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,
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 )
31 import BasicTypes ( Fixity(..), FixityDirection(..), defaultFixity, negateFixity )
32 import PrelNames ( hasKey, assertIdKey,
33 eqClass_RDR, foldr_RDR, build_RDR, eqString_RDR,
34 cCallableClass_RDR, cReturnableClass_RDR,
35 monadClass_RDR, enumClass_RDR, ordClass_RDR,
36 ratioDataCon_RDR, negate_RDR, assertErr_RDR,
37 ioDataCon_RDR, plusInteger_RDR, timesInteger_RDR
39 import TysPrim ( charPrimTyCon, addrPrimTyCon, intPrimTyCon,
40 floatPrimTyCon, doublePrimTyCon
42 import TysWiredIn ( intTyCon )
43 import Name ( NamedThing(..), mkSysLocalName, nameSrcLoc )
45 import UniqFM ( isNullUFM )
46 import FiniteMap ( elemFM )
47 import UniqSet ( emptyUniqSet )
48 import ListSetOps ( unionLists, removeDups )
49 import Maybes ( maybeToBool )
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 = lookupOrigName eqString_RDR `thenRn` \ eq ->
84 returnRn (LitPatIn s, unitFV eq)
87 = litFVs lit `thenRn` \ fvs ->
88 returnRn (LitPatIn lit, fvs)
91 = rnOverLit lit `thenRn` \ (lit', fvs1) ->
92 lookupOrigName eqClass_RDR `thenRn` \ eq -> -- Needed to find equality on pattern
93 returnRn (NPatIn lit', fvs1 `addOneFV` eq)
95 rnPat (NPlusKPatIn name lit minus)
96 = rnOverLit lit `thenRn` \ (lit', fvs) ->
97 lookupOrigName ordClass_RDR `thenRn` \ ord ->
98 lookupBndrRn name `thenRn` \ name' ->
99 lookupOccRn minus `thenRn` \ minus' ->
100 returnRn (NPlusKPatIn name' lit' minus', fvs `addOneFV` ord `addOneFV` minus')
102 rnPat (LazyPatIn pat)
103 = rnPat pat `thenRn` \ (pat', fvs) ->
104 returnRn (LazyPatIn pat', fvs)
106 rnPat (AsPatIn name pat)
107 = rnPat pat `thenRn` \ (pat', fvs) ->
108 lookupBndrRn name `thenRn` \ vname ->
109 returnRn (AsPatIn vname pat', fvs)
111 rnPat (ConPatIn con pats)
112 = lookupOccRn con `thenRn` \ con' ->
113 mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
114 returnRn (ConPatIn con' patslist, fvs `addOneFV` con')
116 rnPat (ConOpPatIn pat1 con _ pat2)
117 = rnPat pat1 `thenRn` \ (pat1', fvs1) ->
118 lookupOccRn con `thenRn` \ con' ->
119 rnPat pat2 `thenRn` \ (pat2', fvs2) ->
121 getModeRn `thenRn` \ mode ->
122 -- See comments with rnExpr (OpApp ...)
