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 )
27 import RnTypes ( rnHsTypeFVs )
28 import RnHiFiles ( lookupFixityRn )
29 import CmdLineOpts ( DynFlag(..), opt_IgnoreAsserts )
30 import Literal ( inIntRange, inCharRange )
31 import BasicTypes ( Fixity(..), FixityDirection(..), IPName(..), defaultFixity, negateFixity )
32 import PrelNames ( hasKey, assertIdKey,
33 eqClassName, foldrName, buildName, eqStringName,
34 cCallableClassName, cReturnableClassName,
35 monadClassName, enumClassName, ordClassName,
36 ratioDataConName, splitIdName, fstIdName, sndIdName,
37 ioDataConName, plusIntegerName, timesIntegerName,
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 UniqSet ( emptyUniqSet )
48 import List ( intersectBy )
49 import ListSetOps ( removeDups )
54 *********************************************************
58 *********************************************************
61 rnPat :: RdrNamePat -> RnMS (RenamedPat, FreeVars)
63 rnPat WildPatIn = returnRn (WildPatIn, emptyFVs)
66 = lookupBndrRn name `thenRn` \ vname ->
67 returnRn (VarPatIn vname, emptyFVs)
69 rnPat (SigPatIn pat ty)
70 = doptRn Opt_GlasgowExts `thenRn` \ glaExts ->
73 then rnPat pat `thenRn` \ (pat', fvs1) ->
74 rnHsTypeFVs doc ty `thenRn` \ (ty', fvs2) ->
75 returnRn (SigPatIn pat' ty', fvs1 `plusFV` fvs2)
77 else addErrRn (patSigErr ty) `thenRn_`
80 doc = text "a pattern type-signature"
82 rnPat (LitPatIn s@(HsString _))
83 = returnRn (LitPatIn s, unitFV eqStringName)
86 = litFVs lit `thenRn` \ fvs ->
87 returnRn (LitPatIn lit, fvs)
90 = rnOverLit lit `thenRn` \ (lit', fvs1) ->
91 returnRn (NPatIn lit', fvs1 `addOneFV` eqClassName) -- Needed to find equality on pattern
93 rnPat (NPlusKPatIn name lit minus)
94 = rnOverLit lit `thenRn` \ (lit', fvs) ->
95 lookupBndrRn name `thenRn` \ name' ->
96 lookupSyntaxName minus `thenRn` \ minus' ->
97 returnRn (NPlusKPatIn name' lit' minus', fvs `addOneFV` ordClassName `addOneFV` minus')
100 = rnPat pat `thenRn` \ (pat', fvs) ->
101 returnRn (LazyPatIn pat', fvs)
103 rnPat (AsPatIn name pat)
104 = rnPat pat `thenRn` \ (pat', fvs) ->
105 lookupBndrRn name `thenRn` \ vname ->
106 returnRn (AsPatIn vname pat', fvs)
108 rnPat (ConPatIn con pats)
109 = lookupOccRn con `thenRn` \ con' ->
110 mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
111 returnRn (ConPatIn con' patslist, fvs `addOneFV` con')
113 rnPat (ConOpPatIn pat1 con _ pat2)
114 = rnPat pat1 `thenRn` \ (pat1', fvs1) ->
115 lookupOccRn con `thenRn` \ con' ->
116 rnPat pat2 `thenRn` \ (pat2', fvs2) ->
118 getModeRn `thenRn` \ mode ->
119 -- See comments with rnExpr (OpApp ...)
