2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
9 -- GHC uses several kinds of name internally:
11 -- * 'OccName.OccName' represents names as strings with just a little more information:
12 -- the "namespace" that the name came from, e.g. the namespace of value, type constructors or
15 -- * 'RdrName.RdrName': see "RdrName#name_types"
17 -- * 'Name.Name': see "Name#name_types"
19 -- * 'Id.Id': see "Id#name_types"
21 -- * 'Var.Var': see "Var#name_types"
23 -- * The 'NameSpace' type
24 NameSpace, -- Abstract
27 -- $real_vs_source_data_constructors
28 tcName, clsName, tcClsName, dataName, varName,
32 pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief,
34 -- * The 'OccName' type
35 OccName, -- Abstract, instance of Outputable
39 mkOccName, mkOccNameFS,
41 mkDataOcc, mkDataOccFS,
42 mkTyVarOcc, mkTyVarOccFS,
49 -- ** Derived 'OccName's
51 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc,
52 mkDerivedTyConOcc, mkNewTyCoOcc,
53 mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
54 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
55 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
56 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc,
57 mkSuperDictSelOcc, mkLocalOcc, mkMethodOcc, mkInstTyTcOcc,
58 mkInstTyCoOcc, mkEqPredCoOcc,
59 mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
60 mkPArrayTyConOcc, mkPArrayDataConOcc,
65 occNameFS, occNameString, occNameSpace,
67 isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,
68 parenSymOcc, reportIfUnused,
70 isTcClsNameSpace, isTvNameSpace, isDataConNameSpace, isVarNameSpace, isValNameSpace,
74 -- * The 'OccEnv' type
75 OccEnv, emptyOccEnv, unitOccEnv, extendOccEnv, mapOccEnv,
76 lookupOccEnv, mkOccEnv, mkOccEnv_C, extendOccEnvList, elemOccEnv,
77 occEnvElts, foldOccEnv, plusOccEnv, plusOccEnv_C, extendOccEnv_C,
78 filterOccEnv, delListFromOccEnv, delFromOccEnv,
80 -- * The 'OccSet' type
81 OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet,
83 unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts,
84 foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet,
87 TidyOccEnv, emptyTidyOccEnv, tidyOccName, initTidyOccEnv,
89 -- * Lexical characteristics of Haskell names
90 isLexCon, isLexVar, isLexId, isLexSym,
91 isLexConId, isLexConSym, isLexVarId, isLexVarSym,
92 startsVarSym, startsVarId, startsConSym, startsConId
111 -- Unicode TODO: put isSymbol in libcompat
112 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
114 isSymbol :: a -> Bool
115 isSymbol = const False
120 %************************************************************************
122 \subsection{Name space}
124 %************************************************************************
127 data NameSpace = VarName -- Variables, including "real" data constructors
128 | DataName -- "Source" data constructors
129 | TvName -- Type variables
130 | TcClsName -- Type constructors and classes; Haskell has them
131 -- in the same name space for now.
133 {-! derive: Binary !-}
135 -- Note [Data Constructors]
136 -- see also: Note [Data Constructor Naming] in DataCon.lhs
138 -- $real_vs_source_data_constructors
139 -- There are two forms of data constructor:
141 -- [Source data constructors] The data constructors mentioned in Haskell source code
143 -- [Real data constructors] The data constructors of the representation type, which may not be the same as the source type
147 -- > data T = T !(Int, Int)
149 -- The source datacon has type @(Int, Int) -> T@
150 -- The real datacon has type @Int -> Int -> T@
152 -- GHC chooses a representation based on the strictness etc.
154 tcName, clsName, tcClsName :: NameSpace
155 dataName, srcDataName :: NameSpace
156 tvName, varName :: NameSpace
158 -- Though type constructors and classes are in the same name space now,
159 -- the NameSpace type is abstract, so we can easily separate them later
160 tcName = TcClsName -- Type constructors
161 clsName = TcClsName -- Classes
162 tcClsName = TcClsName -- Not sure which!
