2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnExpr]{Renaming of expressions}
6 Basically dependency analysis.
8 Handles @Match@, @GRHSsAndBinds@, @HsExpr@, and @Qualifier@ datatypes. In
9 general, all of these functions return a renamed thing, and a set of
14 rnMatch, rnGRHSsAndBinds, rnPat,
18 #include "HsVersions.h"
20 import {-# SOURCE #-} RnBinds ( rnBinds )
21 import {-# SOURCE #-} RnSource ( rnHsSigType )
28 import CmdLineOpts ( opt_GlasgowExts )
29 import BasicTypes ( Fixity(..), FixityDirection(..), IfaceFlavour(..) )
30 import PrelInfo ( numClass_RDR, fractionalClass_RDR, eqClass_RDR,
31 ccallableClass_RDR, creturnableClass_RDR,
32 monadZeroClass_RDR, enumClass_RDR, ordClass_RDR,
33 ratioDataCon_RDR, negate_RDR, assertErr_RDR,
36 import TysPrim ( charPrimTyCon, addrPrimTyCon, intPrimTyCon,
37 floatPrimTyCon, doublePrimTyCon
39 import Name ( nameUnique, isLocallyDefined, NamedThing(..) )
41 import UniqFM ( isNullUFM )
42 import UniqSet ( emptyUniqSet, UniqSet )
43 import Unique ( assertIdKey )
44 import Util ( removeDups )
49 *********************************************************
53 *********************************************************
56 rnPat :: RdrNamePat -> RnMS s RenamedPat
58 rnPat WildPatIn = returnRn WildPatIn
61 = lookupBndrRn name `thenRn` \ vname ->
62 returnRn (VarPatIn vname)
65 = litOccurrence lit `thenRn_`
66 lookupImplicitOccRn eqClass_RDR `thenRn_` -- Needed to find equality on pattern
67 returnRn (LitPatIn lit)
70 = rnPat pat `thenRn` \ pat' ->
71 returnRn (LazyPatIn pat')
73 rnPat (AsPatIn name pat)
74 = rnPat pat `thenRn` \ pat' ->
75 lookupBndrRn name `thenRn` \ vname ->
76 returnRn (AsPatIn vname pat')
78 rnPat (ConPatIn con pats)
79 = lookupOccRn con `thenRn` \ con' ->
80 mapRn rnPat pats `thenRn` \ patslist ->
81 returnRn (ConPatIn con' patslist)
83 rnPat (ConOpPatIn pat1 con _ pat2)
84 = rnPat pat1 `thenRn` \ pat1' ->
85 lookupOccRn con `thenRn` \ con' ->
86 lookupFixity con `thenRn` \ fixity ->
87 rnPat pat2 `thenRn` \ pat2' ->
88 mkConOpPatRn pat1' con' fixity pat2'
90 -- Negated patters can only be literals, and they are dealt with
91 -- by negating the literal at compile time, not by using the negation
92 -- operation in Num. So we don't need to make an implicit reference
94 rnPat neg@(NegPatIn pat)
95 = checkRn (valid_neg_pat pat) (negPatErr neg)
97 rnPat pat `thenRn` \ pat' ->
98 returnRn (NegPatIn pat')
100 valid_neg_pat (LitPatIn (HsInt _)) = True
101 valid_neg_pat (LitPatIn (HsFrac _)) = True
102 valid_neg_pat _ = False
105 = rnPat pat `thenRn` \ pat' ->
106 returnRn (ParPatIn pat')
108 rnPat (NPlusKPatIn name lit)
109 = litOccurrence lit `thenRn_`
110 lookupImplicitOccRn ordClass_RDR `thenRn_`
111 lookupBndrRn name `thenRn` \ name' ->
112 returnRn (NPlusKPatIn name' lit)
114 rnPat (ListPatIn pats)
115 = addImplicitOccRn listTyCon_name `thenRn_`
116 mapRn rnPat pats `thenRn` \ patslist ->
117 returnRn (ListPatIn patslist)
119 rnPat (TuplePatIn pats boxed)
120 = addImplicitOccRn (tupleTyCon_name boxed (length pats)) `thenRn_`
121 mapRn rnPat pats `thenRn` \ patslist ->
122 returnRn (TuplePatIn patslist boxed)
124 rnPat (RecPatIn con rpats)
125 = lookupOccRn con `thenRn` \ con' ->
126 rnRpats rpats `thenRn` \ rpats' ->
127 returnRn (RecPatIn con' rpats')
130 ************************************************************************
134 ************************************************************************
