2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnSource]{Main pass of renamer}
9 rnHsType, rnLHsType, rnLHsTypes, rnContext,
10 rnHsSigType, rnHsTypeFVs,
12 -- Patterns and literals
13 rnLPat, rnPat, rnPatsAndThen, -- Here because it's not part
14 rnLit, rnOverLit, -- of any mutual recursion
16 -- Precence related stuff
17 mkOpAppRn, mkNegAppRn, mkOpFormRn,
18 checkPrecMatch, checkSectionPrec,
21 dupFieldErr, patSigErr, checkTupSize
24 import DynFlags ( DynFlag(Opt_WarnUnusedMatches, Opt_GlasgowExts) )
27 import RdrHsSyn ( extractHsRhoRdrTyVars )
28 import RnHsSyn ( extractHsTyNames, parrTyCon_name, tupleTyCon_name,
31 import RnEnv ( lookupOccRn, lookupBndrRn, lookupSyntaxName,
32 lookupLocatedOccRn, lookupLocatedBndrRn,
33 lookupLocatedGlobalOccRn, bindTyVarsRn,
34 lookupFixityRn, lookupTyFixityRn,
35 mapFvRn, warnUnusedMatches,
36 newIPNameRn, bindPatSigTyVarsFV, bindLocatedLocalsFV )
38 import RdrName ( RdrName, elemLocalRdrEnv )
39 import PrelNames ( eqClassName, integralClassName, geName, eqName,
40 negateName, minusName, lengthPName, indexPName,
41 plusIntegerName, fromIntegerName, timesIntegerName,
42 ratioDataConName, fromRationalName )
43 import TypeRep ( funTyCon )
44 import Constants ( mAX_TUPLE_SIZE )
46 import SrcLoc ( SrcSpan, Located(..), unLoc, noLoc, combineLocs )
49 import Literal ( inIntRange, inCharRange )
50 import BasicTypes ( compareFixity, funTyFixity, negateFixity,
51 Fixity(..), FixityDirection(..) )
52 import ListSetOps ( removeDups )
55 #include "HsVersions.h"
58 These type renamers are in a separate module, rather than in (say) RnSource,
59 to break several loop.
61 %*********************************************************
63 \subsection{Renaming types}
65 %*********************************************************
68 rnHsTypeFVs :: SDoc -> LHsType RdrName -> RnM (LHsType Name, FreeVars)
69 rnHsTypeFVs doc_str ty
70 = rnLHsType doc_str ty `thenM` \ ty' ->
71 returnM (ty', extractHsTyNames ty')
73 rnHsSigType :: SDoc -> LHsType RdrName -> RnM (LHsType Name)
74 -- rnHsSigType is used for source-language type signatures,
75 -- which use *implicit* universal quantification.
76 rnHsSigType doc_str ty
77 = rnLHsType (text "In the type signature for" <+> doc_str) ty
80 rnHsType is here because we call it from loadInstDecl, and I didn't
81 want a gratuitous knot.
84 rnLHsType :: SDoc -> LHsType RdrName -> RnM (LHsType Name)
85 rnLHsType doc = wrapLocM (rnHsType doc)
87 rnHsType :: SDoc -> HsType RdrName -> RnM (HsType Name)
89 rnHsType doc (HsForAllTy Implicit _ ctxt ty)
90 -- Implicit quantifiction in source code (no kinds on tyvars)
91 -- Given the signature C => T we universally quantify
92 -- over FV(T) \ {in-scope-tyvars}
93 = getLocalRdrEnv `thenM` \ name_env ->
95 mentioned = extractHsRhoRdrTyVars ctxt ty
97 -- Don't quantify over type variables that are in scope;
98 -- when GlasgowExts is off, there usually won't be any, except for
100 -- class C a where { op :: a -> a }
101 forall_tyvars = filter (not . (`elemLocalRdrEnv` name_env) . unLoc) mentioned
102 tyvar_bndrs = userHsTyVarBndrs forall_tyvars
104 rnForAll doc Implicit tyvar_bndrs ctxt ty
106 rnHsType doc (HsForAllTy Explicit forall_tyvars ctxt tau)
107 -- Explicit quantification.
