2 % (c) The University of Glasgow 2006
3 % (c) The AQUA Project, Glasgow University, 1996-1998
6 TcHsSyn: Specialisations of the @HsSyn@ syntax for the typechecker
8 This module is an extension of @HsSyn@ syntax, for use in the type
13 mkHsConApp, mkHsDictLet, mkHsApp,
14 hsLitType, hsLPatType, hsPatType,
15 mkHsAppTy, mkSimpleHsAlt,
17 shortCutLit, hsOverLitName,
19 -- re-exported from TcMonad
22 zonkTopDecls, zonkTopExpr, zonkTopLExpr,
26 #include "HsVersions.h"
29 import HsSyn -- oodles of it
47 import DynFlags( DynFlag(..) )
55 -- import Data.Traversable( traverse )
60 thenM :: Monad a => a b -> (b -> a c) -> a c
63 returnM :: Monad m => a -> m a
66 mappM :: (Monad m) => (a -> m b) -> [a] -> m [b]
71 %************************************************************************
73 \subsection[mkFailurePair]{Code for pattern-matching and other failures}
75 %************************************************************************
77 Note: If @hsLPatType@ doesn't bear a strong resemblance to @exprType@,
78 then something is wrong.
80 hsLPatType :: OutPat Id -> Type
81 hsLPatType (L _ pat) = hsPatType pat
83 hsPatType :: Pat Id -> Type
84 hsPatType (ParPat pat) = hsLPatType pat
85 hsPatType (WildPat ty) = ty
86 hsPatType (VarPat var) = idType var
87 hsPatType (BangPat pat) = hsLPatType pat
88 hsPatType (LazyPat pat) = hsLPatType pat
89 hsPatType (LitPat lit) = hsLitType lit
90 hsPatType (AsPat var _) = idType (unLoc var)
91 hsPatType (ViewPat _ _ ty) = ty
92 hsPatType (ListPat _ ty) = mkListTy ty
93 hsPatType (PArrPat _ ty) = mkPArrTy ty
94 hsPatType (TuplePat _ _ ty) = ty
95 hsPatType (ConPatOut { pat_ty = ty }) = ty
96 hsPatType (SigPatOut _ ty) = ty
97 hsPatType (NPat lit _ _) = overLitType lit
98 hsPatType (NPlusKPat id _ _ _) = idType (unLoc id)
99 hsPatType (CoPat _ _ ty) = ty
100 hsPatType p = pprPanic "hsPatType" (ppr p)
102 hsLitType :: HsLit -> TcType
103 hsLitType (HsChar _) = charTy
104 hsLitType (HsCharPrim _) = charPrimTy
105 hsLitType (HsString _) = stringTy
106 hsLitType (HsStringPrim _) = addrPrimTy
107 hsLitType (HsInt _) = intTy
108 hsLitType (HsIntPrim _) = intPrimTy
109 hsLitType (HsWordPrim _) = wordPrimTy
110 hsLitType (HsInteger _ ty) = ty
111 hsLitType (HsRat _ ty) = ty
112 hsLitType (HsFloatPrim _) = floatPrimTy
113 hsLitType (HsDoublePrim _) = doublePrimTy
116 Overloaded literals. Here mainly becuase it uses isIntTy etc
119 shortCutLit :: OverLitVal -> TcType -> Maybe (HsExpr TcId)
120 shortCutLit (HsIntegral i) ty
121 | isIntTy ty && inIntRange i = Just (HsLit (HsInt i))
122 | isWordTy ty && inWordRange i = Just (mkLit wordDataCon (HsWordPrim i))
123 | isIntegerTy ty = Just (HsLit (HsInteger i ty))
124 | otherwise = shortCutLit (HsFractional (integralFractionalLit i)) ty
125 -- The 'otherwise' case is important
126 -- Consider (3 :: Float). Syntactically it looks like an IntLit,
127 -- so we'll call shortCutIntLit, but of course it's a float
128 -- This can make a big difference for programs with a lot of
129 -- literals, compiled without -O
131 shortCutLit (HsFractional f) ty
132 | isFloatTy ty = Just (mkLit floatDataCon (HsFloatPrim f))
133 | isDoubleTy ty = Just (mkLit doubleDataCon (HsDoublePrim f))
134 | otherwise = Nothing
136 shortCutLit (HsIsString s) ty
137 | isStringTy ty = Just (HsLit (HsString s))
138 | otherwise = Nothing
140 mkLit :: DataCon -> HsLit -> HsExpr Id
141 mkLit con lit = HsApp (nlHsVar (dataConWrapId con)) (nlHsLit lit)
143 ------------------------------
144 hsOverLitName :: OverLitVal -> Name
145 -- Get the canonical 'fromX' name for a particular OverLitVal
146 hsOverLitName (HsIntegral {}) = fromIntegerName
147 hsOverLitName (HsFractional {}) = fromRationalName
148 hsOverLitName (HsIsString {}) = fromStringName
151 %************************************************************************
153 \subsection[BackSubst-HsBinds]{Running a substitution over @HsBinds@}
155 %************************************************************************
158 -- zonkId is used *during* typechecking just to zonk the Id's type
159 zonkId :: TcId -> TcM TcId
161 = zonkTcType (idType id) `thenM` \ ty' ->
162 returnM (Id.setIdType id ty')
165 The rest of the zonking is done *after* typechecking.
166 The main zonking pass runs over the bindings
168 a) to convert TcTyVars to TyVars etc, dereferencing any bindings etc
169 b) convert unbound TcTyVar to Void
170 c) convert each TcId to an Id by zonking its type
172 The type variables are converted by binding mutable tyvars to immutable ones
173 and then zonking as normal.
175 The Ids are converted by binding them in the normal Tc envt; that
176 way we maintain sharing; eg an Id is zonked at its binding site and they
177 all occurrences of that Id point to the common zonked copy
179 It's all pretty boring stuff, because HsSyn is such a large type, and
180 the environment manipulation is tiresome.
183 data ZonkEnv = ZonkEnv (TcType -> TcM Type) -- How to zonk a type
184 (VarEnv Var) -- What variables are in scope
185 -- Maps an Id or EvVar to its zonked version; both have the same Name
186 -- Note that all evidence (coercion variables as well as dictionaries)
187 -- are kept in the ZonkEnv
188 -- Only *type* abstraction is done by side effect
189 -- Is only consulted lazily; hence knot-tying
191 emptyZonkEnv :: ZonkEnv
192 emptyZonkEnv = ZonkEnv zonkTypeZapping emptyVarEnv
194 extendZonkEnv :: ZonkEnv -> [Var] -> ZonkEnv
195 extendZonkEnv (ZonkEnv zonk_ty env) ids
196 = ZonkEnv zonk_ty (extendVarEnvList env [(id,id) | id <- ids])
198 extendZonkEnv1 :: ZonkEnv -> Var -> ZonkEnv
199 extendZonkEnv1 (ZonkEnv zonk_ty env) id
200 = ZonkEnv zonk_ty (extendVarEnv env id id)
202 setZonkType :: ZonkEnv -> (TcType -> TcM Type) -> ZonkEnv
203 setZonkType (ZonkEnv _ env) zonk_ty = ZonkEnv zonk_ty env
205 zonkEnvIds :: ZonkEnv -> [Id]
206 zonkEnvIds (ZonkEnv _ env) = varEnvElts env
208 zonkIdOcc :: ZonkEnv -> TcId -> Id
209 -- Ids defined in this module should be in the envt;
210 -- ignore others. (Actually, data constructors are also
211 -- not LocalVars, even when locally defined, but that is fine.)