165 srcDataName = DataName -- Haskell-source data constructors should be
166 -- in the Data name space
171 isDataConNameSpace :: NameSpace -> Bool
172 isDataConNameSpace DataName = True
173 isDataConNameSpace _ = False
175 isTcClsNameSpace :: NameSpace -> Bool
176 isTcClsNameSpace TcClsName = True
177 isTcClsNameSpace _ = False
179 isTvNameSpace :: NameSpace -> Bool
180 isTvNameSpace TvName = True
181 isTvNameSpace _ = False
183 isVarNameSpace :: NameSpace -> Bool -- Variables or type variables, but not constructors
184 isVarNameSpace TvName = True
185 isVarNameSpace VarName = True
186 isVarNameSpace _ = False
188 isValNameSpace :: NameSpace -> Bool
189 isValNameSpace DataName = True
190 isValNameSpace VarName = True
191 isValNameSpace _ = False
193 pprNameSpace :: NameSpace -> SDoc
194 pprNameSpace DataName = ptext (sLit "data constructor")
195 pprNameSpace VarName = ptext (sLit "variable")
196 pprNameSpace TvName = ptext (sLit "type variable")
197 pprNameSpace TcClsName = ptext (sLit "type constructor or class")
199 pprNonVarNameSpace :: NameSpace -> SDoc
200 pprNonVarNameSpace VarName = empty
201 pprNonVarNameSpace ns = pprNameSpace ns
203 pprNameSpaceBrief :: NameSpace -> SDoc
204 pprNameSpaceBrief DataName = char 'd'
205 pprNameSpaceBrief VarName = char 'v'
206 pprNameSpaceBrief TvName = ptext (sLit "tv")
207 pprNameSpaceBrief TcClsName = ptext (sLit "tc")
211 %************************************************************************
213 \subsection[Name-pieces-datatypes]{The @OccName@ datatypes}
215 %************************************************************************
218 data OccName = OccName
219 { occNameSpace :: !NameSpace
220 , occNameFS :: !FastString
226 instance Eq OccName where
227 (OccName sp1 s1) == (OccName sp2 s2) = s1 == s2 && sp1 == sp2
229 instance Ord OccName where
230 -- Compares lexicographically, *not* by Unique of the string
231 compare (OccName sp1 s1) (OccName sp2 s2)
232 = (s1 `compare` s2) `thenCmp` (sp1 `compare` sp2)
236 %************************************************************************
238 \subsection{Printing}
240 %************************************************************************
243 instance Outputable OccName where
246 pprOccName :: OccName -> SDoc
247 pprOccName (OccName sp occ)
248 = getPprStyle $ \ sty ->
250 then ftext (zEncodeFS occ)
251 else ftext occ <> if debugStyle sty
252 then braces (pprNameSpaceBrief sp)
257 %************************************************************************
259 \subsection{Construction}
261 %************************************************************************
264 mkOccName :: NameSpace -> String -> OccName
265 mkOccName occ_sp str = OccName occ_sp (mkFastString str)
