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 mkPDataTyConOcc, mkPDataDataConOcc,
65 occNameFS, occNameString, occNameSpace,
67 isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,
68 parenSymOcc, startsWithUnderscore,
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
108 -- Unicode TODO: put isSymbol in libcompat
109 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
111 isSymbol :: a -> Bool
112 isSymbol = const False
117 %************************************************************************
119 \subsection{Name space}
121 %************************************************************************
124 data NameSpace = VarName -- Variables, including "real" data constructors
125 | DataName -- "Source" data constructors
126 | TvName -- Type variables
127 | TcClsName -- Type constructors and classes; Haskell has them
128 -- in the same name space for now.
130 {-! derive: Binary !-}
132 -- Note [Data Constructors]
133 -- see also: Note [Data Constructor Naming] in DataCon.lhs
135 -- $real_vs_source_data_constructors
136 -- There are two forms of data constructor:
138 -- [Source data constructors] The data constructors mentioned in Haskell source code
140 -- [Real data constructors] The data constructors of the representation type, which may not be the same as the source type
144 -- > data T = T !(Int, Int)
146 -- The source datacon has type @(Int, Int) -> T@
147 -- The real datacon has type @Int -> Int -> T@
149 -- GHC chooses a representation based on the strictness etc.
151 tcName, clsName, tcClsName :: NameSpace
152 dataName, srcDataName :: NameSpace
153 tvName, varName :: NameSpace
155 -- Though type constructors and classes are in the same name space now,
156 -- the NameSpace type is abstract, so we can easily separate them later
157 tcName = TcClsName -- Type constructors
158 clsName = TcClsName -- Classes
159 tcClsName = TcClsName -- Not sure which!
162 srcDataName = DataName -- Haskell-source data constructors should be
163 -- in the Data name space
168 isDataConNameSpace :: NameSpace -> Bool
169 isDataConNameSpace DataName = True
170 isDataConNameSpace _ = False
172 isTcClsNameSpace :: NameSpace -> Bool
173 isTcClsNameSpace TcClsName = True
174 isTcClsNameSpace _ = False
176 isTvNameSpace :: NameSpace -> Bool
177 isTvNameSpace TvName = True
178 isTvNameSpace _ = False
180 isVarNameSpace :: NameSpace -> Bool -- Variables or type variables, but not constructors
181 isVarNameSpace TvName = True
182 isVarNameSpace VarName = True
183 isVarNameSpace _ = False
185 isValNameSpace :: NameSpace -> Bool
186 isValNameSpace DataName = True
187 isValNameSpace VarName = True
188 isValNameSpace _ = False
190 pprNameSpace :: NameSpace -> SDoc
191 pprNameSpace DataName = ptext (sLit "data constructor")
192 pprNameSpace VarName = ptext (sLit "variable")
193 pprNameSpace TvName = ptext (sLit "type variable")
194 pprNameSpace TcClsName = ptext (sLit "type constructor or class")
196 pprNonVarNameSpace :: NameSpace -> SDoc
197 pprNonVarNameSpace VarName = empty
198 pprNonVarNameSpace ns = pprNameSpace ns
200 pprNameSpaceBrief :: NameSpace -> SDoc
201 pprNameSpaceBrief DataName = char 'd'
202 pprNameSpaceBrief VarName = char 'v'
203 pprNameSpaceBrief TvName = ptext (sLit "tv")
204 pprNameSpaceBrief TcClsName = ptext (sLit "tc")
208 %************************************************************************
210 \subsection[Name-pieces-datatypes]{The @OccName@ datatypes}
212 %************************************************************************
215 data OccName = OccName
216 { occNameSpace :: !NameSpace