124 InterfaceMode -> returnRn (ConOpPatIn pat1' con' defaultFixity pat2')
125 SourceMode -> lookupFixityRn con' `thenRn` \ fixity ->
126 mkConOpPatRn pat1' con' fixity pat2'
128 returnRn (pat', fvs1 `plusFV` fvs2 `addOneFV` con')
131 = rnPat pat `thenRn` \ (pat', fvs) ->
132 returnRn (ParPatIn pat', fvs)
134 rnPat (ListPatIn pats)
135 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
136 returnRn (ListPatIn patslist, fvs `addOneFV` listTyCon_name)
138 rnPat (TuplePatIn pats boxed)
139 = mapFvRn rnPat pats `thenRn` \ (patslist, fvs) ->
140 returnRn (TuplePatIn patslist boxed, fvs `addOneFV` tycon_name)
142 tycon_name = tupleTyCon_name boxed (length pats)
144 rnPat (RecPatIn con rpats)
145 = lookupOccRn con `thenRn` \ con' ->
146 rnRpats rpats `thenRn` \ (rpats', fvs) ->
147 returnRn (RecPatIn con' rpats', fvs `addOneFV` con')
148 rnPat (TypePatIn name) =
149 (rnHsTypeFVs (text "type pattern") name) `thenRn` \ (name', fvs) ->
150 returnRn (TypePatIn name', fvs)
153 ************************************************************************
157 ************************************************************************
160 rnMatch :: RdrNameMatch -> RnMS (RenamedMatch, FreeVars)
162 rnMatch match@(Match _ pats maybe_rhs_sig grhss)
163 = pushSrcLocRn (getMatchLoc match) $
165 -- Find the universally quantified type variables
166 -- in the pattern type signatures
167 getLocalNameEnv `thenRn` \ name_env ->
169 tyvars_in_sigs = rhs_sig_tyvars `unionLists` tyvars_in_pats
170 rhs_sig_tyvars = case maybe_rhs_sig of
172 Just ty -> extractHsTyRdrTyVars ty
173 tyvars_in_pats = extractPatsTyVars pats
174 forall_tyvars = filter (not . (`elemFM` name_env)) tyvars_in_sigs
175 doc_sig = text "a pattern type-signature"
176 doc_pats = text "in a pattern match"
178 bindNakedTyVarsFVRn doc_sig forall_tyvars $ \ sig_tyvars ->
180 -- Note that we do a single bindLocalsRn for all the
181 -- matches together, so that we spot the repeated variable in
183 bindLocalsFVRn doc_pats (collectPatsBinders pats) $ \ new_binders ->
185 mapFvRn rnPat pats `thenRn` \ (pats', pat_fvs) ->
186 rnGRHSs grhss `thenRn` \ (grhss', grhss_fvs) ->
187 doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
188 (case maybe_rhs_sig of
189 Nothing -> returnRn (Nothing, emptyFVs)
190 Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenRn` \ (ty', ty_fvs) ->
191 returnRn (Just ty', ty_fvs)
192 | otherwise -> addErrRn (patSigErr ty) `thenRn_`
193 returnRn (Nothing, emptyFVs)
194 ) `thenRn` \ (maybe_rhs_sig', ty_fvs) ->
197 binder_set = mkNameSet new_binders
198 unused_binders = nameSetToList (binder_set `minusNameSet` grhss_fvs)
199 all_fvs = grhss_fvs `plusFV` pat_fvs `plusFV` ty_fvs
201 warnUnusedMatches unused_binders `thenRn_`
203 returnRn (Match sig_tyvars pats' maybe_rhs_sig' grhss', all_fvs)
204 -- The bindLocals and bindTyVars will remove the bound FVs
207 %************************************************************************
209 \subsubsection{Guarded right-hand sides (GRHSs)}
211 %************************************************************************
214 rnGRHSs :: RdrNameGRHSs -> RnMS (RenamedGRHSs, FreeVars)
216 rnGRHSs (GRHSs grhss binds maybe_ty)
217 = ASSERT( not (maybeToBool maybe_ty) )
218 rnBinds binds $ \ binds' ->
219 mapFvRn rnGRHS grhss `thenRn` \ (grhss', fvGRHSs) ->
220 returnRn (GRHSs grhss' binds' Nothing, fvGRHSs)
222 rnGRHS (GRHS guarded locn)
223 = doptRn Opt_GlasgowExts `thenRn` \ opt_GlasgowExts ->
225 (if not (opt_GlasgowExts || is_standard_guard guarded) then
226 addWarnRn (nonStdGuardErr guarded)
231 rnStmts rnExpr guarded `thenRn` \ (guarded', fvs) ->
232 returnRn (GRHS guarded' locn, fvs)
234 -- Standard Haskell 1.4 guards are just a single boolean
235 -- expression, rather than a list of qualifiers as in the
237 is_standard_guard [ExprStmt _ _] = True
238 is_standard_guard [GuardStmt _ _, ExprStmt _ _] = True
239 is_standard_guard other = False
242 %************************************************************************
244 \subsubsection{Expressions}
246 %************************************************************************
249 rnExprs :: [RdrNameHsExpr] -> RnMS ([RenamedHsExpr], FreeVars)
250 rnExprs ls = rnExprs' ls emptyUniqSet
252 rnExprs' [] acc = returnRn ([], acc)
253 rnExprs' (expr:exprs) acc
254 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
256 -- Now we do a "seq" on the free vars because typically it's small
257 -- or empty, especially in very long lists of constants
259 acc' = acc `plusFV` fvExpr
261 (grubby_seqNameSet acc' rnExprs') exprs acc' `thenRn` \ (exprs', fvExprs) ->
262 returnRn (expr':exprs', fvExprs)