267 mkOccNameFS :: NameSpace -> FastString -> OccName
268 mkOccNameFS occ_sp fs = OccName occ_sp fs
270 mkVarOcc :: String -> OccName
271 mkVarOcc s = mkOccName varName s
273 mkVarOccFS :: FastString -> OccName
274 mkVarOccFS fs = mkOccNameFS varName fs
276 mkDataOcc :: String -> OccName
277 mkDataOcc = mkOccName dataName
279 mkDataOccFS :: FastString -> OccName
280 mkDataOccFS = mkOccNameFS dataName
282 mkTyVarOcc :: String -> OccName
283 mkTyVarOcc = mkOccName tvName
285 mkTyVarOccFS :: FastString -> OccName
286 mkTyVarOccFS fs = mkOccNameFS tvName fs
288 mkTcOcc :: String -> OccName
289 mkTcOcc = mkOccName tcName
291 mkTcOccFS :: FastString -> OccName
292 mkTcOccFS = mkOccNameFS tcName
294 mkClsOcc :: String -> OccName
295 mkClsOcc = mkOccName clsName
297 mkClsOccFS :: FastString -> OccName
298 mkClsOccFS = mkOccNameFS clsName
302 %************************************************************************
306 %************************************************************************
308 OccEnvs are used mainly for the envts in ModIfaces.
310 They are efficient, because FastStrings have unique Int# keys. We assume
311 this key is less than 2^24, so we can make a Unique using
312 mkUnique ns key :: Unique
313 where 'ns' is a Char reprsenting the name space. This in turn makes it
314 easy to build an OccEnv.
317 instance Uniquable OccName where
318 getUnique (OccName ns fs)
319 = mkUnique char (iBox (uniqueOfFS fs))
320 where -- See notes above about this getUnique function
327 newtype OccEnv a = A (UniqFM a)
329 emptyOccEnv :: OccEnv a
330 unitOccEnv :: OccName -> a -> OccEnv a
331 extendOccEnv :: OccEnv a -> OccName -> a -> OccEnv a
332 extendOccEnvList :: OccEnv a -> [(OccName, a)] -> OccEnv a
333 lookupOccEnv :: OccEnv a -> OccName -> Maybe a
334 mkOccEnv :: [(OccName,a)] -> OccEnv a
335 mkOccEnv_C :: (a -> a -> a) -> [(OccName,a)] -> OccEnv a
336 elemOccEnv :: OccName -> OccEnv a -> Bool
337 foldOccEnv :: (a -> b -> b) -> b -> OccEnv a -> b
338 occEnvElts :: OccEnv a -> [a]
339 extendOccEnv_C :: (a->a->a) -> OccEnv a -> OccName -> a -> OccEnv a
340 plusOccEnv :: OccEnv a -> OccEnv a -> OccEnv a
341 plusOccEnv_C :: (a->a->a) -> OccEnv a -> OccEnv a -> OccEnv a
342 mapOccEnv :: (a->b) -> OccEnv a -> OccEnv b
343 delFromOccEnv :: OccEnv a -> OccName -> OccEnv a
344 delListFromOccEnv :: OccEnv a -> [OccName] -> OccEnv a
345 filterOccEnv :: (elt -> Bool) -> OccEnv elt -> OccEnv elt
347 emptyOccEnv = A emptyUFM
348 unitOccEnv x y = A $ unitUFM x y
349 extendOccEnv (A x) y z = A $ addToUFM x y z
350 extendOccEnvList (A x) l = A $ addListToUFM x l
351 lookupOccEnv (A x) y = lookupUFM x y
352 mkOccEnv l = A $ listToUFM l
353 elemOccEnv x (A y) = elemUFM x y
354 foldOccEnv a b (A c) = foldUFM a b c
355 occEnvElts (A x) = eltsUFM x
356 plusOccEnv (A x) (A y) = A $ plusUFM x y
357 plusOccEnv_C f (A x) (A y) = A $ plusUFM_C f x y
358 extendOccEnv_C f (A x) y z = A $ addToUFM_C f x y z
359 mapOccEnv f (A x) = A $ mapUFM f x
360 mkOccEnv_C comb l = A $ addListToUFM_C comb emptyUFM l
361 delFromOccEnv (A x) y = A $ delFromUFM x y
362 delListFromOccEnv (A x) y = A $ delListFromUFM x y
363 filterOccEnv x (A y) = A $ filterUFM x y
365 instance Outputable a => Outputable (OccEnv a) where
368 type OccSet = UniqSet OccName
370 emptyOccSet :: OccSet
371 unitOccSet :: OccName -> OccSet
372 mkOccSet :: [OccName] -> OccSet
373 extendOccSet :: OccSet -> OccName -> OccSet
374 extendOccSetList :: OccSet -> [OccName] -> OccSet
375 unionOccSets :: OccSet -> OccSet -> OccSet
376 unionManyOccSets :: [OccSet] -> OccSet
377 minusOccSet :: OccSet -> OccSet -> OccSet
378 elemOccSet :: OccName -> OccSet -> Bool
379 occSetElts :: OccSet -> [OccName]
380 foldOccSet :: (OccName -> b -> b) -> b -> OccSet -> b
381 isEmptyOccSet :: OccSet -> Bool