108 -- Check that the forall'd tyvars are actually
109 -- mentioned in the type, and produce a warning if not
111 mentioned = map unLoc (extractHsRhoRdrTyVars ctxt tau)
112 forall_tyvar_names = hsLTyVarLocNames forall_tyvars
114 -- Explicitly quantified but not mentioned in ctxt or tau
115 warn_guys = filter ((`notElem` mentioned) . unLoc) forall_tyvar_names
117 mappM_ (forAllWarn doc tau) warn_guys `thenM_`
118 rnForAll doc Explicit forall_tyvars ctxt tau
120 rnHsType doc (HsTyVar tyvar)
121 = lookupOccRn tyvar `thenM` \ tyvar' ->
122 returnM (HsTyVar tyvar')
124 rnHsType doc (HsOpTy ty1 (L loc op) ty2)
126 lookupOccRn op `thenM` \ op' ->
130 lookupTyFixityRn l_op' `thenM` \ fix ->
131 rnLHsType doc ty1 `thenM` \ ty1' ->
132 rnLHsType doc ty2 `thenM` \ ty2' ->
133 mkHsOpTyRn (\t1 t2 -> HsOpTy t1 l_op' t2) (ppr op') fix ty1' ty2'
136 rnHsType doc (HsParTy ty)
137 = rnLHsType doc ty `thenM` \ ty' ->
138 returnM (HsParTy ty')
140 rnHsType doc (HsBangTy b ty)
141 = rnLHsType doc ty `thenM` \ ty' ->
142 returnM (HsBangTy b ty')
144 rnHsType doc (HsNumTy i)
145 | i == 1 = returnM (HsNumTy i)
146 | otherwise = addErr err_msg `thenM_` returnM (HsNumTy i)
148 err_msg = ptext SLIT("Only unit numeric type pattern is valid")
151 rnHsType doc (HsFunTy ty1 ty2)
152 = rnLHsType doc ty1 `thenM` \ ty1' ->
153 -- Might find a for-all as the arg of a function type
154 rnLHsType doc ty2 `thenM` \ ty2' ->
155 -- Or as the result. This happens when reading Prelude.hi
156 -- when we find return :: forall m. Monad m -> forall a. a -> m a
158 -- Check for fixity rearrangements
159 mkHsOpTyRn HsFunTy (ppr funTyCon) funTyFixity ty1' ty2'
161 rnHsType doc (HsListTy ty)
162 = rnLHsType doc ty `thenM` \ ty' ->
163 returnM (HsListTy ty')
165 rnHsType doc (HsKindSig ty k)
166 = rnLHsType doc ty `thenM` \ ty' ->
167 returnM (HsKindSig ty' k)
169 rnHsType doc (HsPArrTy ty)
170 = rnLHsType doc ty `thenM` \ ty' ->
171 returnM (HsPArrTy ty')
173 -- Unboxed tuples are allowed to have poly-typed arguments. These
174 -- sometimes crop up as a result of CPR worker-wrappering dictionaries.
