN_IE(UVar) )
-import Util ( zipEqual, panic,
- pprPanic, pprTrace
-#ifdef DEBUG
- , assertPanic
-#endif
- )
-
-import PprType ( GenType, GenTyVar ) -- instances
-import Type ( mkTyVarTy, tyVarsOfType, SYN_IE(Type) )
-import TyVar ( GenTyVar {- instances -}, SYN_IE(TyVar),
- SYN_IE(TyVarEnv), nullTyVarEnv, growTyVarEnvList, emptyTyVarSet )
-import TysPrim ( voidTy )
-import CoreSyn ( GenCoreExpr )
-import Unique ( Unique ) -- instances
+import Id ( idType, setIdType, Id )
+import DataCon ( dataConWrapId )
+
+import TcRnMonad
+import Type ( Type )
+import TcType ( TcType, TcTyVar, eqKind, isTypeKind, mkTyVarTy,
+ tcGetTyVar, isAnyTypeKind, mkTyConApp )
+import qualified Type
+import TcMType ( zonkTcTyVarToTyVar, zonkType, zonkTcType, zonkTcTyVars,
+ putTcTyVar )
+import TysPrim ( charPrimTy, intPrimTy, floatPrimTy,
+ doublePrimTy, addrPrimTy
+ )
+import TysWiredIn ( charTy, stringTy, intTy, integerTy,
+ mkListTy, mkPArrTy, mkTupleTy, unitTy,
+ voidTy, listTyCon, tupleTyCon )
+import TyCon ( mkPrimTyCon, tyConKind )
+import PrimRep ( PrimRep(VoidRep) )
+import CoreSyn ( CoreExpr )
+import Name ( Name, getOccName, mkInternalName, mkDerivedTyConOcc )
+import Var ( isId, isLocalVar, tyVarKind )
+import VarSet
+import VarEnv
+import BasicTypes ( RecFlag(..), Boxity(..), IPName(..), ipNameName, mapIPName )
+import Maybes ( orElse )
+import Maybe ( isNothing )
+import Unique ( Uniquable(..) )
+import SrcLoc ( noSrcLoc )
import Bag
-import UniqFM
import Outputable
-import Pretty
\end{code}
which have immutable type variables in them.
\begin{code}
-type TcHsBinds s = HsBinds (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcMonoBinds s = MonoBinds (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcDictBinds s = TcMonoBinds s
-type TcPat s = OutPat (TcTyVar s) UVar (TcIdOcc s)
-type TcExpr s = HsExpr (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcGRHSsAndBinds s = GRHSsAndBinds (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcGRHS s = GRHS (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcMatch s = Match (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcStmt s = Stmt (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcArithSeqInfo s = ArithSeqInfo (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcRecordBinds s = HsRecordBinds (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-type TcHsModule s = HsModule (TcTyVar s) UVar (TcIdOcc s) (TcPat s)
-
-type TcCoreExpr s = GenCoreExpr (TcIdOcc s) (TcIdOcc s) (TcTyVar s) UVar
-
-type TypecheckedPat = OutPat TyVar UVar Id
-type TypecheckedMonoBinds = MonoBinds TyVar UVar Id TypecheckedPat
+type TcHsBinds = HsBinds TcId
+type TcMonoBinds = MonoBinds TcId
+type TcDictBinds = TcMonoBinds
+type TcPat = OutPat TcId
+type TcExpr = HsExpr TcId
+type TcGRHSs = GRHSs TcId
+type TcGRHS = GRHS TcId
+type TcMatch = Match TcId
+type TcStmt = Stmt TcId
+type TcArithSeqInfo = ArithSeqInfo TcId
+type TcRecordBinds = HsRecordBinds TcId
+type TcHsModule = HsModule TcId
+type TcForeignDecl = ForeignDecl TcId
+type TcRuleDecl = RuleDecl TcId
+type TcCmd = HsCmd TcId
+type TcCmdTop = HsCmdTop TcId
+
+type TypecheckedPat = OutPat Id
+type TypecheckedMonoBinds = MonoBinds Id
type TypecheckedDictBinds = TypecheckedMonoBinds
-type TypecheckedHsBinds = HsBinds TyVar UVar Id TypecheckedPat
-type TypecheckedHsExpr = HsExpr TyVar UVar Id TypecheckedPat
-type TypecheckedArithSeqInfo = ArithSeqInfo TyVar UVar Id TypecheckedPat
-type TypecheckedStmt = Stmt TyVar UVar Id TypecheckedPat
-type TypecheckedMatch = Match TyVar UVar Id TypecheckedPat
-type TypecheckedGRHSsAndBinds = GRHSsAndBinds TyVar UVar Id TypecheckedPat
-type TypecheckedGRHS = GRHS TyVar UVar Id TypecheckedPat
-type TypecheckedRecordBinds = HsRecordBinds TyVar UVar Id TypecheckedPat
-type TypecheckedHsModule = HsModule TyVar UVar Id TypecheckedPat
+type TypecheckedHsBinds = HsBinds Id
+type TypecheckedHsExpr = HsExpr Id
+type TypecheckedArithSeqInfo = ArithSeqInfo Id
+type TypecheckedStmt = Stmt Id
+type TypecheckedMatch = Match Id
+type TypecheckedGRHSs = GRHSs Id
+type TypecheckedGRHS = GRHS Id
+type TypecheckedRecordBinds = HsRecordBinds Id
+type TypecheckedHsModule = HsModule Id
+type TypecheckedForeignDecl = ForeignDecl Id
+type TypecheckedRuleDecl = RuleDecl Id