382 intersectOccSet :: OccSet -> OccSet -> OccSet
383 intersectsOccSet :: OccSet -> OccSet -> Bool
385 emptyOccSet = emptyUniqSet
386 unitOccSet = unitUniqSet
388 extendOccSet = addOneToUniqSet
389 extendOccSetList = addListToUniqSet
390 unionOccSets = unionUniqSets
391 unionManyOccSets = unionManyUniqSets
392 minusOccSet = minusUniqSet
393 elemOccSet = elementOfUniqSet
394 occSetElts = uniqSetToList
395 foldOccSet = foldUniqSet
396 isEmptyOccSet = isEmptyUniqSet
397 intersectOccSet = intersectUniqSets
398 intersectsOccSet s1 s2 = not (isEmptyOccSet (s1 `intersectOccSet` s2))
402 %************************************************************************
404 \subsection{Predicates and taking them apart}
406 %************************************************************************
409 occNameString :: OccName -> String
410 occNameString (OccName _ s) = unpackFS s
412 setOccNameSpace :: NameSpace -> OccName -> OccName
413 setOccNameSpace sp (OccName _ occ) = OccName sp occ
415 isVarOcc, isTvOcc, isTcOcc, isDataOcc :: OccName -> Bool
417 isVarOcc (OccName VarName _) = True
420 isTvOcc (OccName TvName _) = True
423 isTcOcc (OccName TcClsName _) = True
426 -- | /Value/ 'OccNames's are those that are either in
427 -- the variable or data constructor namespaces
428 isValOcc :: OccName -> Bool
429 isValOcc (OccName VarName _) = True
430 isValOcc (OccName DataName _) = True
433 isDataOcc (OccName DataName _) = True
434 isDataOcc (OccName VarName s)
435 | isLexCon s = pprPanic "isDataOcc: check me" (ppr s)
436 -- Jan06: I don't think this should happen
439 -- | Test if the 'OccName' is a data constructor that starts with
440 -- a symbol (e.g. @:@, or @[]@)
441 isDataSymOcc :: OccName -> Bool
442 isDataSymOcc (OccName DataName s) = isLexConSym s
443 isDataSymOcc (OccName VarName s)
444 | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
445 -- Jan06: I don't think this should happen
446 isDataSymOcc _ = False
447 -- Pretty inefficient!
449 -- | Test if the 'OccName' is that for any operator (whether
450 -- it is a data constructor or variable or whatever)
451 isSymOcc :: OccName -> Bool
452 isSymOcc (OccName DataName s) = isLexConSym s
453 isSymOcc (OccName TcClsName s) = isLexConSym s
454 isSymOcc (OccName VarName s) = isLexSym s
455 isSymOcc (OccName TvName s) = isLexSym s
456 -- Pretty inefficient!
458 parenSymOcc :: OccName -> SDoc -> SDoc
459 -- ^ Wrap parens around an operator
460 parenSymOcc occ doc | isSymOcc occ = parens doc
466 reportIfUnused :: OccName -> Bool
467 -- ^ Haskell 98 encourages compilers to suppress warnings about
468 -- unused names in a pattern if they start with @_@: this implements
470 reportIfUnused occ = case occNameString occ of
476 %************************************************************************
478 \subsection{Making system names}
480 %************************************************************************
482 Here's our convention for splitting up the interface file name space:
484 d... dictionary identifiers
485 (local variables, so no name-clash worries)
487 All of these other OccNames contain a mixture of alphabetic
488 and symbolic characters, and hence cannot possibly clash with
489 a user-written type or function name
491 $f... Dict-fun identifiers (from inst decls)
492 $dmop Default method for 'op'
493 $pnC n'th superclass selector for class C
494 $wf Worker for functtoin 'f'
495 $sf.. Specialised version of f
496 T:C Tycon for dictionary for class C
497 D:C Data constructor for dictionary for class C
498 NTCo:T Coercion connecting newtype T with its representation type
499 TFCo:R Coercion connecting a data family to its respresentation type R
501 In encoded form these appear as Zdfxxx etc
503 :... keywords (export:, letrec: etc.)
