{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 -} {-# LANGUAGE DeriveDataTypeable #-} -- | -- #name_types# -- GHC uses several kinds of name internally: -- -- * 'OccName.OccName' represents names as strings with just a little more information: -- the \"namespace\" that the name came from, e.g. the namespace of value, type constructors or -- data constructors -- -- * 'RdrName.RdrName': see "RdrName#name_types" -- -- * 'Name.Name': see "Name#name_types" -- -- * 'Id.Id': see "Id#name_types" -- -- * 'Var.Var': see "Var#name_types" module OccName ( -- * The 'NameSpace' type NameSpace, -- Abstract nameSpacesRelated, -- ** Construction -- $real_vs_source_data_constructors tcName, clsName, tcClsName, dataName, varName, tvName, srcDataName, -- ** Pretty Printing pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief, -- * The 'OccName' type OccName, -- Abstract, instance of Outputable pprOccName, -- ** Construction mkOccName, mkOccNameFS, mkVarOcc, mkVarOccFS, mkDataOcc, mkDataOccFS, mkTyVarOcc, mkTyVarOccFS, mkTcOcc, mkTcOccFS, mkClsOcc, mkClsOccFS, mkDFunOcc, setOccNameSpace, demoteOccName, HasOccName(..), -- ** Derived 'OccName's isDerivedOccName, mkDataConWrapperOcc, mkWorkerOcc, mkMatcherOcc, mkBuilderOcc, mkDefaultMethodOcc, mkGenDefMethodOcc, mkDerivedTyConOcc, mkNewTyCoOcc, mkClassOpAuxOcc, mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc, mkSpecOcc, mkForeignExportOcc, mkRepEqOcc, mkGenOcc1, mkGenOcc2, mkGenD, mkGenR, mkGen1R, mkGenRCo, mkGenC, mkGenS, mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkSuperDictSelOcc, mkSuperDictAuxOcc, mkLocalOcc, mkMethodOcc, mkInstTyTcOcc, mkInstTyCoOcc, mkEqPredCoOcc, mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc, mkPDataTyConOcc, mkPDataDataConOcc, mkPDatasTyConOcc, mkPDatasDataConOcc, mkPReprTyConOcc, mkPADFunOcc, -- ** Deconstruction occNameFS, occNameString, occNameSpace, isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc, parenSymOcc, startsWithUnderscore, isTcClsNameSpace, isTvNameSpace, isDataConNameSpace, isVarNameSpace, isValNameSpace, -- * The 'OccEnv' type OccEnv, emptyOccEnv, unitOccEnv, extendOccEnv, mapOccEnv, lookupOccEnv, mkOccEnv, mkOccEnv_C, extendOccEnvList, elemOccEnv, occEnvElts, foldOccEnv, plusOccEnv, plusOccEnv_C, extendOccEnv_C, extendOccEnv_Acc, filterOccEnv, delListFromOccEnv, delFromOccEnv, alterOccEnv, pprOccEnv, -- * The 'OccSet' type OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet, extendOccSetList, unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts, foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet, -- * Tidying up TidyOccEnv, emptyTidyOccEnv, tidyOccName, initTidyOccEnv, -- FsEnv FastStringEnv, emptyFsEnv, lookupFsEnv, extendFsEnv, mkFsEnv ) where import Util import Unique import DynFlags import UniqFM import UniqSet import FastString import Outputable import Lexeme import Binary import Data.Char import Data.Data {- ************************************************************************ * * FastStringEnv * * ************************************************************************ FastStringEnv can't be in FastString because the env depends on UniqFM -} type FastStringEnv a = UniqFM a -- Keyed by FastString emptyFsEnv :: FastStringEnv a lookupFsEnv :: FastStringEnv a -> FastString -> Maybe a extendFsEnv :: FastStringEnv a -> FastString -> a -> FastStringEnv a mkFsEnv :: [(FastString,a)] -> FastStringEnv a emptyFsEnv = emptyUFM lookupFsEnv = lookupUFM extendFsEnv = addToUFM mkFsEnv = listToUFM {- ************************************************************************ * * \subsection{Name space} * * ************************************************************************ -} data NameSpace = VarName -- Variables, including "real" data constructors | DataName -- "Source" data constructors | TvName -- Type variables | TcClsName -- Type constructors and classes; Haskell has them -- in the same name space for now. deriving( Eq, Ord ) {-! derive: Binary !