137 rnMatch, rnMatch1 :: RdrNameMatch -> RnMS s (RenamedMatch, FreeVars)
139 -- The only tricky bit here is that we want to do a single
140 -- bindLocalsRn for all the matches together, so that we spot
141 -- the repeated variable in
145 = pushSrcLocRn (getMatchLoc match) $
146 bindLocalsRn "pattern" (get_binders match) $ \ new_binders ->
147 rnMatch1 match `thenRn` \ (match', fvs) ->
149 binder_set = mkNameSet new_binders
150 unused_binders = binder_set `minusNameSet` fvs
151 net_fvs = fvs `minusNameSet` binder_set
153 warnUnusedMatches unused_binders `thenRn_`
155 returnRn (match', net_fvs)
157 get_binders (GRHSMatch _) = []
158 get_binders (PatMatch pat match) = collectPatBinders pat ++ get_binders match
160 rnMatch1 (PatMatch pat match)
161 = rnPat pat `thenRn` \ pat' ->
162 rnMatch1 match `thenRn` \ (match', fvs) ->
163 returnRn (PatMatch pat' match', fvs)
165 rnMatch1 (GRHSMatch grhss_and_binds)
166 = rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) ->
167 returnRn (GRHSMatch grhss_and_binds', fvs)
170 %************************************************************************
172 \subsubsection{Guarded right-hand sides (GRHSsAndBinds)}
174 %************************************************************************
177 rnGRHSsAndBinds :: RdrNameGRHSsAndBinds -> RnMS s (RenamedGRHSsAndBinds, FreeVars)
179 rnGRHSsAndBinds (GRHSsAndBindsIn grhss binds)
180 = rnBinds binds $ \ binds' ->
181 rnGRHSs grhss `thenRn` \ (grhss', fvGRHS) ->
182 returnRn (GRHSsAndBindsIn grhss' binds', fvGRHS)
184 rnGRHSs [] = returnRn ([], emptyNameSet)
187 = rnGRHS grhs `thenRn` \ (grhs', fvs) ->
188 rnGRHSs grhss `thenRn` \ (grhss', fvss) ->
189 returnRn (grhs' : grhss', fvs `unionNameSets` fvss)
191 rnGRHS (GRHS guarded locn)
192 = pushSrcLocRn locn $
193 (if not (opt_GlasgowExts || is_standard_guard guarded) then
194 addWarnRn (nonStdGuardErr guarded)
199 rnStmts rnExpr guarded `thenRn` \ (guarded', fvs) ->
200 returnRn (GRHS guarded' locn, fvs)
202 -- Standard Haskell 1.4 guards are just a single boolean
203 -- expression, rather than a list of qualifiers as in the
205 is_standard_guard [ExprStmt _ _] = True
206 is_standard_guard [GuardStmt _ _, ExprStmt _ _] = True
207 is_standard_guard other = False
210 %************************************************************************
212 \subsubsection{Expressions}
214 %************************************************************************
217 rnExprs :: [RdrNameHsExpr] -> RnMS s ([RenamedHsExpr], FreeVars)
218 rnExprs ls = rnExprs' ls emptyUniqSet
220 rnExprs' [] acc = returnRn ([], acc)
221 rnExprs' (expr:exprs) acc
222 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
224 -- Now we do a "seq" on the free vars because typically it's small
225 -- or empty, especially in very long lists of constants
227 acc' = acc `unionNameSets` fvExpr
229 (grubby_seqNameSet acc' rnExprs') exprs acc' `thenRn` \ (exprs', fvExprs) ->
230 returnRn (expr':exprs', fvExprs)
232 -- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
233 grubby_seqNameSet ns result | isNullUFM ns = result
237 Variables. We look up the variable and return the resulting name. The
238 interesting question is what the free-variable set should be. We
239 don't want to return imported or prelude things as free vars. So we
240 look at the Name returned from the lookup, and make it part of the
241 free-var set iff if it's a LocallyDefined Name.
