2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnExpr]{Renaming of expressions}
6 Basically dependency analysis.
8 Handles @Match@, @GRHSs@, @HsExpr@, and @Qualifier@ datatypes. In
9 general, all of these functions return a renamed thing, and a set of
14 rnMatch, rnGRHSs, rnPat, rnExpr, rnExprs, rnStmt,
18 #include "HsVersions.h"
20 import {-# SOURCE #-} RnBinds ( rnBinds )
21 import {-# SOURCE #-} RnSource ( rnHsTypeFVs )
28 import RnHiFiles ( lookupFixityRn )
29 import CmdLineOpts ( DynFlag(..), opt_IgnoreAsserts )
30 import Literal ( inIntRange, inCharRange )
31 import BasicTypes ( Fixity(..), FixityDirection(..), defaultFixity, negateFixity )
32 import PrelNames ( hasKey, assertIdKey, minusName, negateName, fromIntegerName,
33 eqClass_RDR, foldr_RDR, build_RDR, eqString_RDR,
34 cCallableClass_RDR, cReturnableClass_RDR,
35 monadClass_RDR, enumClass_RDR, ordClass_RDR,
36 ratioDataCon_RDR, assertErr_RDR,
37 ioDataCon_RDR, plusInteger_RDR, timesInteger_RDR,
38 fromInteger_RDR, fromRational_RDR,
40 import TysPrim ( charPrimTyCon, addrPrimTyCon, intPrimTyCon,
41 floatPrimTyCon, doublePrimTyCon
43 import TysWiredIn ( intTyCon )
44 import Name ( NamedThing(..), mkSysLocalName, nameSrcLoc )
46 import UniqFM ( isNullUFM )
47 import FiniteMap ( elemFM )
48 import UniqSet ( emptyUniqSet )
49 import List ( intersectBy )
50 import ListSetOps ( unionLists, removeDups )
51 import Maybes ( maybeToBool )
56 *********************************************************
60 *********************************************************
63 rnPat :: RdrNamePat -> RnMS (RenamedPat, FreeVars)
65 rnPat WildPatIn = returnRn (WildPatIn, emptyFVs)
68 = lookupBndrRn name `thenRn` \ vname ->
69 returnRn (VarPatIn vname, emptyFVs)
71 rnPat (SigPatIn pat ty)
72 = doptRn Opt_GlasgowExts `thenRn` \ glaExts ->
75 then rnPat pat `thenRn` \ (pat', fvs1) ->
76 rnHsTypeFVs doc ty `thenRn` \ (ty', fvs2) ->
77 returnRn (SigPatIn pat' ty', fvs1 `plusFV` fvs2)
79 else addErrRn (patSigErr ty) `thenRn_`
82 doc = text "a pattern type-signature"
84 rnPat (LitPatIn s@(HsString _))
85 = lookupOrigName eqString_RDR `thenRn` \ eq ->
86 returnRn (LitPatIn s, unitFV eq)
89 = litFVs lit `thenRn` \ fvs ->
90 returnRn (LitPatIn lit, fvs)
93 = rnOverLit lit `thenRn` \ (lit', fvs1) ->
94 lookupOrigName eqClass_RDR `thenRn` \ eq -> -- Needed to find equality on pattern
95 returnRn (NPatIn lit', fvs1 `addOneFV` eq)
97 rnPat (NPlusKPatIn name lit)
98 = rnOverLit lit `thenRn` \ (lit', fvs) ->
99 lookupOrigName ordClass_RDR `thenRn` \ ord ->
100 lookupBndrRn name `thenRn` \ name' ->
101 returnRn (NPlusKPatIn name' lit', fvs `addOneFV` ord `addOneFV` minusName)
103 rnPat (LazyPatIn pat)
104 = rnPat pat `thenRn` \ (pat', fvs) ->
105 returnRn (LazyPatIn pat', fvs)
107 rnPat (AsPatIn name pat)
108 = rnPat pat `thenRn` \ (pat', fvs) ->
109 lookupBndrRn name `thenRn` \ vname ->
110 returnRn (AsPatIn vname pat', fvs)
112 rnPat (ConPatIn con pats)
113 = lookupOccRn con `thenRn` \ con' ->
114 mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
115 returnRn (ConPatIn con' patslist, fvs `addOneFV` con')
117 rnPat (ConOpPatIn pat1 con _ pat2)
118 = rnPat pat1 `thenRn` \ (pat1', fvs1) ->
119 lookupOccRn con `thenRn` \ con' ->
120 rnPat pat2 `thenRn` \ (pat2', fvs2) ->
122 getModeRn `thenRn` \ mode ->
123 -- See comments with rnExpr (OpApp ...)
