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, 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
109 -- Unicode TODO: put isSymbol in libcompat
110 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
112 isSymbol :: a -> Bool
113 isSymbol = const False
118 %************************************************************************
120 \subsection{Name space}
122 %************************************************************************
125 data NameSpace = VarName -- Variables, including "real" data constructors
126 | DataName -- "Source" data constructors
127 | TvName -- Type variables
128 | TcClsName -- Type constructors and classes; Haskell has them
129 -- in the same name space for now.
131 {-! derive: Binary !-}
133 -- Note [Data Constructors]
134 -- see also: Note [Data Constructor Naming] in DataCon.lhs
136 -- $real_vs_source_data_constructors
137 -- There are two forms of data constructor:
139 -- [Source data constructors] The data constructors mentioned in Haskell source code
141 -- [Real data constructors] The data constructors of the representation type, which may not be the same as the source type
145 -- > data T = T !(Int, Int)
147 -- The source datacon has type @(Int, Int) -> T@
148 -- The real datacon has type @Int -> Int -> T@
150 -- GHC chooses a representation based on the strictness etc.
152 tcName, clsName, tcClsName :: NameSpace
153 dataName, srcDataName :: NameSpace
154 tvName, varName :: NameSpace
156 -- Though type constructors and classes are in the same name space now,
157 -- the NameSpace type is abstract, so we can easily separate them later
158 tcName = TcClsName -- Type constructors
159 clsName = TcClsName -- Classes
160 tcClsName = TcClsName -- Not sure which!
163 srcDataName = DataName -- Haskell-source data constructors should be
164 -- in the Data name space
169 isDataConNameSpace :: NameSpace -> Bool
170 isDataConNameSpace DataName = True
171 isDataConNameSpace _ = False
173 isTcClsNameSpace :: NameSpace -> Bool
174 isTcClsNameSpace TcClsName = True
175 isTcClsNameSpace _ = False
177 isTvNameSpace :: NameSpace -> Bool
178 isTvNameSpace TvName = True
179 isTvNameSpace _ = False
181 isVarNameSpace :: NameSpace -> Bool -- Variables or type variables, but not constructors
182 isVarNameSpace TvName = True
183 isVarNameSpace VarName = True
184 isVarNameSpace _ = False
186 isValNameSpace :: NameSpace -> Bool
187 isValNameSpace DataName = True
188 isValNameSpace VarName = True
189 isValNameSpace _ = False
191 pprNameSpace :: NameSpace -> SDoc
192 pprNameSpace DataName = ptext (sLit "data constructor")
193 pprNameSpace VarName = ptext (sLit "variable")
194 pprNameSpace TvName = ptext (sLit "type variable")
195 pprNameSpace TcClsName = ptext (sLit "type constructor or class")
197 pprNonVarNameSpace :: NameSpace -> SDoc
198 pprNonVarNameSpace VarName = empty
199 pprNonVarNameSpace ns = pprNameSpace ns
201 pprNameSpaceBrief :: NameSpace -> SDoc
202 pprNameSpaceBrief DataName = char 'd'
203 pprNameSpaceBrief VarName = char 'v'
204 pprNameSpaceBrief TvName = ptext (sLit "tv")
205 pprNameSpaceBrief TcClsName = ptext (sLit "tc")
209 %************************************************************************
211 \subsection[Name-pieces-datatypes]{The @OccName@ datatypes}
213 %************************************************************************
216 data OccName = OccName
217 { occNameSpace :: !NameSpace
218 , occNameFS :: !FastString
224 instance Eq OccName where
225 (OccName sp1 s1) == (OccName sp2 s2) = s1 == s2 && sp1 == sp2