245 rnExpr :: RdrNameHsExpr -> RnMS s (RenamedHsExpr, FreeVars)
248 = lookupOccRn v `thenRn` \ name ->
249 if nameUnique name == assertIdKey then
250 -- We expand it to (GHCerr.assert__ location)
251 mkAssertExpr `thenRn` \ expr ->
252 returnRn (expr, emptyUniqSet)
255 returnRn (HsVar name, if isLocallyDefined name
256 then unitNameSet name
260 = litOccurrence lit `thenRn_`
261 returnRn (HsLit lit, emptyNameSet)
264 = rnMatch match `thenRn` \ (match', fvMatch) ->
265 returnRn (HsLam match', fvMatch)
267 rnExpr (HsApp fun arg)
268 = rnExpr fun `thenRn` \ (fun',fvFun) ->
269 rnExpr arg `thenRn` \ (arg',fvArg) ->
270 returnRn (HsApp fun' arg', fvFun `unionNameSets` fvArg)
272 rnExpr (OpApp e1 op@(HsVar op_name) _ e2)
273 = rnExpr e1 `thenRn` \ (e1', fv_e1) ->
274 rnExpr e2 `thenRn` \ (e2', fv_e2) ->
275 rnExpr op `thenRn` \ (op', fv_op) ->
278 -- When renaming code synthesised from "deriving" declarations
279 -- we're in Interface mode, and we should ignore fixity; assume
280 -- that the deriving code generator got the association correct
281 lookupFixity op_name `thenRn` \ fixity ->
282 getModeRn `thenRn` \ mode ->
284 SourceMode -> mkOpAppRn e1' op' fixity e2'
285 InterfaceMode _ _ -> returnRn (OpApp e1' op' fixity e2')
286 ) `thenRn` \ final_e ->
289 fv_e1 `unionNameSets` fv_op `unionNameSets` fv_e2)
292 = rnExpr e `thenRn` \ (e', fv_e) ->
293 lookupImplicitOccRn negate_RDR `thenRn` \ neg ->
294 mkNegAppRn e' (HsVar neg) `thenRn` \ final_e ->
295 returnRn (final_e, fv_e)
298 = rnExpr e `thenRn` \ (e', fvs_e) ->
299 returnRn (HsPar e', fvs_e)
301 rnExpr (SectionL expr op)
302 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
303 rnExpr op `thenRn` \ (op', fvs_op) ->
304 returnRn (SectionL expr' op', fvs_op `unionNameSets` fvs_expr)
306 rnExpr (SectionR op expr)
307 = rnExpr op `thenRn` \ (op', fvs_op) ->
308 rnExpr expr `thenRn` \ (expr', fvs_expr) ->
309 returnRn (SectionR op' expr', fvs_op `unionNameSets` fvs_expr)
311 rnExpr (CCall fun args may_gc is_casm fake_result_ty)
312 -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls
313 = lookupImplicitOccRn ccallableClass_RDR `thenRn_`
314 lookupImplicitOccRn creturnableClass_RDR `thenRn_`
315 lookupImplicitOccRn ioDataCon_RDR `thenRn_`
316 rnExprs args `thenRn` \ (args', fvs_args) ->
317 returnRn (CCall fun args' may_gc is_casm fake_result_ty, fvs_args)
319 rnExpr (HsSCC label expr)
320 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
321 returnRn (HsSCC label expr', fvs_expr)
323 rnExpr (HsCase expr ms src_loc)
324 = pushSrcLocRn src_loc $
325 rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
326 mapAndUnzipRn rnMatch ms `thenRn` \ (new_ms, ms_fvs) ->
327 returnRn (HsCase new_expr new_ms src_loc, unionManyNameSets (e_fvs : ms_fvs))
329 rnExpr (HsLet binds expr)
330 = rnBinds binds $ \ binds' ->
331 rnExpr expr `thenRn` \ (expr',fvExpr) ->
332 returnRn (HsLet binds' expr', fvExpr)
334 rnExpr (HsDo do_or_lc stmts src_loc)
335 = pushSrcLocRn src_loc $
336 lookupImplicitOccRn monadZeroClass_RDR `thenRn_` -- Forces Monad to come too
337 rnStmts rnExpr stmts `thenRn` \ (stmts', fvs) ->
338 returnRn (HsDo do_or_lc stmts' src_loc, fvs)
340 rnExpr (ExplicitList exps)