264 -- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
265 grubby_seqNameSet ns result | isNullUFM ns = result
269 Variables. We look up the variable and return the resulting name.
272 rnExpr :: RdrNameHsExpr -> RnMS (RenamedHsExpr, FreeVars)
275 = lookupOccRn v `thenRn` \ name ->
276 if name `hasKey` assertIdKey then
277 -- We expand it to (GHCerr.assert__ location)
281 returnRn (HsVar name, unitFV name)
284 = newIPName v `thenRn` \ name ->
285 returnRn (HsIPVar name, emptyFVs)
288 = litFVs lit `thenRn` \ fvs ->
289 returnRn (HsLit lit, fvs)
291 rnExpr (HsOverLit lit)
292 = rnOverLit lit `thenRn` \ (lit', fvs) ->
293 returnRn (HsOverLit lit', fvs)
296 = rnMatch match `thenRn` \ (match', fvMatch) ->
297 returnRn (HsLam match', fvMatch)
299 rnExpr (HsApp fun arg)
300 = rnExpr fun `thenRn` \ (fun',fvFun) ->
301 rnExpr arg `thenRn` \ (arg',fvArg) ->
302 returnRn (HsApp fun' arg', fvFun `plusFV` fvArg)
304 rnExpr (OpApp e1 op _ e2)
305 = rnExpr e1 `thenRn` \ (e1', fv_e1) ->
306 rnExpr e2 `thenRn` \ (e2', fv_e2) ->
307 rnExpr op `thenRn` \ (op'@(HsVar op_name), fv_op) ->
310 -- When renaming code synthesised from "deriving" declarations
311 -- we're in Interface mode, and we should ignore fixity; assume
312 -- that the deriving code generator got the association correct
313 -- Don't even look up the fixity when in interface mode
314 getModeRn `thenRn` \ mode ->
316 SourceMode -> lookupFixityRn op_name `thenRn` \ fixity ->
317 mkOpAppRn e1' op' fixity e2'
318 InterfaceMode -> returnRn (OpApp e1' op' defaultFixity e2')
319 ) `thenRn` \ final_e ->
322 fv_e1 `plusFV` fv_op `plusFV` fv_e2)
325 = rnExpr e `thenRn` \ (e', fv_e) ->
326 lookupOrigName negate_RDR `thenRn` \ neg ->
327 mkNegAppRn e' neg `thenRn` \ final_e ->
328 returnRn (final_e, fv_e `addOneFV` neg)
331 = rnExpr e `thenRn` \ (e', fvs_e) ->
332 returnRn (HsPar e', fvs_e)
334 rnExpr section@(SectionL expr op)
335 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
336 rnExpr op `thenRn` \ (op', fvs_op) ->
337 checkSectionPrec "left" section op' expr' `thenRn_`
338 returnRn (SectionL expr' op', fvs_op `plusFV` fvs_expr)
340 rnExpr section@(SectionR op expr)
341 = rnExpr op `thenRn` \ (op', fvs_op) ->
342 rnExpr expr `thenRn` \ (expr', fvs_expr) ->
343 checkSectionPrec "right" section op' expr' `thenRn_`
344 returnRn (SectionR op' expr', fvs_op `plusFV` fvs_expr)
346 rnExpr (HsCCall fun args may_gc is_casm fake_result_ty)
347 -- Check out the comment on RnIfaces.getNonWiredDataDecl about ccalls
348 = lookupOrigNames [cCallableClass_RDR,
349 cReturnableClass_RDR,
350 ioDataCon_RDR] `thenRn` \ implicit_fvs ->
351 rnExprs args `thenRn` \ (args', fvs_args) ->
352 returnRn (HsCCall fun args' may_gc is_casm fake_result_ty,
353 fvs_args `plusFV` implicit_fvs)
355 rnExpr (HsSCC lbl expr)
356 = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
357 returnRn (HsSCC lbl expr', fvs_expr)
359 rnExpr (HsCase expr ms src_loc)
360 = pushSrcLocRn src_loc $
361 rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
362 mapFvRn rnMatch ms `thenRn` \ (new_ms, ms_fvs) ->
363 returnRn (HsCase new_expr new_ms src_loc, e_fvs `plusFV` ms_fvs)
365 rnExpr (HsLet binds expr)
366 = rnBinds binds $ \ binds' ->
367 rnExpr expr `thenRn` \ (expr',fvExpr) ->
368 returnRn (HsLet binds' expr', fvExpr)