212 -- (Also foreign-imported things aren't currently in the ZonkEnv;
213 -- that's ok because they don't need zonking.)
215 -- Actually, Template Haskell works in 'chunks' of declarations, and
216 -- an earlier chunk won't be in the 'env' that the zonking phase
217 -- carries around. Instead it'll be in the tcg_gbl_env, already fully
218 -- zonked. There's no point in looking it up there (except for error
219 -- checking), and it's not conveniently to hand; hence the simple
220 -- 'orElse' case in the LocalVar branch.
222 -- Even without template splices, in module Main, the checking of
223 -- 'main' is done as a separate chunk.
224 zonkIdOcc (ZonkEnv _zonk_ty env) id
225 | isLocalVar id = lookupVarEnv env id `orElse` id
228 zonkIdOccs :: ZonkEnv -> [TcId] -> [Id]
229 zonkIdOccs env ids = map (zonkIdOcc env) ids
231 -- zonkIdBndr is used *after* typechecking to get the Id's type
232 -- to its final form. The TyVarEnv give
233 zonkIdBndr :: ZonkEnv -> TcId -> TcM Id
235 = zonkTcTypeToType env (idType id) `thenM` \ ty' ->
236 returnM (Id.setIdType id ty')
238 zonkIdBndrs :: ZonkEnv -> [TcId] -> TcM [Id]
239 zonkIdBndrs env ids = mappM (zonkIdBndr env) ids
241 zonkTopBndrs :: [TcId] -> TcM [Id]
242 zonkTopBndrs ids = zonkIdBndrs emptyZonkEnv ids
244 zonkEvBndrsX :: ZonkEnv -> [EvVar] -> TcM (ZonkEnv, [Var])
245 zonkEvBndrsX = mapAccumLM zonkEvBndrX
247 zonkEvBndrX :: ZonkEnv -> EvVar -> TcM (ZonkEnv, EvVar)
248 -- Works for dictionaries and coercions
250 = do { var' <- zonkEvBndr env var
251 ; return (extendZonkEnv1 env var', var') }
253 zonkEvBndr :: ZonkEnv -> EvVar -> TcM EvVar
254 -- Works for dictionaries and coercions
255 -- Does not extend the ZonkEnv
257 = do { ty' <- zonkTcTypeToType env (varType var)
258 ; return (setVarType var ty') }
260 zonkEvVarOcc :: ZonkEnv -> EvVar -> EvVar
261 zonkEvVarOcc env v = zonkIdOcc env v
266 zonkTopExpr :: HsExpr TcId -> TcM (HsExpr Id)
267 zonkTopExpr e = zonkExpr emptyZonkEnv e
269 zonkTopLExpr :: LHsExpr TcId -> TcM (LHsExpr Id)
270 zonkTopLExpr e = zonkLExpr emptyZonkEnv e
272 zonkTopDecls :: Bag EvBind
273 -> LHsBinds TcId -> NameSet
274 -> [LRuleDecl TcId] -> [LVectDecl TcId] -> [LTcSpecPrag] -> [LForeignDecl TcId]
282 zonkTopDecls ev_binds binds sig_ns rules vects imp_specs fords
283 = do { (env1, ev_binds') <- zonkEvBinds emptyZonkEnv ev_binds
285 -- Warn about missing signatures
286 -- Do this only when we we have a type to offer
287 ; warn_missing_sigs <- doptM Opt_WarnMissingSigs
288 ; let sig_warn | warn_missing_sigs = topSigWarn sig_ns
289 | otherwise = noSigWarn
291 ; (env2, binds') <- zonkRecMonoBinds env1 sig_warn binds
292 -- Top level is implicitly recursive
293 ; rules' <- zonkRules env2 rules
294 ; vects' <- zonkVects env2 vects
295 ; specs' <- zonkLTcSpecPrags env2 imp_specs
296 ; fords' <- zonkForeignExports env2 fords
297 ; return (zonkEnvIds env2, ev_binds', binds', fords', specs', rules', vects') }
299 ---------------------------------------------
300 zonkLocalBinds :: ZonkEnv -> HsLocalBinds TcId -> TcM (ZonkEnv, HsLocalBinds Id)
301 zonkLocalBinds env EmptyLocalBinds
302 = return (env, EmptyLocalBinds)
304 zonkLocalBinds _ (HsValBinds (ValBindsIn {}))
305 = panic "zonkLocalBinds" -- Not in typechecker output
307 zonkLocalBinds env (HsValBinds vb@(ValBindsOut binds sigs))
308 = do { warn_missing_sigs <- doptM Opt_WarnMissingLocalSigs
309 ; let sig_warn | not warn_missing_sigs = noSigWarn
310 | otherwise = localSigWarn sig_ns
311 sig_ns = getTypeSigNames vb
312 ; (env1, new_binds) <- go env sig_warn binds
313 ; return (env1, HsValBinds (ValBindsOut new_binds sigs)) }
317 go env sig_warn ((r,b):bs)
318 = do { (env1, b') <- zonkRecMonoBinds env sig_warn b
319 ; (env2, bs') <- go env1 sig_warn bs
320 ; return (env2, (r,b'):bs') }
322 zonkLocalBinds env (HsIPBinds (IPBinds binds dict_binds))
323 = mappM (wrapLocM zonk_ip_bind) binds `thenM` \ new_binds ->
325 env1 = extendZonkEnv env [ipNameName n | L _ (IPBind n _) <- new_binds]
327 zonkTcEvBinds env1 dict_binds `thenM` \ (env2, new_dict_binds) ->
328 returnM (env2, HsIPBinds (IPBinds new_binds new_dict_binds))
330 zonk_ip_bind (IPBind n e)
331 = mapIPNameTc (zonkIdBndr env) n `thenM` \ n' ->
332 zonkLExpr env e `thenM` \ e' ->
333 returnM (IPBind n' e')
335 ---------------------------------------------
336 zonkRecMonoBinds :: ZonkEnv -> SigWarn -> LHsBinds TcId -> TcM (ZonkEnv, LHsBinds Id)
337 zonkRecMonoBinds env sig_warn binds
338 = fixM (\ ~(_, new_binds) -> do
339 { let env1 = extendZonkEnv env (collectHsBindsBinders new_binds)
340 ; binds' <- zonkMonoBinds env1 sig_warn binds
341 ; return (env1, binds') })
343 ---------------------------------------------
344 type SigWarn = Bool -> [Id] -> TcM ()
345 -- Missing-signature warning
346 -- The Bool is True for an AbsBinds, False otherwise
349 noSigWarn _ _ = return ()
351 topSigWarn :: NameSet -> SigWarn
352 topSigWarn sig_ns _ ids = mapM_ (topSigWarnId sig_ns) ids
354 topSigWarnId :: NameSet -> Id -> TcM ()