124 (if isInterfaceMode mode
125 then returnRn (ConOpPatIn pat1' con' defaultFixity pat2')
126 else lookupFixityRn con' `thenRn` \ fixity ->
127 mkConOpPatRn pat1' con' fixity pat2'
129 returnRn (pat', fvs1 `plusFV` fvs2 `addOneFV` con')
132 = rnPat pat `thenRn` \ (pat', fvs) ->
133 returnRn (ParPatIn pat', fvs)
135 rnPat (ListPatIn pats)
136 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
137 returnRn (ListPatIn patslist, fvs `addOneFV` listTyCon_name)
139 rnPat (TuplePatIn pats boxed)
140 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
141 returnRn (TuplePatIn patslist boxed, fvs `addOneFV` tycon_name)
143 tycon_name = tupleTyCon_name boxed (length pats)
145 rnPat (RecPatIn con rpats)
146 = lookupOccRn con `thenRn` \ con' ->
147 rnRpats rpats `thenRn` \ (rpats', fvs) ->
148 returnRn (RecPatIn con' rpats', fvs `addOneFV` con')
150 rnPat (TypePatIn name) =
151 rnHsTypeFVs (text "type pattern") name `thenRn` \ (name', fvs) ->
152 returnRn (TypePatIn name', fvs)
155 ************************************************************************
159 ************************************************************************
162 rnMatch :: HsMatchContext RdrName -> RdrNameMatch -> RnMS (RenamedMatch, FreeVars)
164 rnMatch ctxt match@(Match _ pats maybe_rhs_sig grhss)
165 = pushSrcLocRn (getMatchLoc match) $
167 -- Bind pattern-bound type variables
169 rhs_sig_tys = case maybe_rhs_sig of
172 pat_sig_tys = collectSigTysFromPats pats
173 doc_sig = text "In a result type-signature"
174 doc_pat = pprMatchContext ctxt
176 bindPatSigTyVars (rhs_sig_tys ++ pat_sig_tys) $ \ sig_tyvars ->
178 -- Note that we do a single bindLocalsRn for all the
179 -- matches together, so that we spot the repeated variable in
181 bindLocalsFVRn doc_pat (collectPatsBinders pats) $ \ new_binders ->
183 mapFvRn rnPat pats `thenRn` \ (pats', pat_fvs) ->
184 rnGRHSs grhss `thenRn` \ (grhss', grhss_fvs) ->
185 doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
186 (case maybe_rhs_sig of
187 Nothing -> returnRn (Nothing, emptyFVs)
188 Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenRn` \ (ty', ty_fvs) ->
189 returnRn (Just ty', ty_fvs)
190 | otherwise -> addErrRn (patSigErr ty) `thenRn_`
191 returnRn (Nothing, emptyFVs)
192 ) `thenRn` \ (maybe_rhs_sig', ty_fvs) ->
195 binder_set = mkNameSet new_binders
196 unused_binders = nameSetToList (binder_set `minusNameSet` grhss_fvs)
197 all_fvs = grhss_fvs `plusFV` pat_fvs `plusFV` ty_fvs
199 warnUnusedMatches unused_binders `thenRn_`
201 returnRn (Match sig_tyvars pats' maybe_rhs_sig' grhss', all_fvs)
202 -- The bindLocals and bindTyVars will remove the bound FVs
205 bindPatSigTyVars :: [RdrNameHsType]
206 -> ([Name] -> RnMS (a, FreeVars))
207 -> RnMS (a, FreeVars)
208 -- Find the type variables in the pattern type
209 -- signatures that must be brought into scope
210 bindPatSigTyVars tys thing_inside
211 = getLocalNameEnv `thenRn` \ name_env ->
213 tyvars_in_sigs = extractHsTysRdrTyVars tys
214 forall_tyvars = filter (not . (`elemFM` name_env)) tyvars_in_sigs
215 doc_sig = text "In a pattern type-signature"
217 bindNakedTyVarsFVRn doc_sig forall_tyvars thing_inside
220 %************************************************************************
222 \subsubsection{Guarded right-hand sides (GRHSs)}
224 %************************************************************************
227 rnGRHSs :: RdrNameGRHSs -> RnMS (RenamedGRHSs, FreeVars)
229 rnGRHSs (GRHSs grhss binds _)
230 = rnBinds binds $ \ binds' ->
231 mapFvRn rnGRHS grhss `thenRn` \ (grhss', fvGRHSs) ->
232 returnRn (GRHSs grhss' binds' placeHolderType, fvGRHSs)
234 rnGRHS (GRHS guarded locn)
235 = doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
237 (if not (opt_GlasgowExts || is_standard_guard guarded) then
238 addWarnRn (nonStdGuardErr guarded)