+type TypecheckedCoreBind = (Id, CoreExpr)
+type TypecheckedHsCmd = HsCmd Id
+type TypecheckedHsCmdTop = HsCmdTop Id
+
+type TypecheckedMatchContext = HsMatchContext Name -- Keeps consistency with
+ -- HsDo arg StmtContext
\end{code}
\begin{code}
mkHsDictLam [] expr = expr
mkHsDictLam dicts expr = DictLam dicts expr
-tcIdType :: TcIdOcc s -> TcType s
-tcIdType (TcId id) = idType id
-tcIdType (RealId id) = pprPanic "tcIdType:" (ppr PprDebug id)
+mkHsLet EmptyMonoBinds expr = expr
+mkHsLet mbinds expr = HsLet (MonoBind mbinds [] Recursive) expr
-tcIdTyVars (TcId id) = tyVarsOfType (idType id)
-tcIdTyVars (RealId _) = emptyTyVarSet -- Top level Ids have no free type variables
+mkHsConApp data_con tys args = foldl HsApp (HsVar (dataConWrapId data_con) `mkHsTyApp` tys) args
\end{code}
+
%************************************************************************
%* *
-\subsection[BackSubst-HsBinds]{Running a substitution over @HsBinds@}
+\subsection[mkFailurePair]{Code for pattern-matching and other failures}
%* *
%************************************************************************
-This 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
-
-We pass an environment around so that
+Note: If @hsPatType@ doesn't bear a strong resemblance to @exprType@,
+then something is wrong.
+\begin{code}
+hsPatType :: TypecheckedPat -> Type
+
+hsPatType (ParPat pat) = hsPatType pat
+hsPatType (WildPat ty) = ty
+hsPatType (VarPat var) = idType var
+hsPatType (LazyPat pat) = hsPatType pat
+hsPatType (LitPat lit) = hsLitType lit
+hsPatType (AsPat var pat) = idType var
+hsPatType (ListPat _ ty) = mkListTy ty
+hsPatType (PArrPat _ ty) = mkPArrTy ty
+hsPatType (TuplePat pats box) = mkTupleTy box (length pats) (map hsPatType pats)
+hsPatType (ConPatOut _ _ ty _ _) = ty
+hsPatType (SigPatOut _ ty _) = ty
+hsPatType (NPatOut lit ty _) = ty
+hsPatType (NPlusKPatOut id _ _ _) = idType id
+hsPatType (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) = integerTy
+hsLitType (HsRat _ ty) = ty
+hsLitType (HsFloatPrim f) = floatPrimTy
+hsLitType (HsDoublePrim d) = doublePrimTy
+hsLitType (HsLitLit _ ty) = ty
+\end{code}
- 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
+%************************************************************************
+%* *
+\subsection{Coercion functions}
+%* *
+%************************************************************************
-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.)
+\begin{code}
+type Coercion a = Maybe (a -> a)
+ -- Nothing => identity fn
-It's all pretty boring stuff, because HsSyn is such a large type, and
-the environment manipulation is tiresome.
+type ExprCoFn = Coercion TypecheckedHsExpr
+type PatCoFn = Coercion TcPat
+(<.>) :: Coercion a -> Coercion a -> Coercion a -- Composition
+Nothing <.> Nothing = Nothing
+Nothing <.> Just f = Just f
+Just f <.> Nothing = Just f
+Just f1 <.> Just f2 = Just (f1 . f2)
-\begin{code}
-extend_te te tyvars = growTyVarEnvList te [(tyvar, mkTyVarTy tyvar) | tyvar <- tyvars]
+(<$>) :: Coercion a -> a -> a
+Just f <$> e = f e
+Nothing <$> e = e
-zonkIdBndr :: TyVarEnv Type -> TcIdOcc s -> NF_TcM s 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)
+mkCoercion :: (a -> a) -> Coercion a
+mkCoercion f = Just f
-zonkIdBndr te (RealId id) = returnNF_Tc id
+idCoercion :: Coercion a
+idCoercion = Nothing
-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 PprDebug id) $
- Id u n voidTy details prags info
- where
- Id u n _ details prags info = id
- in
- returnNF_Tc new_id
+isIdCoercion :: Coercion a -> Bool
+isIdCoercion = isNothing
\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 nullTyVarEnv 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}
+%************************************************************************
+%* *
+\subsection[BackSubst-HsBinds]{Running a substitution over @HsBinds@}
+%* *
+%************************************************************************
\begin{code}
--------------------------------------------------------------------------
-zonkMonoBinds :: TyVarEnv Type
- -> TcMonoBinds s
- -> NF_TcM s (TypecheckedMonoBinds, Bag Id)
+-- 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}
-zonkMonoBinds te EmptyMonoBinds = returnNF_Tc (EmptyMonoBinds, emptyBag)
+The rest of the zonking is done *after* typechecking.