-} -- Note [Data Constructors] -- see also: Note [Data Constructor Naming] in DataCon.lhs -- -- $real_vs_source_data_constructors -- There are two forms of data constructor: -- -- [Source data constructors] The data constructors mentioned in Haskell source code -- -- [Real data constructors] The data constructors of the representation type, which may not be the same as the source type -- -- For example: -- -- > data T = T !(Int, Int) -- -- The source datacon has type @(Int, Int) -> T@ -- The real datacon has type @Int -> Int -> T@ -- -- GHC chooses a representation based on the strictness etc. tcName, clsName, tcClsName :: NameSpace dataName, srcDataName :: NameSpace tvName, varName :: NameSpace -- Though type constructors and classes are in the same name space now, -- the NameSpace type is abstract, so we can easily separate them later tcName = TcClsName -- Type constructors clsName = TcClsName -- Classes tcClsName = TcClsName -- Not sure which! dataName = DataName srcDataName = DataName -- Haskell-source data constructors should be -- in the Data name space tvName = TvName varName = VarName isDataConNameSpace :: NameSpace -> Bool isDataConNameSpace DataName = True isDataConNameSpace _ = False isTcClsNameSpace :: NameSpace -> Bool isTcClsNameSpace TcClsName = True isTcClsNameSpace _ = False isTvNameSpace :: NameSpace -> Bool isTvNameSpace TvName = True isTvNameSpace _ = False isVarNameSpace :: NameSpace -> Bool -- Variables or type variables, but not constructors isVarNameSpace TvName = True isVarNameSpace VarName = True isVarNameSpace _ = False isValNameSpace :: NameSpace -> Bool isValNameSpace DataName = True isValNameSpace VarName = True isValNameSpace _ = False pprNameSpace :: NameSpace -> SDoc pprNameSpace DataName = ptext (sLit "data constructor") pprNameSpace VarName = ptext (sLit "variable") pprNameSpace TvName = ptext (sLit "type variable") pprNameSpace TcClsName = ptext (sLit "type constructor or class") pprNonVarNameSpace :: NameSpace -> SDoc pprNonVarNameSpace VarName = empty pprNonVarNameSpace ns = pprNameSpace ns pprNameSpaceBrief :: NameSpace -> SDoc pprNameSpaceBrief DataName = char 'd' pprNameSpaceBrief VarName = char 'v' pprNameSpaceBrief TvName = ptext (sLit "tv") pprNameSpaceBrief TcClsName = ptext (sLit "tc") -- demoteNameSpace lowers the NameSpace if possible. We can not know -- in advance, since a TvName can appear in an HsTyVar. -- See Note [Demotion] in RnEnv demoteNameSpace :: NameSpace -> Maybe NameSpace demoteNameSpace VarName = Nothing demoteNameSpace DataName = Nothing demoteNameSpace TvName = Nothing demoteNameSpace TcClsName = Just DataName {- ************************************************************************ * * \subsection[Name-pieces-datatypes]{The @OccName@ datatypes} * * ************************************************************************ -} data OccName = OccName { occNameSpace :: !NameSpace , occNameFS :: !FastString } deriving Typeable instance Eq OccName where (OccName sp1 s1) == (OccName sp2 s2) = s1 == s2 && sp1 == sp2 instance Ord OccName where -- Compares lexicographically, *not* by Unique of the string compare (OccName