243 rnStmts guarded `thenRn` \ ((_, guarded'), fvs) ->
244 returnRn (GRHS guarded' locn, fvs)
246 -- Standard Haskell 1.4 guards are just a single boolean
247 -- expression, rather than a list of qualifiers as in the
249 is_standard_guard [ResultStmt _ _] = True
250 is_standard_guard [ExprStmt _ _ _, ResultStmt _ _] = True
251 is_standard_guard other = False
254 %************************************************************************
256 \subsubsection{Expressions}
258 %************************************************************************
261 rnExprs :: [RdrNameHsExpr] -> RnMS ([RenamedHsExpr], FreeVars)
262 rnExprs ls = rnExprs' ls emptyUniqSet
264 rnExprs' [] acc = returnRn ([], acc)
265 rnExprs' (expr:exprs) acc
266 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
268 -- Now we do a "seq" on the free vars because typically it's small
269 -- or empty, especially in very long lists of constants
271 acc' = acc `plusFV` fvExpr
273 (grubby_seqNameSet acc' rnExprs') exprs acc' `thenRn` \ (exprs', fvExprs) ->
274 returnRn (expr':exprs', fvExprs)
276 -- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
277 grubby_seqNameSet ns result | isNullUFM ns = result
281 Variables. We look up the variable and return the resulting name.
284 rnExpr :: RdrNameHsExpr -> RnMS (RenamedHsExpr, FreeVars)
287 = lookupOccRn v `thenRn` \ name ->
288 if name `hasKey` assertIdKey then
289 -- We expand it to (GHCerr.assert__ location)
293 returnRn (HsVar name, unitFV name)
296 = newIPName v `thenRn` \ name ->
297 returnRn (HsIPVar name, emptyFVs)
300 = litFVs lit `thenRn` \ fvs ->
301 returnRn (HsLit lit, fvs)
303 rnExpr (HsOverLit lit)
304 = rnOverLit lit `thenRn` \ (lit', fvs) ->
305 returnRn (HsOverLit lit', fvs)
308 = rnMatch LambdaExpr match `thenRn` \ (match', fvMatch) ->
309 returnRn (HsLam match', fvMatch)
311 rnExpr (HsApp fun arg)
312 = rnExpr fun `thenRn` \ (fun',fvFun) ->
313 rnExpr arg `thenRn` \ (arg',fvArg) ->
314 returnRn (HsApp fun' arg', fvFun `plusFV` fvArg)
316 rnExpr (OpApp e1 op _ e2)
317 = rnExpr e1 `thenRn` \ (e1', fv_e1) ->
318 rnExpr e2 `thenRn` \ (e2', fv_e2) ->
319 rnExpr op `thenRn` \ (op'@(HsVar op_name), fv_op) ->
322 -- When renaming code synthesised from "deriving" declarations
323 -- we're in Interface mode, and we should ignore fixity; assume
324 -- that the deriving code generator got the association correct
325 -- Don't even look up the fixity when in interface mode
326 getModeRn `thenRn` \ mode ->
327 (if isInterfaceMode mode
328 then returnRn (OpApp e1' op' defaultFixity e2')
329 else lookupFixityRn op_name `thenRn` \ fixity ->
330 mkOpAppRn e1' op' fixity e2'
331 ) `thenRn` \ final_e ->
334 fv_e1 `plusFV` fv_op `plusFV` fv_e2)
337 = rnExpr e `thenRn` \ (e', fv_e) ->
338 mkNegAppRn e' `thenRn` \ final_e ->
339 returnRn (final_e, fv_e `addOneFV` negateName)
342 = rnExpr e `thenRn` \ (e', fvs_e) ->
343 returnRn (HsPar e', fvs_e)
345 rnExpr section@(SectionL expr op)
346 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
347 rnExpr op `thenRn` \ (op', fvs_op) ->
348 checkSectionPrec "left" section op' expr' `thenRn_`
349 returnRn (SectionL expr' op', fvs_op `plusFV` fvs_expr)
351 rnExpr section@(SectionR op expr)
352 = rnExpr op `thenRn` \ (op', fvs_op) ->
353 rnExpr expr `thenRn` \ (expr', fvs_expr) ->
354 checkSectionPrec "right" section op' expr' `thenRn_`
355 returnRn (SectionR op' expr', fvs_op `plusFV` fvs_expr)
357 rnExpr (HsCCall fun args may_gc is_casm _)
358 -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls
359 = lookupOrigNames [cCallableClass_RDR,
360 cReturnableClass_RDR,
361 ioDataCon_RDR] `thenRn` \ implicit_fvs ->
362 rnExprs args `thenRn` \ (args', fvs_args) ->
363 returnRn (HsCCall fun args' may_gc is_casm placeHolderType,
364 fvs_args `plusFV` implicit_fvs)