120 (if isInterfaceMode mode
121 then returnRn (ConOpPatIn pat1' con' defaultFixity pat2')
122 else lookupFixityRn con' `thenRn` \ fixity ->
123 mkConOpPatRn pat1' con' fixity pat2'
125 returnRn (pat', fvs1 `plusFV` fvs2 `addOneFV` con')
128 = rnPat pat `thenRn` \ (pat', fvs) ->
129 returnRn (ParPatIn pat', fvs)
131 rnPat (ListPatIn pats)
132 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
133 returnRn (ListPatIn patslist, fvs `addOneFV` listTyCon_name)
135 rnPat (TuplePatIn pats boxed)
136 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
137 returnRn (TuplePatIn patslist boxed, fvs `addOneFV` tycon_name)
139 tycon_name = tupleTyCon_name boxed (length pats)
141 rnPat (RecPatIn con rpats)
142 = lookupOccRn con `thenRn` \ con' ->
143 rnRpats rpats `thenRn` \ (rpats', fvs) ->
144 returnRn (RecPatIn con' rpats', fvs `addOneFV` con')
146 rnPat (TypePatIn name) =
147 rnHsTypeFVs (text "type pattern") name `thenRn` \ (name', fvs) ->
148 returnRn (TypePatIn name', fvs)
151 ************************************************************************
155 ************************************************************************
158 rnMatch :: HsMatchContext RdrName -> RdrNameMatch -> RnMS (RenamedMatch, FreeVars)
160 rnMatch ctxt match@(Match pats maybe_rhs_sig grhss)
161 = pushSrcLocRn (getMatchLoc match) $
163 -- Bind pattern-bound type variables
165 rhs_sig_tys = case maybe_rhs_sig of
168 pat_sig_tys = collectSigTysFromPats pats
169 doc_sig = text "In a result type-signature"
170 doc_pat = pprMatchContext ctxt
172 bindPatSigTyVars (rhs_sig_tys ++ pat_sig_tys) $
174 -- Note that we do a single bindLocalsRn for all the
175 -- matches together, so that we spot the repeated variable in
177 bindLocalsFVRn doc_pat (collectPatsBinders pats) $ \ new_binders ->
179 mapFvRn rnPat pats `thenRn` \ (pats', pat_fvs) ->
180 rnGRHSs grhss `thenRn` \ (grhss', grhss_fvs) ->
181 doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
182 (case maybe_rhs_sig of
183 Nothing -> returnRn (Nothing, emptyFVs)
184 Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenRn` \ (ty', ty_fvs) ->
185 returnRn (Just ty', ty_fvs)
186 | otherwise -> addErrRn (patSigErr ty) `thenRn_`
187 returnRn (Nothing, emptyFVs)
188 ) `thenRn` \ (maybe_rhs_sig', ty_fvs) ->
191 binder_set = mkNameSet new_binders
192 unused_binders = nameSetToList (binder_set `minusNameSet` grhss_fvs)
193 all_fvs = grhss_fvs `plusFV` pat_fvs `plusFV` ty_fvs
195 warnUnusedMatches unused_binders `thenRn_`
197 returnRn (Match pats' maybe_rhs_sig' grhss', all_fvs)
198 -- The bindLocals and bindTyVars will remove the bound FVs
202 %************************************************************************
204 \subsubsection{Guarded right-hand sides (GRHSs)}
206 %************************************************************************
209 rnGRHSs :: RdrNameGRHSs -> RnMS (RenamedGRHSs, FreeVars)
211 rnGRHSs (GRHSs grhss binds _)
212 = rnBinds binds $ \ binds' ->
213 mapFvRn rnGRHS grhss `thenRn` \ (grhss', fvGRHSs) ->
214 returnRn (GRHSs grhss' binds' placeHolderType, fvGRHSs)
216 rnGRHS (GRHS guarded locn)
217 = doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
219 (if not (opt_GlasgowExts || is_standard_guard guarded) then
220 addWarnRn (nonStdGuardErr guarded)
225 rnStmts guarded `thenRn` \ ((_, guarded'), fvs) ->
226 returnRn (GRHS guarded' locn, fvs)
228 -- Standard Haskell 1.4 guards are just a single boolean
229 -- expression, rather than a list of qualifiers as in the
231 is_standard_guard [ResultStmt _ _] = True
232 is_standard_guard [ExprStmt _ _ _, ResultStmt _ _] = True
233 is_standard_guard other = False
236 %************************************************************************
238 \subsubsection{Expressions}
240 %************************************************************************
243 rnExprs :: [RdrNameHsExpr] -> RnMS ([RenamedHsExpr], FreeVars)
244 rnExprs ls = rnExprs' ls emptyUniqSet
246 rnExprs' [] acc = returnRn ([], acc)
247 rnExprs' (expr:exprs) acc
248 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
250 -- Now we do a "seq" on the free vars because typically it's small
251 -- or empty, especially in very long lists of constants
253 acc' = acc `plusFV` fvExpr
255 (grubby_seqNameSet acc' rnExprs') exprs acc' `thenRn` \ (exprs', fvExprs) ->
256 returnRn (expr':exprs', fvExprs)