227 instance Ord OccName where
228 -- Compares lexicographically, *not* by Unique of the string
229 compare (OccName sp1 s1) (OccName sp2 s2)
230 = (s1 `compare` s2) `thenCmp` (sp1 `compare` sp2)
234 %************************************************************************
236 \subsection{Printing}
238 %************************************************************************
241 instance Outputable OccName where
244 pprOccName :: OccName -> SDoc
245 pprOccName (OccName sp occ)
246 = getPprStyle $ \ sty ->
248 then ftext (zEncodeFS occ)
249 else ftext occ <> if debugStyle sty
250 then braces (pprNameSpaceBrief sp)
255 %************************************************************************
257 \subsection{Construction}
259 %************************************************************************
262 mkOccName :: NameSpace -> String -> OccName
263 mkOccName occ_sp str = OccName occ_sp (mkFastString str)
265 mkOccNameFS :: NameSpace -> FastString -> OccName
266 mkOccNameFS occ_sp fs = OccName occ_sp fs
268 mkVarOcc :: String -> OccName
269 mkVarOcc s = mkOccName varName s
271 mkVarOccFS :: FastString -> OccName
272 mkVarOccFS fs = mkOccNameFS varName fs
274 mkDataOcc :: String -> OccName
275 mkDataOcc = mkOccName dataName
277 mkDataOccFS :: FastString -> OccName
278 mkDataOccFS = mkOccNameFS dataName
280 mkTyVarOcc :: String -> OccName
281 mkTyVarOcc = mkOccName tvName
283 mkTyVarOccFS :: FastString -> OccName
284 mkTyVarOccFS fs = mkOccNameFS tvName fs
286 mkTcOcc :: String -> OccName
287 mkTcOcc = mkOccName tcName
289 mkTcOccFS :: FastString -> OccName
290 mkTcOccFS = mkOccNameFS tcName
292 mkClsOcc :: String -> OccName
293 mkClsOcc = mkOccName clsName
295 mkClsOccFS :: FastString -> OccName
296 mkClsOccFS = mkOccNameFS clsName
300 %************************************************************************
304 %************************************************************************
306 OccEnvs are used mainly for the envts in ModIfaces.
308 They are efficient, because FastStrings have unique Int# keys. We assume
309 this key is less than 2^24, so we can make a Unique using
310 mkUnique ns key :: Unique
311 where 'ns' is a Char reprsenting the name space. This in turn makes it
312 easy to build an OccEnv.
315 instance Uniquable OccName where
316 getUnique (OccName ns fs)
317 = mkUnique char (iBox (uniqueOfFS fs))
318 where -- See notes above about this getUnique function
325 newtype OccEnv a = A (UniqFM a)
327 emptyOccEnv :: OccEnv a
328 unitOccEnv :: OccName -> a -> OccEnv a
329 extendOccEnv :: OccEnv a -> OccName -> a -> OccEnv a
330 extendOccEnvList :: OccEnv a -> [(OccName, a)] -> OccEnv a
331 lookupOccEnv :: OccEnv a -> OccName -> Maybe a
332 mkOccEnv :: [(OccName,a)] -> OccEnv a
333 mkOccEnv_C :: (a -> a -> a) -> [(OccName,a)] -> OccEnv a
334 elemOccEnv :: OccName -> OccEnv a -> Bool
335 foldOccEnv :: (a -> b -> b) -> b -> OccEnv a -> b
336 occEnvElts :: OccEnv a -> [a]
337 extendOccEnv_C :: (a->a->a) -> OccEnv a -> OccName -> a -> OccEnv a
338 plusOccEnv :: OccEnv a -> OccEnv a -> OccEnv a
339 plusOccEnv_C :: (a->a->a) -> OccEnv a -> OccEnv a -> OccEnv a
340 mapOccEnv :: (a->b) -> OccEnv a -> OccEnv b
341 delFromOccEnv :: OccEnv a -> OccName -> OccEnv a
342 delListFromOccEnv :: OccEnv a -> [OccName] -> OccEnv a
343 filterOccEnv :: (elt -> Bool) -> OccEnv elt -> OccEnv elt
345 emptyOccEnv = A emptyUFM
346 unitOccEnv x y = A $ unitUFM x y
347 extendOccEnv (A x) y z = A $ addToUFM x y z
348 extendOccEnvList (A x) l = A $ addListToUFM x l