217 , occNameFS :: !FastString
223 instance Eq OccName where
224 (OccName sp1 s1) == (OccName sp2 s2) = s1 == s2 && sp1 == sp2
226 instance Ord OccName where
227 -- Compares lexicographically, *not* by Unique of the string
228 compare (OccName sp1 s1) (OccName sp2 s2)
229 = (s1 `compare` s2) `thenCmp` (sp1 `compare` sp2)
233 %************************************************************************
235 \subsection{Printing}
237 %************************************************************************
240 instance Outputable OccName where
243 pprOccName :: OccName -> SDoc
244 pprOccName (OccName sp occ)
245 = getPprStyle $ \ sty ->
247 then ftext (zEncodeFS occ)
248 else ftext occ <> if debugStyle sty
249 then braces (pprNameSpaceBrief sp)
254 %************************************************************************
256 \subsection{Construction}
258 %************************************************************************
261 mkOccName :: NameSpace -> String -> OccName
262 mkOccName occ_sp str = OccName occ_sp (mkFastString str)
264 mkOccNameFS :: NameSpace -> FastString -> OccName
265 mkOccNameFS occ_sp fs = OccName occ_sp fs
267 mkVarOcc :: String -> OccName
268 mkVarOcc s = mkOccName varName s
270 mkVarOccFS :: FastString -> OccName
271 mkVarOccFS fs = mkOccNameFS varName fs
273 mkDataOcc :: String -> OccName
274 mkDataOcc = mkOccName dataName
276 mkDataOccFS :: FastString -> OccName
277 mkDataOccFS = mkOccNameFS dataName
279 mkTyVarOcc :: String -> OccName
280 mkTyVarOcc = mkOccName tvName
282 mkTyVarOccFS :: FastString -> OccName
283 mkTyVarOccFS fs = mkOccNameFS tvName fs
285 mkTcOcc :: String -> OccName
286 mkTcOcc = mkOccName tcName
288 mkTcOccFS :: FastString -> OccName
289 mkTcOccFS = mkOccNameFS tcName
291 mkClsOcc :: String -> OccName
292 mkClsOcc = mkOccName clsName
294 mkClsOccFS :: FastString -> OccName
295 mkClsOccFS = mkOccNameFS clsName
299 %************************************************************************
303 %************************************************************************
305 OccEnvs are used mainly for the envts in ModIfaces.
307 They are efficient, because FastStrings have unique Int# keys. We assume
308 this key is less than 2^24, so we can make a Unique using
309 mkUnique ns key :: Unique
310 where 'ns' is a Char reprsenting the name space. This in turn makes it
311 easy to build an OccEnv.
314 instance Uniquable OccName where
315 getUnique (OccName ns fs)
316 = mkUnique char (iBox (uniqueOfFS fs))
317 where -- See notes above about this getUnique function
324 newtype OccEnv a = A (UniqFM a)
326 emptyOccEnv :: OccEnv a
327 unitOccEnv :: OccName -> a -> OccEnv a
328 extendOccEnv :: OccEnv a -> OccName -> a -> OccEnv a
329 extendOccEnvList :: OccEnv a -> [(OccName, a)] -> OccEnv a
330 lookupOccEnv :: OccEnv a -> OccName -> Maybe a
331 mkOccEnv :: [(OccName,a)] -> OccEnv a
332 mkOccEnv_C :: (a -> a -> a) -> [(OccName,a)] -> OccEnv a
333 elemOccEnv :: OccName -> OccEnv a -> Bool
334 foldOccEnv :: (a -> b -> b) -> b -> OccEnv a -> b
335 occEnvElts :: OccEnv a -> [a]
336 extendOccEnv_C :: (a->a->a) -> OccEnv a -> OccName -> a -> OccEnv a
337 plusOccEnv :: OccEnv a -> OccEnv a -> OccEnv a
338 plusOccEnv_C :: (a->a->a) -> OccEnv a -> OccEnv a -> OccEnv a
339 mapOccEnv :: (a->b) -> OccEnv a -> OccEnv b
340 delFromOccEnv :: OccEnv a -> OccName -> OccEnv a
341 delListFromOccEnv :: OccEnv a -> [OccName] -> OccEnv a
342 filterOccEnv :: (elt -> Bool) -> OccEnv elt -> OccEnv elt
344 emptyOccEnv = A emptyUFM
345 unitOccEnv x y = A $ unitUFM x y
346 extendOccEnv (A x) y z = A $ addToUFM x y z