366 rnExpr (HsSCC lbl expr)
367 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
368 returnRn (HsSCC lbl expr', fvs_expr)
370 rnExpr (HsCase expr ms src_loc)
371 = pushSrcLocRn src_loc $
372 rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
373 mapFvRn (rnMatch CaseAlt) ms `thenRn` \ (new_ms, ms_fvs) ->
374 returnRn (HsCase new_expr new_ms src_loc, e_fvs `plusFV` ms_fvs)
376 rnExpr (HsLet binds expr)
377 = rnBinds binds $ \ binds' ->
378 rnExpr expr `thenRn` \ (expr',fvExpr) ->
379 returnRn (HsLet binds' expr', fvExpr)
381 rnExpr (HsWith expr binds)
382 = rnExpr expr `thenRn` \ (expr',fvExpr) ->
383 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
384 returnRn (HsWith expr' binds', fvExpr `plusFV` fvBinds)
386 rnExpr e@(HsDo do_or_lc stmts src_loc)
387 = pushSrcLocRn src_loc $
388 lookupOrigNames implicit_rdr_names `thenRn` \ implicit_fvs ->
389 rnStmts stmts `thenRn` \ ((_, stmts'), fvs) ->
390 -- check the statement list ends in an expression
391 case last stmts' of {
392 ResultStmt _ _ -> returnRn () ;
393 _ -> addErrRn (doStmtListErr e)
395 returnRn (HsDo do_or_lc stmts' src_loc, fvs `plusFV` implicit_fvs)
397 implicit_rdr_names = [foldr_RDR, build_RDR, monadClass_RDR]
398 -- Monad stuff should not be necessary for a list comprehension
399 -- but the typechecker looks up the bind and return Ids anyway
403 rnExpr (ExplicitList _ exps)
404 = rnExprs exps `thenRn` \ (exps', fvs) ->
405 returnRn (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name)
407 rnExpr (ExplicitTuple exps boxity)
408 = rnExprs exps `thenRn` \ (exps', fvs) ->
409 returnRn (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name)
411 tycon_name = tupleTyCon_name boxity (length exps)
413 rnExpr (RecordCon con_id rbinds)
414 = lookupOccRn con_id `thenRn` \ conname ->
415 rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
416 returnRn (RecordCon conname rbinds', fvRbinds `addOneFV` conname)
418 rnExpr (RecordUpd expr rbinds)
419 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
420 rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
421 returnRn (RecordUpd expr' rbinds', fvExpr `plusFV` fvRbinds)
423 rnExpr (ExprWithTySig expr pty)
424 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
425 rnHsTypeFVs (text "an expression type signature") pty `thenRn` \ (pty', fvTy) ->
426 returnRn (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy)
428 rnExpr (HsIf p b1 b2 src_loc)
429 = pushSrcLocRn src_loc $
430 rnExpr p `thenRn` \ (p', fvP) ->
431 rnExpr b1 `thenRn` \ (b1', fvB1) ->
432 rnExpr b2 `thenRn` \ (b2', fvB2) ->
433 returnRn (HsIf p' b1' b2' src_loc, plusFVs [fvP, fvB1, fvB2])
436 = rnHsTypeFVs doc a `thenRn` \ (t, fvT) ->
437 returnRn (HsType t, fvT)
439 doc = text "renaming a type pattern"
441 rnExpr (ArithSeqIn seq)
442 = lookupOrigName enumClass_RDR `thenRn` \ enum ->
443 rn_seq seq `thenRn` \ (new_seq, fvs) ->
444 returnRn (ArithSeqIn new_seq, fvs `addOneFV` enum)
447 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
448 returnRn (From expr', fvExpr)
450 rn_seq (FromThen expr1 expr2)
451 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
452 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
453 returnRn (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2)
455 rn_seq (FromTo expr1 expr2)
456 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
457 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
458 returnRn (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2)
460 rn_seq (FromThenTo expr1 expr2 expr3)
461 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
462 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
463 rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
464 returnRn (FromThenTo expr1' expr2' expr3',
465 plusFVs [fvExpr1, fvExpr2, fvExpr3])