355 -- The NameSet is the Ids that *lack* a signature
356 -- We have to do it this way round because there are
357 -- lots of top-level bindings that are generated by GHC
358 -- and that don't have signatures
359 topSigWarnId sig_ns id
360 | idName id `elemNameSet` sig_ns = warnMissingSig msg id
361 | otherwise = return ()
363 msg = ptext (sLit "Top-level binding with no type signature:")
365 localSigWarn :: NameSet -> SigWarn
366 localSigWarn sig_ns is_abs_bind ids
367 | not is_abs_bind = return ()
368 | otherwise = mapM_ (localSigWarnId sig_ns) ids
370 localSigWarnId :: NameSet -> Id -> TcM ()
371 -- NameSet are the Ids that *have* type signatures
372 localSigWarnId sig_ns id
373 | not (isSigmaTy (idType id)) = return ()
374 | idName id `elemNameSet` sig_ns = return ()
375 | otherwise = warnMissingSig msg id
377 msg = ptext (sLit "Polymophic local binding with no type signature:")
379 warnMissingSig :: SDoc -> Id -> TcM ()
380 warnMissingSig msg id
381 = do { env0 <- tcInitTidyEnv
382 ; let (env1, tidy_ty) = tidyOpenType env0 (idType id)
383 ; addWarnTcM (env1, mk_msg tidy_ty) }
385 mk_msg ty = sep [ msg, nest 2 $ pprHsVar (idName id) <+> dcolon <+> ppr ty ]
387 ---------------------------------------------
388 zonkMonoBinds :: ZonkEnv -> SigWarn -> LHsBinds TcId -> TcM (LHsBinds Id)
389 zonkMonoBinds env sig_warn binds = mapBagM (wrapLocM (zonk_bind env sig_warn)) binds
391 zonk_bind :: ZonkEnv -> SigWarn -> HsBind TcId -> TcM (HsBind Id)
392 zonk_bind env sig_warn bind@(PatBind { pat_lhs = pat, pat_rhs = grhss, pat_rhs_ty = ty})
393 = do { (_env, new_pat) <- zonkPat env pat -- Env already extended
394 ; sig_warn False (collectPatBinders new_pat)
395 ; new_grhss <- zonkGRHSs env grhss
396 ; new_ty <- zonkTcTypeToType env ty
397 ; return (bind { pat_lhs = new_pat, pat_rhs = new_grhss, pat_rhs_ty = new_ty }) }
399 zonk_bind env sig_warn (VarBind { var_id = var, var_rhs = expr, var_inline = inl })
400 = do { new_var <- zonkIdBndr env var
401 ; sig_warn False [new_var]
402 ; new_expr <- zonkLExpr env expr
403 ; return (VarBind { var_id = new_var, var_rhs = new_expr, var_inline = inl }) }
405 zonk_bind env sig_warn bind@(FunBind { fun_id = L loc var, fun_matches = ms
406 , fun_co_fn = co_fn })
407 = do { new_var <- zonkIdBndr env var
408 ; sig_warn False [new_var]
409 ; (env1, new_co_fn) <- zonkCoFn env co_fn
410 ; new_ms <- zonkMatchGroup env1 ms
411 ; return (bind { fun_id = L loc new_var, fun_matches = new_ms
412 , fun_co_fn = new_co_fn }) }
414 zonk_bind env sig_warn (AbsBinds { abs_tvs = tyvars, abs_ev_vars = evs
415 , abs_ev_binds = ev_binds
416 , abs_exports = exports
417 , abs_binds = val_binds })
418 = ASSERT( all isImmutableTyVar tyvars )
419 do { (env1, new_evs) <- zonkEvBndrsX env evs
420 ; (env2, new_ev_binds) <- zonkTcEvBinds env1 ev_binds
421 ; (new_val_bind, new_exports) <- fixM $ \ ~(new_val_binds, _) ->
422 do { let env3 = extendZonkEnv env2 (collectHsBindsBinders new_val_binds)
423 ; new_val_binds <- zonkMonoBinds env3 noSigWarn val_binds
424 ; new_exports <- mapM (zonkExport env3) exports
425 ; return (new_val_binds, new_exports) }
426 ; sig_warn True [b | (_,b,_,_) <- new_exports]
427 ; return (AbsBinds { abs_tvs = tyvars, abs_ev_vars = new_evs, abs_ev_binds = new_ev_binds
428 , abs_exports = new_exports, abs_binds = new_val_bind }) }
430 zonkExport env (tyvars, global, local, prags)
431 -- The tyvars are already zonked
432 = zonkIdBndr env global `thenM` \ new_global ->
433 zonkSpecPrags env prags `thenM` \ new_prags ->
434 returnM (tyvars, new_global, zonkIdOcc env local, new_prags)
436 zonkSpecPrags :: ZonkEnv -> TcSpecPrags -> TcM TcSpecPrags
437 zonkSpecPrags _ IsDefaultMethod = return IsDefaultMethod
438 zonkSpecPrags env (SpecPrags ps) = do { ps' <- zonkLTcSpecPrags env ps
439 ; return (SpecPrags ps') }
441 zonkLTcSpecPrags :: ZonkEnv -> [LTcSpecPrag] -> TcM [LTcSpecPrag]
442 zonkLTcSpecPrags env ps
445 zonk_prag (L loc (SpecPrag id co_fn inl))
446 = do { (_, co_fn') <- zonkCoFn env co_fn
447 ; return (L loc (SpecPrag (zonkIdOcc env id) co_fn' inl)) }
450 %************************************************************************
452 \subsection[BackSubst-Match-GRHSs]{Match and GRHSs}
454 %************************************************************************
457 zonkMatchGroup :: ZonkEnv -> MatchGroup TcId-> TcM (MatchGroup Id)
458 zonkMatchGroup env (MatchGroup ms ty)
459 = do { ms' <- mapM (zonkMatch env) ms
460 ; ty' <- zonkTcTypeToType env ty
461 ; return (MatchGroup ms' ty') }
463 zonkMatch :: ZonkEnv -> LMatch TcId-> TcM (LMatch Id)
464 zonkMatch env (L loc (Match pats _ grhss))
465 = do { (env1, new_pats) <- zonkPats env pats
466 ; new_grhss <- zonkGRHSs env1 grhss
467 ; return (L loc (Match new_pats Nothing new_grhss)) }
469 -------------------------------------------------------------------------
470 zonkGRHSs :: ZonkEnv -> GRHSs TcId -> TcM (GRHSs Id)
472 zonkGRHSs env (GRHSs grhss binds)
473 = zonkLocalBinds env binds `thenM` \ (new_env, new_binds) ->
475 zonk_grhs (GRHS guarded rhs)