349 lookupOccEnv (A x) y = lookupUFM x y
350 mkOccEnv l = A $ listToUFM l
351 elemOccEnv x (A y) = elemUFM x y
352 foldOccEnv a b (A c) = foldUFM a b c
353 occEnvElts (A x) = eltsUFM x
354 plusOccEnv (A x) (A y) = A $ plusUFM x y
355 plusOccEnv_C f (A x) (A y) = A $ plusUFM_C f x y
356 extendOccEnv_C f (A x) y z = A $ addToUFM_C f x y z
357 mapOccEnv f (A x) = A $ mapUFM f x
358 mkOccEnv_C comb l = A $ addListToUFM_C comb emptyUFM l
359 delFromOccEnv (A x) y = A $ delFromUFM x y
360 delListFromOccEnv (A x) y = A $ delListFromUFM x y
361 filterOccEnv x (A y) = A $ filterUFM x y
363 instance Outputable a => Outputable (OccEnv a) where
366 type OccSet = UniqSet OccName
368 emptyOccSet :: OccSet
369 unitOccSet :: OccName -> OccSet
370 mkOccSet :: [OccName] -> OccSet
371 extendOccSet :: OccSet -> OccName -> OccSet
372 extendOccSetList :: OccSet -> [OccName] -> OccSet
373 unionOccSets :: OccSet -> OccSet -> OccSet
374 unionManyOccSets :: [OccSet] -> OccSet
375 minusOccSet :: OccSet -> OccSet -> OccSet
376 elemOccSet :: OccName -> OccSet -> Bool
377 occSetElts :: OccSet -> [OccName]
378 foldOccSet :: (OccName -> b -> b) -> b -> OccSet -> b
379 isEmptyOccSet :: OccSet -> Bool
380 intersectOccSet :: OccSet -> OccSet -> OccSet
381 intersectsOccSet :: OccSet -> OccSet -> Bool
383 emptyOccSet = emptyUniqSet
384 unitOccSet = unitUniqSet
386 extendOccSet = addOneToUniqSet
387 extendOccSetList = addListToUniqSet
388 unionOccSets = unionUniqSets
389 unionManyOccSets = unionManyUniqSets
390 minusOccSet = minusUniqSet
391 elemOccSet = elementOfUniqSet
392 occSetElts = uniqSetToList
393 foldOccSet = foldUniqSet
394 isEmptyOccSet = isEmptyUniqSet
395 intersectOccSet = intersectUniqSets
396 intersectsOccSet s1 s2 = not (isEmptyOccSet (s1 `intersectOccSet` s2))
400 %************************************************************************
402 \subsection{Predicates and taking them apart}
404 %************************************************************************
407 occNameString :: OccName -> String
408 occNameString (OccName _ s) = unpackFS s
410 setOccNameSpace :: NameSpace -> OccName -> OccName
411 setOccNameSpace sp (OccName _ occ) = OccName sp occ
413 isVarOcc, isTvOcc, isTcOcc, isDataOcc :: OccName -> Bool
415 isVarOcc (OccName VarName _) = True
418 isTvOcc (OccName TvName _) = True
421 isTcOcc (OccName TcClsName _) = True
424 -- | /Value/ 'OccNames's are those that are either in
425 -- the variable or data constructor namespaces
426 isValOcc :: OccName -> Bool
427 isValOcc (OccName VarName _) = True
428 isValOcc (OccName DataName _) = True
431 isDataOcc (OccName DataName _) = True
432 isDataOcc (OccName VarName s)
433 | isLexCon s = pprPanic "isDataOcc: check me" (ppr s)
434 -- Jan06: I don't think this should happen
437 -- | Test if the 'OccName' is a data constructor that starts with
438 -- a symbol (e.g. @:@, or @[]@)
439 isDataSymOcc :: OccName -> Bool
440 isDataSymOcc (OccName DataName s) = isLexConSym s
441 isDataSymOcc (OccName VarName s)
442 | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
443 -- Jan06: I don't think this should happen
444 isDataSymOcc _ = False
445 -- Pretty inefficient!
447 -- | Test if the 'OccName' is that for any operator (whether
448 -- it is a data constructor or variable or whatever)
449 isSymOcc :: OccName -> Bool
450 isSymOcc (OccName DataName s) = isLexConSym s
451 isSymOcc (OccName TcClsName s) = isLexConSym s
452 isSymOcc (OccName VarName s) = isLexSym s
453 isSymOcc (OccName TvName s) = isLexSym s
454 -- Pretty inefficient!