347 extendOccEnvList (A x) l = A $ addListToUFM x l
348 lookupOccEnv (A x) y = lookupUFM x y
349 mkOccEnv l = A $ listToUFM l
350 elemOccEnv x (A y) = elemUFM x y
351 foldOccEnv a b (A c) = foldUFM a b c
352 occEnvElts (A x) = eltsUFM x
353 plusOccEnv (A x) (A y) = A $ plusUFM x y
354 plusOccEnv_C f (A x) (A y) = A $ plusUFM_C f x y
355 extendOccEnv_C f (A x) y z = A $ addToUFM_C f x y z
356 mapOccEnv f (A x) = A $ mapUFM f x
357 mkOccEnv_C comb l = A $ addListToUFM_C comb emptyUFM l
358 delFromOccEnv (A x) y = A $ delFromUFM x y
359 delListFromOccEnv (A x) y = A $ delListFromUFM x y
360 filterOccEnv x (A y) = A $ filterUFM x y
362 instance Outputable a => Outputable (OccEnv a) where
365 type OccSet = UniqSet OccName
367 emptyOccSet :: OccSet
368 unitOccSet :: OccName -> OccSet
369 mkOccSet :: [OccName] -> OccSet
370 extendOccSet :: OccSet -> OccName -> OccSet
371 extendOccSetList :: OccSet -> [OccName] -> OccSet
372 unionOccSets :: OccSet -> OccSet -> OccSet
373 unionManyOccSets :: [OccSet] -> OccSet
374 minusOccSet :: OccSet -> OccSet -> OccSet
375 elemOccSet :: OccName -> OccSet -> Bool
376 occSetElts :: OccSet -> [OccName]
377 foldOccSet :: (OccName -> b -> b) -> b -> OccSet -> b
378 isEmptyOccSet :: OccSet -> Bool
379 intersectOccSet :: OccSet -> OccSet -> OccSet
380 intersectsOccSet :: OccSet -> OccSet -> Bool
382 emptyOccSet = emptyUniqSet
383 unitOccSet = unitUniqSet
385 extendOccSet = addOneToUniqSet
386 extendOccSetList = addListToUniqSet
387 unionOccSets = unionUniqSets
388 unionManyOccSets = unionManyUniqSets
389 minusOccSet = minusUniqSet
390 elemOccSet = elementOfUniqSet
391 occSetElts = uniqSetToList
392 foldOccSet = foldUniqSet
393 isEmptyOccSet = isEmptyUniqSet
394 intersectOccSet = intersectUniqSets
395 intersectsOccSet s1 s2 = not (isEmptyOccSet (s1 `intersectOccSet` s2))
399 %************************************************************************
401 \subsection{Predicates and taking them apart}
403 %************************************************************************
406 occNameString :: OccName -> String
407 occNameString (OccName _ s) = unpackFS s
409 setOccNameSpace :: NameSpace -> OccName -> OccName
410 setOccNameSpace sp (OccName _ occ) = OccName sp occ
412 isVarOcc, isTvOcc, isTcOcc, isDataOcc :: OccName -> Bool
414 isVarOcc (OccName VarName _) = True
417 isTvOcc (OccName TvName _) = True
420 isTcOcc (OccName TcClsName _) = True
423 -- | /Value/ 'OccNames's are those that are either in
424 -- the variable or data constructor namespaces
425 isValOcc :: OccName -> Bool
426 isValOcc (OccName VarName _) = True
427 isValOcc (OccName DataName _) = True
430 isDataOcc (OccName DataName _) = True
431 isDataOcc (OccName VarName s)
432 | isLexCon s = pprPanic "isDataOcc: check me" (ppr s)
433 -- Jan06: I don't think this should happen
436 -- | Test if the 'OccName' is a data constructor that starts with
437 -- a symbol (e.g. @:@, or @[]@)
438 isDataSymOcc :: OccName -> Bool
439 isDataSymOcc (OccName DataName s) = isLexConSym s
440 isDataSymOcc (OccName VarName s)
441 | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
442 -- Jan06: I don't think this should happen
443 isDataSymOcc _ = False
444 -- Pretty inefficient!
446 -- | Test if the 'OccName' is that for any operator (whether
447 -- it is a data constructor or variable or whatever)
448 isSymOcc :: OccName -> Bool
449 isSymOcc (OccName DataName s) = isLexConSym s
450 isSymOcc (OccName TcClsName s) = isLexConSym s
451 isSymOcc (OccName VarName s) = isLexSym s
452 isSymOcc (OccName TvName s) = isLexSym s
453 -- Pretty inefficient!