476 = zonkStmts new_env guarded `thenM` \ (env2, new_guarded) ->
477 zonkLExpr env2 rhs `thenM` \ new_rhs ->
478 returnM (GRHS new_guarded new_rhs)
480 mappM (wrapLocM zonk_grhs) grhss `thenM` \ new_grhss ->
481 returnM (GRHSs new_grhss new_binds)
484 %************************************************************************
486 \subsection[BackSubst-HsExpr]{Running a zonkitution over a TypeCheckedExpr}
488 %************************************************************************
491 zonkLExprs :: ZonkEnv -> [LHsExpr TcId] -> TcM [LHsExpr Id]
492 zonkLExpr :: ZonkEnv -> LHsExpr TcId -> TcM (LHsExpr Id)
493 zonkExpr :: ZonkEnv -> HsExpr TcId -> TcM (HsExpr Id)
495 zonkLExprs env exprs = mappM (zonkLExpr env) exprs
496 zonkLExpr env expr = wrapLocM (zonkExpr env) expr
498 zonkExpr env (HsVar id)
499 = returnM (HsVar (zonkIdOcc env id))
501 zonkExpr env (HsIPVar id)
502 = returnM (HsIPVar (mapIPName (zonkIdOcc env) id))
504 zonkExpr env (HsLit (HsRat f ty))
505 = zonkTcTypeToType env ty `thenM` \ new_ty ->
506 returnM (HsLit (HsRat f new_ty))
508 zonkExpr _ (HsLit lit)
509 = returnM (HsLit lit)
511 zonkExpr env (HsOverLit lit)
512 = do { lit' <- zonkOverLit env lit
513 ; return (HsOverLit lit') }
515 zonkExpr env (HsLam matches)
516 = zonkMatchGroup env matches `thenM` \ new_matches ->
517 returnM (HsLam new_matches)
519 zonkExpr env (HsApp e1 e2)
520 = zonkLExpr env e1 `thenM` \ new_e1 ->
521 zonkLExpr env e2 `thenM` \ new_e2 ->
522 returnM (HsApp new_e1 new_e2)
524 zonkExpr env (HsBracketOut body bs)
525 = mappM zonk_b bs `thenM` \ bs' ->
526 returnM (HsBracketOut body bs')
528 zonk_b (n,e) = zonkLExpr env e `thenM` \ e' ->
531 zonkExpr _ (HsSpliceE s) = WARN( True, ppr s ) -- Should not happen
532 returnM (HsSpliceE s)
534 zonkExpr env (OpApp e1 op fixity e2)
535 = zonkLExpr env e1 `thenM` \ new_e1 ->
536 zonkLExpr env op `thenM` \ new_op ->
537 zonkLExpr env e2 `thenM` \ new_e2 ->
538 returnM (OpApp new_e1 new_op fixity new_e2)
540 zonkExpr env (NegApp expr op)
541 = zonkLExpr env expr `thenM` \ new_expr ->
542 zonkExpr env op `thenM` \ new_op ->
543 returnM (NegApp new_expr new_op)
545 zonkExpr env (HsPar e)
546 = zonkLExpr env e `thenM` \new_e ->
547 returnM (HsPar new_e)
549 zonkExpr env (HsHetMetBrak c e)
550 = do c' <- zonkTcTypeToType env c
551 e' <- zonkLExpr env e
552 return (HsHetMetBrak c' e')
554 zonkExpr env (HsHetMetEsc c t e)
555 = do c' <- zonkTcTypeToType env c
556 t' <- zonkTcTypeToType env t
557 e' <- zonkLExpr env e
558 return (HsHetMetEsc c' t' e')
560 zonkExpr env (HsHetMetCSP c e)
561 = do c' <- zonkTcTypeToType env c
562 e' <- zonkLExpr env e
563 return (HsHetMetCSP c' e')
565 zonkExpr env (SectionL expr op)
566 = zonkLExpr env expr `thenM` \ new_expr ->
567 zonkLExpr env op `thenM` \ new_op ->
568 returnM (SectionL new_expr new_op)
570 zonkExpr env (SectionR op expr)
571 = zonkLExpr env op `thenM` \ new_op ->
572 zonkLExpr env expr `thenM` \ new_expr ->
573 returnM (SectionR new_op new_expr)
575 zonkExpr env (ExplicitTuple tup_args boxed)
576 = do { new_tup_args <- mapM zonk_tup_arg tup_args
577 ; return (ExplicitTuple new_tup_args boxed) }
579 zonk_tup_arg (Present e) = do { e' <- zonkLExpr env e; return (Present e') }
580 zonk_tup_arg (Missing t) = do { t' <- zonkTcTypeToType env t; return (Missing t') }
582 zonkExpr env (HsCase expr ms)
583 = zonkLExpr env expr `thenM` \ new_expr ->
584 zonkMatchGroup env ms `thenM` \ new_ms ->
585 returnM (HsCase new_expr new_ms)
587 zonkExpr env (HsIf e0 e1 e2 e3)
588 = do { new_e0 <- fmapMaybeM (zonkExpr env) e0
589 ; new_e1 <- zonkLExpr env e1
590 ; new_e2 <- zonkLExpr env e2
591 ; new_e3 <- zonkLExpr env e3
592 ; returnM (HsIf new_e0 new_e1 new_e2 new_e3) }
594 zonkExpr env (HsLet binds expr)
595 = zonkLocalBinds env binds `thenM` \ (new_env, new_binds) ->
596 zonkLExpr new_env expr `thenM` \ new_expr ->
597 returnM (HsLet new_binds new_expr)
599 zonkExpr env (HsDo do_or_lc stmts ty)
600 = zonkStmts env stmts `thenM` \ (_, new_stmts) ->
601 zonkTcTypeToType env ty `thenM` \ new_ty ->
602 returnM (HsDo do_or_lc new_stmts new_ty)
604 zonkExpr env (ExplicitList ty exprs)
605 = zonkTcTypeToType env ty `thenM` \ new_ty ->
606 zonkLExprs env exprs `thenM` \ new_exprs ->
607 returnM (ExplicitList new_ty new_exprs)
609 zonkExpr env (ExplicitPArr ty exprs)
610 = zonkTcTypeToType env ty `thenM` \ new_ty ->
611 zonkLExprs env exprs `thenM` \ new_exprs ->
612 returnM (ExplicitPArr new_ty new_exprs)
614 zonkExpr env (RecordCon data_con con_expr rbinds)
615 = do { new_con_expr <- zonkExpr env con_expr
616 ; new_rbinds <- zonkRecFields env rbinds
617 ; return (RecordCon data_con new_con_expr new_rbinds) }
619 zonkExpr env (RecordUpd expr rbinds cons in_tys out_tys)
620 = do { new_expr <- zonkLExpr env expr
621 ; new_in_tys <- mapM (zonkTcTypeToType env) in_tys
622 ; new_out_tys <- mapM (zonkTcTypeToType env) out_tys
623 ; new_rbinds <- zonkRecFields env rbinds
624 ; return (RecordUpd new_expr new_rbinds cons new_in_tys new_out_tys) }