175 rnHsType doc (HsTupleTy tup_con tys)
176 = mappM (rnLHsType doc) tys `thenM` \ tys' ->
177 returnM (HsTupleTy tup_con tys')
179 rnHsType doc (HsAppTy ty1 ty2)
180 = rnLHsType doc ty1 `thenM` \ ty1' ->
181 rnLHsType doc ty2 `thenM` \ ty2' ->
182 returnM (HsAppTy ty1' ty2')
184 rnHsType doc (HsPredTy pred)
185 = rnPred doc pred `thenM` \ pred' ->
186 returnM (HsPredTy pred')
188 rnHsType doc (HsSpliceTy _)
189 = do { addErr (ptext SLIT("Type splices are not yet implemented"))
192 rnLHsTypes doc tys = mappM (rnLHsType doc) tys
197 rnForAll :: SDoc -> HsExplicitForAll -> [LHsTyVarBndr RdrName]
198 -> LHsContext RdrName -> LHsType RdrName -> RnM (HsType Name)
200 rnForAll doc exp [] (L _ []) (L _ ty) = rnHsType doc ty
201 -- One reason for this case is that a type like Int#
202 -- starts off as (HsForAllTy Nothing [] Int), in case
203 -- there is some quantification. Now that we have quantified
204 -- and discovered there are no type variables, it's nicer to turn
205 -- it into plain Int. If it were Int# instead of Int, we'd actually
206 -- get an error, because the body of a genuine for-all is
209 rnForAll doc exp forall_tyvars ctxt ty
210 = bindTyVarsRn doc forall_tyvars $ \ new_tyvars ->
211 rnContext doc ctxt `thenM` \ new_ctxt ->
212 rnLHsType doc ty `thenM` \ new_ty ->
213 returnM (HsForAllTy exp new_tyvars new_ctxt new_ty)
214 -- Retain the same implicit/explicit flag as before
215 -- so that we can later print it correctly
219 %************************************************************************
221 Fixities and precedence parsing
223 %************************************************************************
225 @mkOpAppRn@ deals with operator fixities. The argument expressions
226 are assumed to be already correctly arranged. It needs the fixities
227 recorded in the OpApp nodes, because fixity info applies to the things
228 the programmer actually wrote, so you can't find it out from the Name.
230 Furthermore, the second argument is guaranteed not to be another
231 operator application. Why? Because the parser parses all
232 operator appications left-associatively, EXCEPT negation, which
233 we need to handle specially.
234 Infix types are read in a *right-associative* way, so that
239 mkHsOpTyRn rearranges where necessary. The two arguments
240 have already been renamed and rearranged. It's made rather tiresome
241 by the presence of ->, which is a separate syntactic construct.
245 -- Building (ty1 `op1` (ty21 `op2` ty22))
246 mkHsOpTyRn :: (LHsType Name -> LHsType Name -> HsType Name)
247 -> SDoc -> Fixity -> LHsType Name -> LHsType Name
250 mkHsOpTyRn mk1 pp_op1 fix1 ty1 (L loc2 (HsOpTy ty21 op2 ty22))
251 = do { fix2 <- lookupTyFixityRn op2
252 ; mk_hs_op_ty mk1 pp_op1 fix1 ty1
253 (\t1 t2 -> HsOpTy t1 op2 t2)
254 (ppr op2) fix2 ty21 ty22 loc2 }
256 mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty2@(L loc2 (HsFunTy ty21 ty22))
257 = mk_hs_op_ty mk1 pp_op1 fix1 ty1
258 HsFunTy (ppr funTyCon) funTyFixity ty21 ty22 loc2
260 mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty2 -- Default case, no rearrangment
261 = return (mk1 ty1 ty2)
264 mk_hs_op_ty :: (LHsType Name -> LHsType Name -> HsType Name)
265 -> SDoc -> Fixity -> LHsType Name
266 -> (LHsType Name -> LHsType Name -> HsType Name)
267 -> SDoc -> Fixity -> LHsType Name -> LHsType Name -> SrcSpan
269 mk_hs_op_ty mk1 pp_op1 fix1 ty1
270 mk2 pp_op2 fix2 ty21 ty22 loc2
271 | nofix_error = do { addErr (precParseErr (quotes pp_op1,fix1)
272 (quotes pp_op2,fix2))
273 ; return (mk1 ty1 (L loc2 (mk2 ty21 ty22))) }
274 | associate_right = return (mk1 ty1 (L loc2 (mk2 ty21 ty22)))
275 | otherwise = do { -- Rearrange to ((ty1 `op1` ty21) `op2` ty22)
276 new_ty <- mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty21
277 ; return (mk2 (noLoc new_ty) ty22) }