504 --- I THINK THIS IS WRONG!
506 This knowledge is encoded in the following functions.
508 @mk_deriv@ generates an @OccName@ from the prefix and a string.
509 NB: The string must already be encoded!
512 mk_deriv :: NameSpace
513 -> String -- Distinguishes one sort of derived name from another
517 mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str)
519 isDerivedOccName :: OccName -> Bool
520 isDerivedOccName occ =
521 case occNameString occ of
522 '$':c:_ | isAlphaNum c -> True
523 ':':c:_ | isAlphaNum c -> True
528 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc, mkDerivedTyConOcc,
529 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
530 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
531 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc,
532 mkInstTyCoOcc, mkEqPredCoOcc,
533 mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
534 mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
535 mkPArrayTyConOcc, mkPArrayDataConOcc, mkPReprTyConOcc, mkPADFunOcc
536 :: OccName -> OccName
538 -- These derived variables have a prefix that no Haskell value could have
539 mkDataConWrapperOcc = mk_simple_deriv varName "$W"
540 mkWorkerOcc = mk_simple_deriv varName "$w"
541 mkDefaultMethodOcc = mk_simple_deriv varName "$dm"
542 mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies
543 mkClassTyConOcc = mk_simple_deriv tcName "T:" -- as a tycon/datacon
544 mkClassDataConOcc = mk_simple_deriv dataName "D:" -- We go straight to the "real" data con
545 -- for datacons from classes
546 mkDictOcc = mk_simple_deriv varName "$d"
547 mkIPOcc = mk_simple_deriv varName "$i"
548 mkSpecOcc = mk_simple_deriv varName "$s"
549 mkForeignExportOcc = mk_simple_deriv varName "$f"
550 mkNewTyCoOcc = mk_simple_deriv tcName "NTCo:" -- Coercion for newtypes
551 mkInstTyCoOcc = mk_simple_deriv tcName "TFCo:" -- Coercion for type functions
552 mkEqPredCoOcc = mk_simple_deriv tcName "$co"
554 -- used in derived instances
555 mkCon2TagOcc = mk_simple_deriv varName "$con2tag_"
556 mkTag2ConOcc = mk_simple_deriv varName "$tag2con_"
557 mkMaxTagOcc = mk_simple_deriv varName "$maxtag_"
559 -- Generic derivable classes
560 mkGenOcc1 = mk_simple_deriv varName "$gfrom"
561 mkGenOcc2 = mk_simple_deriv varName "$gto"
563 -- data T = MkT ... deriving( Data ) needs defintions for
564 -- $tT :: Data.Generics.Basics.DataType
565 -- $cMkT :: Data.Generics.Basics.Constr
566 mkDataTOcc = mk_simple_deriv varName "$t"
567 mkDataCOcc = mk_simple_deriv varName "$c"
570 mkVectOcc = mk_simple_deriv varName "$v_"
571 mkVectTyConOcc = mk_simple_deriv tcName ":V_"
572 mkVectDataConOcc = mk_simple_deriv dataName ":VD_"
573 mkVectIsoOcc = mk_simple_deriv varName "$VI_"
574 mkPArrayTyConOcc = mk_simple_deriv tcName ":VP_"
575 mkPArrayDataConOcc = mk_simple_deriv dataName ":VPD_"
576 mkPReprTyConOcc = mk_simple_deriv tcName ":VR_"
577 mkPADFunOcc = mk_simple_deriv varName "$PA_"
579 mk_simple_deriv :: NameSpace -> String -> OccName -> OccName
580 mk_simple_deriv sp px occ = mk_deriv sp px (occNameString occ)
582 -- Data constructor workers are made by setting the name space
583 -- of the data constructor OccName (which should be a DataName)
585 mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ
589 mkSuperDictSelOcc :: Int -- ^ Index of superclass, e.g. 3
590 -> OccName -- ^ Class, e.g. @Ord@
591 -> OccName -- ^ Derived 'Occname', e.g. @$p3Ord@
592 mkSuperDictSelOcc index cls_occ
593 = mk_deriv varName "$p" (show index ++ occNameString cls_occ)
595 mkLocalOcc :: Unique -- ^ Unique to combine with the 'OccName'
596 -> OccName -- ^ Local name, e.g. @sat@
597 -> OccName -- ^ Nice unique version, e.g. @$L23sat@
599 = mk_deriv varName ("$L" ++ show uniq) (occNameString occ)
600 -- The Unique might print with characters
601 -- that need encoding (e.g. 'z'!)
