2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
8 -- * The NameSpace type; abstact
9 NameSpace, tcName, clsName, tcClsName, dataName, varName,
13 pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief,
16 OccName, -- Abstract, instance of Outputable
20 mkOccName, mkOccNameFS,
27 -- ** Derived OccNames
28 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc,
29 mkDerivedTyConOcc, mkNewTyCoOcc,
30 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
31 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
32 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc,
33 mkSuperDictSelOcc, mkLocalOcc, mkMethodOcc, mkInstTyTcOcc,
37 occNameFS, occNameString, occNameSpace,
39 isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,
40 parenSymOcc, reportIfUnused, isTcClsName, isVarName,
45 OccEnv, emptyOccEnv, unitOccEnv, extendOccEnv, mapOccEnv,
46 lookupOccEnv, mkOccEnv, extendOccEnvList, elemOccEnv,
47 occEnvElts, foldOccEnv, plusOccEnv, plusOccEnv_C, extendOccEnv_C,
50 OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet,
52 unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts,
53 foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet,
56 TidyOccEnv, emptyTidyOccEnv, tidyOccName, initTidyOccEnv,
58 -- The basic form of names
59 isLexCon, isLexVar, isLexId, isLexSym,
60 isLexConId, isLexConSym, isLexVarId, isLexVarSym,
61 startsVarSym, startsVarId, startsConSym, startsConId
64 #include "HsVersions.h"
79 -- Unicode TODO: put isSymbol in libcompat
80 #if __GLASGOW_HASKELL__ > 604
81 import Data.Char ( isSymbol )
83 isSymbol = const False
88 %************************************************************************
90 \subsection{Name space}
92 %************************************************************************
95 data NameSpace = VarName -- Variables, including "source" data constructors
96 | DataName -- "Real" data constructors
97 | TvName -- Type variables
98 | TcClsName -- Type constructors and classes; Haskell has them
99 -- in the same name space for now.
101 {-! derive: Binary !-}
103 -- Note [Data Constructors]
104 -- see also: Note [Data Constructor Naming] in DataCon.lhs
106 -- "Source" data constructors are the data constructors mentioned
107 -- in Haskell source code
109 -- "Real" data constructors are the data constructors of the
110 -- representation type, which may not be the same as the source
114 -- data T = T !(Int,Int)
116 -- The source datacon has type (Int,Int) -> T
117 -- The real datacon has type Int -> Int -> T
118 -- GHC chooses a representation based on the strictness etc.
121 -- Though type constructors and classes are in the same name space now,
122 -- the NameSpace type is abstract, so we can easily separate them later
123 tcName = TcClsName -- Type constructors
124 clsName = TcClsName -- Classes
125 tcClsName = TcClsName -- Not sure which!
128 srcDataName = DataName -- Haskell-source data constructors should be
129 -- in the Data name space
134 isTcClsName :: NameSpace -> Bool
135 isTcClsName TcClsName = True
136 isTcClsName _ = False
138 isVarName :: NameSpace -> Bool -- Variables or type variables, but not constructors
139 isVarName TvName = True
140 isVarName VarName = True
141 isVarName other = False
143 pprNameSpace :: NameSpace -> SDoc
144 pprNameSpace DataName = ptext SLIT("data constructor")
145 pprNameSpace VarName = ptext SLIT("variable")
146 pprNameSpace TvName = ptext SLIT("type variable")
147 pprNameSpace TcClsName = ptext SLIT("type constructor or class")
149 pprNonVarNameSpace :: NameSpace -> SDoc
150 pprNonVarNameSpace VarName = empty