341 = addImplicitOccRn listTyCon_name `thenRn_`
342 rnExprs exps `thenRn` \ (exps', fvs) ->
343 returnRn (ExplicitList exps', fvs)
345 rnExpr (ExplicitTuple exps boxed)
346 = addImplicitOccRn (tupleTyCon_name boxed (length exps)) `thenRn_`
347 rnExprs exps `thenRn` \ (exps', fvExps) ->
348 returnRn (ExplicitTuple exps' boxed, fvExps)
350 rnExpr (RecordCon con_id rbinds)
351 = lookupOccRn con_id `thenRn` \ conname ->
352 rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
353 returnRn (RecordCon conname rbinds', fvRbinds)
355 rnExpr (RecordUpd expr rbinds)
356 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
357 rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
358 returnRn (RecordUpd expr' rbinds', fvExpr `unionNameSets` fvRbinds)
360 rnExpr (ExprWithTySig expr pty)
361 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
362 rnHsSigType (text "an expression") pty `thenRn` \ pty' ->
363 returnRn (ExprWithTySig expr' pty', fvExpr)
365 rnExpr (HsIf p b1 b2 src_loc)
366 = pushSrcLocRn src_loc $
367 rnExpr p `thenRn` \ (p', fvP) ->
368 rnExpr b1 `thenRn` \ (b1', fvB1) ->
369 rnExpr b2 `thenRn` \ (b2', fvB2) ->
370 returnRn (HsIf p' b1' b2' src_loc, unionManyNameSets [fvP, fvB1, fvB2])
372 rnExpr (ArithSeqIn seq)
373 = lookupImplicitOccRn enumClass_RDR `thenRn_`
374 rn_seq seq `thenRn` \ (new_seq, fvs) ->
375 returnRn (ArithSeqIn new_seq, fvs)
378 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
379 returnRn (From expr', fvExpr)
381 rn_seq (FromThen expr1 expr2)
382 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
383 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
384 returnRn (FromThen expr1' expr2', fvExpr1 `unionNameSets` fvExpr2)
386 rn_seq (FromTo expr1 expr2)
387 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
388 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
389 returnRn (FromTo expr1' expr2', fvExpr1 `unionNameSets` fvExpr2)
391 rn_seq (FromThenTo expr1 expr2 expr3)
392 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
393 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
394 rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
395 returnRn (FromThenTo expr1' expr2' expr3',
396 unionManyNameSets [fvExpr1, fvExpr2, fvExpr3])
399 %************************************************************************
401 \subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
403 %************************************************************************
407 = mapRn field_dup_err dup_fields `thenRn_`
408 mapAndUnzipRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind_s) ->
409 returnRn (rbinds', unionManyNameSets fvRbind_s)
411 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rbinds ]
413 field_dup_err dups = addErrRn (dupFieldErr str dups)
415 rn_rbind (field, expr, pun)
416 = lookupGlobalOccRn field `thenRn` \ fieldname ->
417 rnExpr expr `thenRn` \ (expr', fvExpr) ->
418 returnRn ((fieldname, expr', pun), fvExpr)
421 = mapRn field_dup_err dup_fields `thenRn_`
424 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rpats ]
426 field_dup_err dups = addErrRn (dupFieldErr "pattern" dups)
428 rn_rpat (field, pat, pun)
429 = lookupGlobalOccRn field `thenRn` \ fieldname ->