605 -- | Derive a name for the representation type constructor of a
606 -- @data@\/@newtype@ instance.
607 mkInstTyTcOcc :: Int -- ^ DFun Index
608 -> OccName -- ^ Family name, e.g. @Map@
609 -> OccName -- ^ Nice unique version, e.g. @:R23Map@
610 mkInstTyTcOcc index occ
611 = mk_deriv tcName ("R" ++ show index ++ ":") (occNameString occ)
615 mkDFunOcc :: String -- ^ Typically the class and type glommed together e.g. @OrdMaybe@.
616 -- Only used in debug mode, for extra clarity
617 -> Bool -- ^ Is this a hs-boot instance DFun?
618 -> Int -- ^ Unique index
619 -> OccName -- ^ E.g. @$f3OrdMaybe@
621 -- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real
622 -- thing when we compile the mother module. Reason: we don't know exactly
623 -- what the mother module will call it.
625 mkDFunOcc info_str is_boot index
626 = mk_deriv VarName prefix string
628 prefix | is_boot = "$fx"
630 string | opt_PprStyle_Debug = show index ++ info_str
631 | otherwise = show index
634 We used to add a '$m' to indicate a method, but that gives rise to bad
635 error messages from the type checker when we print the function name or pattern
636 of an instance-decl binding. Why? Because the binding is zapped
637 to use the method name in place of the selector name.
638 (See TcClassDcl.tcMethodBind)
640 The way it is now, -ddump-xx output may look confusing, but
641 you can always say -dppr-debug to get the uniques.
643 However, we *do* have to zap the first character to be lower case,
644 because overloaded constructors (blarg) generate methods too.
645 And convert to VarName space
647 e.g. a call to constructor MkFoo where
648 data (Ord a) => Foo a = MkFoo a
650 If this is necessary, we do it by prefixing '$m'. These
651 guys never show up in error messages. What a hack.
654 mkMethodOcc :: OccName -> OccName
655 mkMethodOcc occ@(OccName VarName _) = occ
656 mkMethodOcc occ = mk_simple_deriv varName "$m" occ
660 %************************************************************************
662 \subsection{Tidying them up}
664 %************************************************************************
666 Before we print chunks of code we like to rename it so that
667 we don't have to print lots of silly uniques in it. But we mustn't
668 accidentally introduce name clashes! So the idea is that we leave the
669 OccName alone unless it accidentally clashes with one that is already
670 in scope; if so, we tack on '1' at the end and try again, then '2', and
671 so on till we find a unique one.
673 There's a wrinkle for operators. Consider '>>='. We can't use '>>=1'
674 because that isn't a single lexeme. So we encode it to 'lle' and *then*
675 tack on the '1', if necessary.
678 type TidyOccEnv = OccEnv Int -- The in-scope OccNames
679 -- Range gives a plausible starting point for new guesses
681 emptyTidyOccEnv :: TidyOccEnv
682 emptyTidyOccEnv = emptyOccEnv
684 initTidyOccEnv :: [OccName] -> TidyOccEnv -- Initialise with names to avoid!