370 rnExpr (HsWith expr binds)
371 = rnExpr expr `thenRn` \ (expr',fvExpr) ->
372 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
373 returnRn (HsWith expr' binds', fvExpr `plusFV` fvBinds)
375 rnExpr e@(HsDo do_or_lc stmts src_loc)
376 = pushSrcLocRn src_loc $
377 lookupOrigNames implicit_rdr_names `thenRn` \ implicit_fvs ->
378 rnStmts rnExpr stmts `thenRn` \ (stmts', fvs) ->
379 -- check the statement list ends in an expression
380 case last stmts' of {
381 ExprStmt _ _ -> returnRn () ;
382 ReturnStmt _ -> returnRn () ; -- for list comprehensions
383 _ -> addErrRn (doStmtListErr e)
385 returnRn (HsDo do_or_lc stmts' src_loc, fvs `plusFV` implicit_fvs)
387 implicit_rdr_names = [foldr_RDR, build_RDR, monadClass_RDR]
388 -- Monad stuff should not be necessary for a list comprehension
389 -- but the typechecker looks up the bind and return Ids anyway
393 rnExpr (ExplicitList exps)
394 = rnExprs exps `thenRn` \ (exps', fvs) ->
395 returnRn (ExplicitList exps', fvs `addOneFV` listTyCon_name)
397 rnExpr (ExplicitTuple exps boxity)
398 = rnExprs exps `thenRn` \ (exps', fvs) ->
399 returnRn (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name)
401 tycon_name = tupleTyCon_name boxity (length exps)
403 rnExpr (RecordCon con_id rbinds)
404 = lookupOccRn con_id `thenRn` \ conname ->
405 rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
406 returnRn (RecordCon conname rbinds', fvRbinds `addOneFV` conname)
408 rnExpr (RecordUpd expr rbinds)
409 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
410 rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
411 returnRn (RecordUpd expr' rbinds', fvExpr `plusFV` fvRbinds)
413 rnExpr (ExprWithTySig expr pty)
414 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
415 rnHsTypeFVs (text "an expression type signature") pty `thenRn` \ (pty', fvTy) ->
416 returnRn (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy)
418 rnExpr (HsIf p b1 b2 src_loc)
419 = pushSrcLocRn src_loc $
420 rnExpr p `thenRn` \ (p', fvP) ->
421 rnExpr b1 `thenRn` \ (b1', fvB1) ->
422 rnExpr b2 `thenRn` \ (b2', fvB2) ->
423 returnRn (HsIf p' b1' b2' src_loc, plusFVs [fvP, fvB1, fvB2])
426 = rnHsTypeFVs doc a `thenRn` \ (t, fvT) ->
427 returnRn (HsType t, fvT)
429 doc = text "renaming a type pattern"
431 rnExpr (ArithSeqIn seq)
432 = lookupOrigName enumClass_RDR `thenRn` \ enum ->
433 rn_seq seq `thenRn` \ (new_seq, fvs) ->
434 returnRn (ArithSeqIn new_seq, fvs `addOneFV` enum)
437 = rnExpr expr `thenRn` \ (expr', fvExpr) ->
438 returnRn (From expr', fvExpr)
440 rn_seq (FromThen expr1 expr2)
441 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
442 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
443 returnRn (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2)
445 rn_seq (FromTo expr1 expr2)
446 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
447 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
448 returnRn (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2)
450 rn_seq (FromThenTo expr1 expr2 expr3)
451 = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
452 rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
453 rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
454 returnRn (FromThenTo expr1' expr2' expr3',
455 plusFVs [fvExpr1, fvExpr2, fvExpr3])