626 zonkExpr env (ExprWithTySigOut e ty)
627 = do { e' <- zonkLExpr env e
628 ; return (ExprWithTySigOut e' ty) }
630 zonkExpr _ (ExprWithTySig _ _) = panic "zonkExpr env:ExprWithTySig"
632 zonkExpr env (ArithSeq expr info)
633 = zonkExpr env expr `thenM` \ new_expr ->
634 zonkArithSeq env info `thenM` \ new_info ->
635 returnM (ArithSeq new_expr new_info)
637 zonkExpr env (PArrSeq expr info)
638 = zonkExpr env expr `thenM` \ new_expr ->
639 zonkArithSeq env info `thenM` \ new_info ->
640 returnM (PArrSeq new_expr new_info)
642 zonkExpr env (HsSCC lbl expr)
643 = zonkLExpr env expr `thenM` \ new_expr ->
644 returnM (HsSCC lbl new_expr)
646 zonkExpr env (HsTickPragma info expr)
647 = zonkLExpr env expr `thenM` \ new_expr ->
648 returnM (HsTickPragma info new_expr)
650 -- hdaume: core annotations
651 zonkExpr env (HsCoreAnn lbl expr)
652 = zonkLExpr env expr `thenM` \ new_expr ->
653 returnM (HsCoreAnn lbl new_expr)
655 -- arrow notation extensions
656 zonkExpr env (HsProc pat body)
657 = do { (env1, new_pat) <- zonkPat env pat
658 ; new_body <- zonkCmdTop env1 body
659 ; return (HsProc new_pat new_body) }
661 zonkExpr env (HsArrApp e1 e2 ty ho rl)
662 = zonkLExpr env e1 `thenM` \ new_e1 ->
663 zonkLExpr env e2 `thenM` \ new_e2 ->
664 zonkTcTypeToType env ty `thenM` \ new_ty ->
665 returnM (HsArrApp new_e1 new_e2 new_ty ho rl)
667 zonkExpr env (HsArrForm op fixity args)
668 = zonkLExpr env op `thenM` \ new_op ->
669 mappM (zonkCmdTop env) args `thenM` \ new_args ->
670 returnM (HsArrForm new_op fixity new_args)
672 zonkExpr env (HsWrap co_fn expr)
673 = zonkCoFn env co_fn `thenM` \ (env1, new_co_fn) ->
674 zonkExpr env1 expr `thenM` \ new_expr ->
675 return (HsWrap new_co_fn new_expr)
677 zonkExpr _ expr = pprPanic "zonkExpr" (ppr expr)
679 zonkCmdTop :: ZonkEnv -> LHsCmdTop TcId -> TcM (LHsCmdTop Id)
680 zonkCmdTop env cmd = wrapLocM (zonk_cmd_top env) cmd
682 zonk_cmd_top :: ZonkEnv -> HsCmdTop TcId -> TcM (HsCmdTop Id)
683 zonk_cmd_top env (HsCmdTop cmd stack_tys ty ids)
684 = zonkLExpr env cmd `thenM` \ new_cmd ->
685 zonkTcTypeToTypes env stack_tys `thenM` \ new_stack_tys ->
686 zonkTcTypeToType env ty `thenM` \ new_ty ->
687 mapSndM (zonkExpr env) ids `thenM` \ new_ids ->
688 returnM (HsCmdTop new_cmd new_stack_tys new_ty new_ids)
690 -------------------------------------------------------------------------
691 zonkCoFn :: ZonkEnv -> HsWrapper -> TcM (ZonkEnv, HsWrapper)
692 zonkCoFn env WpHole = return (env, WpHole)
693 zonkCoFn env (WpCompose c1 c2) = do { (env1, c1') <- zonkCoFn env c1
694 ; (env2, c2') <- zonkCoFn env1 c2
695 ; return (env2, WpCompose c1' c2') }
696 zonkCoFn env (WpCast co) = do { co' <- zonkTcCoToCo env co
697 ; return (env, WpCast co') }
698 zonkCoFn env (WpEvLam ev) = do { (env', ev') <- zonkEvBndrX env ev
699 ; return (env', WpEvLam ev') }
700 zonkCoFn env (WpEvApp arg) = do { arg' <- zonkEvTerm env arg
701 ; return (env, WpEvApp arg') }
702 zonkCoFn env (WpTyLam tv) = ASSERT( isImmutableTyVar tv )
703 return (env, WpTyLam tv)
704 zonkCoFn env (WpTyApp ty) = do { ty' <- zonkTcTypeToType env ty
705 ; return (env, WpTyApp ty') }
706 zonkCoFn env (WpLet bs) = do { (env1, bs') <- zonkTcEvBinds env bs
707 ; return (env1, WpLet bs') }
709 -------------------------------------------------------------------------
710 zonkOverLit :: ZonkEnv -> HsOverLit TcId -> TcM (HsOverLit Id)
711 zonkOverLit env lit@(OverLit { ol_witness = e, ol_type = ty })
712 = do { ty' <- zonkTcTypeToType env ty
713 ; e' <- zonkExpr env e
714 ; return (lit { ol_witness = e', ol_type = ty' }) }
716 -------------------------------------------------------------------------
717 zonkArithSeq :: ZonkEnv -> ArithSeqInfo TcId -> TcM (ArithSeqInfo Id)
719 zonkArithSeq env (From e)
720 = zonkLExpr env e `thenM` \ new_e ->
723 zonkArithSeq env (FromThen e1 e2)
724 = zonkLExpr env e1 `thenM` \ new_e1 ->
725 zonkLExpr env e2 `thenM` \ new_e2 ->
726 returnM (FromThen new_e1 new_e2)
728 zonkArithSeq env (FromTo e1 e2)
729 = zonkLExpr env e1 `thenM` \ new_e1 ->
730 zonkLExpr env e2 `thenM` \ new_e2 ->
731 returnM (FromTo new_e1 new_e2)
733 zonkArithSeq env (FromThenTo e1 e2 e3)
734 = zonkLExpr env e1 `thenM` \ new_e1 ->
735 zonkLExpr env e2 `thenM` \ new_e2 ->
736 zonkLExpr env e3 `thenM` \ new_e3 ->
737 returnM (FromThenTo new_e1 new_e2 new_e3)
740 -------------------------------------------------------------------------
741 zonkStmts :: ZonkEnv -> [LStmt TcId] -> TcM (ZonkEnv, [LStmt Id])
742 zonkStmts env [] = return (env, [])
743 zonkStmts env (s:ss) = do { (env1, s') <- wrapLocSndM (zonkStmt env) s
744 ; (env2, ss') <- zonkStmts env1 ss
745 ; return (env2, s' : ss') }
747 zonkStmt :: ZonkEnv -> Stmt TcId -> TcM (ZonkEnv, Stmt Id)
748 zonkStmt env (ParStmt stmts_w_bndrs mzip_op bind_op return_op)
749 = mappM zonk_branch stmts_w_bndrs `thenM` \ new_stmts_w_bndrs ->
751 new_binders = concat (map snd new_stmts_w_bndrs)
752 env1 = extendZonkEnv env new_binders
754 zonkExpr env1 mzip_op `thenM` \ new_mzip ->