151 pprNonVarNameSpace ns = pprNameSpace ns
153 pprNameSpaceBrief DataName = char 'd'
154 pprNameSpaceBrief VarName = char 'v'
155 pprNameSpaceBrief TvName = ptext SLIT("tv")
156 pprNameSpaceBrief TcClsName = ptext SLIT("tc")
160 %************************************************************************
162 \subsection[Name-pieces-datatypes]{The @OccName@ datatypes}
164 %************************************************************************
167 data OccName = OccName
168 { occNameSpace :: !NameSpace
169 , occNameFS :: !FastString
175 instance Eq OccName where
176 (OccName sp1 s1) == (OccName sp2 s2) = s1 == s2 && sp1 == sp2
178 instance Ord OccName where
179 compare (OccName sp1 s1) (OccName sp2 s2) = (s1 `compare` s2) `thenCmp`
184 %************************************************************************
186 \subsection{Printing}
188 %************************************************************************
191 instance Outputable OccName where
194 pprOccName :: OccName -> SDoc
195 pprOccName (OccName sp occ)
196 = getPprStyle $ \ sty ->
198 then ftext (zEncodeFS occ)
199 else ftext occ <> if debugStyle sty
200 then braces (pprNameSpaceBrief sp)
205 %************************************************************************
207 \subsection{Construction}
209 %************************************************************************
212 mkOccName :: NameSpace -> String -> OccName
213 mkOccName occ_sp str = OccName occ_sp (mkFastString str)
215 mkOccNameFS :: NameSpace -> FastString -> OccName
216 mkOccNameFS occ_sp fs = OccName occ_sp fs
218 mkVarOcc :: String -> OccName
219 mkVarOcc s = mkOccName varName s
221 mkVarOccFS :: FastString -> OccName
222 mkVarOccFS fs = mkOccNameFS varName fs
224 mkTyVarOcc :: FastString -> OccName
225 mkTyVarOcc fs = mkOccNameFS tvName fs
229 %************************************************************************
233 %************************************************************************
235 OccEnvs are used mainly for the envts in ModIfaces.
237 They are efficient, because FastStrings have unique Int# keys. We assume
238 this key is less than 2^24, so we can make a Unique using
239 mkUnique ns key :: Unique
240 where 'ns' is a Char reprsenting the name space. This in turn makes it
241 easy to build an OccEnv.
244 instance Uniquable OccName where
245 getUnique (OccName ns fs)
246 = mkUnique char (I# (uniqueOfFS fs))
247 where -- See notes above about this getUnique function
254 type OccEnv a = UniqFM a
256 emptyOccEnv :: OccEnv a
257 unitOccEnv :: OccName -> a -> OccEnv a
258 extendOccEnv :: OccEnv a -> OccName -> a -> OccEnv a
259 extendOccEnvList :: OccEnv a -> [(OccName, a)] -> OccEnv a
260 lookupOccEnv :: OccEnv a -> OccName -> Maybe a
261 mkOccEnv :: [(OccName,a)] -> OccEnv a
262 elemOccEnv :: OccName -> OccEnv a -> Bool
263 foldOccEnv :: (a -> b -> b) -> b -> OccEnv a -> b
264 occEnvElts :: OccEnv a -> [a]
265 extendOccEnv_C :: (a->a->a) -> OccEnv a -> OccName -> a -> OccEnv a
266 plusOccEnv :: OccEnv a -> OccEnv a -> OccEnv a
267 plusOccEnv_C :: (a->a->a) -> OccEnv a -> OccEnv a -> OccEnv a
268 mapOccEnv :: (a->b) -> OccEnv a -> OccEnv b
270 emptyOccEnv = emptyUFM
272 extendOccEnv = addToUFM
273 extendOccEnvList = addListToUFM
274 lookupOccEnv = lookupUFM
280 plusOccEnv_C = plusUFM_C
281 extendOccEnv_C = addToUFM_C
284 type OccSet = UniqFM OccName
286 emptyOccSet :: OccSet
287 unitOccSet :: OccName -> OccSet
288 mkOccSet :: [OccName] -> OccSet
289 extendOccSet :: OccSet -> OccName -> OccSet
290 extendOccSetList :: OccSet -> [OccName] -> OccSet
291 unionOccSets :: OccSet -> OccSet -> OccSet