279 (nofix_error, associate_right) = compareFixity fix1 fix2
282 ---------------------------
283 mkOpAppRn :: LHsExpr Name -- Left operand; already rearranged
284 -> LHsExpr Name -> Fixity -- Operator and fixity
285 -> LHsExpr Name -- Right operand (not an OpApp, but might
289 -- (e11 `op1` e12) `op2` e2
290 mkOpAppRn e1@(L _ (OpApp e11 op1 fix1 e12)) op2 fix2 e2
292 = addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenM_`
293 returnM (OpApp e1 op2 fix2 e2)
296 = mkOpAppRn e12 op2 fix2 e2 `thenM` \ new_e ->
297 returnM (OpApp e11 op1 fix1 (L loc' new_e))
299 loc'= combineLocs e12 e2
300 (nofix_error, associate_right) = compareFixity fix1 fix2
302 ---------------------------
303 -- (- neg_arg) `op` e2
304 mkOpAppRn e1@(L _ (NegApp neg_arg neg_name)) op2 fix2 e2
306 = addErr (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenM_`
307 returnM (OpApp e1 op2 fix2 e2)
310 = mkOpAppRn neg_arg op2 fix2 e2 `thenM` \ new_e ->
311 returnM (NegApp (L loc' new_e) neg_name)
313 loc' = combineLocs neg_arg e2
314 (nofix_error, associate_right) = compareFixity negateFixity fix2
316 ---------------------------
318 mkOpAppRn e1 op1 fix1 e2@(L _ (NegApp neg_arg _)) -- NegApp can occur on the right
319 | not associate_right -- We *want* right association
320 = addErr (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenM_`
321 returnM (OpApp e1 op1 fix1 e2)
323 (_, associate_right) = compareFixity fix1 negateFixity
325 ---------------------------
327 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
328 = ASSERT2( right_op_ok fix (unLoc e2),
329 ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
331 returnM (OpApp e1 op fix e2)
333 -- Parser left-associates everything, but
334 -- derived instances may have correctly-associated things to
335 -- in the right operarand. So we just check that the right operand is OK
336 right_op_ok fix1 (OpApp _ _ fix2 _)
337 = not error_please && associate_right
339 (error_please, associate_right) = compareFixity fix1 fix2
340 right_op_ok fix1 other
343 -- Parser initially makes negation bind more tightly than any other operator
344 -- And "deriving" code should respect this (use HsPar if not)
345 mkNegAppRn :: LHsExpr id -> SyntaxExpr id -> RnM (HsExpr id)
346 mkNegAppRn neg_arg neg_name
347 = ASSERT( not_op_app (unLoc neg_arg) )
348 returnM (NegApp neg_arg neg_name)
350 not_op_app (OpApp _ _ _ _) = False
351 not_op_app other = True
353 ---------------------------
354 mkOpFormRn :: LHsCmdTop Name -- Left operand; already rearranged
355 -> LHsExpr Name -> Fixity -- Operator and fixity
356 -> LHsCmdTop Name -- Right operand (not an infix)
359 -- (e11 `op1` e12) `op2` e2
360 mkOpFormRn a1@(L loc (HsCmdTop (L _ (HsArrForm op1 (Just fix1) [a11,a12])) _ _ _))
363 = addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenM_`
364 returnM (HsArrForm op2 (Just fix2) [a1, a2])
367 = mkOpFormRn a12 op2 fix2 a2 `thenM` \ new_c ->
368 returnM (HsArrForm op1 (Just fix1)
369 [a11, L loc (HsCmdTop (L loc new_c) [] placeHolderType [])])
370 -- TODO: locs are wrong
372 (nofix_error, associate_right) = compareFixity fix1 fix2
375 mkOpFormRn arg1 op fix arg2 -- Default case, no rearrangment
376 = returnM (HsArrForm op (Just fix) [arg1, arg2])
379 --------------------------------------
380 mkConOpPatRn :: Located Name -> Fixity -> LPat Name -> LPat Name
383 mkConOpPatRn op2 fix2 p1@(L loc (ConPatIn op1 (InfixCon p11 p12))) p2
384 = lookupFixityRn (unLoc op1) `thenM` \ fix1 ->
386 (nofix_error, associate_right) = compareFixity fix1 fix2
389 addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenM_`
390 returnM (ConPatIn op2 (InfixCon p1 p2))
392 if associate_right then
393 mkConOpPatRn op2 fix2 p12 p2 `thenM` \ new_p ->
394 returnM (ConPatIn op1 (InfixCon p11 (L loc new_p))) -- XXX loc right?