458 These three are pattern syntax appearing in expressions.
459 Since all the symbols are reservedops we can simply reject them.
460 We return a (bogus) EWildPat in each case.
463 rnExpr e@EWildPat = addErrRn (patSynErr e) `thenRn_`
464 returnRn (EWildPat, emptyFVs)
466 rnExpr e@(EAsPat _ _) = addErrRn (patSynErr e) `thenRn_`
467 returnRn (EWildPat, emptyFVs)
469 rnExpr e@(ELazyPat _) = addErrRn (patSynErr e) `thenRn_`
470 returnRn (EWildPat, emptyFVs)
475 %************************************************************************
477 \subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
479 %************************************************************************
483 = mapRn_ field_dup_err dup_fields `thenRn_`
484 mapFvRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind) ->
485 returnRn (rbinds', fvRbind)
487 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rbinds ]
489 field_dup_err dups = addErrRn (dupFieldErr str dups)
491 rn_rbind (field, expr, pun)
492 = lookupGlobalOccRn field `thenRn` \ fieldname ->
493 rnExpr expr `thenRn` \ (expr', fvExpr) ->
494 returnRn ((fieldname, expr', pun), fvExpr `addOneFV` fieldname)
497 = mapRn_ field_dup_err dup_fields `thenRn_`
498 mapFvRn rn_rpat rpats `thenRn` \ (rpats', fvs) ->
499 returnRn (rpats', fvs)
501 (_, dup_fields) = removeDups compare [ f | (f,_,_) <- rpats ]
503 field_dup_err dups = addErrRn (dupFieldErr "pattern" dups)
505 rn_rpat (field, pat, pun)
506 = lookupGlobalOccRn field `thenRn` \ fieldname ->
507 rnPat pat `thenRn` \ (pat', fvs) ->
508 returnRn ((fieldname, pat', pun), fvs `addOneFV` fieldname)
511 %************************************************************************
513 \subsubsection{@rnIPBinds@s: in implicit parameter bindings} *
515 %************************************************************************
518 rnIPBinds [] = returnRn ([], emptyFVs)
519 rnIPBinds ((n, expr) : binds)
520 = newIPName n `thenRn` \ name ->
521 rnExpr expr `thenRn` \ (expr',fvExpr) ->
522 rnIPBinds binds `thenRn` \ (binds',fvBinds) ->
523 returnRn ((name, expr') : binds', fvExpr `plusFV` fvBinds)
527 %************************************************************************
529 \subsubsection{@Stmt@s: in @do@ expressions}
531 %************************************************************************
533 Note that although some bound vars may appear in the free var set for
534 the first qual, these will eventually be removed by the caller. For
535 example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
536 @[q <- r, p <- q]@, the free var set for @q <- r@ will
537 be @{r}@, and the free var set for the entire Quals will be @{r}@. This
538 @r@ will be removed only when we finally return from examining all the
542 type RnExprTy = RdrNameHsExpr -> RnMS (RenamedHsExpr, FreeVars)
546 -> RnMS ([RenamedStmt], FreeVars)
549 = returnRn ([], emptyFVs)
551 rnStmts rn_expr (stmt:stmts)
552 = rnStmt rn_expr stmt $ \ stmt' ->
553 rnStmts rn_expr stmts `thenRn` \ (stmts', fvs) ->
554 returnRn (stmt' : stmts', fvs)
556 rnStmt :: RnExprTy -> RdrNameStmt
557 -> (RenamedStmt -> RnMS (a, FreeVars))
558 -> RnMS (a, FreeVars)
559 -- Because of mutual recursion we have to pass in rnExpr.