+The main zonking pass runs over the bindings
-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)
+ a) to convert TcTyVars to TyVars etc, dereferencing any bindings etc
+ b) convert unbound TcTyVar to Void
+ c) convert each TcId to an Id by zonking its type
-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)
+The type variables are converted by binding mutable tyvars to immutable ones
+and then zonking as normal.
-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)
+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
-zonkMonoBinds te (CoreMonoBind var core_expr)
- = zonkIdBndr te var `thenNF_Tc` \ new_var ->
- returnNF_Tc (CoreMonoBind new_var core_expr, unitBag new_var)
+It's all pretty boring stuff, because HsSyn is such a large type, and
+the environment manipulation is tiresome.
-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)
+\begin{code}
+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])
+
+setZonkType :: ZonkEnv -> (TcType -> TcM Type) -> ZonkEnv
+setZonkType (ZonkEnv _ env) zonk_ty = ZonkEnv zonk_ty env
+
+mkZonkEnv :: [Id] -> ZonkEnv
+mkZonkEnv ids = extendZonkEnv emptyZonkEnv ids
+
+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.)
+--
+-- 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 separte 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}
-zonkMonoBinds te (AbsBinds tyvars dicts exports val_bind)
- = mapNF_Tc zonkTcTyVarToTyVar tyvars `thenNF_Tc` \ new_tyvars ->
+\begin{code}
+zonkTopExpr :: TcExpr -> TcM TypecheckedHsExpr
+zonkTopExpr e = zonkExpr emptyZonkEnv e
+
+zonkTopDecls :: TcMonoBinds -> [TcRuleDecl] -> [TcForeignDecl]
+ -> TcM ([Id],
+ TypecheckedMonoBinds,
+ [TypecheckedForeignDecl],
+ [TypecheckedRuleDecl])
+zonkTopDecls binds rules fords -- Top level is implicitly recursive
+ = fixM (\ ~(new_ids, _, _, _) ->
+ let
+ zonk_env = mkZonkEnv new_ids
+ in
+ zonkMonoBinds zonk_env binds `thenM` \ (binds', new_ids) ->
+ zonkRules zonk_env rules `thenM` \ rules' ->
+ zonkForeignExports zonk_env fords `thenM` \ fords' ->
+
+ returnM (bagToList new_ids, binds', fords', rules')
+ )
+
+zonkTopBinds :: TcMonoBinds -> TcM ([Id], TypecheckedMonoBinds)
+zonkTopBinds binds
+ = fixM (\ ~(new_ids, _) ->
+ let
+ zonk_env = mkZonkEnv new_ids
+ in
+ zonkMonoBinds zonk_env binds `thenM` \ (binds', new_ids) ->
+ returnM (bagToList new_ids, binds')
+ )
+
+---------------------------------------------
+zonkBinds :: ZonkEnv -> TcHsBinds -> TcM (ZonkEnv, TypecheckedHsBinds)
+zonkBinds env EmptyBinds = returnM (env, EmptyBinds)
+
+zonkBinds env (ThenBinds b1 b2)
+ = zonkBinds env b1 `thenM` \ (env1, b1') ->
+ zonkBinds env1 b2 `thenM` \ (env2, b2') ->
+ returnM (env2, b1' `ThenBinds` b2')
+
+zonkBinds env (MonoBind bind sigs is_rec)
+ = ASSERT( null sigs )
+ fixM (\ ~(_, _, new_ids) ->
+ let
+ env1 = extendZonkEnv env (bagToList new_ids)
+ in
+ zonkMonoBinds env1 bind `thenM` \ (new_bind, new_ids) ->
+ returnM (env1, new_bind, new_ids)
+ ) `thenM` \ (env1, new_bind, _) ->
+ returnM (env1, mkMonoBind is_rec new_bind)
+
+zonkBinds env (IPBinds binds is_with)
+ = mappM zonk_ip_bind binds `thenM` \ new_binds ->
let
- new_te = extend_te te new_tyvars
+ env1 = extendZonkEnv env (map (ipNameName . fst) 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, _) ->
+ returnM (env1, IPBinds new_binds is_with)
+ where
+ zonk_ip_bind (n, e)
+ = mapIPNameTc (zonkIdBndr env) n `thenM` \ n' ->
+ zonkExpr env e `thenM` \ e' ->
+ returnM (n', e')
+
+
+---------------------------------------------
+zonkMonoBinds :: ZonkEnv -> TcMonoBinds
+ -> TcM (TypecheckedMonoBinds, Bag Id)
+
+zonkMonoBinds env EmptyMonoBinds = returnM (EmptyMonoBinds, emptyBag)
+
+zonkMonoBinds env (AndMonoBinds mbinds1 mbinds2)
+ = zonkMonoBinds env mbinds1 `thenM` \ (b1', ids1) ->
+ zonkMonoBinds env mbinds2 `thenM` \ (b2', ids2) ->
+ returnM (b1' `AndMonoBinds` b2',
+ ids1 `unionBags` ids2)
+
+zonkMonoBinds env (PatMonoBind pat grhss locn)
+ = zonkPat env pat `thenM` \ (new_pat, ids) ->
+ zonkGRHSs env grhss `thenM` \ new_grhss ->