258 -- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
259 grubby_seqNameSet ns result | isNullUFM ns = result
263 Variables. We look up the variable and return the resulting name.
266 rnExpr :: RdrNameHsExpr -> RnMS (RenamedHsExpr, FreeVars)
269 = lookupOccRn v `thenRn` \ name ->
270 if name `hasKey` assertIdKey then
271 -- We expand it to (GHCerr.assert__ location)
275 returnRn (HsVar name, unitFV name)
278 = newIPName v `thenRn` \ name ->
281 Linear _ -> mkFVs [splitIdName, fstIdName, sndIdName]
282 Dupable _ -> emptyFVs
284 returnRn (HsIPVar name, fvs)
287 = litFVs lit `thenRn` \ fvs ->
288 returnRn (HsLit lit, fvs)
290 rnExpr (HsOverLit lit)
291 = rnOverLit lit `thenRn` \ (lit', fvs) ->
292 returnRn (HsOverLit lit', fvs)
295 = rnMatch LambdaExpr match `thenRn` \ (match', fvMatch) ->
296 returnRn (HsLam match', fvMatch)
298 rnExpr (HsApp fun arg)
299 = rnExpr fun `thenRn` \ (fun',fvFun) ->
300 rnExpr arg `thenRn` \ (arg',fvArg) ->
301 returnRn (HsApp fun' arg', fvFun `plusFV` fvArg)
303 rnExpr (OpApp e1 op _ e2)
304 = rnExpr e1 `thenRn` \ (e1', fv_e1) ->
305 rnExpr e2 `thenRn` \ (e2', fv_e2) ->
306 rnExpr op `thenRn` \ (op'@(HsVar op_name), fv_op) ->
309 -- When renaming code synthesised from "deriving" declarations
310 -- we're in Interface mode, and we should ignore fixity; assume
311 -- that the deriving code generator got the association correct
312 -- Don't even look up the fixity when in interface mode
313 getModeRn `thenRn` \ mode ->
314 (if isInterfaceMode mode
315 then returnRn (OpApp e1' op' defaultFixity e2')
316 else lookupFixityRn op_name `thenRn` \ fixity ->
317 mkOpAppRn e1' op' fixity e2'
318 ) `thenRn` \ final_e ->
321 fv_e1 `plusFV` fv_op `plusFV` fv_e2)
323 rnExpr (NegApp e neg_name)
324 = rnExpr e `thenRn` \ (e', fv_e) ->
325 lookupSyntaxName neg_name `thenRn` \ neg_name' ->
326 mkNegAppRn e' neg_name' `thenRn` \ final_e ->
327 returnRn (final_e, fv_e `addOneFV` neg_name')
330 = rnExpr e `thenRn` \ (e', fvs_e) ->
331 returnRn (HsPar e', fvs_e)
333 rnExpr section@(SectionL expr op)
334 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
335 rnExpr op `thenRn` \ (op', fvs_op) ->
336 checkSectionPrec "left" section op' expr' `thenRn_`
337 returnRn (SectionL expr' op', fvs_op `plusFV` fvs_expr)
339 rnExpr section@(SectionR op expr)
340 = rnExpr op `thenRn` \ (op', fvs_op) ->
341 rnExpr expr `thenRn` \ (expr', fvs_expr) ->
342 checkSectionPrec "right" section op' expr' `thenRn_`
343 returnRn (SectionR op' expr', fvs_op `plusFV` fvs_expr)
345 rnExpr (HsCCall fun args may_gc is_casm _)
346 -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls
347 = lookupOrigNames [] `thenRn` \ implicit_fvs ->
348 rnExprs args `thenRn` \ (args', fvs_args) ->
349 returnRn (HsCCall fun args' may_gc is_casm placeHolderType,
350 fvs_args `plusFV` mkFVs [cCallableClassName,
351 cReturnableClassName,
354 rnExpr (HsSCC lbl expr)
355 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
356 returnRn (HsSCC lbl expr', fvs_expr)
358 rnExpr (HsCase expr ms src_loc)
359 = pushSrcLocRn src_loc $
360 rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
361 mapFvRn (rnMatch CaseAlt) ms `thenRn` \ (new_ms, ms_fvs) ->
362 returnRn (HsCase new_expr new_ms src_loc, e_fvs `plusFV` ms_fvs)
364 rnExpr (HsLet binds expr)