468 These three are pattern syntax appearing in expressions.
469 Since all the symbols are reservedops we can simply reject them.
470 We return a (bogus) EWildPat in each case.
473 rnExpr e@EWildPat = addErrRn (patSynErr e) `thenRn_`
474 returnRn (EWildPat, emptyFVs)
476 rnExpr e@(EAsPat _ _) = addErrRn (patSynErr e) `thenRn_`
477 returnRn (EWildPat, emptyFVs)
479 rnExpr e@(ELazyPat _) = addErrRn (patSynErr e) `thenRn_`
480 returnRn (EWildPat, emptyFVs)
485 %************************************************************************
487 \subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
489 %************************************************************************
493 = mapRn_ field_dup_err dup_fields `thenRn_`
494 mapFvRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind) ->
495 returnRn (rbinds', fvRbind)
497 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rbinds ]
499 field_dup_err dups = addErrRn (dupFieldErr str dups)
501 rn_rbind (field, expr, pun)
502 = lookupGlobalOccRn field `thenRn` \ fieldname ->
503 rnExpr expr `thenRn` \ (expr', fvExpr) ->
504 returnRn ((fieldname, expr', pun), fvExpr `addOneFV` fieldname)
507 = mapRn_ field_dup_err dup_fields `thenRn_`
508 mapFvRn rn_rpat rpats `thenRn` \ (rpats', fvs) ->
509 returnRn (rpats', fvs)
511 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rpats ]
513 field_dup_err dups = addErrRn (dupFieldErr "pattern" dups)
515 rn_rpat (field, pat, pun)
516 = lookupGlobalOccRn field `thenRn` \ fieldname ->
517 rnPat pat `thenRn` \ (pat', fvs) ->
518 returnRn ((fieldname, pat', pun), fvs `addOneFV` fieldname)
521 %************************************************************************
523 \subsubsection{@rnIPBinds@s: in implicit parameter bindings} *
525 %************************************************************************
528 rnIPBinds [] = returnRn ([], emptyFVs)
529 rnIPBinds ((n, expr) : binds)
530 = newIPName n `thenRn` \ name ->
531 rnExpr expr `thenRn` \ (expr',fvExpr) ->
532 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
533 returnRn ((name, expr') : binds', fvExpr `plusFV` fvBinds)
537 %************************************************************************
539 \subsubsection{@Stmt@s: in @do@ expressions}
541 %************************************************************************
543 Note that although some bound vars may appear in the free var set for
544 the first qual, these will eventually be removed by the caller. For
545 example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
546 @[q <- r, p <- q]@, the free var set for @q <- r@ will
547 be @{r}@, and the free var set for the entire Quals will be @{r}@. This
548 @r@ will be removed only when we finally return from examining all the
552 rnStmts :: [RdrNameStmt]
553 -> RnMS (([Name], [RenamedStmt]), FreeVars)
556 = returnRn (([], []), emptyFVs)
559 = getLocalNameEnv `thenRn` \ name_env ->
560 rnStmt stmt $ \ stmt' ->
561 rnStmts stmts `thenRn` \ ((binders, stmts'), fvs) ->
562 returnRn ((binders, stmt' : stmts'), fvs)
564 rnStmt :: RdrNameStmt
565 -> (RenamedStmt -> RnMS (([Name], a), FreeVars))
566 -> RnMS (([Name], a), FreeVars)
567 -- The thing list of names returned is the list returned by the
568 -- thing_inside, plus the binders of the arguments stmt
570 -- Because of mutual recursion we have to pass in rnExpr.