755 zonkExpr env1 bind_op `thenM` \ new_bind ->
756 zonkExpr env1 return_op `thenM` \ new_return ->
757 return (env1, ParStmt new_stmts_w_bndrs new_mzip new_bind new_return)
759 zonk_branch (stmts, bndrs) = zonkStmts env stmts `thenM` \ (env1, new_stmts) ->
760 returnM (new_stmts, zonkIdOccs env1 bndrs)
762 zonkStmt env (RecStmt { recS_stmts = segStmts, recS_later_ids = lvs, recS_rec_ids = rvs
763 , recS_ret_fn = ret_id, recS_mfix_fn = mfix_id, recS_bind_fn = bind_id
764 , recS_rec_rets = rets, recS_ret_ty = ret_ty })
765 = do { new_rvs <- zonkIdBndrs env rvs
766 ; new_lvs <- zonkIdBndrs env lvs
767 ; new_ret_ty <- zonkTcTypeToType env ret_ty
768 ; new_ret_id <- zonkExpr env ret_id
769 ; new_mfix_id <- zonkExpr env mfix_id
770 ; new_bind_id <- zonkExpr env bind_id
771 ; let env1 = extendZonkEnv env new_rvs
772 ; (env2, new_segStmts) <- zonkStmts env1 segStmts
773 -- Zonk the ret-expressions in an envt that
774 -- has the polymorphic bindings in the envt
775 ; new_rets <- mapM (zonkExpr env2) rets
776 ; return (extendZonkEnv env new_lvs, -- Only the lvs are needed
777 RecStmt { recS_stmts = new_segStmts, recS_later_ids = new_lvs
778 , recS_rec_ids = new_rvs, recS_ret_fn = new_ret_id
779 , recS_mfix_fn = new_mfix_id, recS_bind_fn = new_bind_id
780 , recS_rec_rets = new_rets, recS_ret_ty = new_ret_ty }) }
782 zonkStmt env (ExprStmt expr then_op guard_op ty)
783 = zonkLExpr env expr `thenM` \ new_expr ->
784 zonkExpr env then_op `thenM` \ new_then ->
785 zonkExpr env guard_op `thenM` \ new_guard ->
786 zonkTcTypeToType env ty `thenM` \ new_ty ->
787 returnM (env, ExprStmt new_expr new_then new_guard new_ty)
789 zonkStmt env (LastStmt expr ret_op)
790 = zonkLExpr env expr `thenM` \ new_expr ->
791 zonkExpr env ret_op `thenM` \ new_ret ->
792 returnM (env, LastStmt new_expr new_ret)
794 zonkStmt env (TransStmt { trS_stmts = stmts, trS_bndrs = binderMap
795 , trS_by = by, trS_form = form, trS_using = using
796 , trS_ret = return_op, trS_bind = bind_op, trS_fmap = liftM_op })
797 = do { (env', stmts') <- zonkStmts env stmts
798 ; binderMap' <- mappM (zonkBinderMapEntry env') binderMap
799 ; by' <- fmapMaybeM (zonkLExpr env') by
800 ; using' <- zonkLExpr env using
801 ; return_op' <- zonkExpr env' return_op
802 ; bind_op' <- zonkExpr env' bind_op
803 ; liftM_op' <- zonkExpr env' liftM_op
804 ; let env'' = extendZonkEnv env' (map snd binderMap')
805 ; return (env'', TransStmt { trS_stmts = stmts', trS_bndrs = binderMap'
806 , trS_by = by', trS_form = form, trS_using = using'
807 , trS_ret = return_op', trS_bind = bind_op', trS_fmap = liftM_op' }) }
809 zonkBinderMapEntry env (oldBinder, newBinder) = do
810 let oldBinder' = zonkIdOcc env oldBinder
811 newBinder' <- zonkIdBndr env newBinder
812 return (oldBinder', newBinder')
814 zonkStmt env (LetStmt binds)
815 = zonkLocalBinds env binds `thenM` \ (env1, new_binds) ->
816 returnM (env1, LetStmt new_binds)
818 zonkStmt env (BindStmt pat expr bind_op fail_op)
819 = do { new_expr <- zonkLExpr env expr
820 ; (env1, new_pat) <- zonkPat env pat
821 ; new_bind <- zonkExpr env bind_op
822 ; new_fail <- zonkExpr env fail_op
823 ; return (env1, BindStmt new_pat new_expr new_bind new_fail) }
825 -------------------------------------------------------------------------
826 zonkRecFields :: ZonkEnv -> HsRecordBinds TcId -> TcM (HsRecordBinds TcId)
827 zonkRecFields env (HsRecFields flds dd)
828 = do { flds' <- mappM zonk_rbind flds
829 ; return (HsRecFields flds' dd) }
832 = do { new_id <- wrapLocM (zonkIdBndr env) (hsRecFieldId fld)
833 ; new_expr <- zonkLExpr env (hsRecFieldArg fld)
834 ; return (fld { hsRecFieldId = new_id, hsRecFieldArg = new_expr }) }
836 -------------------------------------------------------------------------
837 mapIPNameTc :: (a -> TcM b) -> IPName a -> TcM (IPName b)
838 mapIPNameTc f (IPName n) = f n `thenM` \ r -> returnM (IPName r)
842 %************************************************************************
844 \subsection[BackSubst-Pats]{Patterns}
846 %************************************************************************
849 zonkPat :: ZonkEnv -> OutPat TcId -> TcM (ZonkEnv, OutPat Id)
850 -- Extend the environment as we go, because it's possible for one
851 -- pattern to bind something that is used in another (inside or
853 zonkPat env pat = wrapLocSndM (zonk_pat env) pat
855 zonk_pat :: ZonkEnv -> Pat TcId -> TcM (ZonkEnv, Pat Id)
856 zonk_pat env (ParPat p)
857 = do { (env', p') <- zonkPat env p
858 ; return (env', ParPat p') }
860 zonk_pat env (WildPat ty)
861 = do { ty' <- zonkTcTypeToType env ty
862 ; return (env, WildPat ty') }
864 zonk_pat env (VarPat v)
865 = do { v' <- zonkIdBndr env v
866 ; return (extendZonkEnv1 env v', VarPat v') }
868 zonk_pat env (LazyPat pat)
869 = do { (env', pat') <- zonkPat env pat
870 ; return (env', LazyPat pat') }
872 zonk_pat env (BangPat pat)
873 = do { (env', pat') <- zonkPat env pat
874 ; return (env', BangPat pat') }
876 zonk_pat env (AsPat (L loc v) pat)
877 = do { v' <- zonkIdBndr env v