365 = rnBinds binds $ \ binds' ->
366 rnExpr expr `thenRn` \ (expr',fvExpr) ->
367 returnRn (HsLet binds' expr', fvExpr)
369 rnExpr (HsWith expr binds)
370 = rnExpr expr `thenRn` \ (expr',fvExpr) ->
371 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
372 returnRn (HsWith expr' binds', fvExpr `plusFV` fvBinds)
374 rnExpr e@(HsDo do_or_lc stmts src_loc)
375 = pushSrcLocRn src_loc $
376 rnStmts stmts `thenRn` \ ((_, stmts'), fvs) ->
377 -- check the statement list ends in an expression
378 case last stmts' of {
379 ResultStmt _ _ -> returnRn () ;
380 _ -> addErrRn (doStmtListErr e)
382 returnRn (HsDo do_or_lc stmts' src_loc, fvs `plusFV` implicit_fvs)
384 implicit_fvs = mkFVs [foldrName, buildName, monadClassName]
385 -- Monad stuff should not be necessary for a list comprehension
386 -- but the typechecker looks up the bind and return Ids anyway
390 rnExpr (ExplicitList _ exps)
391 = rnExprs exps `thenRn` \ (exps', fvs) ->
392 returnRn (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name)
394 rnExpr (ExplicitTuple exps boxity)
395 = rnExprs exps `thenRn` \ (exps', fvs) ->
396 returnRn (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name)
398 tycon_name = tupleTyCon_name boxity (length exps)
400 rnExpr (RecordCon con_id rbinds)
401 = lookupOccRn con_id `thenRn` \ conname ->
402 rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
403 returnRn (RecordCon conname rbinds', fvRbinds `addOneFV` conname)
405 rnExpr (RecordUpd expr rbinds)
406 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
407 rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
408 returnRn (RecordUpd expr' rbinds', fvExpr `plusFV` fvRbinds)
410 rnExpr (ExprWithTySig expr pty)
411 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
412 rnHsTypeFVs (text "an expression type signature") pty `thenRn` \ (pty', fvTy) ->
413 returnRn (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy)
415 rnExpr (HsIf p b1 b2 src_loc)
416 = pushSrcLocRn src_loc $
417 rnExpr p `thenRn` \ (p', fvP) ->
418 rnExpr b1 `thenRn` \ (b1', fvB1) ->
419 rnExpr b2 `thenRn` \ (b2', fvB2) ->
420 returnRn (HsIf p' b1' b2' src_loc, plusFVs [fvP, fvB1, fvB2])
423 = rnHsTypeFVs doc a `thenRn` \ (t, fvT) ->
424 returnRn (HsType t, fvT)
426 doc = text "renaming a type pattern"
428 rnExpr (ArithSeqIn seq)
429 = rn_seq seq `thenRn` \ (new_seq, fvs) ->
430 returnRn (ArithSeqIn new_seq, fvs `addOneFV` enumClassName)
433 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
434 returnRn (From expr', fvExpr)
436 rn_seq (FromThen expr1 expr2)
437 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
438 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
439 returnRn (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2)
441 rn_seq (FromTo expr1 expr2)
442 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
443 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
444 returnRn (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2)
446 rn_seq (FromThenTo expr1 expr2 expr3)
447 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
448 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
449 rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
450 returnRn (FromThenTo expr1' expr2' expr3',
451 plusFVs [fvExpr1, fvExpr2, fvExpr3])