430 rnPat pat `thenRn` \ pat' ->
431 returnRn (fieldname, pat', pun)
434 %************************************************************************
436 \subsubsection{@Stmt@s: in @do@ expressions}
438 %************************************************************************
440 Note that although some bound vars may appear in the free var set for
441 the first qual, these will eventually be removed by the caller. For
442 example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
443 @[q <- r, p <- q]@, the free var set for @q <- r@ will
444 be @{r}@, and the free var set for the entire Quals will be @{r}@. This
445 @r@ will be removed only when we finally return from examining all the
449 type RnExprTy s = RdrNameHsExpr -> RnMS s (RenamedHsExpr, FreeVars)
451 rnStmts :: RnExprTy s
453 -> RnMS s ([RenamedStmt], FreeVars)
456 = returnRn ([], emptyNameSet)
458 rnStmts rn_expr (stmt:stmts)
459 = rnStmt rn_expr stmt $ \ stmt' ->
460 rnStmts rn_expr stmts `thenRn` \ (stmts', fvs) ->
461 returnRn (stmt' : stmts', fvs)
463 rnStmt :: RnExprTy s -> RdrNameStmt
464 -> (RenamedStmt -> RnMS s (a, FreeVars))
465 -> RnMS s (a, FreeVars)
466 -- Because of mutual recursion we have to pass in rnExpr.
468 rnStmt rn_expr (BindStmt pat expr src_loc) thing_inside
469 = pushSrcLocRn src_loc $
470 rn_expr expr `thenRn` \ (expr', fv_expr) ->
471 bindLocalsRn "pattern in do binding" binders $ \ new_binders ->
472 rnPat pat `thenRn` \ pat' ->
474 thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ (result, fvs) ->
475 returnRn (result, fv_expr `unionNameSets` (fvs `minusNameSet` mkNameSet new_binders))
477 binders = collectPatBinders pat
479 rnStmt rn_expr (ExprStmt expr src_loc) thing_inside
480 = pushSrcLocRn src_loc $
481 rn_expr expr `thenRn` \ (expr', fv_expr) ->
482 thing_inside (ExprStmt expr' src_loc) `thenRn` \ (result, fvs) ->
483 returnRn (result, fv_expr `unionNameSets` fvs)
485 rnStmt rn_expr (GuardStmt expr src_loc) thing_inside
486 = pushSrcLocRn src_loc $
487 rn_expr expr `thenRn` \ (expr', fv_expr) ->
488 thing_inside (GuardStmt expr' src_loc) `thenRn` \ (result, fvs) ->
489 returnRn (result, fv_expr `unionNameSets` fvs)
491 rnStmt rn_expr (ReturnStmt expr) thing_inside
492 = rn_expr expr `thenRn` \ (expr', fv_expr) ->
493 thing_inside (ReturnStmt expr') `thenRn` \ (result, fvs) ->
494 returnRn (result, fv_expr `unionNameSets` fvs)
496 rnStmt rn_expr (LetStmt binds) thing_inside
497 = rnBinds binds $ \ binds' ->
498 thing_inside (LetStmt binds')
501 %************************************************************************
503 \subsubsection{Precedence Parsing}
505 %************************************************************************
507 @mkOpAppRn@ deals with operator fixities. The argument expressions
508 are assumed to be already correctly arranged. It needs the fixities
509 recorded in the OpApp nodes, because fixity info applies to the things
510 the programmer actually wrote, so you can't find it out from the Name.
512 Furthermore, the second argument is guaranteed not to be another
513 operator application. Why? Because the parser parses all
514 operator appications left-associatively.