+ returnM (PatMonoBind new_pat new_grhss locn, ids)
+
+zonkMonoBinds env (VarMonoBind var expr)
+ = zonkIdBndr env var `thenM` \ new_var ->
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (VarMonoBind new_var new_expr, unitBag new_var)
+
+zonkMonoBinds env (FunMonoBind var inf ms locn)
+ = zonkIdBndr env var `thenM` \ new_var ->
+ mappM (zonkMatch env) ms `thenM` \ new_ms ->
+ returnM (FunMonoBind new_var inf new_ms locn, unitBag new_var)
+
+
+zonkMonoBinds env (AbsBinds tyvars dicts exports inlines val_bind)
+ = mappM zonkTcTyVarToTyVar tyvars `thenM` \ new_tyvars ->
+ -- No need to extend tyvar env: the effects are
+ -- propagated through binding the tyvars themselves
+
+ zonkIdBndrs env dicts `thenM` \ new_dicts ->
+ fixM (\ ~(_, _, val_bind_ids) ->
+ let
+ env1 = extendZonkEnv (extendZonkEnv env new_dicts)
+ (bagToList val_bind_ids)
+ in
+ zonkMonoBinds env1 val_bind `thenM` \ (new_val_bind, val_bind_ids) ->
+ mappM (zonkExport env1) exports `thenM` \ new_exports ->
+ returnM (new_val_bind, new_exports, val_bind_ids)
+ ) `thenM ` \ (new_val_bind, new_exports, _) ->
let
- new_globals = listToBag [global | (_, global, local) <- new_exports]
+ new_globals = listToBag [global | (_, global, local) <- new_exports]
in
- returnNF_Tc (AbsBinds new_tyvars new_dicts new_exports new_val_bind,
+ returnM (AbsBinds new_tyvars new_dicts new_exports inlines new_val_bind,
new_globals)
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)
+ zonkExport env (tyvars, global, local)
+ = zonkTcTyVars tyvars `thenM` \ tys ->
+ let
+ new_tyvars = map (tcGetTyVar "zonkExport") tys
+ -- This isn't the binding occurrence of these tyvars
+ -- but they should *be* tyvars. Hence tcGetTyVar.
+ in
+ zonkIdBndr env global `thenM` \ new_global ->
+ returnM (new_tyvars, new_global, zonkIdOcc env local)
\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 :: ZonkEnv -> TcMatch -> TcM TypecheckedMatch
-zonkMatch te (SimpleMatch expr)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (SimpleMatch new_expr)
+zonkMatch env (Match pats _ grhss)
+ = zonkPats env pats `thenM` \ (new_pats, new_ids) ->
+ zonkGRHSs (extendZonkEnv env (bagToList new_ids)) grhss `thenM` \ new_grhss ->
+ returnM (Match new_pats Nothing new_grhss)
-------------------------------------------------------------------------
-zonkGRHSsAndBinds :: TyVarEnv Type
- -> TcGRHSsAndBinds s
- -> NF_TcM s TypecheckedGRHSsAndBinds
+zonkGRHSs :: ZonkEnv -> TcGRHSs -> TcM TypecheckedGRHSs
-zonkGRHSsAndBinds te (GRHSsAndBindsOut grhss binds ty)
- = zonkBinds te binds `thenNF_Tc` \ (new_binds, new_env) ->
- tcSetEnv new_env $
+zonkGRHSs env (GRHSs grhss binds ty)
+ = zonkBinds 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 (OtherwiseGRHS expr locn)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- returnNF_Tc (OtherwiseGRHS new_expr locn)
+ zonk_grhs (GRHS guarded locn)
+ = zonkStmts new_env guarded `thenM` \ new_guarded ->
+ returnM (GRHS new_guarded locn)
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 zonk_grhs grhss `thenM` \ new_grhss ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (GRHSs new_grhss new_binds new_ty)
\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 (RecordConOut 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 (RecordConOut 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)
+zonkExprs :: ZonkEnv -> [TcExpr] -> TcM [TypecheckedHsExpr]
+zonkExpr :: ZonkEnv -> TcExpr -> TcM TypecheckedHsExpr
-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)
+zonkExprs env exprs = mappM (zonkExpr env) exprs
-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 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 (HsVar id)
+ = returnM (HsVar (zonkIdOcc env id))
-zonkExpr te (ClassDictLam dicts methods expr)
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- mapNF_Tc zonkIdOcc dicts `thenNF_Tc` \ new_dicts ->
- mapNF_Tc zonkIdOcc methods `thenNF_Tc` \ new_methods ->
- returnNF_Tc (ClassDictLam new_dicts new_methods new_expr)
+zonkExpr env (HsIPVar id)
+ = returnM (HsIPVar (mapIPName (zonkIdOcc env) id))