sp1 s1) (OccName sp2 s2) = (s1 `compare` s2) `thenCmp` (sp1 `compare` sp2) instance Data OccName where -- don't traverse? toConstr _ = abstractConstr "OccName" gunfold _ _ = error "gunfold" dataTypeOf _ = mkNoRepType "OccName" instance HasOccName OccName where occName = id {- ************************************************************************ * * \subsection{Printing} * * ************************************************************************ -} instance Outputable OccName where ppr = pprOccName instance OutputableBndr OccName where pprBndr _ = ppr pprInfixOcc n = pprInfixVar (isSymOcc n) (ppr n) pprPrefixOcc n = pprPrefixVar (isSymOcc n) (ppr n) pprOccName :: OccName -> SDoc pprOccName (OccName sp occ) = getPprStyle $ \ sty -> if codeStyle sty then ztext (zEncodeFS occ) else pp_occ <> pp_debug sty where pp_debug sty | debugStyle sty = braces (pprNameSpaceBrief sp) | otherwise = empty pp_occ = sdocWithDynFlags $ \dflags -> if gopt Opt_SuppressUniques dflags then text (strip_th_unique (unpackFS occ)) else ftext occ -- See Note [Suppressing uniques in OccNames] strip_th_unique ('[' : c : _) | isAlphaNum c = [] strip_th_unique (c : cs) = c : strip_th_unique cs strip_th_unique [] = [] {- Note [Suppressing uniques in OccNames] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is a hack to de-wobblify the OccNames that contain uniques from Template Haskell that have been turned into a string in the OccName. See Note [Unique OccNames from Template Haskell] in Convert.hs ************************************************************************ * * \subsection{Construction} * * ************************************************************************ -} mkOccName :: NameSpace -> String -> OccName mkOccName occ_sp str = OccName occ_sp (mkFastString str) mkOccNameFS :: NameSpace -> FastString -> OccName mkOccNameFS occ_sp fs = OccName occ_sp fs mkVarOcc :: String -> OccName mkVarOcc s = mkOccName varName s mkVarOccFS :: FastString -> OccName mkVarOccFS fs = mkOccNameFS varName fs mkDataOcc :: String -> OccName mkDataOcc = mkOccName dataName mkDataOccFS :: FastString -> OccName mkDataOccFS = mkOccNameFS dataName mkTyVarOcc :: String -> OccName mkTyVarOcc = mkOccName tvName mkTyVarOccFS :: FastString -> OccName mkTyVarOccFS fs = mkOccNameFS tvName fs mkTcOcc :: String -> OccName mkTcOcc = mkOccName tcName mkTcOccFS :: FastString -> OccName mkTcOccFS = mkOccNameFS tcName mkClsOcc :: String -> OccName mkClsOcc = mkOccName clsName mkClsOccFS :: FastString -> OccName mkClsOccFS = mkOccNameFS clsName -- demoteOccName lowers the Namespace of OccName. -- see Note [Demotion] demoteOccName :: OccName -> Maybe OccName demoteOccName (OccName space name) = do space' <- demoteNameSpace space return $ OccName space' name -- Name spaces are related if there is a chance to mean the one when one writes -- the other, i.e. variables <-> data constructors and type variables <-> type constructors nameSpacesRelated :: NameSpace -> NameSpace -> Bool nameSpacesRelated ns1 ns2 = ns1 == ns2 || otherNameSpace ns1 == ns2 otherNameSpace :: NameSpace -> NameSpace otherNameSpace VarName = DataName otherNameSpace DataName = VarName otherNameSpace TvName = TcClsName otherNameSpace TcClsName = TvName {- | Other names in the compiler add additional information to an OccName. This class provides a consistent way to access the underlying OccName. -} class HasOccName name where occName :: name -> OccName {- ************************************************************************ * * Environments * * ************************************************************************ OccEnvs are used mainly for the envts in ModIfaces. Note [The Unique of an OccName] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ They are efficient, because FastStrings have unique Int# keys. We assume this key is less than 2^24, and indeed FastStrings are allocated keys sequentially starting at 0. So we can make a Unique using mkUnique ns key :: Unique where 'ns' is a Char representing the name space. This in turn makes it easy to build an OccEnv. -} instance Uniquable OccName where -- See Note [The Unique of an OccName] getUnique (OccName VarName fs) = mkVarOccUnique fs getUnique (OccName DataName fs) = mkDataOccUnique fs getUnique (OccName TvName fs) = mkTvOccUnique fs getUnique (OccName TcClsName fs) = mkTcOccUnique fs newtype OccEnv a = A (UniqFM a) emptyOccEnv :: OccEnv a unitOccEnv :: OccName -> a -> OccEnv a extendOccEnv :: OccEnv a -> OccName -> a -> OccEnv a extendOccEnvList :: OccEnv a -> [(OccName, a)] -> OccEnv a lookupOccEnv :: OccEnv a -> OccName -> Maybe a mkOccEnv :: [(OccName,a)] -> OccEnv a mkOccEnv_C :: (a -> a -> a) -> [(OccName,a)] -> OccEnv a elemOccEnv :: OccName -> OccEnv a -> Bool foldOccEnv :: (a -> b -> b) -> b -> OccEnv a -> b occEnvElts :: OccEnv a -> [a] extendOccEnv_C :: (a->a->a) -> OccEnv a -> OccName -> a -> OccEnv a extendOccEnv_Acc :: (a->b->b) -> (a->b) -> OccEnv b -> OccName -> a -> OccEnv b plusOccEnv :: OccEnv a -> OccEnv a -> OccEnv a plusOccEnv_C :: (a->a->a) -> OccEnv a -> OccEnv a -> OccEnv a mapOccEnv :: (a->b) -> OccEnv a -> OccEnv b delFromOccEnv :: OccEnv a -> OccName -> OccEnv a delListFromOccEnv :: OccEnv a -> [OccName] -> OccEnv a filterOccEnv :: (elt -> Bool) -> OccEnv elt -> OccEnv elt alterOccEnv :: (Maybe elt -> Maybe elt) -> OccEnv elt -> OccName -> OccEnv elt emptyOccEnv = A emptyUFM unitOccEnv x y = A $ unitUFM x y extendOccEnv (A x) y z = A $ addToUFM x y z extendOccEnvList (A x) l = A $ addListToUFM x l lookupOccEnv (A x) y = lookupUFM x y mkOccEnv l = A $ listToUFM l elemOccEnv x (A y) = elemUFM x y foldOccEnv a b (A c) = foldUFM a b c occEnvElts (A x) = eltsUFM x plusOccEnv (A x) (A y) = A $ plusUFM x y plusOccEnv_C f (A x) (A y) = A $ plusUFM_C f x y extendOccEnv_C f (A x) y z = A $ addToUFM_C f x y z extendOccEnv_Acc f g (A x) y z = A $ addToUFM_Acc f g x y z mapOccEnv f (A x) = A $ mapUFM f x mkOccEnv_C comb l = A $ addListToUFM_C comb emptyUFM l delFromOccEnv (A x) y = A $ delFromUFM x y delListFromOccEnv (A x) y = A $ delListFromUFM x y filterOccEnv x (A y) = A $ filterUFM x y alterOccEnv fn (A y) k = A $ alterUFM fn y k instance Outputable a => Outputable (OccEnv a) where ppr x = pprOccEnv ppr x pprOccEnv :: (a -> SDoc) -> OccEnv a -> SDoc pprOccEnv ppr_elt (A env) = pprUniqFM ppr_elt env type OccSet = UniqSet OccName emptyOccSet :: OccSet unitOccSet :: OccName -> OccSet mkOccSet :: [OccName] -> OccSet extendOccSet :: OccSet -> OccName -> OccSet extendOccSetList :: OccSet -> [OccName] -> OccSet unionOccSets :: OccSet -> OccSet -> OccSet unionManyOccSets :: [OccSet] -> OccSet minusOccSet :: OccSet -> OccSet -> OccSet elemOccSet :: OccName -> OccSet -> Bool occSetElts :: OccSet -> [OccName] foldOccSet :: (OccName -> b -> b) -> b -> OccSet -> b isEmptyOccSet :: OccSet -> Bool intersectOccSet :: OccSet -> OccSet -> OccSet intersectsOccSet :: OccSet -> OccSet -> Bool emptyOccSet = emptyUniqSet unitOccSet = unitUniqSet mkOccSet = mkUniqSet extendOccSet = addOneToUniqSet extendOccSetList = addListToUniqSet unionOccSets = unionUniqSets unionManyOccSets = unionManyUniqSets minusOccSet = minusUniqSet elemOccSet = elementOfUniqSet occSetElts = uniqSetToList foldOccSet = foldUniqSet isEmptyOccSet = isEmptyUniqSet intersectOccSet = intersectUniqSets intersectsOccSet s1 s2 = not (isEmptyOccSet (s1 `intersectOccSet` s2)) {- ************************************************************************ * * \subsection{Predicates and taking them apart} * * ************************************************************************ -} occNameString :: OccName -> String occNameString (OccName _ s) = unpackFS s setOccNameSpace :: NameSpace -> OccName -> OccName setOccNameSpace sp (OccName _ occ) = OccName sp occ isVarOcc, isTvOcc, isTcOcc, isDataOcc :: OccName -> Bool isVarOcc (OccName VarName _) = True isVarOcc _ = False isTvOcc (OccName TvName _) = True isTvOcc _ = False isTcOcc (OccName TcClsName _) = True isTcOcc _ = False -- | /Value/ 'OccNames's are those that are either in -- the variable or data constructor namespaces isValOcc :: OccName -> Bool isValOcc (OccName VarName _) = True isValOcc (OccName DataName _) = True isValOcc _ = False isDataOcc (OccName DataName _) = True isDataOcc _ = False -- | Test if the 'OccName' is a data constructor that starts with -- a symbol (e.g. @:@, or @[]@) isDataSymOcc :: OccName -> Bool isDataSymOcc (OccName DataName s) = isLexConSym s isDataSymOcc _ = False -- Pretty inefficient! -- | Test if the 'OccName' is that for any operator (whether -- it is a data constructor or variable or whatever) isSymOcc :: OccName -> Bool isSymOcc (OccName DataName s) = isLexConSym s isSymOcc (OccName TcClsName s) = isLexSym s isSymOcc (OccName VarName s) = isLexSym s isSymOcc (OccName TvName s) = isLexSym s -- Pretty inefficient! parenSymOcc :: OccName -> SDoc -> SDoc -- ^ Wrap parens around an operator parenSymOcc occ doc | isSymOcc occ = parens doc | otherwise = doc startsWithUnderscore :: OccName -> Bool -- ^ Haskell 98 encourages compilers to suppress warnings about unsed -- names in a pattern if they start with @_@: this implements that test startsWithUnderscore occ = case occNameString occ of ('_' : _) -> True _other -> False {- ************************************************************************ * * \subsection{Making system names} * * ************************************************************************ Here's our convention for splitting up the interface file name space: d... dictionary identifiers (local variables, so no name-clash worries) All of these other OccNames contain a mixture of alphabetic and symbolic characters, and hence cannot possibly clash with a user-written type or function name $f... Dict-fun identifiers (from inst decls) $dmop Default method for 'op' $pnC n'th superclass selector for class C $wf Worker for functtoin 'f' $sf.. Specialised version of f T:C Tycon for dictionary for class C D:C Data constructor for dictionary for class C NTCo:T Coercion connecting newtype T with its representation type TFCo:R Coercion connecting a data family to its respresentation type R In encoded form these appear as Zdfxxx etc :... keywords (export:, letrec: etc.) --- I THINK THIS IS WRONG! This knowledge is encoded in the following functions. @mk_deriv@ generates an @OccName@ from the prefix and a string. NB: The string must already be encoded! -} mk_deriv :: NameSpace -> String -- Distinguishes one sort of derived name from another -> String -> OccName mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str) isDerivedOccName :: OccName -> Bool isDerivedOccName occ = case occNameString occ of '$':c:_ | isAlphaNum