561 rnStmt rn_expr (BindStmt pat expr src_loc) thing_inside
562 = pushSrcLocRn src_loc $
563 rn_expr expr `thenRn` \ (expr', fv_expr) ->
564 bindLocalsFVRn doc binders $ \ new_binders ->
565 rnPat pat `thenRn` \ (pat', fv_pat) ->
566 thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ (result, fvs) ->
567 returnRn (result, fv_expr `plusFV` fvs `plusFV` fv_pat)
569 binders = collectPatBinders pat
570 doc = text "a pattern in do binding"
572 rnStmt rn_expr (ExprStmt expr src_loc) thing_inside
573 = pushSrcLocRn src_loc $
574 rn_expr expr `thenRn` \ (expr', fv_expr) ->
575 thing_inside (ExprStmt expr' src_loc) `thenRn` \ (result, fvs) ->
576 returnRn (result, fv_expr `plusFV` fvs)
578 rnStmt rn_expr (GuardStmt expr src_loc) thing_inside
579 = pushSrcLocRn src_loc $
580 rn_expr expr `thenRn` \ (expr', fv_expr) ->
581 thing_inside (GuardStmt expr' src_loc) `thenRn` \ (result, fvs) ->
582 returnRn (result, fv_expr `plusFV` fvs)
584 rnStmt rn_expr (ReturnStmt expr) thing_inside
585 = rn_expr expr `thenRn` \ (expr', fv_expr) ->
586 thing_inside (ReturnStmt expr') `thenRn` \ (result, fvs) ->
587 returnRn (result, fv_expr `plusFV` fvs)
589 rnStmt rn_expr (LetStmt binds) thing_inside
590 = rnBinds binds $ \ binds' ->
591 thing_inside (LetStmt binds')
594 %************************************************************************
596 \subsubsection{Precedence Parsing}
598 %************************************************************************
600 @mkOpAppRn@ deals with operator fixities. The argument expressions
601 are assumed to be already correctly arranged. It needs the fixities
602 recorded in the OpApp nodes, because fixity info applies to the things
603 the programmer actually wrote, so you can't find it out from the Name.
605 Furthermore, the second argument is guaranteed not to be another
606 operator application. Why? Because the parser parses all
607 operator appications left-associatively, EXCEPT negation, which
608 we need to handle specially.
611 mkOpAppRn :: RenamedHsExpr -- Left operand; already rearranged
612 -> RenamedHsExpr -> Fixity -- Operator and fixity
613 -> RenamedHsExpr -- Right operand (not an OpApp, but might
615 -> RnMS RenamedHsExpr
617 ---------------------------
618 -- (e11 `op1` e12) `op2` e2
619 mkOpAppRn e1@(OpApp e11 op1 fix1 e12) op2 fix2 e2
621 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
622 returnRn (OpApp e1 op2 fix2 e2)
625 = mkOpAppRn e12 op2 fix2 e2 `thenRn` \ new_e ->
626 returnRn (OpApp e11 op1 fix1 new_e)
628 (nofix_error, associate_right) = compareFixity fix1 fix2
630 ---------------------------
631 -- (- neg_arg) `op` e2
632 mkOpAppRn e1@(NegApp neg_arg neg_op) op2 fix2 e2
634 = addErrRn (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) `thenRn_`
635 returnRn (OpApp e1 op2 fix2 e2)
638 = mkOpAppRn neg_arg op2 fix2 e2 `thenRn` \ new_e ->
639 returnRn (NegApp new_e neg_op)
641 (nofix_error, associate_right) = compareFixity negateFixity fix2
643 ---------------------------
645 mkOpAppRn e1 op1 fix1 e2@(NegApp neg_arg neg_op) -- NegApp can occur on the right
646 | not associate_right -- We *want* right association
647 = addErrRn (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) `thenRn_`