454 These three are pattern syntax appearing in expressions.
455 Since all the symbols are reservedops we can simply reject them.
456 We return a (bogus) EWildPat in each case.
459 rnExpr e@EWildPat = addErrRn (patSynErr e) `thenRn_`
460 returnRn (EWildPat, emptyFVs)
462 rnExpr e@(EAsPat _ _) = addErrRn (patSynErr e) `thenRn_`
463 returnRn (EWildPat, emptyFVs)
465 rnExpr e@(ELazyPat _) = addErrRn (patSynErr e) `thenRn_`
466 returnRn (EWildPat, emptyFVs)
471 %************************************************************************
473 \subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
475 %************************************************************************
479 = mapRn_ field_dup_err dup_fields `thenRn_`
480 mapFvRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind) ->
481 returnRn (rbinds', fvRbind)
483 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rbinds ]
485 field_dup_err dups = addErrRn (dupFieldErr str dups)
487 rn_rbind (field, expr, pun)
488 = lookupGlobalOccRn field `thenRn` \ fieldname ->
489 rnExpr expr `thenRn` \ (expr', fvExpr) ->
490 returnRn ((fieldname, expr', pun), fvExpr `addOneFV` fieldname)
493 = mapRn_ field_dup_err dup_fields `thenRn_`
494 mapFvRn rn_rpat rpats `thenRn` \ (rpats', fvs) ->
495 returnRn (rpats', fvs)
497 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rpats ]
499 field_dup_err dups = addErrRn (dupFieldErr "pattern" dups)
501 rn_rpat (field, pat, pun)
502 = lookupGlobalOccRn field `thenRn` \ fieldname ->
503 rnPat pat `thenRn` \ (pat', fvs) ->
504 returnRn ((fieldname, pat', pun), fvs `addOneFV` fieldname)
507 %************************************************************************
509 \subsubsection{@rnIPBinds@s: in implicit parameter bindings} *
511 %************************************************************************
514 rnIPBinds [] = returnRn ([], emptyFVs)
515 rnIPBinds ((n, expr) : binds)
516 = newIPName n `thenRn` \ name ->
517 rnExpr expr `thenRn` \ (expr',fvExpr) ->
518 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
519 returnRn ((name, expr') : binds', fvExpr `plusFV` fvBinds)
523 %************************************************************************
525 \subsubsection{@Stmt@s: in @do@ expressions}
527 %************************************************************************
529 Note that although some bound vars may appear in the free var set for
530 the first qual, these will eventually be removed by the caller. For
531 example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
532 @[q <- r, p <- q]@, the free var set for @q <- r@ will
533 be @{r}@, and the free var set for the entire Quals will be @{r}@. This
534 @r@ will be removed only when we finally return from examining all the
538 rnStmts :: [RdrNameStmt]
539 -> RnMS (([Name], [RenamedStmt]), FreeVars)
542 = returnRn (([], []), emptyFVs)
545 = getLocalNameEnv `thenRn` \ name_env ->
546 rnStmt stmt $ \ stmt' ->
547 rnStmts stmts `thenRn` \ ((binders, stmts'), fvs) ->
548 returnRn ((binders, stmt' : stmts'), fvs)
550 rnStmt :: RdrNameStmt
551 -> (RenamedStmt -> RnMS (([Name], a), FreeVars))
552 -> RnMS (([Name], a), FreeVars)
553 -- The thing list of names returned is the list returned by the
554 -- thing_inside, plus the binders of the arguments stmt
556 -- Because of mutual recursion we have to pass in rnExpr.