c -> True ':':c:_ | isAlphaNum c -> True _other -> False mkDataConWrapperOcc, mkWorkerOcc, mkMatcherOcc, mkBuilderOcc, mkDefaultMethodOcc, mkGenDefMethodOcc, mkDerivedTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc, mkSpecOcc, mkForeignExportOcc, mkRepEqOcc, mkGenOcc1, mkGenOcc2, mkGenD, mkGenR, mkGen1R, mkGenRCo, mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc, mkInstTyCoOcc, mkEqPredCoOcc, mkClassOpAuxOcc, mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc :: OccName -> OccName -- These derived variables have a prefix that no Haskell value could have mkDataConWrapperOcc = mk_simple_deriv varName "$W" mkWorkerOcc = mk_simple_deriv varName "$w" mkMatcherOcc = mk_simple_deriv varName "$m" mkBuilderOcc = mk_simple_deriv varName "$b" mkDefaultMethodOcc = mk_simple_deriv varName "$dm" mkGenDefMethodOcc = mk_simple_deriv varName "$gdm" mkClassOpAuxOcc = mk_simple_deriv varName "$c" mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies as a tycon/datacon mkClassDataConOcc = mk_simple_deriv dataName "D:" -- We go straight to the "real" data con -- for datacons from classes mkDictOcc = mk_simple_deriv varName "$d" mkIPOcc = mk_simple_deriv varName "$i" mkSpecOcc = mk_simple_deriv varName "$s" mkForeignExportOcc = mk_simple_deriv varName "$f" mkRepEqOcc = mk_simple_deriv tvName "$r" -- In RULES involving Coercible mkNewTyCoOcc = mk_simple_deriv tcName "NTCo:" -- Coercion for newtypes mkInstTyCoOcc = mk_simple_deriv tcName "TFCo:" -- Coercion for type functions mkEqPredCoOcc = mk_simple_deriv tcName "$co" -- used in derived instances mkCon2TagOcc = mk_simple_deriv varName "$con2tag_" mkTag2ConOcc = mk_simple_deriv varName "$tag2con_" mkMaxTagOcc = mk_simple_deriv varName "$maxtag_" -- Generic derivable classes (old) mkGenOcc1 = mk_simple_deriv varName "$gfrom" mkGenOcc2 = mk_simple_deriv varName "$gto" -- Generic deriving mechanism (new) mkGenD = mk_simple_deriv tcName "D1" mkGenC :: OccName -> Int -> OccName mkGenC occ m = mk_deriv tcName ("C1_" ++ show m) (occNameString occ) mkGenS :: OccName -> Int -> Int -> OccName mkGenS occ m n = mk_deriv tcName ("S1_" ++ show m ++ "_" ++ show n) (occNameString occ) mkGenR = mk_simple_deriv tcName "Rep_" mkGen1R = mk_simple_deriv tcName "Rep1_" mkGenRCo = mk_simple_deriv tcName "CoRep_" -- data T = MkT ... deriving( Data ) needs definitions for -- $tT :: Data.Generics.Basics.DataType -- $cMkT :: Data.Generics.Basics.Constr mkDataTOcc = mk_simple_deriv varName "$t" mkDataCOcc = mk_simple_deriv varName "$c" -- Vectorisation mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc, mkPADFunOcc, mkPReprTyConOcc, mkPDataTyConOcc, mkPDataDataConOcc, mkPDatasTyConOcc, mkPDatasDataConOcc :: Maybe String -> OccName -> OccName mkVectOcc = mk_simple_deriv_with varName "$v" mkVectTyConOcc = mk_simple_deriv_with tcName "V:" mkVectDataConOcc = mk_simple_deriv_with dataName "VD:" mkVectIsoOcc = mk_simple_deriv_with varName "$vi" mkPADFunOcc = mk_simple_deriv_with varName "$pa" mkPReprTyConOcc = mk_simple_deriv_with tcName "VR:" mkPDataTyConOcc = mk_simple_deriv_with tcName "VP:" mkPDatasTyConOcc = mk_simple_deriv_with tcName "VPs:" mkPDataDataConOcc = mk_simple_deriv_with dataName "VPD:" mkPDatasDataConOcc = mk_simple_deriv_with dataName "VPDs:" mk_simple_deriv :: NameSpace -> String -> OccName -> OccName mk_simple_deriv sp px occ = mk_deriv sp px (occNameString occ) mk_simple_deriv_with :: NameSpace -> String -> Maybe String -> OccName -> OccName mk_simple_deriv_with sp px Nothing occ = mk_deriv sp px (occNameString occ) mk_simple_deriv_with