878 ; (env', pat') <- zonkPat (extendZonkEnv1 env v') pat
879 ; return (env', AsPat (L loc v') pat') }
881 zonk_pat env (ViewPat expr pat ty)
882 = do { expr' <- zonkLExpr env expr
883 ; (env', pat') <- zonkPat env pat
884 ; ty' <- zonkTcTypeToType env ty
885 ; return (env', ViewPat expr' pat' ty') }
887 zonk_pat env (ListPat pats ty)
888 = do { ty' <- zonkTcTypeToType env ty
889 ; (env', pats') <- zonkPats env pats
890 ; return (env', ListPat pats' ty') }
892 zonk_pat env (PArrPat pats ty)
893 = do { ty' <- zonkTcTypeToType env ty
894 ; (env', pats') <- zonkPats env pats
895 ; return (env', PArrPat pats' ty') }
897 zonk_pat env (TuplePat pats boxed ty)
898 = do { ty' <- zonkTcTypeToType env ty
899 ; (env', pats') <- zonkPats env pats
900 ; return (env', TuplePat pats' boxed ty') }
902 zonk_pat env p@(ConPatOut { pat_ty = ty, pat_dicts = evs, pat_binds = binds, pat_args = args })
903 = ASSERT( all isImmutableTyVar (pat_tvs p) )
904 do { new_ty <- zonkTcTypeToType env ty
905 ; (env1, new_evs) <- zonkEvBndrsX env evs
906 ; (env2, new_binds) <- zonkTcEvBinds env1 binds
907 ; (env', new_args) <- zonkConStuff env2 args
908 ; returnM (env', p { pat_ty = new_ty, pat_dicts = new_evs,
909 pat_binds = new_binds, pat_args = new_args }) }
911 zonk_pat env (LitPat lit) = return (env, LitPat lit)
913 zonk_pat env (SigPatOut pat ty)
914 = do { ty' <- zonkTcTypeToType env ty
915 ; (env', pat') <- zonkPat env pat
916 ; return (env', SigPatOut pat' ty') }
918 zonk_pat env (NPat lit mb_neg eq_expr)
919 = do { lit' <- zonkOverLit env lit
920 ; mb_neg' <- fmapMaybeM (zonkExpr env) mb_neg
921 ; eq_expr' <- zonkExpr env eq_expr
922 ; return (env, NPat lit' mb_neg' eq_expr') }
924 zonk_pat env (NPlusKPat (L loc n) lit e1 e2)
925 = do { n' <- zonkIdBndr env n
926 ; lit' <- zonkOverLit env lit
927 ; e1' <- zonkExpr env e1
928 ; e2' <- zonkExpr env e2
929 ; return (extendZonkEnv1 env n', NPlusKPat (L loc n') lit' e1' e2') }
931 zonk_pat env (CoPat co_fn pat ty)
932 = do { (env', co_fn') <- zonkCoFn env co_fn
933 ; (env'', pat') <- zonkPat env' (noLoc pat)
934 ; ty' <- zonkTcTypeToType env'' ty
935 ; return (env'', CoPat co_fn' (unLoc pat') ty') }
937 zonk_pat _ pat = pprPanic "zonk_pat" (ppr pat)
939 ---------------------------
940 zonkConStuff :: ZonkEnv
941 -> HsConDetails (OutPat TcId) (HsRecFields id (OutPat TcId))
943 HsConDetails (OutPat Id) (HsRecFields id (OutPat Id)))
944 zonkConStuff env (PrefixCon pats)
945 = do { (env', pats') <- zonkPats env pats
946 ; return (env', PrefixCon pats') }
948 zonkConStuff env (InfixCon p1 p2)
949 = do { (env1, p1') <- zonkPat env p1
950 ; (env', p2') <- zonkPat env1 p2
951 ; return (env', InfixCon p1' p2') }
953 zonkConStuff env (RecCon (HsRecFields rpats dd))
954 = do { (env', pats') <- zonkPats env (map hsRecFieldArg rpats)
955 ; let rpats' = zipWith (\rp p' -> rp { hsRecFieldArg = p' }) rpats pats'
956 ; returnM (env', RecCon (HsRecFields rpats' dd)) }
957 -- Field selectors have declared types; hence no zonking
959 ---------------------------
960 zonkPats :: ZonkEnv -> [OutPat TcId] -> TcM (ZonkEnv, [OutPat Id])
961 zonkPats env [] = return (env, [])
962 zonkPats env (pat:pats) = do { (env1, pat') <- zonkPat env pat
963 ; (env', pats') <- zonkPats env1 pats
964 ; return (env', pat':pats') }
967 %************************************************************************
969 \subsection[BackSubst-Foreign]{Foreign exports}
971 %************************************************************************
975 zonkForeignExports :: ZonkEnv -> [LForeignDecl TcId] -> TcM [LForeignDecl Id]
976 zonkForeignExports env ls = mappM (wrapLocM (zonkForeignExport env)) ls
978 zonkForeignExport :: ZonkEnv -> ForeignDecl TcId -> TcM (ForeignDecl Id)
979 zonkForeignExport env (ForeignExport i _hs_ty spec) =
980 returnM (ForeignExport (fmap (zonkIdOcc env) i) undefined spec)
981 zonkForeignExport _ for_imp
982 = returnM for_imp -- Foreign imports don't need zonking
986 zonkRules :: ZonkEnv -> [LRuleDecl TcId] -> TcM [LRuleDecl Id]
987 zonkRules env rs = mappM (wrapLocM (zonkRule env)) rs
989 zonkRule :: ZonkEnv -> RuleDecl TcId -> TcM (RuleDecl Id)
990 zonkRule env (HsRule name act (vars{-::[RuleBndr TcId]-}) lhs fv_lhs rhs fv_rhs)
991 = do { (env_rhs, new_bndrs) <- mapAccumLM zonk_bndr env vars
993 ; unbound_tv_set <- newMutVar emptyVarSet
994 ; let env_lhs = setZonkType env_rhs (zonkTypeCollecting unbound_tv_set)
995 -- We need to gather the type variables mentioned on the LHS so we can
996 -- quantify over them. Example:
1002 -- {-# RULES "myrule" foo C = 1 #-}
1004 -- After type checking the LHS becomes (foo a (C a))
1005 -- and we do not want to zap the unbound tyvar 'a' to (), because
1006 -- that limits the applicability of the rule. Instead, we
1007 -- want to quantify over it!
1009 -- It's easiest to find the free tyvars here. Attempts to do so earlier
1010 -- are tiresome, because (a) the data type is big and (b) finding the
1011 -- free type vars of an expression is necessarily monadic operation.