685 initTidyOccEnv = foldl (\env occ -> extendOccEnv env occ 1) emptyTidyOccEnv
687 tidyOccName :: TidyOccEnv -> OccName -> (TidyOccEnv, OccName)
689 tidyOccName in_scope occ@(OccName occ_sp fs)
690 = case lookupOccEnv in_scope occ of
691 Nothing -> -- Not already used: make it used
692 (extendOccEnv in_scope occ 1, occ)
694 Just n -> -- Already used: make a new guess,
695 -- change the guess base, and try again
696 tidyOccName (extendOccEnv in_scope occ (n+1))
697 (mkOccName occ_sp (unpackFS fs ++ show n))
700 %************************************************************************
702 Stuff for dealing with tuples
704 %************************************************************************
707 mkTupleOcc :: NameSpace -> Boxity -> Arity -> OccName
708 mkTupleOcc ns bx ar = OccName ns (mkFastString str)
710 -- no need to cache these, the caching is done in the caller
711 -- (TysWiredIn.mk_tuple)
713 Boxed -> '(' : commas ++ ")"
714 Unboxed -> '(' : '#' : commas ++ "#)"
716 commas = take (ar-1) (repeat ',')
718 isTupleOcc_maybe :: OccName -> Maybe (NameSpace, Boxity, Arity)
719 -- Tuples are special, because there are so many of them!
720 isTupleOcc_maybe (OccName ns fs)
721 = case unpackFS fs of
722 '(':'#':',':rest -> Just (ns, Unboxed, 2 + count_commas rest)
723 '(':',':rest -> Just (ns, Boxed, 2 + count_commas rest)
726 count_commas (',':rest) = 1 + count_commas rest
730 %************************************************************************
732 \subsection{Lexical categories}
734 %************************************************************************
736 These functions test strings to see if they fit the lexical categories
737 defined in the Haskell report.
740 isLexCon, isLexVar, isLexId, isLexSym :: FastString -> Bool
741 isLexConId, isLexConSym, isLexVarId, isLexVarSym :: FastString -> Bool
743 isLexCon cs = isLexConId cs || isLexConSym cs
744 isLexVar cs = isLexVarId cs || isLexVarSym cs
746 isLexId cs = isLexConId cs || isLexVarId cs
747 isLexSym cs = isLexConSym cs || isLexVarSym cs
751 isLexConId cs -- Prefix type or data constructors
752 | nullFS cs = False -- e.g. "Foo", "[]", "(,)"
753 | cs == (fsLit "[]") = True
754 | otherwise = startsConId (headFS cs)
756 isLexVarId cs -- Ordinary prefix identifiers
757 | nullFS cs = False -- e.g. "x", "_x"
758 | otherwise = startsVarId (headFS cs)
760 isLexConSym cs -- Infix type or data constructors
761 | nullFS cs = False -- e.g. ":-:", ":", "->"
762 | cs == (fsLit "->") = True
763 | otherwise = startsConSym (headFS cs)
765 isLexVarSym cs -- Infix identifiers
766 | nullFS cs = False -- e.g. "+"
767 | otherwise = startsVarSym (headFS cs)
770 startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool
771 startsVarSym c = isSymbolASCII c || (ord c > 0x7f && isSymbol c) -- Infix Ids
772 startsConSym c = c == ':' -- Infix data constructors
773 startsVarId c = isLower c || c == '_' -- Ordinary Ids
774 startsConId c = isUpper c || c == '(' -- Ordinary type constructors and data constructors
776 isSymbolASCII :: Char -> Bool
777 isSymbolASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-"
780 %************************************************************************
783 Here rather than BinIface because OccName is abstract
785 %************************************************************************
788 instance Binary NameSpace where
791 put_ bh DataName = do
795 put_ bh TcClsName = do
800 0 -> do return VarName
801 1 -> do return DataName
802 2 -> do return TvName
803 _ -> do return TcClsName
805 instance Binary OccName where
806 put_ bh (OccName aa ab) = do
812 return (OccName aa ab)