517 mkOpAppRn :: RenamedHsExpr -> RenamedHsExpr -> Fixity -> RenamedHsExpr
518 -> RnMS s RenamedHsExpr
520 mkOpAppRn e1@(OpApp e11 op1 fix1 e12)
523 = addErrRn (precParseErr (get op1,fix1) (get op2,fix2)) `thenRn_`
524 returnRn (OpApp e1 op2 fix2 e2)
527 = mkOpAppRn e12 op2 fix2 e2 `thenRn` \ new_e ->
528 returnRn (OpApp e11 op1 fix1 new_e)
530 (nofix_error, rearrange_me) = compareFixity fix1 fix2
532 mkOpAppRn e1@(NegApp neg_arg neg_op)
534 fix2@(Fixity prec2 dir2)
537 = addErrRn (precParseErr (get neg_op,fix_neg) (get op2,fix2)) `thenRn_`
538 returnRn (OpApp e1 op2 fix2 e2)
541 = mkOpAppRn neg_arg op2 fix2 e2 `thenRn` \ new_e ->
542 returnRn (NegApp new_e neg_op)
544 fix_neg = Fixity 6 InfixL -- Precedence of unary negate is wired in as infixl 6!
545 (nofix_error, rearrange_me) = compareFixity fix_neg fix2
547 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
548 = ASSERT( if right_op_ok fix e2 then True
549 else pprPanic "mkOpAppRn" (vcat [ppr e1, text "---", ppr op, text "---", ppr fix, text "---", ppr e2])
551 returnRn (OpApp e1 op fix e2)
555 -- Parser left-associates everything, but
556 -- derived instances may have correctly-associated things to
557 -- in the right operarand. So we just check that the right operand is OK
558 right_op_ok fix1 (OpApp _ _ fix2 _)
559 = not error_please && associate_right
561 (error_please, associate_right) = compareFixity fix1 fix2
562 right_op_ok fix1 other
565 -- Parser initially makes negation bind more tightly than any other operator
566 mkNegAppRn neg_arg neg_op
569 getModeRn `thenRn` \ mode ->
570 ASSERT( not_op_app mode neg_arg )
572 returnRn (NegApp neg_arg neg_op)
574 not_op_app SourceMode (OpApp _ _ _ _) = False
575 not_op_app mode other = True
579 mkConOpPatRn :: RenamedPat -> Name -> Fixity -> RenamedPat
582 mkConOpPatRn p1@(ConOpPatIn p11 op1 fix1 p12)
585 = addErrRn (precParseErr (op1,fix1) (op2,fix2)) `thenRn_`
586 returnRn (ConOpPatIn p1 op2 fix2 p2)
589 = mkConOpPatRn p12 op2 fix2 p2 `thenRn` \ new_p ->
590 returnRn (ConOpPatIn p11 op1 fix1 new_p)
593 (nofix_error, rearrange_me) = compareFixity fix1 fix2
595 mkConOpPatRn p1@(NegPatIn neg_arg)
597 fix2@(Fixity prec2 dir2)
599 | prec2 > 6 -- Precedence of unary - is wired in as 6!
600 = addErrRn (precParseNegPatErr (op2,fix2)) `thenRn_`
601 returnRn (ConOpPatIn p1 op2 fix2 p2)
603 mkConOpPatRn p1 op fix p2 -- Default case, no rearrangment
604 = ASSERT( not_op_pat p2 )
605 returnRn (ConOpPatIn p1 op fix p2)
607 not_op_pat (ConOpPatIn _ _ _ _) = False
608 not_op_pat other = True
612 checkPrecMatch :: Bool -> RdrName -> RdrNameMatch -> RnMS s ()
614 checkPrecMatch False fn match
616 checkPrecMatch True op (PatMatch p1 (PatMatch p2 (GRHSMatch _)))
617 = checkPrec op p1 False `thenRn_`
619 checkPrecMatch True op _
620 = panic "checkPrecMatch"
622 checkPrec op (ConOpPatIn _ op1 _ _) right
623 = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
624 lookupFixity op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) ->
626 inf_ok = op1_prec > op_prec ||
627 (op1_prec == op_prec &&
628 (op1_dir == InfixR && op_dir == InfixR && right ||
629 op1_dir == InfixL && op_dir == InfixL && not right))
632 info1 = (op1,op1_fix)
633 (infol, infor) = if right then (info, info1) else (info1, info)
635 checkRn inf_ok (precParseErr infol infor)
637 checkPrec op (NegPatIn _) right
638 = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
639 checkRn (op_prec <= 6) (precParseNegPatErr (op,op_fix))
641 checkPrec op pat right
648 (compareFixity op1 op2) tells which way to arrange appication, or
649 whether there's an error.