572 rnStmt (ParStmt stmtss) thing_inside
573 = mapFvRn rnStmts stmtss `thenRn` \ (bndrstmtss, fv_stmtss) ->
574 let binderss = map fst bndrstmtss
575 checkBndrs all_bndrs bndrs
576 = checkRn (null (intersectBy eqOcc all_bndrs bndrs)) err `thenRn_`
577 returnRn (bndrs ++ all_bndrs)
578 eqOcc n1 n2 = nameOccName n1 == nameOccName n2
579 err = text "duplicate binding in parallel list comprehension"
581 foldlRn checkBndrs [] binderss `thenRn` \ new_binders ->
582 bindLocalNamesFV new_binders $
583 thing_inside (ParStmtOut bndrstmtss)`thenRn` \ ((rest_bndrs, result), fv_rest) ->
584 returnRn ((new_binders ++ rest_bndrs, result), fv_stmtss `plusFV` fv_rest)
586 rnStmt (BindStmt pat expr src_loc) thing_inside
587 = pushSrcLocRn src_loc $
588 rnExpr expr `thenRn` \ (expr', fv_expr) ->
589 bindPatSigTyVars (collectSigTysFromPat pat) $ \ sig_tyvars ->
590 bindLocalsFVRn doc (collectPatBinders pat) $ \ new_binders ->
591 rnPat pat `thenRn` \ (pat', fv_pat) ->
592 thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ ((rest_binders, result), fvs) ->
593 returnRn ((new_binders ++ rest_binders, result),
594 fv_expr `plusFV` fvs `plusFV` fv_pat)
596 doc = text "In a pattern in 'do' binding"
598 rnStmt (ExprStmt expr _ src_loc) thing_inside
599 = pushSrcLocRn src_loc $
600 rnExpr expr `thenRn` \ (expr', fv_expr) ->
601 thing_inside (ExprStmt expr' placeHolderType src_loc) `thenRn` \ (result, fvs) ->
602 returnRn (result, fv_expr `plusFV` fvs)
604 rnStmt (ResultStmt expr src_loc) thing_inside
605 = pushSrcLocRn src_loc $
606 rnExpr expr `thenRn` \ (expr', fv_expr) ->
607 thing_inside (ResultStmt expr' src_loc) `thenRn` \ (result, fvs) ->
608 returnRn (result, fv_expr `plusFV` fvs)
610 rnStmt (LetStmt binds) thing_inside
611 = rnBinds binds $ \ binds' ->
612 let new_binders = collectHsBinders binds' in
613 thing_inside (LetStmt binds') `thenRn` \ ((rest_binders, result), fvs) ->
614 returnRn ((new_binders ++ rest_binders, result), fvs )
617 %************************************************************************
619 \subsubsection{Precedence Parsing}
621 %************************************************************************
623 @mkOpAppRn@ deals with operator fixities. The argument expressions
624 are assumed to be already correctly arranged. It needs the fixities
625 recorded in the OpApp nodes, because fixity info applies to the things
626 the programmer actually wrote, so you can't find it out from the Name.
628 Furthermore, the second argument is guaranteed not to be another
629 operator application. Why? Because the parser parses all
630 operator appications left-associatively, EXCEPT negation, which
631 we need to handle specially.
634 mkOpAppRn :: RenamedHsExpr -- Left operand; already rearranged
635 -> RenamedHsExpr -> Fixity -- Operator and fixity
636 -> RenamedHsExpr -- Right operand (not an OpApp, but might
638 -> RnMS RenamedHsExpr
640 ---------------------------
641 -- (e11 `op1` e12) `op2` e2
642 mkOpAppRn e1@(OpApp e11 op1 fix1 e12) op2 fix2 e2
644 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
645 returnRn (OpApp e1 op2 fix2 e2)
648 = mkOpAppRn e12 op2 fix2 e2 `thenRn` \ new_e ->
649 returnRn (OpApp e11 op1 fix1 new_e)
651 (nofix_error, associate_right) = compareFixity fix1 fix2
653 ---------------------------
654 -- (- neg_arg) `op` e2
655 mkOpAppRn e1@(NegApp neg_arg) op2 fix2 e2
657 = addErrRn (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenRn_`
658 returnRn (OpApp e1 op2 fix2 e2)
661 = mkOpAppRn neg_arg op2 fix2 e2 `thenRn` \ new_e ->