1012 -- (consider /\a -> f @ b, where b is side-effected to a)
1014 ; new_lhs <- zonkLExpr env_lhs lhs
1015 ; new_rhs <- zonkLExpr env_rhs rhs
1017 ; unbound_tvs <- readMutVar unbound_tv_set
1018 ; let final_bndrs :: [RuleBndr Var]
1019 final_bndrs = map (RuleBndr . noLoc) (varSetElems unbound_tvs) ++ new_bndrs
1021 ; return (HsRule name act final_bndrs new_lhs fv_lhs new_rhs fv_rhs) }
1023 zonk_bndr env (RuleBndr (L loc v))
1024 = do { (env', v') <- zonk_it env v; return (env', RuleBndr (L loc v')) }
1025 zonk_bndr _ (RuleBndrSig {}) = panic "zonk_bndr RuleBndrSig"
1028 | isId v = do { v' <- zonkIdBndr env v; return (extendZonkEnv1 env v', v') }
1029 | otherwise = ASSERT( isImmutableTyVar v) return (env, v)
1033 zonkVects :: ZonkEnv -> [LVectDecl TcId] -> TcM [LVectDecl Id]
1034 zonkVects env = mappM (wrapLocM (zonkVect env))
1036 zonkVect :: ZonkEnv -> VectDecl TcId -> TcM (VectDecl Id)
1037 zonkVect env (HsVect v Nothing)
1038 = do { v' <- wrapLocM (zonkIdBndr env) v
1039 ; return $ HsVect v' Nothing
1041 zonkVect env (HsVect v (Just e))
1042 = do { v' <- wrapLocM (zonkIdBndr env) v
1043 ; e' <- zonkLExpr env e
1044 ; return $ HsVect v' (Just e')
1046 zonkVect env (HsNoVect v)
1047 = do { v' <- wrapLocM (zonkIdBndr env) v
1048 ; return $ HsNoVect v'
1052 %************************************************************************
1054 Constraints and evidence
1056 %************************************************************************
1059 zonkEvTerm :: ZonkEnv -> EvTerm -> TcM EvTerm
1060 zonkEvTerm env (EvId v) = ASSERT2( isId v, ppr v )
1061 return (EvId (zonkIdOcc env v))
1062 zonkEvTerm env (EvCoercion co) = do { co' <- zonkTcCoToCo env co
1063 ; return (EvCoercion co') }
1064 zonkEvTerm env (EvCast v co) = ASSERT( isId v)
1065 do { co' <- zonkTcCoToCo env co
1066 ; return (EvCast (zonkIdOcc env v) co') }
1067 zonkEvTerm env (EvSuperClass d n) = return (EvSuperClass (zonkIdOcc env d) n)
1068 zonkEvTerm env (EvDFunApp df tys tms)
1069 = do { tys' <- zonkTcTypeToTypes env tys
1070 ; let tms' = map (zonkEvVarOcc env) tms
1071 ; return (EvDFunApp (zonkIdOcc env df) tys' tms') }
1073 zonkTcEvBinds :: ZonkEnv -> TcEvBinds -> TcM (ZonkEnv, TcEvBinds)
1074 zonkTcEvBinds env (TcEvBinds var) = do { (env', bs') <- zonkEvBindsVar env var
1075 ; return (env', EvBinds bs') }
1076 zonkTcEvBinds env (EvBinds bs) = do { (env', bs') <- zonkEvBinds env bs
1077 ; return (env', EvBinds bs') }
1079 zonkEvBindsVar :: ZonkEnv -> EvBindsVar -> TcM (ZonkEnv, Bag EvBind)
1080 zonkEvBindsVar env (EvBindsVar ref _) = do { bs <- readMutVar ref
1081 ; zonkEvBinds env (evBindMapBinds bs) }
1083 zonkEvBinds :: ZonkEnv -> Bag EvBind -> TcM (ZonkEnv, Bag EvBind)
1084 zonkEvBinds env binds
1085 = fixM (\ ~( _, new_binds) -> do
1086 { let env1 = extendZonkEnv env (collect_ev_bndrs new_binds)
1087 ; binds' <- mapBagM (zonkEvBind env1) binds
1088 ; return (env1, binds') })
1090 collect_ev_bndrs :: Bag EvBind -> [EvVar]
1091 collect_ev_bndrs = foldrBag add []
1092 add (EvBind var _) vars = var : vars
1094 zonkEvBind :: ZonkEnv -> EvBind -> TcM EvBind
1095 zonkEvBind env (EvBind var term)
1096 = do { var' <- zonkEvBndr env var
1097 ; term' <- zonkEvTerm env term
1098 ; return (EvBind var' term') }
1101 %************************************************************************
1105 %************************************************************************
1108 zonkTcTypeToType :: ZonkEnv -> TcType -> TcM Type
1109 zonkTcTypeToType (ZonkEnv zonk_ty _) ty = zonk_ty ty
1111 zonkTcTypeToTypes :: ZonkEnv -> [TcType] -> TcM [Type]
1112 zonkTcTypeToTypes env tys = mapM (zonkTcTypeToType env) tys
1114 zonkTypeCollecting :: TcRef TyVarSet -> TcType -> TcM Type
1115 -- This variant collects unbound type variables in a mutable variable
1116 zonkTypeCollecting unbound_tv_set
1117 = zonkType (mkZonkTcTyVar zonk_unbound_tyvar)
1119 zonk_unbound_tyvar tv
1120 = do { tv' <- zonkQuantifiedTyVar tv
1121 ; tv_set <- readMutVar unbound_tv_set
1122 ; writeMutVar unbound_tv_set (extendVarSet tv_set tv')
1123 ; return (mkTyVarTy tv') }
1125 zonkTypeZapping :: TcType -> TcM Type
1126 -- This variant is used for everything except the LHS of rules
1127 -- It zaps unbound type variables to (), or some other arbitrary type
1129 = zonkType (mkZonkTcTyVar zonk_unbound_tyvar) ty
1131 -- Zonk a mutable but unbound type variable to an arbitrary type
1132 -- We know it's unbound even though we don't carry an environment,
1133 -- because at the binding site for a type variable we bind the
1134 -- mutable tyvar to a fresh immutable one. So the mutable store
1135 -- plays the role of an environment. If we come across a mutable
1136 -- type variable that isn't so bound, it must be completely free.
1137 zonk_unbound_tyvar tv = do { let ty = anyTypeOfKind (tyVarKind tv)
1138 ; writeMetaTyVar tv ty
1141 zonkTcCoToCo :: ZonkEnv -> Coercion -> TcM Coercion
1145 go (CoVarCo cv) = return (CoVarCo (zonkEvVarOcc env cv))
1146 go (Refl ty) = do { ty' <- zonkTcTypeToType env ty
1147 ; return (Refl ty') }
1148 go (TyConAppCo tc cos) = do { cos' <- mapM go cos; return (mkTyConAppCo tc cos') }
1149 go (AxiomInstCo ax cos) = do { cos' <- mapM go cos; return (AxiomInstCo ax cos') }
1150 go (AppCo co1 co2) = do { co1' <- go co1; co2' <- go co2
1151 ; return (mkAppCo co1' co2') }
1152 go (UnsafeCo t1 t2) = do { t1' <- zonkTcTypeToType env t1
1153 ; t2' <- zonkTcTypeToType env t2
1154 ; return (mkUnsafeCo t1' t2') }
1155 go (SymCo co) = do { co' <- go co; return (mkSymCo co') }
1156 go (NthCo n co) = do { co' <- go co; return (mkNthCo n co') }
1157 go (TransCo co1 co2) = do { co1' <- go co1; co2' <- go co2
1158 ; return (mkTransCo co1' co2') }
1159 go (InstCo co ty) = do { co' <- go co; ty' <- zonkTcTypeToType env ty
1160 ; return (mkInstCo co' ty') }
1161 go (ForAllCo tv co) = ASSERT( isImmutableTyVar tv )
1162 do { co' <- go co; return (mkForAllCo tv co') }