558 rnStmt (ParStmt stmtss) thing_inside
559 = mapFvRn rnStmts stmtss `thenRn` \ (bndrstmtss, fv_stmtss) ->
560 let binderss = map fst bndrstmtss
561 checkBndrs all_bndrs bndrs
562 = checkRn (null (intersectBy eqOcc all_bndrs bndrs)) err `thenRn_`
563 returnRn (bndrs ++ all_bndrs)
564 eqOcc n1 n2 = nameOccName n1 == nameOccName n2
565 err = text "duplicate binding in parallel list comprehension"
567 foldlRn checkBndrs [] binderss `thenRn` \ new_binders ->
568 bindLocalNamesFV new_binders $
569 thing_inside (ParStmtOut bndrstmtss)`thenRn` \ ((rest_bndrs, result), fv_rest) ->
570 returnRn ((new_binders ++ rest_bndrs, result), fv_stmtss `plusFV` fv_rest)
572 rnStmt (BindStmt pat expr src_loc) thing_inside
573 = pushSrcLocRn src_loc $
574 rnExpr expr `thenRn` \ (expr', fv_expr) ->
575 bindPatSigTyVars (collectSigTysFromPat pat) $
576 bindLocalsFVRn doc (collectPatBinders pat) $ \ new_binders ->
577 rnPat pat `thenRn` \ (pat', fv_pat) ->
578 thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ ((rest_binders, result), fvs) ->
579 returnRn ((new_binders ++ rest_binders, result),
580 fv_expr `plusFV` fvs `plusFV` fv_pat)
582 doc = text "In a pattern in 'do' binding"
584 rnStmt (ExprStmt expr _ src_loc) thing_inside
585 = pushSrcLocRn src_loc $
586 rnExpr expr `thenRn` \ (expr', fv_expr) ->
587 thing_inside (ExprStmt expr' placeHolderType src_loc) `thenRn` \ (result, fvs) ->
588 returnRn (result, fv_expr `plusFV` fvs)
590 rnStmt (ResultStmt expr src_loc) thing_inside
591 = pushSrcLocRn src_loc $
592 rnExpr expr `thenRn` \ (expr', fv_expr) ->
593 thing_inside (ResultStmt expr' src_loc) `thenRn` \ (result, fvs) ->
594 returnRn (result, fv_expr `plusFV` fvs)
596 rnStmt (LetStmt binds) thing_inside
597 = rnBinds binds $ \ binds' ->
598 let new_binders = collectHsBinders binds' in
599 thing_inside (LetStmt binds') `thenRn` \ ((rest_binders, result), fvs) ->
600 returnRn ((new_binders ++ rest_binders, result), fvs )
603 %************************************************************************
605 \subsubsection{Precedence Parsing}
607 %************************************************************************
609 @mkOpAppRn@ deals with operator fixities. The argument expressions
610 are assumed to be already correctly arranged. It needs the fixities
611 recorded in the OpApp nodes, because fixity info applies to the things
612 the programmer actually wrote, so you can't find it out from the Name.
614 Furthermore, the second argument is guaranteed not to be another
615 operator application. Why? Because the parser parses all
616 operator appications left-associatively, EXCEPT negation, which
617 we need to handle specially.
620 mkOpAppRn :: RenamedHsExpr -- Left operand; already rearranged
621 -> RenamedHsExpr -> Fixity -- Operator and fixity
622 -> RenamedHsExpr -- Right operand (not an OpApp, but might
624 -> RnMS RenamedHsExpr
626 ---------------------------
627 -- (e11 `op1` e12) `op2` e2
628 mkOpAppRn e1@(OpApp e11 op1 fix1 e12) op2 fix2 e2
630 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
631 returnRn (OpApp e1 op2 fix2 e2)
634 = mkOpAppRn e12 op2 fix2 e2 `thenRn` \ new_e ->
635 returnRn (OpApp e11 op1 fix1 new_e)
637 (nofix_error, associate_right) = compareFixity fix1 fix2
639 ---------------------------
640 -- (- neg_arg) `op` e2
641 mkOpAppRn e1@(NegApp neg_arg neg_name) op2 fix2 e2
643 = addErrRn (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenRn_`
644 returnRn (OpApp e1 op2 fix2 e2)
647 = mkOpAppRn neg_arg op2 fix2 e2 `thenRn` \ new_e ->
648 returnRn (NegApp new_e neg_name)
650 (nofix_error, associate_right) = compareFixity negateFixity fix2
652 ---------------------------
654 mkOpAppRn e1 op1 fix1 e2@(NegApp neg_arg _) -- NegApp can occur on the right
655 | not associate_right -- We *want* right association
656 = addErrRn (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenRn_`
657 returnRn (OpApp e1 op1 fix1 e2)
659 (_, associate_right) = compareFixity fix1 negateFixity
661 ---------------------------
663 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
664 = ASSERT2( right_op_ok fix e2,
665 ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
667 returnRn (OpApp e1 op fix e2)
669 -- Parser left-associates everything, but
670 -- derived instances may have correctly-associated things to
671 -- in the right operarand. So we just check that the right operand is OK
672 right_op_ok fix1 (OpApp _ _ fix2 _)
673 = not error_please && associate_right