456 parenSymOcc :: OccName -> SDoc -> SDoc
457 -- ^ Wrap parens around an operator
458 parenSymOcc occ doc | isSymOcc occ = parens doc
464 startsWithUnderscore :: OccName -> Bool
465 -- ^ Haskell 98 encourages compilers to suppress warnings about unsed
466 -- names in a pattern if they start with @_@: this implements that test
467 startsWithUnderscore occ = case occNameString occ of
473 %************************************************************************
475 \subsection{Making system names}
477 %************************************************************************
479 Here's our convention for splitting up the interface file name space:
481 d... dictionary identifiers
482 (local variables, so no name-clash worries)
484 All of these other OccNames contain a mixture of alphabetic
485 and symbolic characters, and hence cannot possibly clash with
486 a user-written type or function name
488 $f... Dict-fun identifiers (from inst decls)
489 $dmop Default method for 'op'
490 $pnC n'th superclass selector for class C
491 $wf Worker for functtoin 'f'
492 $sf.. Specialised version of f
493 T:C Tycon for dictionary for class C
494 D:C Data constructor for dictionary for class C
495 NTCo:T Coercion connecting newtype T with its representation type
496 TFCo:R Coercion connecting a data family to its respresentation type R
498 In encoded form these appear as Zdfxxx etc
500 :... keywords (export:, letrec: etc.)
501 --- I THINK THIS IS WRONG!
503 This knowledge is encoded in the following functions.
505 @mk_deriv@ generates an @OccName@ from the prefix and a string.
506 NB: The string must already be encoded!
509 mk_deriv :: NameSpace
510 -> String -- Distinguishes one sort of derived name from another
514 mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str)
516 isDerivedOccName :: OccName -> Bool
517 isDerivedOccName occ =
518 case occNameString occ of
519 '$':c:_ | isAlphaNum c -> True
520 ':':c:_ | isAlphaNum c -> True
525 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc, mkDerivedTyConOcc,
526 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
527 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
528 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc,
529 mkInstTyCoOcc, mkEqPredCoOcc,
530 mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
531 mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
532 mkPArrayTyConOcc, mkPArrayDataConOcc, mkPReprTyConOcc, mkPADFunOcc
533 :: OccName -> OccName
535 -- These derived variables have a prefix that no Haskell value could have
536 mkDataConWrapperOcc = mk_simple_deriv varName "$W"
537 mkWorkerOcc = mk_simple_deriv varName "$w"
538 mkDefaultMethodOcc = mk_simple_deriv varName "$dm"
539 mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies
540 mkClassTyConOcc = mk_simple_deriv tcName "T:" -- as a tycon/datacon
541 mkClassDataConOcc = mk_simple_deriv dataName "D:" -- We go straight to the "real" data con
542 -- for datacons from classes
543 mkDictOcc = mk_simple_deriv varName "$d"
544 mkIPOcc = mk_simple_deriv varName "$i"
545 mkSpecOcc = mk_simple_deriv varName "$s"
546 mkForeignExportOcc = mk_simple_deriv varName "$f"
547 mkNewTyCoOcc = mk_simple_deriv tcName "NTCo:" -- Coercion for newtypes
548 mkInstTyCoOcc = mk_simple_deriv tcName "TFCo:" -- Coercion for type functions
549 mkEqPredCoOcc = mk_simple_deriv tcName "$co"
551 -- used in derived instances
552 mkCon2TagOcc = mk_simple_deriv varName "$con2tag_"
553 mkTag2ConOcc = mk_simple_deriv varName "$tag2con_"
554 mkMaxTagOcc = mk_simple_deriv varName "$maxtag_"
556 -- Generic derivable classes
557 mkGenOcc1 = mk_simple_deriv varName "$gfrom"
558 mkGenOcc2 = mk_simple_deriv varName "$gto"
560 -- data T = MkT ... deriving( Data ) needs defintions for
561 -- $tT :: Data.Generics.Basics.DataType
562 -- $cMkT :: Data.Generics.Basics.Constr
563 mkDataTOcc = mk_simple_deriv varName "$t"
564 mkDataCOcc = mk_simple_deriv varName "$c"
567 mkVectOcc = mk_simple_deriv varName "$v_"