396 returnM (ConPatIn op2 (InfixCon p1 p2))
398 mkConOpPatRn op fix p1 p2 -- Default case, no rearrangment
399 = ASSERT( not_op_pat (unLoc p2) )
400 returnM (ConPatIn op (InfixCon p1 p2))
402 not_op_pat (ConPatIn _ (InfixCon _ _)) = False
403 not_op_pat other = True
405 --------------------------------------
406 checkPrecMatch :: Bool -> Name -> MatchGroup Name -> RnM ()
407 -- True indicates an infix lhs
408 -- See comments with rnExpr (OpApp ...) about "deriving"
410 checkPrecMatch False fn match
412 checkPrecMatch True op (MatchGroup ms _)
415 check (L _ (Match (p1:p2:_) _ _))
416 = checkPrec op (unLoc p1) False `thenM_`
417 checkPrec op (unLoc p2) True
419 check _ = panic "checkPrecMatch"
421 checkPrec op (ConPatIn op1 (InfixCon _ _)) right
422 = lookupFixityRn op `thenM` \ op_fix@(Fixity op_prec op_dir) ->
423 lookupFixityRn (unLoc op1) `thenM` \ op1_fix@(Fixity op1_prec op1_dir) ->
425 inf_ok = op1_prec > op_prec ||
426 (op1_prec == op_prec &&
427 (op1_dir == InfixR && op_dir == InfixR && right ||
428 op1_dir == InfixL && op_dir == InfixL && not right))
430 info = (ppr_op op, op_fix)
431 info1 = (ppr_op op1, op1_fix)
432 (infol, infor) = if right then (info, info1) else (info1, info)
434 checkErr inf_ok (precParseErr infol infor)
436 checkPrec op pat right
439 -- Check precedence of (arg op) or (op arg) respectively
440 -- If arg is itself an operator application, then either
441 -- (a) its precedence must be higher than that of op
442 -- (b) its precedency & associativity must be the same as that of op
443 checkSectionPrec :: FixityDirection -> HsExpr RdrName
444 -> LHsExpr Name -> LHsExpr Name -> RnM ()
445 checkSectionPrec direction section op arg
447 OpApp _ op fix _ -> go_for_it (ppr_op op) fix
448 NegApp _ _ -> go_for_it pp_prefix_minus negateFixity
451 L _ (HsVar op_name) = op
452 go_for_it pp_arg_op arg_fix@(Fixity arg_prec assoc)
453 = lookupFixityRn op_name `thenM` \ op_fix@(Fixity op_prec _) ->
454 checkErr (op_prec < arg_prec
455 || op_prec == arg_prec && direction == assoc)
456 (sectionPrecErr (ppr_op op_name, op_fix)
457 (pp_arg_op, arg_fix) section)
460 Precedence-related error messages
464 = hang (ptext SLIT("precedence parsing error"))
465 4 (hsep [ptext SLIT("cannot mix"), ppr_opfix op1, ptext SLIT("and"),
467 ptext SLIT("in the same infix expression")])
469 sectionPrecErr op arg_op section
470 = vcat [ptext SLIT("The operator") <+> ppr_opfix op <+> ptext SLIT("of a section"),
471 nest 4 (ptext SLIT("must have lower precedence than the operand") <+> ppr_opfix arg_op),
472 nest 4 (ptext SLIT("in the section:") <+> quotes (ppr section))]
474 pp_prefix_minus = ptext SLIT("prefix `-'")
475 ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name
476 ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity)
479 %*********************************************************
481 \subsection{Contexts and predicates}