675 (error_please, associate_right) = compareFixity fix1 fix2
676 right_op_ok fix1 other
679 -- Parser initially makes negation bind more tightly than any other operator
680 mkNegAppRn neg_arg neg_name
683 getModeRn `thenRn` \ mode ->
684 ASSERT( not_op_app mode neg_arg )
686 returnRn (NegApp neg_arg neg_name)
688 not_op_app SourceMode (OpApp _ _ _ _) = False
689 not_op_app mode other = True
693 mkConOpPatRn :: RenamedPat -> Name -> Fixity -> RenamedPat
696 mkConOpPatRn p1@(ConOpPatIn p11 op1 fix1 p12)
699 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
700 returnRn (ConOpPatIn p1 op2 fix2 p2)
703 = mkConOpPatRn p12 op2 fix2 p2 `thenRn` \ new_p ->
704 returnRn (ConOpPatIn p11 op1 fix1 new_p)
707 (nofix_error, associate_right) = compareFixity fix1 fix2
709 mkConOpPatRn p1 op fix p2 -- Default case, no rearrangment
710 = ASSERT( not_op_pat p2 )
711 returnRn (ConOpPatIn p1 op fix p2)
713 not_op_pat (ConOpPatIn _ _ _ _) = False
714 not_op_pat other = True
718 checkPrecMatch :: Bool -> Name -> RenamedMatch -> RnMS ()
720 checkPrecMatch False fn match
723 checkPrecMatch True op (Match (p1:p2:_) _ _)
724 -- True indicates an infix lhs
725 = getModeRn `thenRn` \ mode ->
726 -- See comments with rnExpr (OpApp ...)
727 if isInterfaceMode mode
729 else checkPrec op p1 False `thenRn_`
732 checkPrecMatch True op _ = panic "checkPrecMatch"
734 checkPrec op (ConOpPatIn _ op1 _ _) right
735 = lookupFixityRn op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
736 lookupFixityRn op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) ->
738 inf_ok = op1_prec > op_prec ||
739 (op1_prec == op_prec &&
740 (op1_dir == InfixR && op_dir == InfixR && right ||
741 op1_dir == InfixL && op_dir == InfixL && not right))
743 info = (ppr_op op, op_fix)
744 info1 = (ppr_op op1, op1_fix)
745 (infol, infor) = if right then (info, info1) else (info1, info)
747 checkRn inf_ok (precParseErr infol infor)
749 checkPrec op pat right
752 -- Check precedence of (arg op) or (op arg) respectively
753 -- If arg is itself an operator application, its precedence should
754 -- be higher than that of op
755 checkSectionPrec left_or_right section op arg
757 OpApp _ op fix _ -> go_for_it (ppr_op op) fix
758 NegApp _ _ -> go_for_it pp_prefix_minus negateFixity
762 go_for_it pp_arg_op arg_fix@(Fixity arg_prec _)
763 = lookupFixityRn op_name `thenRn` \ op_fix@(Fixity op_prec _) ->
764 checkRn (op_prec < arg_prec)
765 (sectionPrecErr (ppr_op op_name, op_fix) (pp_arg_op, arg_fix) section)
772 @(compareFixity op1 op2)@ tells which way to arrange appication, or
773 whether there's an error.
776 compareFixity :: Fixity -> Fixity
777 -> (Bool, -- Error please
778 Bool) -- Associate to the right: a op1 (b op2 c)
779 compareFixity (Fixity prec1 dir1) (Fixity prec2 dir2)
780 = case prec1 `compare` prec2 of
783 EQ -> case (dir1, dir2) of
784 (InfixR, InfixR) -> right
785 (InfixL, InfixL) -> left
788 right = (False, True)
789 left = (False, False)
790 error_please = (True, False)
793 %************************************************************************
795 \subsubsection{Literals}
797 %************************************************************************
799 When literals occur we have to make sure
800 that the types and classes they involve
805 = checkRn (inCharRange c) (bogusCharError c) `thenRn_`
806 returnRn (unitFV charTyCon_name)
808 litFVs (HsCharPrim c) = returnRn (unitFV (getName charPrimTyCon))
809 litFVs (HsString s) = returnRn (mkFVs [listTyCon_name, charTyCon_name])
810 litFVs (HsStringPrim s) = returnRn (unitFV (getName addrPrimTyCon))
811 litFVs (HsInt i) = returnRn (unitFV (getName intTyCon))
812 litFVs (HsIntPrim i) = returnRn (unitFV (getName intPrimTyCon))
813 litFVs (HsFloatPrim f) = returnRn (unitFV (getName floatPrimTyCon))
814 litFVs (HsDoublePrim d) = returnRn (unitFV (getName doublePrimTyCon))
815 litFVs (HsLitLit l bogus_ty) = returnRn (unitFV cCallableClassName)
816 litFVs lit = pprPanic "RnExpr.litFVs" (ppr lit) -- HsInteger and HsRat only appear
817 -- in post-typechecker translations
819 rnOverLit (HsIntegral i from_integer_name)
820 = lookupSyntaxName from_integer_name `thenRn` \ from_integer_name' ->
822 returnRn (HsIntegral i from_integer_name', unitFV from_integer_name')
824 fvs = mkFVs [plusIntegerName, timesIntegerName]
825 -- Big integer literals are built, using + and *,
826 -- out of small integers (DsUtils.mkIntegerLit)
827 -- [NB: plusInteger, timesInteger aren't rebindable...