-zonkExpr te (Dictionary dicts methods)
- = mapNF_Tc zonkIdOcc dicts `thenNF_Tc` \ new_dicts ->
- mapNF_Tc zonkIdOcc methods `thenNF_Tc` \ new_methods ->
- returnNF_Tc (Dictionary new_dicts new_methods)
+zonkExpr env (HsLit (HsRat f ty))
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsLit (HsRat f new_ty))
-zonkExpr te (SingleDict name)
- = zonkIdOcc name `thenNF_Tc` \ name' ->
- returnNF_Tc (SingleDict name')
+zonkExpr env (HsLit (HsLitLit lit ty))
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsLit (HsLitLit lit new_ty))
+zonkExpr env (HsLit lit)
+ = returnM (HsLit lit)
--------------------------------------------------------------------------
-zonkArithSeq :: TyVarEnv Type
- -> TcArithSeqInfo s -> NF_TcM s TypecheckedArithSeqInfo
+-- HsOverLit doesn't appear in typechecker output
+
+zonkExpr env (HsLam match)
+ = zonkMatch env match `thenM` \ new_match ->
+ returnM (HsLam new_match)
+
+zonkExpr env (HsApp e1 e2)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ returnM (HsApp new_e1 new_e2)
+
+zonkExpr env (HsBracketOut body bs)
+ = mappM zonk_b bs `thenM` \ bs' ->
+ returnM (HsBracketOut body bs')
+ where
+ zonk_b (n,e) = zonkExpr env e `thenM` \ e' ->
+ returnM (n,e')
+
+zonkExpr env (HsReify r) = returnM (HsReify r) -- Nothing to zonk; only top
+ -- level things can be reified (for now)
+zonkExpr env (HsSplice n e loc) = WARN( True, ppr e ) -- Should not happen
+ returnM (HsSplice n e loc)
+
+zonkExpr env (OpApp e1 op fixity e2)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env op `thenM` \ new_op ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ returnM (OpApp new_e1 new_op fixity new_e2)
+
+zonkExpr env (NegApp _ _) = panic "zonkExpr env: NegApp"
+
+zonkExpr env (HsPar e)
+ = zonkExpr env e `thenM` \new_e ->
+ returnM (HsPar new_e)
+
+zonkExpr env (SectionL expr op)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkExpr env op `thenM` \ new_op ->
+ returnM (SectionL new_expr new_op)
+
+zonkExpr env (SectionR op expr)
+ = zonkExpr env op `thenM` \ new_op ->
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (SectionR new_op new_expr)
+
+zonkExpr env (HsCase expr ms src_loc)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ mappM (zonkMatch env) ms `thenM` \ new_ms ->
+ returnM (HsCase new_expr new_ms src_loc)
+
+zonkExpr env (HsIf e1 e2 e3 src_loc)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ zonkExpr env e3 `thenM` \ new_e3 ->
+ returnM (HsIf new_e1 new_e2 new_e3 src_loc)
+
+zonkExpr env (HsLet binds expr)
+ = zonkBinds env binds `thenM` \ (new_env, new_binds) ->
+ zonkExpr new_env expr `thenM` \ new_expr ->
+ returnM (HsLet new_binds new_expr)
+
+zonkExpr env (HsDo do_or_lc stmts ids ty src_loc)
+ = zonkStmts env stmts `thenM` \ new_stmts ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkReboundNames env ids `thenM` \ new_ids ->
+ returnM (HsDo do_or_lc new_stmts new_ids
+ new_ty src_loc)
+
+zonkExpr env (ExplicitList ty exprs)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitList new_ty new_exprs)
+
+zonkExpr env (ExplicitPArr ty exprs)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitPArr new_ty new_exprs)
+
+zonkExpr env (ExplicitTuple exprs boxed)
+ = zonkExprs env exprs `thenM` \ new_exprs ->
+ returnM (ExplicitTuple new_exprs boxed)
+
+zonkExpr env (RecordConOut data_con con_expr rbinds)
+ = zonkExpr env con_expr `thenM` \ new_con_expr ->
+ zonkRbinds env rbinds `thenM` \ new_rbinds ->
+ returnM (RecordConOut data_con new_con_expr new_rbinds)
+
+zonkExpr env (RecordUpd _ _) = panic "zonkExpr env:RecordUpd"
+
+zonkExpr env (RecordUpdOut expr in_ty out_ty rbinds)
+ = zonkExpr 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 (RecordUpdOut new_expr new_in_ty new_out_ty new_rbinds)
+
+zonkExpr env (ExprWithTySig _ _) = panic "zonkExpr env:ExprWithTySig"
+zonkExpr env (ArithSeqIn _) = panic "zonkExpr env:ArithSeqIn"
+zonkExpr env (PArrSeqIn _) = panic "zonkExpr env:PArrSeqIn"
+
+zonkExpr env (ArithSeqOut expr info)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkArithSeq env info `thenM` \ new_info ->