648 returnRn (OpApp e1 op1 fix1 e2)
650 (_, associate_right) = compareFixity fix1 negateFixity
652 ---------------------------
654 mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
655 = ASSERT2( right_op_ok fix e2,
656 ppr e1 $$ text "---" $$ ppr op $$ text "---" $$ ppr fix $$ text "---" $$ ppr e2
658 returnRn (OpApp e1 op fix e2)
660 -- Parser left-associates everything, but
661 -- derived instances may have correctly-associated things to
662 -- in the right operarand. So we just check that the right operand is OK
663 right_op_ok fix1 (OpApp _ _ fix2 _)
664 = not error_please && associate_right
666 (error_please, associate_right) = compareFixity fix1 fix2
667 right_op_ok fix1 other
670 -- Parser initially makes negation bind more tightly than any other operator
671 mkNegAppRn neg_arg neg_op
674 getModeRn `thenRn` \ mode ->
675 ASSERT( not_op_app mode neg_arg )
677 returnRn (NegApp neg_arg neg_op)
679 not_op_app SourceMode (OpApp _ _ _ _) = False
680 not_op_app mode other = True
684 mkConOpPatRn :: RenamedPat -> Name -> Fixity -> RenamedPat
687 mkConOpPatRn p1@(ConOpPatIn p11 op1 fix1 p12)
690 = addErrRn (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) `thenRn_`
691 returnRn (ConOpPatIn p1 op2 fix2 p2)
694 = mkConOpPatRn p12 op2 fix2 p2 `thenRn` \ new_p ->
695 returnRn (ConOpPatIn p11 op1 fix1 new_p)
698 (nofix_error, associate_right) = compareFixity fix1 fix2
700 mkConOpPatRn p1 op fix p2 -- Default case, no rearrangment
701 = ASSERT( not_op_pat p2 )
702 returnRn (ConOpPatIn p1 op fix p2)
704 not_op_pat (ConOpPatIn _ _ _ _) = False
705 not_op_pat other = True
709 checkPrecMatch :: Bool -> Name -> RenamedMatch -> RnMS ()
711 checkPrecMatch False fn match
714 checkPrecMatch True op (Match _ (p1:p2:_) _ _)
715 -- True indicates an infix lhs
716 = getModeRn `thenRn` \ mode ->
717 -- See comments with rnExpr (OpApp ...)
719 InterfaceMode -> returnRn ()
720 SourceMode -> checkPrec op p1 False `thenRn_`
723 checkPrecMatch True op _ = panic "checkPrecMatch"
725 checkPrec op (ConOpPatIn _ op1 _ _) right
726 = lookupFixityRn op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
727 lookupFixityRn op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) ->
729 inf_ok = op1_prec > op_prec ||
730 (op1_prec == op_prec &&
731 (op1_dir == InfixR && op_dir == InfixR && right ||
732 op1_dir == InfixL && op_dir == InfixL && not right))
734 info = (ppr_op op, op_fix)
735 info1 = (ppr_op op1, op1_fix)
736 (infol, infor) = if right then (info, info1) else (info1, info)
738 checkRn inf_ok (precParseErr infol infor)
740 checkPrec op pat right
743 -- Check precedence of (arg op) or (op arg) respectively
744 -- If arg is itself an operator application, its precedence should
745 -- be higher than that of op
746 checkSectionPrec left_or_right section op arg
748 OpApp _ op fix _ -> go_for_it (ppr_op op) fix
749 NegApp _ _ -> go_for_it pp_prefix_minus negateFixity
753 go_for_it pp_arg_op arg_fix@(Fixity arg_prec _)
754 = lookupFixityRn op_name `thenRn` \ op_fix@(Fixity op_prec _) ->
755 checkRn (op_prec < arg_prec)
756 (sectionPrecErr (ppr_op op_name, op_fix) (pp_arg_op, arg_fix) section)
763 @(compareFixity op1 op2)@ tells which way to arrange appication, or
764 whether there's an error.