292 unionManyOccSets :: [OccSet] -> OccSet
293 minusOccSet :: OccSet -> OccSet -> OccSet
294 elemOccSet :: OccName -> OccSet -> Bool
295 occSetElts :: OccSet -> [OccName]
296 foldOccSet :: (OccName -> b -> b) -> b -> OccSet -> b
297 isEmptyOccSet :: OccSet -> Bool
298 intersectOccSet :: OccSet -> OccSet -> OccSet
299 intersectsOccSet :: OccSet -> OccSet -> Bool
301 emptyOccSet = emptyUniqSet
302 unitOccSet = unitUniqSet
304 extendOccSet = addOneToUniqSet
305 extendOccSetList = addListToUniqSet
306 unionOccSets = unionUniqSets
307 unionManyOccSets = unionManyUniqSets
308 minusOccSet = minusUniqSet
309 elemOccSet = elementOfUniqSet
310 occSetElts = uniqSetToList
311 foldOccSet = foldUniqSet
312 isEmptyOccSet = isEmptyUniqSet
313 intersectOccSet = intersectUniqSets
314 intersectsOccSet s1 s2 = not (isEmptyOccSet (s1 `intersectOccSet` s2))
318 %************************************************************************
320 \subsection{Predicates and taking them apart}
322 %************************************************************************
325 occNameString :: OccName -> String
326 occNameString (OccName _ s) = unpackFS s
328 setOccNameSpace :: NameSpace -> OccName -> OccName
329 setOccNameSpace sp (OccName _ occ) = OccName sp occ
331 isVarOcc, isTvOcc, isDataSymOcc, isSymOcc, isTcOcc :: OccName -> Bool
333 isVarOcc (OccName VarName _) = True
334 isVarOcc other = False
336 isTvOcc (OccName TvName _) = True
337 isTvOcc other = False
339 isTcOcc (OccName TcClsName _) = True
340 isTcOcc other = False
342 isValOcc (OccName VarName _) = True
343 isValOcc (OccName DataName _) = True
344 isValOcc other = False
346 -- Data constructor operator (starts with ':', or '[]')
347 -- Pretty inefficient!
348 isDataSymOcc (OccName DataName s) = isLexConSym s
349 isDataSymOcc (OccName VarName s)
350 | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
351 -- Jan06: I don't think this should happen
352 isDataSymOcc other = False
354 isDataOcc (OccName DataName _) = True
355 isDataOcc (OccName VarName s)
356 | isLexCon s = pprPanic "isDataOcc: check me" (ppr s)
357 -- Jan06: I don't think this should happen
358 isDataOcc other = False
360 -- Any operator (data constructor or variable)
361 -- Pretty inefficient!
362 isSymOcc (OccName DataName s) = isLexConSym s
363 isSymOcc (OccName TcClsName s) = isLexConSym s
364 isSymOcc (OccName VarName s) = isLexSym s
365 isSymOcc other = False
367 parenSymOcc :: OccName -> SDoc -> SDoc
368 -- Wrap parens around an operator
369 parenSymOcc occ doc | isSymOcc occ = parens doc
375 reportIfUnused :: OccName -> Bool
376 -- Haskell 98 encourages compilers to suppress warnings about
377 -- unused names in a pattern if they start with "_".
378 reportIfUnused occ = case occNameString occ of
384 %************************************************************************
386 \subsection{Making system names}
388 %************************************************************************
390 Here's our convention for splitting up the interface file name space:
392 d... dictionary identifiers
393 (local variables, so no name-clash worries)
395 $f... dict-fun identifiers (from inst decls)
396 $dm... default methods
397 $p... superclass selectors
399 :T... compiler-generated tycons for dictionaries
400 :D... ...ditto data cons
401 $sf.. specialised version of f
403 in encoded form these appear as Zdfxxx etc
405 :... keywords (export:, letrec: etc.)
406 --- I THINK THIS IS WRONG!
408 This knowledge is encoded in the following functions.
411 @mk_deriv@ generates an @OccName@ from the prefix and a string.