483 %*********************************************************
486 rnContext :: SDoc -> LHsContext RdrName -> RnM (LHsContext Name)
487 rnContext doc = wrapLocM (rnContext' doc)
489 rnContext' :: SDoc -> HsContext RdrName -> RnM (HsContext Name)
490 rnContext' doc ctxt = mappM (rnLPred doc) ctxt
492 rnLPred :: SDoc -> LHsPred RdrName -> RnM (LHsPred Name)
493 rnLPred doc = wrapLocM (rnPred doc)
495 rnPred doc (HsClassP clas tys)
496 = lookupOccRn clas `thenM` \ clas_name ->
497 rnLHsTypes doc tys `thenM` \ tys' ->
498 returnM (HsClassP clas_name tys')
500 rnPred doc (HsIParam n ty)
501 = newIPNameRn n `thenM` \ name ->
502 rnLHsType doc ty `thenM` \ ty' ->
503 returnM (HsIParam name ty')
507 *********************************************************
509 \subsection{Patterns}
511 *********************************************************
514 rnPatsAndThen :: HsMatchContext Name
516 -> ([LPat Name] -> RnM (a, FreeVars))
518 -- Bring into scope all the binders and type variables
519 -- bound by the patterns; then rename the patterns; then
520 -- do the thing inside.
522 -- Note that we do a single bindLocalsRn for all the
523 -- matches together, so that we spot the repeated variable in
526 rnPatsAndThen ctxt pats thing_inside
527 = bindPatSigTyVarsFV pat_sig_tys $
528 bindLocatedLocalsFV doc_pat bndrs $ \ new_bndrs ->
529 rnLPats pats `thenM` \ (pats', pat_fvs) ->
530 thing_inside pats' `thenM` \ (res, res_fvs) ->
533 unused_binders = filter (not . (`elemNameSet` res_fvs)) new_bndrs
535 warnUnusedMatches unused_binders `thenM_`
536 returnM (res, res_fvs `plusFV` pat_fvs)
538 pat_sig_tys = collectSigTysFromPats pats
539 bndrs = collectLocatedPatsBinders pats
540 doc_pat = ptext SLIT("In") <+> pprMatchContext ctxt
542 rnLPats :: [LPat RdrName] -> RnM ([LPat Name], FreeVars)
543 rnLPats ps = mapFvRn rnLPat ps
545 rnLPat :: LPat RdrName -> RnM (LPat Name, FreeVars)
546 rnLPat = wrapLocFstM rnPat
548 -- -----------------------------------------------------------------------------
551 rnPat :: Pat RdrName -> RnM (Pat Name, FreeVars)
553 rnPat (WildPat _) = returnM (WildPat placeHolderType, emptyFVs)
556 = lookupBndrRn name `thenM` \ vname ->
557 returnM (VarPat vname, emptyFVs)
559 rnPat (SigPatIn pat ty)
560 = doptM Opt_GlasgowExts `thenM` \ glaExts ->
563 then rnLPat pat `thenM` \ (pat', fvs1) ->
564 rnHsTypeFVs doc ty `thenM` \ (ty', fvs2) ->
565 returnM (SigPatIn pat' ty', fvs1 `plusFV` fvs2)
567 else addErr (patSigErr ty) `thenM_`
568 rnPat (unLoc pat) -- XXX shouldn't throw away the loc
570 doc = text "In a pattern type-signature"
574 returnM (LitPat lit, emptyFVs)
576 rnPat (NPat lit mb_neg eq _)
577 = rnOverLit lit `thenM` \ (lit', fvs1) ->
579 Nothing -> returnM (Nothing, emptyFVs)
580 Just _ -> lookupSyntaxName negateName `thenM` \ (neg, fvs) ->
581 returnM (Just neg, fvs)
582 ) `thenM` \ (mb_neg', fvs2) ->
583 lookupSyntaxName eqName `thenM` \ (eq', fvs3) ->