767 compareFixity :: Fixity -> Fixity
768 -> (Bool, -- Error please
769 Bool) -- Associate to the right: a op1 (b op2 c)
770 compareFixity (Fixity prec1 dir1) (Fixity prec2 dir2)
771 = case prec1 `compare` prec2 of
774 EQ -> case (dir1, dir2) of
775 (InfixR, InfixR) -> right
776 (InfixL, InfixL) -> left
779 right = (False, True)
780 left = (False, False)
781 error_please = (True, False)
784 %************************************************************************
786 \subsubsection{Literals}
788 %************************************************************************
790 When literals occur we have to make sure
791 that the types and classes they involve
795 litFVs (HsChar c) = returnRn (unitFV charTyCon_name)
796 litFVs (HsCharPrim c) = returnRn (unitFV (getName charPrimTyCon))
797 litFVs (HsString s) = returnRn (mkFVs [listTyCon_name, charTyCon_name])
798 litFVs (HsStringPrim s) = returnRn (unitFV (getName addrPrimTyCon))
799 litFVs (HsInt i) = returnRn (unitFV (getName intTyCon))
800 litFVs (HsIntPrim i) = returnRn (unitFV (getName intPrimTyCon))
801 litFVs (HsFloatPrim f) = returnRn (unitFV (getName floatPrimTyCon))
802 litFVs (HsDoublePrim d) = returnRn (unitFV (getName doublePrimTyCon))
803 litFVs (HsLitLit l bogus_ty) = lookupOrigName cCallableClass_RDR `thenRn` \ cc ->
805 litFVs lit = pprPanic "RnExpr.litFVs" (ppr lit) -- HsInteger and HsRat only appear
806 -- in post-typechecker translations
808 rnOverLit (HsIntegral i from_integer)
809 = lookupOccRn from_integer `thenRn` \ from_integer' ->
810 (if inIntRange i then
813 lookupOrigNames [plusInteger_RDR, timesInteger_RDR]
815 returnRn (HsIntegral i from_integer', ns `addOneFV` from_integer')
817 rnOverLit (HsFractional i n)
818 = lookupOccRn n `thenRn` \ n' ->
819 lookupOrigNames [ratioDataCon_RDR, plusInteger_RDR, timesInteger_RDR] `thenRn` \ ns' ->
820 -- We have to make sure that the Ratio type is imported with
821 -- its constructor, because literals of type Ratio t are
822 -- built with that constructor.
823 -- The Rational type is needed too, but that will come in
824 -- when fractionalClass does.
825 -- The plus/times integer operations may be needed to construct the numerator
826 -- and denominator (see DsUtils.mkIntegerLit)
827 returnRn (HsFractional i n', ns' `addOneFV` n')
830 %************************************************************************
832 \subsubsection{Assertion utils}
834 %************************************************************************
837 mkAssertExpr :: RnMS (RenamedHsExpr, FreeVars)
839 lookupOrigName assertErr_RDR `thenRn` \ name ->
840 getSrcLocRn `thenRn` \ sloc ->
842 -- if we're ignoring asserts, return (\ _ e -> e)
843 -- if not, return (assertError "src-loc")
845 if opt_IgnoreAsserts then
846 getUniqRn `thenRn` \ uniq ->
848 vname = mkSysLocalName uniq SLIT("v")
849 expr = HsLam ignorePredMatch
850 loc = nameSrcLoc vname
851 ignorePredMatch = Match [] [WildPatIn, VarPatIn vname] Nothing
852 (GRHSs [GRHS [ExprStmt (HsVar vname) loc] loc]
855 returnRn (expr, unitFV name)
860 (HsLit (HsString (_PK_ (showSDoc (ppr sloc)))))
863 returnRn (expr, unitFV name)
867 %************************************************************************
869 \subsubsection{Errors}
871 %************************************************************************
874 ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name
875 ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity)
876 pp_prefix_minus = ptext SLIT("prefix `-'")
878 dupFieldErr str (dup:rest)
879 = hsep [ptext SLIT("duplicate field name"),
881 ptext SLIT("in record"), text str]
884 = hang (ptext SLIT("precedence parsing error"))
885 4 (hsep [ptext SLIT("cannot mix"), ppr_opfix op1, ptext SLIT("and"),
887 ptext SLIT("in the same infix expression")])
889 sectionPrecErr op arg_op section
890 = vcat [ptext SLIT("The operator") <+> ppr_opfix op <+> ptext SLIT("of a section"),
891 nest 4 (ptext SLIT("must have lower precedence than the operand") <+> ppr_opfix arg_op),
892 nest 4 (ptext SLIT("In the section:") <+> quotes (ppr section))]
896 SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)")
900 = (ptext SLIT("Illegal signature in pattern:") <+> ppr ty)
901 $$ nest 4 (ptext SLIT("Use -fglasgow-exts to permit it"))
904 = sep [ptext SLIT("Pattern syntax in expression context:"),
908 = sep [ptext SLIT("`do' statements must end in expression:"),