455 parenSymOcc :: OccName -> SDoc -> SDoc
456 -- ^ Wrap parens around an operator
457 parenSymOcc occ doc | isSymOcc occ = parens doc
463 startsWithUnderscore :: OccName -> Bool
464 -- ^ Haskell 98 encourages compilers to suppress warnings about unsed
465 -- names in a pattern if they start with @_@: this implements that test
466 startsWithUnderscore occ = case occNameString occ of
472 %************************************************************************
474 \subsection{Making system names}
476 %************************************************************************
478 Here's our convention for splitting up the interface file name space:
480 d... dictionary identifiers
481 (local variables, so no name-clash worries)
483 All of these other OccNames contain a mixture of alphabetic
484 and symbolic characters, and hence cannot possibly clash with
485 a user-written type or function name
487 $f... Dict-fun identifiers (from inst decls)
488 $dmop Default method for 'op'
489 $pnC n'th superclass selector for class C
490 $wf Worker for functtoin 'f'
491 $sf.. Specialised version of f
492 T:C Tycon for dictionary for class C
493 D:C Data constructor for dictionary for class C
494 NTCo:T Coercion connecting newtype T with its representation type
495 TFCo:R Coercion connecting a data family to its respresentation type R
497 In encoded form these appear as Zdfxxx etc
499 :... keywords (export:, letrec: etc.)
500 --- I THINK THIS IS WRONG!
502 This knowledge is encoded in the following functions.
504 @mk_deriv@ generates an @OccName@ from the prefix and a string.
505 NB: The string must already be encoded!
508 mk_deriv :: NameSpace
509 -> String -- Distinguishes one sort of derived name from another
513 mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str)
515 isDerivedOccName :: OccName -> Bool
516 isDerivedOccName occ =
517 case occNameString occ of
518 '$':c:_ | isAlphaNum c -> True
519 ':':c:_ | isAlphaNum c -> True
524 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc, mkDerivedTyConOcc,
525 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
526 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
527 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc,
528 mkInstTyCoOcc, mkEqPredCoOcc,
529 mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
530 mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
531 mkPDataTyConOcc, mkPDataDataConOcc, mkPReprTyConOcc, mkPADFunOcc
532 :: OccName -> OccName
534 -- These derived variables have a prefix that no Haskell value could have
535 mkDataConWrapperOcc = mk_simple_deriv varName "$W"
536 mkWorkerOcc = mk_simple_deriv varName "$w"
537 mkDefaultMethodOcc = mk_simple_deriv varName "$dm"
538 mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies
539 mkClassTyConOcc = mk_simple_deriv tcName "T:" -- as a tycon/datacon
540 mkClassDataConOcc = mk_simple_deriv dataName "D:" -- We go straight to the "real" data con
541 -- for datacons from classes
542 mkDictOcc = mk_simple_deriv varName "$d"
543 mkIPOcc = mk_simple_deriv varName "$i"
544 mkSpecOcc = mk_simple_deriv varName "$s"
545 mkForeignExportOcc = mk_simple_deriv varName "$f"
546 mkNewTyCoOcc = mk_simple_deriv tcName "NTCo:" -- Coercion for newtypes
547 mkInstTyCoOcc = mk_simple_deriv tcName "TFCo:" -- Coercion for type functions
548 mkEqPredCoOcc = mk_simple_deriv tcName "$co"
550 -- used in derived instances
551 mkCon2TagOcc = mk_simple_deriv varName "$con2tag_"
552 mkTag2ConOcc = mk_simple_deriv varName "$tag2con_"
553 mkMaxTagOcc = mk_simple_deriv varName "$maxtag_"
555 -- Generic derivable classes
556 mkGenOcc1 = mk_simple_deriv varName "$gfrom"
557 mkGenOcc2 = mk_simple_deriv varName "$gto"
559 -- data T = MkT ... deriving( Data ) needs defintions for
560 -- $tT :: Data.Generics.Basics.DataType
561 -- $cMkT :: Data.Generics.Basics.Constr
562 mkDataTOcc = mk_simple_deriv varName "$t"
563 mkDataCOcc = mk_simple_deriv varName "$c"
566 mkVectOcc = mk_simple_deriv varName "$v_"
567 mkVectTyConOcc = mk_simple_deriv tcName ":V_"
568 mkVectDataConOcc = mk_simple_deriv dataName ":VD_"
569 mkVectIsoOcc = mk_simple_deriv varName "$VI_"
570 mkPDataTyConOcc = mk_simple_deriv tcName ":VP_"
571 mkPDataDataConOcc = mk_simple_deriv dataName ":VPD_"
572 mkPReprTyConOcc = mk_simple_deriv tcName ":VR_"
573 mkPADFunOcc = mk_simple_deriv varName "$PA_"
575 mk_simple_deriv :: NameSpace -> String -> OccName -> OccName
576 mk_simple_deriv sp px occ = mk_deriv sp px (occNameString occ)
578 -- Data constructor workers are made by setting the name space
579 -- of the data constructor OccName (which should be a DataName)
581 mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ
585 mkSuperDictSelOcc :: Int -- ^ Index of superclass, e.g. 3
586 -> OccName -- ^ Class, e.g. @Ord@
587 -> OccName -- ^ Derived 'Occname', e.g. @$p3Ord@
588 mkSuperDictSelOcc index cls_occ
589 = mk_deriv varName "$p" (show index ++ occNameString cls_occ)
591 mkLocalOcc :: Unique -- ^ Unique to combine with the 'OccName'
592 -> OccName -- ^ Local name, e.g. @sat@
593 -> OccName -- ^ Nice unique version, e.g. @$L23sat@
595 = mk_deriv varName ("$L" ++ show uniq) (occNameString occ)
596 -- The Unique might print with characters
597 -- that need encoding (e.g. 'z'!)