662 returnRn (NegApp new_e)
664 (nofix_error, associate_right) = compareFixity negateFixity fix2
666 ---------------------------
668 mkOpAppRn e1 op1 fix1 e2@(NegApp neg_arg) -- NegApp can occur on the right
669 | not associate_right -- We *want* right association
670 = addErrRn (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenRn_`
671 returnRn (OpApp e1 op1 fix1 e2)
673 (_, associate_right) = compareFixity fix1 negateFixity
675 ---------------------------
677 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
678 = ASSERT2( right_op_ok fix e2,
679 ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
681 returnRn (OpApp e1 op fix e2)
683 -- Parser left-associates everything, but
684 -- derived instances may have correctly-associated things to
685 -- in the right operarand. So we just check that the right operand is OK
686 right_op_ok fix1 (OpApp _ _ fix2 _)
687 = not error_please && associate_right
689 (error_please, associate_right) = compareFixity fix1 fix2
690 right_op_ok fix1 other
693 -- Parser initially makes negation bind more tightly than any other operator
697 getModeRn `thenRn` \ mode ->
698 ASSERT( not_op_app mode neg_arg )
700 returnRn (NegApp neg_arg)
702 not_op_app SourceMode (OpApp _ _ _ _) = False
703 not_op_app mode other = True
707 mkConOpPatRn :: RenamedPat -> Name -> Fixity -> RenamedPat
710 mkConOpPatRn p1@(ConOpPatIn p11 op1 fix1 p12)
713 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
714 returnRn (ConOpPatIn p1 op2 fix2 p2)
717 = mkConOpPatRn p12 op2 fix2 p2 `thenRn` \ new_p ->
718 returnRn (ConOpPatIn p11 op1 fix1 new_p)
721 (nofix_error, associate_right) = compareFixity fix1 fix2
723 mkConOpPatRn p1 op fix p2 -- Default case, no rearrangment
724 = ASSERT( not_op_pat p2 )
725 returnRn (ConOpPatIn p1 op fix p2)
727 not_op_pat (ConOpPatIn _ _ _ _) = False
728 not_op_pat other = True
732 checkPrecMatch :: Bool -> Name -> RenamedMatch -> RnMS ()
734 checkPrecMatch False fn match
737 checkPrecMatch True op (Match _ (p1:p2:_) _ _)
738 -- True indicates an infix lhs
739 = getModeRn `thenRn` \ mode ->
740 -- See comments with rnExpr (OpApp ...)
741 if isInterfaceMode mode
743 else checkPrec op p1 False `thenRn_`
746 checkPrecMatch True op _ = panic "checkPrecMatch"
748 checkPrec op (ConOpPatIn _ op1 _ _) right
749 = lookupFixityRn op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
750 lookupFixityRn op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) ->
752 inf_ok = op1_prec > op_prec ||
753 (op1_prec == op_prec &&
754 (op1_dir == InfixR && op_dir == InfixR && right ||
755 op1_dir == InfixL && op_dir == InfixL && not right))
757 info = (ppr_op op, op_fix)
758 info1 = (ppr_op op1, op1_fix)
759 (infol, infor) = if right then (info, info1) else (info1, info)
761 checkRn inf_ok (precParseErr infol infor)
763 checkPrec op pat right
766 -- Check precedence of (arg op) or (op arg) respectively
767 -- If arg is itself an operator application, its precedence should
768 -- be higher than that of op
769 checkSectionPrec left_or_right section op arg
771 OpApp _ op fix _ -> go_for_it (ppr_op op) fix
772 NegApp _ -> go_for_it pp_prefix_minus negateFixity
776 go_for_it pp_arg_op arg_fix@(Fixity arg_prec _)
777 = lookupFixityRn op_name `thenRn` \ op_fix@(Fixity op_prec _) ->
778 checkRn (op_prec < arg_prec)
779 (sectionPrecErr (ppr_op op_name, op_fix) (pp_arg_op, arg_fix) section)
786 @(compareFixity op1 op2)@ tells which way to arrange appication, or
787 whether there's an error.