412 NB: The string must already be encoded!
415 mk_deriv :: NameSpace
416 -> String -- Distinguishes one sort of derived name from another
420 mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str)
424 mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc, mkDerivedTyConOcc,
425 mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
426 mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
427 mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc
428 :: OccName -> OccName
430 -- These derived variables have a prefix that no Haskell value could have
431 mkDataConWrapperOcc = mk_simple_deriv varName "$W"
432 mkWorkerOcc = mk_simple_deriv varName "$w"
433 mkDefaultMethodOcc = mk_simple_deriv varName "$dm"
434 mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies
435 mkClassTyConOcc = mk_simple_deriv tcName ":T" -- as a tycon/datacon
436 mkClassDataConOcc = mk_simple_deriv dataName ":D" -- We go straight to the "real" data con
437 -- for datacons from classes
438 mkDictOcc = mk_simple_deriv varName "$d"
439 mkIPOcc = mk_simple_deriv varName "$i"
440 mkSpecOcc = mk_simple_deriv varName "$s"
441 mkForeignExportOcc = mk_simple_deriv varName "$f"
442 mkNewTyCoOcc = mk_simple_deriv tcName ":Co"
443 mkInstTyCoOcc = mk_simple_deriv tcName ":Co" -- derived from rep ty
445 -- Generic derivable classes
446 mkGenOcc1 = mk_simple_deriv varName "$gfrom"
447 mkGenOcc2 = mk_simple_deriv varName "$gto"
449 -- data T = MkT ... deriving( Data ) needs defintions for
450 -- $tT :: Data.Generics.Basics.DataType
451 -- $cMkT :: Data.Generics.Basics.Constr
452 mkDataTOcc = mk_simple_deriv varName "$t"
453 mkDataCOcc = mk_simple_deriv varName "$c"
455 mk_simple_deriv sp px occ = mk_deriv sp px (occNameString occ)
457 -- Data constructor workers are made by setting the name space
458 -- of the data constructor OccName (which should be a DataName)
460 mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ
464 mkSuperDictSelOcc :: Int -- Index of superclass, eg 3
465 -> OccName -- Class, eg "Ord"
466 -> OccName -- eg "$p3Ord"
467 mkSuperDictSelOcc index cls_occ
468 = mk_deriv varName "$p" (show index ++ occNameString cls_occ)
470 mkLocalOcc :: Unique -- Unique
471 -> OccName -- Local name (e.g. "sat")
472 -> OccName -- Nice unique version ("$L23sat")
474 = mk_deriv varName ("$L" ++ show uniq) (occNameString occ)
475 -- The Unique might print with characters
476 -- that need encoding (e.g. 'z'!)
479 Derive a name for the representation type constructor of a data/newtype
483 mkInstTyTcOcc :: Int -- Index
484 -> OccName -- Family name (e.g. "Map")
485 -> OccName -- Nice unique version (":R23Map")
486 mkInstTyTcOcc index occ
487 = mk_deriv tcName (":R" ++ show index) (occNameString occ)
491 mkDFunOcc :: String -- Typically the class and type glommed together e.g. "OrdMaybe"
492 -- Only used in debug mode, for extra clarity
493 -> Bool -- True <=> hs-boot instance dfun
494 -> Int -- Unique index
495 -> OccName -- "$f3OrdMaybe"
497 -- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real
498 -- thing when we compile the mother module. Reason: we don't know exactly
499 -- what the mother module will call it.
501 mkDFunOcc info_str is_boot index
502 = mk_deriv VarName prefix string
504 prefix | is_boot = "$fx"
506 string | opt_PprStyle_Debug = show index ++ info_str
507 | otherwise = show index
510 We used to add a '$m' to indicate a method, but that gives rise to bad
511 error messages from the type checker when we print the function name or pattern
512 of an instance-decl binding. Why? Because the binding is zapped
513 to use the method name in place of the selector name.
514 (See TcClassDcl.tcMethodBind)
516 The way it is now, -ddump-xx output may look confusing, but
517 you can always say -dppr-debug to get the uniques.
519 However, we *do* have to zap the first character to be lower case,
520 because overloaded constructors (blarg) generate methods too.
521 And convert to VarName space
523 e.g. a call to constructor MkFoo where
524 data (Ord a) => Foo a = MkFoo a
526 If this is necessary, we do it by prefixing '$m'. These
527 guys never show up in error messages. What a hack.
530 mkMethodOcc :: OccName -> OccName
531 mkMethodOcc occ@(OccName VarName fs) = occ
532 mkMethodOcc occ = mk_simple_deriv varName "$m" occ
536 %************************************************************************
538 \subsection{Tidying them up}
540 %************************************************************************
542 Before we print chunks of code we like to rename it so that
543 we don't have to print lots of silly uniques in it. But we mustn't
544 accidentally introduce name clashes! So the idea is that we leave the
545 OccName alone unless it accidentally clashes with one that is already
546 in scope; if so, we tack on '1' at the end and try again, then '2', and
547 so on till we find a unique one.
549 There's a wrinkle for operators. Consider '>>='. We can't use '>>=1'
550 because that isn't a single lexeme. So we encode it to 'lle' and *then*
551 tack on the '1', if necessary.