584 returnM (NPat lit' mb_neg' eq' placeHolderType,
585 fvs1 `plusFV` fvs2 `plusFV` fvs3 `addOneFV` eqClassName)
586 -- Needed to find equality on pattern
588 rnPat (NPlusKPat name lit _ _)
589 = rnOverLit lit `thenM` \ (lit', fvs1) ->
590 lookupLocatedBndrRn name `thenM` \ name' ->
591 lookupSyntaxName minusName `thenM` \ (minus, fvs2) ->
592 lookupSyntaxName geName `thenM` \ (ge, fvs3) ->
593 returnM (NPlusKPat name' lit' ge minus,
594 fvs1 `plusFV` fvs2 `plusFV` fvs3 `addOneFV` integralClassName)
595 -- The Report says that n+k patterns must be in Integral
598 = rnLPat pat `thenM` \ (pat', fvs) ->
599 returnM (LazyPat pat', fvs)
602 = rnLPat pat `thenM` \ (pat', fvs) ->
603 returnM (BangPat pat', fvs)
605 rnPat (AsPat name pat)
606 = rnLPat pat `thenM` \ (pat', fvs) ->
607 lookupLocatedBndrRn name `thenM` \ vname ->
608 returnM (AsPat vname pat', fvs)
610 rnPat (ConPatIn con stuff) = rnConPat con stuff
614 = rnLPat pat `thenM` \ (pat', fvs) ->
615 returnM (ParPat pat', fvs)
617 rnPat (ListPat pats _)
618 = rnLPats pats `thenM` \ (patslist, fvs) ->
619 returnM (ListPat patslist placeHolderType, fvs `addOneFV` listTyCon_name)
621 rnPat (PArrPat pats _)
622 = rnLPats pats `thenM` \ (patslist, fvs) ->
623 returnM (PArrPat patslist placeHolderType,
624 fvs `plusFV` implicit_fvs `addOneFV` parrTyCon_name)
626 implicit_fvs = mkFVs [lengthPName, indexPName]
628 rnPat (TuplePat pats boxed _)
629 = checkTupSize tup_size `thenM_`
630 rnLPats pats `thenM` \ (patslist, fvs) ->
631 returnM (TuplePat patslist boxed placeHolderType,
632 fvs `addOneFV` tycon_name)
634 tup_size = length pats
635 tycon_name = tupleTyCon_name boxed tup_size
637 rnPat (TypePat name) =
638 rnHsTypeFVs (text "In a type pattern") name `thenM` \ (name', fvs) ->
639 returnM (TypePat name', fvs)
641 -- -----------------------------------------------------------------------------
644 rnConPat con (PrefixCon pats)
645 = lookupLocatedOccRn con `thenM` \ con' ->
646 rnLPats pats `thenM` \ (pats', fvs) ->
647 returnM (ConPatIn con' (PrefixCon pats'), fvs `addOneFV` unLoc con')
649 rnConPat con (RecCon rpats)
650 = lookupLocatedOccRn con `thenM` \ con' ->
651 rnRpats rpats `thenM` \ (rpats', fvs) ->
652 returnM (ConPatIn con' (RecCon rpats'), fvs `addOneFV` unLoc con')
654 rnConPat con (InfixCon pat1 pat2)
655 = lookupLocatedOccRn con `thenM` \ con' ->
656 rnLPat pat1 `thenM` \ (pat1', fvs1) ->
657 rnLPat pat2 `thenM` \ (pat2', fvs2) ->
658 lookupFixityRn (unLoc con') `thenM` \ fixity ->
659 mkConOpPatRn con' fixity pat1' pat2' `thenM` \ pat' ->
660 returnM (pat', fvs1 `plusFV` fvs2 `addOneFV` unLoc con')
662 -- -----------------------------------------------------------------------------
665 rnRpats :: [(Located RdrName, LPat RdrName)]
666 -> RnM ([(Located Name, LPat Name)], FreeVars)
668 = mappM_ field_dup_err dup_fields `thenM_`
669 mapFvRn rn_rpat rpats `thenM` \ (rpats', fvs) ->