+ returnM (ArithSeqOut new_expr new_info)
+
+zonkExpr env (PArrSeqOut expr info)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkArithSeq env info `thenM` \ new_info ->
+ returnM (PArrSeqOut new_expr new_info)
+
+zonkExpr env (HsCCall fun args may_gc is_casm result_ty)
+ = zonkExprs env args `thenM` \ new_args ->
+ zonkTcTypeToType env result_ty `thenM` \ new_result_ty ->
+ returnM (HsCCall fun new_args may_gc is_casm new_result_ty)
+
+zonkExpr env (HsSCC lbl expr)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ returnM (HsSCC lbl new_expr)
+
+-- hdaume: core annotations
+zonkExpr env (HsCoreAnn lbl expr)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ returnM (HsCoreAnn lbl new_expr)
+
+zonkExpr env (TyLam tyvars expr)
+ = mappM zonkTcTyVarToTyVar tyvars `thenM` \ new_tyvars ->
+ -- No need to extend tyvar env; see AbsBinds
+
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (TyLam new_tyvars new_expr)
+
+zonkExpr env (TyApp expr tys)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ mappM (zonkTcTypeToType 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
+ zonkExpr env1 expr `thenM` \ new_expr ->
+ returnM (DictLam new_dicts new_expr)
-zonkArithSeq te (From e)
- = zonkExpr te e `thenNF_Tc` \ new_e ->
- returnNF_Tc (From new_e)
+zonkExpr env (DictApp expr dicts)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ returnM (DictApp new_expr (zonkIdOccs env dicts))
-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)
+-- arrow notation extensions
+zonkExpr env (HsProc pat body src_loc)
+ = zonkPat env pat `thenM` \ (new_pat, new_ids) ->
+ let
+ env1 = extendZonkEnv env (bagToList new_ids)
+ in
+ zonkCmdTop env1 body `thenM` \ new_body ->
+ returnM (HsProc new_pat new_body src_loc)
+
+zonkExpr env (HsArrApp e1 e2 ty ho rl src_loc)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (HsArrApp new_e1 new_e2 new_ty ho rl src_loc)
+
+zonkExpr env (HsArrForm op fixity args src_loc)
+ = zonkExpr env op `thenM` \ new_op ->
+ mappM (zonkCmdTop env) args `thenM` \ new_args ->
+ returnM (HsArrForm new_op fixity new_args src_loc)
+
+zonkCmdTop :: ZonkEnv -> TcCmdTop -> TcM TypecheckedHsCmdTop
+zonkCmdTop env (HsCmdTop cmd stack_tys ty ids)
+ = zonkExpr env cmd `thenM` \ new_cmd ->
+ mappM (zonkTcTypeToType env) stack_tys
+ `thenM` \ new_stack_tys ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkReboundNames env ids `thenM` \ new_ids ->
+ returnM (HsCmdTop new_cmd new_stack_tys new_ty new_ids)
-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)
+-------------------------------------------------------------------------
+zonkReboundNames :: ZonkEnv -> ReboundNames Id -> TcM (ReboundNames Id)
+zonkReboundNames env prs
+ = mapM zonk prs
+ where
+ zonk (n, e) = zonkExpr env e `thenM` \ new_e ->
+ returnM (n, new_e)
-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)
+zonkArithSeq :: ZonkEnv -> TcArithSeqInfo -> TcM TypecheckedArithSeqInfo
+
+zonkArithSeq env (From e)
+ = zonkExpr env e `thenM` \ new_e ->
+ returnM (From new_e)
-zonkStmts te [] = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc ([], env)
+zonkArithSeq env (FromThen e1 e2)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ returnM (FromThen new_e1 new_e2)
-zonkStmts te [ReturnStmt expr]
- = zonkExpr te expr `thenNF_Tc` \ new_expr ->
- tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc ([ReturnStmt new_expr], env)
+zonkArithSeq env (FromTo e1 e2)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr 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)
+ = zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ zonkExpr 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 -> [TcStmt] -> TcM [TypecheckedStmt]
+
+zonkStmts env stmts = zonk_stmts env stmts `thenM` \ (_, stmts) ->
+ returnM stmts
+
+zonk_stmts :: ZonkEnv -> [TcStmt] -> TcM (ZonkEnv, [TypecheckedStmt])
+
+zonk_stmts env [] = returnM (env, [])
+
+zonk_stmts env (ParStmt stmts_w_bndrs : stmts)
+ = 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