652 compareFixity :: Fixity -> Fixity
653 -> (Bool, -- Error please
654 Bool) -- Associate to the right: a op1 (b op2 c)
655 compareFixity (Fixity prec1 dir1) (Fixity prec2 dir2)
656 = case prec1 `compare` prec2 of
659 EQ -> case (dir1, dir2) of
660 (InfixR, InfixR) -> right
661 (InfixL, InfixL) -> left
664 right = (False, True)
665 left = (False, False)
666 error_please = (True, False)
669 %************************************************************************
671 \subsubsection{Literals}
673 %************************************************************************
675 When literals occur we have to make sure that the types and classes they involve
679 litOccurrence (HsChar _)
680 = addImplicitOccRn charTyCon_name
682 litOccurrence (HsCharPrim _)
683 = addImplicitOccRn (getName charPrimTyCon)
685 litOccurrence (HsString _)
686 = addImplicitOccRn listTyCon_name `thenRn_`
687 addImplicitOccRn charTyCon_name
689 litOccurrence (HsStringPrim _)
690 = addImplicitOccRn (getName addrPrimTyCon)
692 litOccurrence (HsInt _)
693 = lookupImplicitOccRn numClass_RDR -- Int and Integer are forced in by Num
695 litOccurrence (HsFrac _)
696 = lookupImplicitOccRn fractionalClass_RDR `thenRn_`
697 lookupImplicitOccRn ratioDataCon_RDR
698 -- We have to make sure that the Ratio type is imported with
699 -- its constructor, because literals of type Ratio t are
700 -- built with that constructor.
701 -- The Rational type is needed too, but that will come in
702 -- when fractionalClass does.
704 litOccurrence (HsIntPrim _)
705 = addImplicitOccRn (getName intPrimTyCon)
707 litOccurrence (HsFloatPrim _)
708 = addImplicitOccRn (getName floatPrimTyCon)
710 litOccurrence (HsDoublePrim _)
711 = addImplicitOccRn (getName doublePrimTyCon)
713 litOccurrence (HsLitLit _)
714 = lookupImplicitOccRn ccallableClass_RDR
717 %************************************************************************
719 \subsubsection{Assertion utils}
721 %************************************************************************
724 mkAssertExpr :: RnMS s RenamedHsExpr
726 newImportedGlobalName mod occ HiFile `thenRn` \ name ->
727 addOccurrenceName name `thenRn_`
728 getSrcLocRn `thenRn` \ sloc ->
730 expr = HsApp (HsVar name)
731 (HsLit (HsString (_PK_ (showSDoc (ppr sloc)))))
736 mod = rdrNameModule assertErr_RDR
737 occ = rdrNameOcc assertErr_RDR
740 %************************************************************************
742 \subsubsection{Errors}
744 %************************************************************************
747 dupFieldErr str (dup:rest)
748 = hsep [ptext SLIT("duplicate field name"),
750 ptext SLIT("in record"), text str]
753 = sep [ptext SLIT("prefix `-' not applied to literal in pattern"), quotes (ppr pat)]
755 precParseNegPatErr op
756 = hang (ptext SLIT("precedence parsing error"))
757 4 (hsep [ptext SLIT("prefix `-' has lower precedence than"),
759 ptext SLIT("in pattern")])
762 = hang (ptext SLIT("precedence parsing error"))
763 4 (hsep [ptext SLIT("cannot mix"), quotes (pp_op op1), ptext SLIT("and"),
765 ptext SLIT("in the same infix expression")])
768 = hang (ptext SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)"))
771 pp_op (op, fix) = hcat [ppr op, space, parens (ppr fix)]