568 mkVectTyConOcc = mk_simple_deriv tcName ":V_"
569 mkVectDataConOcc = mk_simple_deriv dataName ":VD_"
570 mkVectIsoOcc = mk_simple_deriv varName "$VI_"
571 mkPArrayTyConOcc = mk_simple_deriv tcName ":VP_"
572 mkPArrayDataConOcc = mk_simple_deriv dataName ":VPD_"
573 mkPReprTyConOcc = mk_simple_deriv tcName ":VR_"
574 mkPADFunOcc = mk_simple_deriv varName "$PA_"
576 mk_simple_deriv :: NameSpace -> String -> OccName -> OccName
577 mk_simple_deriv sp px occ = mk_deriv sp px (occNameString occ)
579 -- Data constructor workers are made by setting the name space
580 -- of the data constructor OccName (which should be a DataName)
582 mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ
586 mkSuperDictSelOcc :: Int -- ^ Index of superclass, e.g. 3
587 -> OccName -- ^ Class, e.g. @Ord@
588 -> OccName -- ^ Derived 'Occname', e.g. @$p3Ord@
589 mkSuperDictSelOcc index cls_occ
590 = mk_deriv varName "$p" (show index ++ occNameString cls_occ)
592 mkLocalOcc :: Unique -- ^ Unique to combine with the 'OccName'
593 -> OccName -- ^ Local name, e.g. @sat@
594 -> OccName -- ^ Nice unique version, e.g. @$L23sat@
596 = mk_deriv varName ("$L" ++ show uniq) (occNameString occ)
597 -- The Unique might print with characters
598 -- that need encoding (e.g. 'z'!)
602 -- | Derive a name for the representation type constructor of a
603 -- @data@\/@newtype@ instance.
604 mkInstTyTcOcc :: Int -- ^ DFun Index
605 -> OccName -- ^ Family name, e.g. @Map@
606 -> OccName -- ^ Nice unique version, e.g. @:R23Map@
607 mkInstTyTcOcc index occ
608 = mk_deriv tcName ("R" ++ show index ++ ":") (occNameString occ)
612 mkDFunOcc :: String -- ^ Typically the class and type glommed together e.g. @OrdMaybe@.
613 -- Only used in debug mode, for extra clarity
614 -> Bool -- ^ Is this a hs-boot instance DFun?
615 -> Int -- ^ Unique index
616 -> OccName -- ^ E.g. @$f3OrdMaybe@
618 -- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real
619 -- thing when we compile the mother module. Reason: we don't know exactly
620 -- what the mother module will call it.
622 mkDFunOcc info_str is_boot index
623 = mk_deriv VarName prefix string
625 prefix | is_boot = "$fx"
627 string | opt_PprStyle_Debug = show index ++ info_str
628 | otherwise = show index
631 We used to add a '$m' to indicate a method, but that gives rise to bad
632 error messages from the type checker when we print the function name or pattern
633 of an instance-decl binding. Why? Because the binding is zapped
634 to use the method name in place of the selector name.
635 (See TcClassDcl.tcMethodBind)
637 The way it is now, -ddump-xx output may look confusing, but
638 you can always say -dppr-debug to get the uniques.
640 However, we *do* have to zap the first character to be lower case,
641 because overloaded constructors (blarg) generate methods too.
642 And convert to VarName space
644 e.g. a call to constructor MkFoo where
645 data (Ord a) => Foo a = MkFoo a
647 If this is necessary, we do it by prefixing '$m'. These
648 guys never show up in error messages. What a hack.
651 mkMethodOcc :: OccName -> OccName
652 mkMethodOcc occ@(OccName VarName _) = occ
653 mkMethodOcc occ = mk_simple_deriv varName "$m" occ
657 %************************************************************************
659 \subsection{Tidying them up}
661 %************************************************************************
663 Before we print chunks of code we like to rename it so that
664 we don't have to print lots of silly uniques in it. But we mustn't
665 accidentally introduce name clashes! So the idea is that we leave the
666 OccName alone unless it accidentally clashes with one that is already
667 in scope; if so, we tack on '1' at the end and try again, then '2', and
668 so on till we find a unique one.
670 There's a wrinkle for operators. Consider '>>='. We can't use '>>=1'
671 because that isn't a single lexeme. So we encode it to 'lle' and *then*
672 tack on the '1', if necessary.