790 compareFixity :: Fixity -> Fixity
791 -> (Bool, -- Error please
792 Bool) -- Associate to the right: a op1 (b op2 c)
793 compareFixity (Fixity prec1 dir1) (Fixity prec2 dir2)
794 = case prec1 `compare` prec2 of
797 EQ -> case (dir1, dir2) of
798 (InfixR, InfixR) -> right
799 (InfixL, InfixL) -> left
802 right = (False, True)
803 left = (False, False)
804 error_please = (True, False)
807 %************************************************************************
809 \subsubsection{Literals}
811 %************************************************************************
813 When literals occur we have to make sure
814 that the types and classes they involve
819 = checkRn (inCharRange c) (bogusCharError c) `thenRn_`
820 returnRn (unitFV charTyCon_name)
822 litFVs (HsCharPrim c) = returnRn (unitFV (getName charPrimTyCon))
823 litFVs (HsString s) = returnRn (mkFVs [listTyCon_name, charTyCon_name])
824 litFVs (HsStringPrim s) = returnRn (unitFV (getName addrPrimTyCon))
825 litFVs (HsInt i) = returnRn (unitFV (getName intTyCon))
826 litFVs (HsIntPrim i) = returnRn (unitFV (getName intPrimTyCon))
827 litFVs (HsFloatPrim f) = returnRn (unitFV (getName floatPrimTyCon))
828 litFVs (HsDoublePrim d) = returnRn (unitFV (getName doublePrimTyCon))
829 litFVs (HsLitLit l bogus_ty) = lookupOrigName cCallableClass_RDR `thenRn` \ cc ->
831 litFVs lit = pprPanic "RnExpr.litFVs" (ppr lit) -- HsInteger and HsRat only appear
832 -- in post-typechecker translations
834 rnOverLit (HsIntegral i)
836 = returnRn (HsIntegral i, unitFV fromIntegerName)
838 = lookupOrigNames [fromInteger_RDR, plusInteger_RDR, timesInteger_RDR] `thenRn` \ ns ->
839 -- Big integers are built, using + and *, out of small integers
840 -- [No particular reason why we use fromIntegerName in one case can
841 -- fromInteger_RDR in the other; but plusInteger_RDR means we
842 -- can get away without plusIntegerName altogether.]
843 returnRn (HsIntegral i, ns)
845 rnOverLit (HsFractional i)
846 = lookupOrigNames [fromRational_RDR, ratioDataCon_RDR,
847 plusInteger_RDR, timesInteger_RDR] `thenRn` \ ns ->
848 -- We have to make sure that the Ratio type is imported with
849 -- its constructor, because literals of type Ratio t are
850 -- built with that constructor.
851 -- The Rational type is needed too, but that will come in
852 -- when fractionalClass does.
853 -- The plus/times integer operations may be needed to construct the numerator
854 -- and denominator (see DsUtils.mkIntegerLit)
855 returnRn (HsFractional i, ns)
858 %************************************************************************
860 \subsubsection{Assertion utils}
862 %************************************************************************
865 mkAssertExpr :: RnMS (RenamedHsExpr, FreeVars)
867 lookupOrigName assertErr_RDR `thenRn` \ name ->
868 getSrcLocRn `thenRn` \ sloc ->
870 -- if we're ignoring asserts, return (\ _ e -> e)
871 -- if not, return (assertError "src-loc")
873 if opt_IgnoreAsserts then
874 getUniqRn `thenRn` \ uniq ->
876 vname = mkSysLocalName uniq SLIT("v")
877 expr = HsLam ignorePredMatch
878 loc = nameSrcLoc vname
879 ignorePredMatch = mkSimpleMatch [WildPatIn, VarPatIn vname] (HsVar vname) placeHolderType loc
881 returnRn (expr, unitFV name)
886 (HsLit (HsString (_PK_ (showSDoc (ppr sloc)))))
889 returnRn (expr, unitFV name)
893 %************************************************************************
895 \subsubsection{Errors}
897 %************************************************************************
900 ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name
901 ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity)
902 pp_prefix_minus = ptext SLIT("prefix `-'")
904 dupFieldErr str (dup:rest)
905 = hsep [ptext SLIT("duplicate field name"),
907 ptext SLIT("in record"), text str]
910 = hang (ptext SLIT("precedence parsing error"))
911 4 (hsep [ptext SLIT("cannot mix"), ppr_opfix op1, ptext SLIT("and"),
913 ptext SLIT("in the same infix expression")])
915 sectionPrecErr op arg_op section
916 = vcat [ptext SLIT("The operator") <+> ppr_opfix op <+> ptext SLIT("of a section"),
917 nest 4 (ptext SLIT("must have lower precedence than the operand") <+> ppr_opfix arg_op),
918 nest 4 (ptext SLIT("in the section:") <+> quotes (ppr section))]
922 SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)")
926 = (ptext SLIT("Illegal signature in pattern:") <+> ppr ty)
927 $$ nest 4 (ptext SLIT("Use -fglasgow-exts to permit it"))
930 = sep [ptext SLIT("Pattern syntax in expression context:"),
934 = sep [ptext SLIT("`do' statements must end in expression:"),
938 = ptext SLIT("character literal out of range: '\\") <> int c <> char '\''