554 type TidyOccEnv = OccEnv Int -- The in-scope OccNames
555 -- Range gives a plausible starting point for new guesses
557 emptyTidyOccEnv = emptyOccEnv
559 initTidyOccEnv :: [OccName] -> TidyOccEnv -- Initialise with names to avoid!
560 initTidyOccEnv = foldl (\env occ -> extendOccEnv env occ 1) emptyTidyOccEnv
562 tidyOccName :: TidyOccEnv -> OccName -> (TidyOccEnv, OccName)
564 tidyOccName in_scope occ@(OccName occ_sp fs)
565 = case lookupOccEnv in_scope occ of
566 Nothing -> -- Not already used: make it used
567 (extendOccEnv in_scope occ 1, occ)
569 Just n -> -- Already used: make a new guess,
570 -- change the guess base, and try again
571 tidyOccName (extendOccEnv in_scope occ (n+1))
572 (mkOccName occ_sp (unpackFS fs ++ show n))
575 %************************************************************************
577 Stuff for dealing with tuples
579 %************************************************************************
582 mkTupleOcc :: NameSpace -> Boxity -> Arity -> OccName
583 mkTupleOcc ns bx ar = OccName ns (mkFastString str)
585 -- no need to cache these, the caching is done in the caller
586 -- (TysWiredIn.mk_tuple)
588 Boxed -> '(' : commas ++ ")"
589 Unboxed -> '(' : '#' : commas ++ "#)"
591 commas = take (ar-1) (repeat ',')
593 isTupleOcc_maybe :: OccName -> Maybe (NameSpace, Boxity, Arity)
594 -- Tuples are special, because there are so many of them!
595 isTupleOcc_maybe (OccName ns fs)
596 = case unpackFS fs of
597 '(':'#':',':rest -> Just (ns, Unboxed, 2 + count_commas rest)
598 '(':',':rest -> Just (ns, Boxed, 2 + count_commas rest)
601 count_commas (',':rest) = 1 + count_commas rest
605 %************************************************************************
607 \subsection{Lexical categories}
609 %************************************************************************
611 These functions test strings to see if they fit the lexical categories
612 defined in the Haskell report.
615 isLexCon, isLexVar, isLexId, isLexSym :: FastString -> Bool
616 isLexConId, isLexConSym, isLexVarId, isLexVarSym :: FastString -> Bool
618 isLexCon cs = isLexConId cs || isLexConSym cs
619 isLexVar cs = isLexVarId cs || isLexVarSym cs
621 isLexId cs = isLexConId cs || isLexVarId cs
622 isLexSym cs = isLexConSym cs || isLexVarSym cs
626 isLexConId cs -- Prefix type or data constructors
627 | nullFS cs = False -- e.g. "Foo", "[]", "(,)"
628 | cs == FSLIT("[]") = True
629 | otherwise = startsConId (headFS cs)
631 isLexVarId cs -- Ordinary prefix identifiers
632 | nullFS cs = False -- e.g. "x", "_x"
633 | otherwise = startsVarId (headFS cs)
635 isLexConSym cs -- Infix type or data constructors
636 | nullFS cs = False -- e.g. ":-:", ":", "->"
637 | cs == FSLIT("->") = True
638 | otherwise = startsConSym (headFS cs)
640 isLexVarSym cs -- Infix identifiers
641 | nullFS cs = False -- e.g. "+"
642 | otherwise = startsVarSym (headFS cs)
645 startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool
646 startsVarSym c = isSymbolASCII c || (ord c > 0x7f && isSymbol c) -- Infix Ids
647 startsConSym c = c == ':' -- Infix data constructors
648 startsVarId c = isLower c || c == '_' -- Ordinary Ids
649 startsConId c = isUpper c || c == '(' -- Ordinary type constructors and data constructors
651 isSymbolASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-"
654 %************************************************************************
657 Here rather than BinIface because OccName is abstract
659 %************************************************************************
662 instance Binary NameSpace where
665 put_ bh DataName = do
669 put_ bh TcClsName = do
674 0 -> do return VarName
675 1 -> do return DataName
676 2 -> do return TvName
677 _ -> do return TcClsName
679 instance Binary OccName where
680 put_ bh (OccName aa ab) = do
686 return (OccName aa ab)