+ zonk_stmts env1 stmts `thenM` \ (env2, new_stmts) ->
+ returnM (env2, ParStmt new_stmts_w_bndrs : new_stmts)
+ where
+ zonk_branch (stmts, bndrs) = zonk_stmts env stmts `thenM` \ (env1, new_stmts) ->
+ returnM (new_stmts, zonkIdOccs env1 bndrs)
-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)
+zonk_stmts env (RecStmt segStmts lvs rvs rets : stmts)
+ = zonkIdBndrs env rvs `thenM` \ new_rvs ->
+ let
+ env1 = extendZonkEnv env new_rvs
+ in
+ zonk_stmts env1 segStmts `thenM` \ (env2, new_segStmts) ->
+ -- Zonk the ret-expressions in an envt that
+ -- has the polymorphic bindings in the envt
+ zonkExprs env2 rets `thenM` \ new_rets ->
+ let
+ new_lvs = zonkIdOccs env2 lvs
+ env3 = extendZonkEnv env new_lvs -- Only the lvs are needed
+ in
+ zonk_stmts env3 stmts `thenM` \ (env4, new_stmts) ->
+ returnM (env4, RecStmt new_segStmts new_lvs new_rvs new_rets : new_stmts)
+
+zonk_stmts env (ResultStmt expr locn : stmts)
+ = ASSERT( null stmts )
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (env, [ResultStmt new_expr locn])
+
+zonk_stmts env (ExprStmt expr ty locn : stmts)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonk_stmts env stmts `thenM` \ (env1, new_stmts) ->
+ returnM (env1, ExprStmt new_expr new_ty locn : new_stmts)
+
+zonk_stmts env (LetStmt binds : stmts)
+ = zonkBinds env binds `thenM` \ (env1, new_binds) ->
+ zonk_stmts env1 stmts `thenM` \ (env2, new_stmts) ->
+ returnM (env2, LetStmt new_binds : new_stmts)
+
+zonk_stmts env (BindStmt pat expr locn : stmts)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ zonkPat env pat `thenM` \ (new_pat, new_ids) ->
+ let
+ env1 = extendZonkEnv env (bagToList new_ids)
+ in
+ zonk_stmts env1 stmts `thenM` \ (env2, new_stmts) ->
+ returnM (env2, BindStmt new_pat new_expr locn : new_stmts)
-------------------------------------------------------------------------
-zonkRbinds :: TyVarEnv Type
- -> TcRecordBinds s -> NF_TcM s TypecheckedRecordBinds
+zonkRbinds :: ZonkEnv -> TcRecordBinds -> TcM TypecheckedRecordBinds
-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)
+ = zonkExpr env expr `thenM` \ new_expr ->
+ returnM (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)
- 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,
+zonkPat :: ZonkEnv -> TcPat -> TcM (TypecheckedPat, Bag Id)
+
+zonkPat env (ParPat p)
+ = zonkPat env p `thenM` \ (new_p, ids) ->
+ returnM (ParPat new_p, ids)
+
+zonkPat env (WildPat ty)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ returnM (WildPat new_ty, emptyBag)
+
+zonkPat env (VarPat v)
+ = zonkIdBndr env v `thenM` \ new_v ->
+ returnM (VarPat new_v, unitBag new_v)
+
+zonkPat env (LazyPat pat)
+ = zonkPat env pat `thenM` \ (new_pat, ids) ->
+ returnM (LazyPat new_pat, ids)
+
+zonkPat env (AsPat n pat)
+ = zonkIdBndr env n `thenM` \ new_n ->
+ zonkPat env pat `thenM` \ (new_pat, ids) ->
+ returnM (AsPat new_n new_pat, new_n `consBag` ids)
+
+zonkPat env (ListPat pats ty)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkPats env pats `thenM` \ (new_pats, ids) ->
+ returnM (ListPat new_pats new_ty, ids)
+
+zonkPat env (PArrPat pats ty)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkPats env pats `thenM` \ (new_pats, ids) ->
+ returnM (PArrPat new_pats new_ty, ids)
+
+zonkPat env (TuplePat pats boxed)
+ = zonkPats env pats `thenM` \ (new_pats, ids) ->
+ returnM (TuplePat new_pats boxed, ids)
+
+zonkPat env (ConPatOut n stuff ty tvs dicts)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ mappM zonkTcTyVarToTyVar tvs `thenM` \ new_tvs ->
+ zonkIdBndrs env dicts `thenM` \ new_dicts ->
+ let
+ env1 = extendZonkEnv env new_dicts
+ in
+ zonkConStuff env stuff `thenM` \ (new_stuff, ids) ->
+ returnM (ConPatOut n new_stuff new_ty new_tvs new_dicts,
+ listToBag new_dicts `unionBags` ids)
+
+zonkPat env (LitPat lit) = returnM (LitPat lit, emptyBag)
+
+zonkPat env (SigPatOut pat ty expr)
+ = zonkPat env pat `thenM` \ (new_pat, ids) ->
+ zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (SigPatOut new_pat new_ty new_expr, ids)
+