601 -- | Derive a name for the representation type constructor of a
602 -- @data@\/@newtype@ instance.
603 mkInstTyTcOcc :: String -- ^ Family name, e.g. @Map@
604 -> OccSet -- ^ avoid these Occs
605 -> OccName -- ^ @R:Map@
606 mkInstTyTcOcc str set =
607 chooseUniqueOcc tcName ('R' : ':' : str) set
611 mkDFunOcc :: String -- ^ Typically the class and type glommed together e.g. @OrdMaybe@.
612 -- Only used in debug mode, for extra clarity
613 -> Bool -- ^ Is this a hs-boot instance DFun?
614 -> OccSet -- ^ avoid these Occs
615 -> OccName -- ^ E.g. @$f3OrdMaybe@
617 -- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real
618 -- thing when we compile the mother module. Reason: we don't know exactly
619 -- what the mother module will call it.
621 mkDFunOcc info_str is_boot set
622 = chooseUniqueOcc VarName (prefix ++ info_str) set
624 prefix | is_boot = "$fx"
628 Sometimes we need to pick an OccName that has not already been used,
629 given a set of in-use OccNames.
632 chooseUniqueOcc :: NameSpace -> String -> OccSet -> OccName
633 chooseUniqueOcc ns str set = loop (mkOccName ns str) (0::Int)
636 | occ `elemOccSet` set = loop (mkOccName ns (str ++ show n)) (n+1)
640 We used to add a '$m' to indicate a method, but that gives rise to bad
641 error messages from the type checker when we print the function name or pattern
642 of an instance-decl binding. Why? Because the binding is zapped
643 to use the method name in place of the selector name.
644 (See TcClassDcl.tcMethodBind)
646 The way it is now, -ddump-xx output may look confusing, but
647 you can always say -dppr-debug to get the uniques.
649 However, we *do* have to zap the first character to be lower case,
650 because overloaded constructors (blarg) generate methods too.
651 And convert to VarName space
653 e.g. a call to constructor MkFoo where
654 data (Ord a) => Foo a = MkFoo a
656 If this is necessary, we do it by prefixing '$m'. These
657 guys never show up in error messages. What a hack.
660 mkMethodOcc :: OccName -> OccName
661 mkMethodOcc occ@(OccName VarName _) = occ
662 mkMethodOcc occ = mk_simple_deriv varName "$m" occ
666 %************************************************************************
668 \subsection{Tidying them up}
670 %************************************************************************
672 Before we print chunks of code we like to rename it so that
673 we don't have to print lots of silly uniques in it. But we mustn't
674 accidentally introduce name clashes! So the idea is that we leave the
675 OccName alone unless it accidentally clashes with one that is already
676 in scope; if so, we tack on '1' at the end and try again, then '2', and
677 so on till we find a unique one.
679 There's a wrinkle for operators. Consider '>>='. We can't use '>>=1'
680 because that isn't a single lexeme. So we encode it to 'lle' and *then*
681 tack on the '1', if necessary.