828 -- they are used to construct the argument to fromInteger,
829 -- which is the rebindable one.]
831 returnRn (HsIntegral i from_integer_name', fvs `addOneFV` from_integer_name')
833 rnOverLit (HsFractional i from_rat_name)
834 = lookupSyntaxName from_rat_name `thenRn` \ from_rat_name' ->
836 fvs = mkFVs [ratioDataConName, plusIntegerName, timesIntegerName]
837 -- We have to make sure that the Ratio type is imported with
838 -- its constructor, because literals of type Ratio t are
839 -- built with that constructor.
840 -- The Rational type is needed too, but that will come in
841 -- when fractionalClass does.
842 -- The plus/times integer operations may be needed to construct the numerator
843 -- and denominator (see DsUtils.mkIntegerLit)
845 returnRn (HsFractional i from_rat_name', fvs `addOneFV` from_rat_name')
848 %************************************************************************
850 \subsubsection{Assertion utils}
852 %************************************************************************
855 mkAssertExpr :: RnMS (RenamedHsExpr, FreeVars)
857 lookupOrigName assertErr_RDR `thenRn` \ name ->
858 getSrcLocRn `thenRn` \ sloc ->
860 -- if we're ignoring asserts, return (\ _ e -> e)
861 -- if not, return (assertError "src-loc")
863 if opt_IgnoreAsserts then
864 getUniqRn `thenRn` \ uniq ->
866 vname = mkSysLocalName uniq SLIT("v")
867 expr = HsLam ignorePredMatch
868 loc = nameSrcLoc vname
869 ignorePredMatch = mkSimpleMatch [WildPatIn, VarPatIn vname] (HsVar vname) placeHolderType loc
871 returnRn (expr, unitFV name)
876 (HsLit (HsString (_PK_ (showSDoc (ppr sloc)))))
879 returnRn (expr, unitFV name)
883 %************************************************************************
885 \subsubsection{Errors}
887 %************************************************************************
890 ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name
891 ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity)
892 pp_prefix_minus = ptext SLIT("prefix `-'")
894 dupFieldErr str (dup:rest)
895 = hsep [ptext SLIT("duplicate field name"),
897 ptext SLIT("in record"), text str]
900 = hang (ptext SLIT("precedence parsing error"))
901 4 (hsep [ptext SLIT("cannot mix"), ppr_opfix op1, ptext SLIT("and"),
903 ptext SLIT("in the same infix expression")])
905 sectionPrecErr op arg_op section
906 = vcat [ptext SLIT("The operator") <+> ppr_opfix op <+> ptext SLIT("of a section"),
907 nest 4 (ptext SLIT("must have lower precedence than the operand") <+> ppr_opfix arg_op),
908 nest 4 (ptext SLIT("in the section:") <+> quotes (ppr section))]
912 SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)")
916 = (ptext SLIT("Illegal signature in pattern:") <+> ppr ty)
917 $$ nest 4 (ptext SLIT("Use -fglasgow-exts to permit it"))
920 = sep [ptext SLIT("Pattern syntax in expression context:"),
924 = sep [ptext SLIT("`do' statements must end in expression:"),
928 = ptext SLIT("character literal out of range: '\\") <> int c <> char '\''