+zonkPat env (NPatOut lit ty expr)
+ = zonkTcTypeToType env ty `thenM` \ new_ty ->
+ zonkExpr env expr `thenM` \ new_expr ->
+ returnM (NPatOut lit new_ty new_expr, emptyBag)
+
+zonkPat env (NPlusKPatOut n k e1 e2)
+ = zonkIdBndr env n `thenM` \ new_n ->
+ zonkExpr env e1 `thenM` \ new_e1 ->
+ zonkExpr env e2 `thenM` \ new_e2 ->
+ returnM (NPlusKPatOut new_n k new_e1 new_e2, unitBag new_n)
+
+zonkPat env (DictPat ds ms)
+ = zonkIdBndrs env ds `thenM` \ new_ds ->
+ zonkIdBndrs env ms `thenM` \ new_ms ->
+ returnM (DictPat new_ds new_ms,
listToBag new_ds `unionBags` listToBag new_ms)
+---------------------------
+zonkConStuff env (PrefixCon pats)
+ = zonkPats env pats `thenM` \ (new_pats, ids) ->
+ returnM (PrefixCon new_pats, ids)
+
+zonkConStuff env (InfixCon p1 p2)
+ = zonkPat env p1 `thenM` \ (new_p1, ids1) ->
+ zonkPat env p2 `thenM` \ (new_p2, ids2) ->
+ returnM (InfixCon new_p1 new_p2, ids1 `unionBags` ids2)
+
+zonkConStuff env (RecCon rpats)
+ = mapAndUnzipM zonk_rpat rpats `thenM` \ (new_rpats, ids_s) ->
+ returnM (RecCon new_rpats, unionManyBags ids_s)
+ where
+ zonk_rpat (f, pat)
+ = zonkPat env pat `thenM` \ (new_pat, ids) ->
+ returnM ((f, new_pat), ids)
+
+---------------------------
+zonkPats env []
+ = returnM ([], emptyBag)
+
+zonkPats env (pat:pats)
+ = zonkPat env pat `thenM` \ (pat', ids1) ->
+ zonkPats env pats `thenM` \ (pats', ids2) ->
+ returnM (pat':pats', ids1 `unionBags` ids2)
+\end{code}
+
+%************************************************************************
+%* *
+\subsection[BackSubst-Foreign]{Foreign exports}
+%* *
+%************************************************************************
+
+
+\begin{code}
+zonkForeignExports :: ZonkEnv -> [TcForeignDecl] -> TcM [TypecheckedForeignDecl]
+zonkForeignExports env ls = mappM (zonkForeignExport env) ls
+
+zonkForeignExport :: ZonkEnv -> TcForeignDecl -> TcM (TypecheckedForeignDecl)
+zonkForeignExport env (ForeignExport i hs_ty spec isDeprec src_loc) =
+ returnM (ForeignExport (zonkIdOcc env i) undefined spec isDeprec src_loc)
+zonkForeignExport env for_imp
+ = returnM for_imp -- Foreign imports don't need zonking
+\end{code}
+
+\begin{code}
+zonkRules :: ZonkEnv -> [TcRuleDecl] -> TcM [TypecheckedRuleDecl]
+zonkRules env rs = mappM (zonkRule env) rs
+
+zonkRule env (HsRule name act vars lhs rhs loc)
+ = mappM zonk_bndr vars `thenM` \ new_bndrs ->
+ newMutVar emptyVarSet `thenM` \ unbound_tv_set ->
+ let
+ env_rhs = extendZonkEnv env (filter isId new_bndrs)
+ -- 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
+ zonkExpr env_lhs lhs `thenM` \ new_lhs ->
+ zonkExpr env_rhs rhs `thenM` \ new_rhs ->
-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)
+ readMutVar unbound_tv_set `thenM` \ unbound_tvs ->
+ let
+ final_bndrs = map RuleBndr (varSetElems unbound_tvs ++ new_bndrs)
+ -- I hate this map RuleBndr stuff
+ in
+ returnM (HsRule name act final_bndrs new_lhs new_rhs loc)
+ where
+ zonk_bndr (RuleBndr v)
+ | isId v = zonkIdBndr env v
+ | otherwise = zonkTcTyVarToTyVar v
+
+zonkRule env (IfaceRuleOut fun rule)
+ = returnM (IfaceRuleOut (zonkIdOcc env fun) rule)
\end{code}
+%************************************************************************
+%* *
+\subsection[BackSubst-Foreign]{Foreign exports}
+%* *
+%************************************************************************
+
+\begin{code}
+zonkTcTypeToType :: ZonkEnv -> TcType -> TcM Type
+zonkTcTypeToType (ZonkEnv zonk_ty _) ty = zonk_ty ty
+
+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
+ = zonkTcTyVarToTyVar 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 = putTcTyVar tv (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
+ | isAnyTypeKind kind = voidTy -- The vastly common case
+ | otherwise = mkTyConApp tycon []
+ where
+ kind = tyVarKind tv
+ (args,res) = Type.splitFunTys kind -- Kinds are simple; use Type.splitFunTys
+
+ tycon | kind `eqKind` tyConKind listTyCon -- *->*
+ = listTyCon -- No tuples this size
+
+ | all isTypeKind args && isTypeKind 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