684 type TidyOccEnv = OccEnv Int -- The in-scope OccNames
685 -- Range gives a plausible starting point for new guesses
687 emptyTidyOccEnv :: TidyOccEnv
688 emptyTidyOccEnv = emptyOccEnv
690 initTidyOccEnv :: [OccName] -> TidyOccEnv -- Initialise with names to avoid!
691 initTidyOccEnv = foldl (\env occ -> extendOccEnv env occ 1) emptyTidyOccEnv
693 tidyOccName :: TidyOccEnv -> OccName -> (TidyOccEnv, OccName)
695 tidyOccName in_scope occ@(OccName occ_sp fs)
696 = case lookupOccEnv in_scope occ of
697 Nothing -> -- Not already used: make it used
698 (extendOccEnv in_scope occ 1, occ)
700 Just n -> -- Already used: make a new guess,
701 -- change the guess base, and try again
702 tidyOccName (extendOccEnv in_scope occ (n+1))
703 (mkOccName occ_sp (unpackFS fs ++ show n))
706 %************************************************************************
708 Stuff for dealing with tuples
710 %************************************************************************
713 mkTupleOcc :: NameSpace -> Boxity -> Arity -> OccName
714 mkTupleOcc ns bx ar = OccName ns (mkFastString str)
716 -- no need to cache these, the caching is done in the caller
717 -- (TysWiredIn.mk_tuple)
719 Boxed -> '(' : commas ++ ")"
720 Unboxed -> '(' : '#' : commas ++ "#)"
722 commas = take (ar-1) (repeat ',')
724 isTupleOcc_maybe :: OccName -> Maybe (NameSpace, Boxity, Arity)
725 -- Tuples are special, because there are so many of them!
726 isTupleOcc_maybe (OccName ns fs)
727 = case unpackFS fs of
728 '(':'#':',':rest -> Just (ns, Unboxed, 2 + count_commas rest)
729 '(':',':rest -> Just (ns, Boxed, 2 + count_commas rest)
732 count_commas (',':rest) = 1 + count_commas rest
736 %************************************************************************
738 \subsection{Lexical categories}
740 %************************************************************************
742 These functions test strings to see if they fit the lexical categories
743 defined in the Haskell report.
746 isLexCon, isLexVar, isLexId, isLexSym :: FastString -> Bool
747 isLexConId, isLexConSym, isLexVarId, isLexVarSym :: FastString -> Bool
749 isLexCon cs = isLexConId cs || isLexConSym cs
750 isLexVar cs = isLexVarId cs || isLexVarSym cs
752 isLexId cs = isLexConId cs || isLexVarId cs
753 isLexSym cs = isLexConSym cs || isLexVarSym cs
757 isLexConId cs -- Prefix type or data constructors
758 | nullFS cs = False -- e.g. "Foo", "[]", "(,)"
759 | cs == (fsLit "[]") = True
760 | otherwise = startsConId (headFS cs)
762 isLexVarId cs -- Ordinary prefix identifiers
763 | nullFS cs = False -- e.g. "x", "_x"
764 | otherwise = startsVarId (headFS cs)
766 isLexConSym cs -- Infix type or data constructors
767 | nullFS cs = False -- e.g. ":-:", ":", "->"
768 | cs == (fsLit "->") = True
769 | otherwise = startsConSym (headFS cs)
771 isLexVarSym cs -- Infix identifiers
772 | nullFS cs = False -- e.g. "+"
773 | otherwise = startsVarSym (headFS cs)
776 startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool
777 startsVarSym c = isSymbolASCII c || (ord c > 0x7f && isSymbol c) -- Infix Ids
778 startsConSym c = c == ':' -- Infix data constructors
779 startsVarId c = isLower c || c == '_' -- Ordinary Ids
780 startsConId c = isUpper c || c == '(' -- Ordinary type constructors and data constructors
782 isSymbolASCII :: Char -> Bool
783 isSymbolASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-"
786 %************************************************************************
789 Here rather than BinIface because OccName is abstract
791 %************************************************************************
794 instance Binary NameSpace where
797 put_ bh DataName = do
801 put_ bh TcClsName = do
806 0 -> do return VarName
807 1 -> do return DataName
808 2 -> do return TvName
809 _ -> do return TcClsName
811 instance Binary OccName where
812 put_ bh (OccName aa ab) = do
818 return (OccName aa ab)