670 returnM (rpats', fvs)
672 (_, dup_fields) = removeDups compare [ unLoc f | (f,_) <- rpats ]
674 field_dup_err dups = addErr (dupFieldErr "pattern" dups)
677 = lookupLocatedGlobalOccRn field `thenM` \ fieldname ->
678 rnLPat pat `thenM` \ (pat', fvs) ->
679 returnM ((fieldname, pat'), fvs `addOneFV` unLoc fieldname)
684 %************************************************************************
686 \subsubsection{Literals}
688 %************************************************************************
690 When literals occur we have to make sure
691 that the types and classes they involve
695 rnLit :: HsLit -> RnM ()
696 rnLit (HsChar c) = checkErr (inCharRange c) (bogusCharError c)
697 rnLit other = returnM ()
699 rnOverLit (HsIntegral i _)
700 = lookupSyntaxName fromIntegerName `thenM` \ (from_integer_name, fvs) ->
702 returnM (HsIntegral i from_integer_name, fvs)
704 extra_fvs = mkFVs [plusIntegerName, timesIntegerName]
705 -- Big integer literals are built, using + and *,
706 -- out of small integers (DsUtils.mkIntegerLit)
707 -- [NB: plusInteger, timesInteger aren't rebindable...
708 -- they are used to construct the argument to fromInteger,
709 -- which is the rebindable one.]
711 returnM (HsIntegral i from_integer_name, fvs `plusFV` extra_fvs)
713 rnOverLit (HsFractional i _)
714 = lookupSyntaxName fromRationalName `thenM` \ (from_rat_name, fvs) ->
716 extra_fvs = mkFVs [ratioDataConName, plusIntegerName, timesIntegerName]
717 -- We have to make sure that the Ratio type is imported with
718 -- its constructor, because literals of type Ratio t are
719 -- built with that constructor.
720 -- The Rational type is needed too, but that will come in
721 -- as part of the type for fromRational.
722 -- The plus/times integer operations may be needed to construct the numerator
723 -- and denominator (see DsUtils.mkIntegerLit)
725 returnM (HsFractional i from_rat_name, fvs `plusFV` extra_fvs)
730 %*********************************************************
734 %*********************************************************
737 checkTupSize :: Int -> RnM ()
738 checkTupSize tup_size
739 | tup_size <= mAX_TUPLE_SIZE
742 = addErr (sep [ptext SLIT("A") <+> int tup_size <> ptext SLIT("-tuple is too large for GHC"),
743 nest 2 (parens (ptext SLIT("max size is") <+> int mAX_TUPLE_SIZE)),
744 nest 2 (ptext SLIT("Workaround: use nested tuples or define a data type"))])
746 forAllWarn doc ty (L loc tyvar)
747 = ifOptM Opt_WarnUnusedMatches $
749 addWarn (sep [ptext SLIT("The universally quantified type variable") <+> quotes (ppr tyvar),
750 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
756 = ptext SLIT("character literal out of range: '\\") <> char c <> char '\''
759 = (ptext SLIT("Illegal signature in pattern:") <+> ppr ty)
760 $$ nest 4 (ptext SLIT("Use -fglasgow-exts to permit it"))
763 = hsep [ptext SLIT("duplicate field name"),
765 ptext SLIT("in record"), text str]