675 type TidyOccEnv = OccEnv Int -- The in-scope OccNames
676 -- Range gives a plausible starting point for new guesses
678 emptyTidyOccEnv :: TidyOccEnv
679 emptyTidyOccEnv = emptyOccEnv
681 initTidyOccEnv :: [OccName] -> TidyOccEnv -- Initialise with names to avoid!
682 initTidyOccEnv = foldl (\env occ -> extendOccEnv env occ 1) emptyTidyOccEnv
684 tidyOccName :: TidyOccEnv -> OccName -> (TidyOccEnv, OccName)
686 tidyOccName in_scope occ@(OccName occ_sp fs)
687 = case lookupOccEnv in_scope occ of
688 Nothing -> -- Not already used: make it used
689 (extendOccEnv in_scope occ 1, occ)
691 Just n -> -- Already used: make a new guess,
692 -- change the guess base, and try again
693 tidyOccName (extendOccEnv in_scope occ (n+1))
694 (mkOccName occ_sp (unpackFS fs ++ show n))
697 %************************************************************************
699 Stuff for dealing with tuples
701 %************************************************************************
704 mkTupleOcc :: NameSpace -> Boxity -> Arity -> OccName
705 mkTupleOcc ns bx ar = OccName ns (mkFastString str)
707 -- no need to cache these, the caching is done in the caller
708 -- (TysWiredIn.mk_tuple)
710 Boxed -> '(' : commas ++ ")"
711 Unboxed -> '(' : '#' : commas ++ "#)"
713 commas = take (ar-1) (repeat ',')
715 isTupleOcc_maybe :: OccName -> Maybe (NameSpace, Boxity, Arity)
716 -- Tuples are special, because there are so many of them!
717 isTupleOcc_maybe (OccName ns fs)
718 = case unpackFS fs of
719 '(':'#':',':rest -> Just (ns, Unboxed, 2 + count_commas rest)
720 '(':',':rest -> Just (ns, Boxed, 2 + count_commas rest)
723 count_commas (',':rest) = 1 + count_commas rest
727 %************************************************************************
729 \subsection{Lexical categories}
731 %************************************************************************
733 These functions test strings to see if they fit the lexical categories
734 defined in the Haskell report.
737 isLexCon, isLexVar, isLexId, isLexSym :: FastString -> Bool
738 isLexConId, isLexConSym, isLexVarId, isLexVarSym :: FastString -> Bool
740 isLexCon cs = isLexConId cs || isLexConSym cs
741 isLexVar cs = isLexVarId cs || isLexVarSym cs
743 isLexId cs = isLexConId cs || isLexVarId cs
744 isLexSym cs = isLexConSym cs || isLexVarSym cs
748 isLexConId cs -- Prefix type or data constructors
749 | nullFS cs = False -- e.g. "Foo", "[]", "(,)"
750 | cs == (fsLit "[]") = True
751 | otherwise = startsConId (headFS cs)
753 isLexVarId cs -- Ordinary prefix identifiers
754 | nullFS cs = False -- e.g. "x", "_x"
755 | otherwise = startsVarId (headFS cs)
757 isLexConSym cs -- Infix type or data constructors
758 | nullFS cs = False -- e.g. ":-:", ":", "->"
759 | cs == (fsLit "->") = True
760 | otherwise = startsConSym (headFS cs)
762 isLexVarSym cs -- Infix identifiers
763 | nullFS cs = False -- e.g. "+"
764 | otherwise = startsVarSym (headFS cs)
767 startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool
768 startsVarSym c = isSymbolASCII c || (ord c > 0x7f && isSymbol c) -- Infix Ids
769 startsConSym c = c == ':' -- Infix data constructors
770 startsVarId c = isLower c || c == '_' -- Ordinary Ids
771 startsConId c = isUpper c || c == '(' -- Ordinary type constructors and data constructors
773 isSymbolASCII :: Char -> Bool
774 isSymbolASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-"
777 %************************************************************************
780 Here rather than BinIface because OccName is abstract
782 %************************************************************************
785 instance Binary NameSpace where
788 put_ bh DataName = do
792 put_ bh TcClsName = do
797 0 -> do return VarName
798 1 -> do return DataName
799 2 -> do return TvName
800 _ -> do return TcClsName
802 instance Binary OccName where
803 put_ bh (OccName aa ab) = do
809 return (OccName aa ab)