sp px (Just with) occ = mk_deriv sp (px ++ with ++ "_") (occNameString occ) -- Data constructor workers are made by setting the name space -- of the data constructor OccName (which should be a DataName) -- to VarName mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ mkSuperDictAuxOcc :: Int -> OccName -> OccName mkSuperDictAuxOcc index cls_tc_occ = mk_deriv varName "$cp" (show index ++ occNameString cls_tc_occ) mkSuperDictSelOcc :: Int -- ^ Index of superclass, e.g. 3 -> OccName -- ^ Class, e.g. @Ord@ -> OccName -- ^ Derived 'Occname', e.g. @$p3Ord@ mkSuperDictSelOcc index cls_tc_occ = mk_deriv varName "$p" (show index ++ occNameString cls_tc_occ) mkLocalOcc :: Unique -- ^ Unique to combine with the 'OccName' -> OccName -- ^ Local name, e.g. @sat@ -> OccName -- ^ Nice unique version, e.g. @$L23sat@ mkLocalOcc uniq occ = mk_deriv varName ("$L" ++ show uniq) (occNameString occ) -- The Unique might print with characters -- that need encoding (e.g. 'z'!) -- | Derive a name for the representation type constructor of a -- @data@\/@newtype@ instance. mkInstTyTcOcc :: String -- ^ Family name, e.g. @Map@ -> OccSet -- ^ avoid these Occs -> OccName -- ^ @R:Map@ mkInstTyTcOcc str set = chooseUniqueOcc tcName ('R' : ':' : str) set mkDFunOcc :: String -- ^ Typically the class and type glommed together e.g. @OrdMaybe@. -- Only used in debug mode, for extra clarity -> Bool -- ^ Is this a hs-boot instance DFun? -> OccSet -- ^ avoid these Occs -> OccName -- ^ E.g. @$f3OrdMaybe@ -- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real -- thing when we compile the mother module. Reason: we don't know exactly -- what the mother module will call it. mkDFunOcc info_str is_boot set = chooseUniqueOcc VarName (prefix ++ info_str) set where prefix | is_boot = "$fx" | otherwise = "$f" {- Sometimes we need to pick an OccName that has not already been used, given a set of in-use OccNames. -} chooseUniqueOcc :: NameSpace -> String -> OccSet -> OccName chooseUniqueOcc ns str set = loop (mkOccName ns str) (0::Int) where loop occ n | occ `elemOccSet` set = loop (mkOccName ns (str ++ show n)) (n+1) | otherwise = occ {- We used to add a '$m' to indicate a method, but that gives rise to bad error messages from the type checker when we print the function name or pattern of an instance-decl binding. Why? Because the binding is zapped to use the method name in place of the selector name. (See TcClassDcl.tcMethodBind) The way it is now, -ddump-xx output may look confusing, but you can always say -dppr-debug to get the uniques. However, we *do* have to zap the first character to be lower case, because overloaded constructors (blarg) generate methods too. And convert to VarName space e.g. a call to constructor MkFoo where data (Ord a) => Foo a = MkFoo a If this is necessary, we do it by prefixing '$m'. These guys never show up in error messages. What a hack. -} mkMethodOcc :: OccName -> OccName mkMethodOcc occ@(OccName VarName _) = occ mkMethodOcc occ = mk_simple_deriv varName "$m" occ {- ************************************************************************ * * \subsection{Tidying them up} * * ************************************************************************ Before we print chunks of code we like to rename it so that we don't have to print lots of silly uniques in it. But we mustn't accidentally introduce name clashes! So the idea is that we leave the OccName alone unless it accidentally clashes with one that is already in scope; if so, we tack on '1' at the end and try again, then '2', and so on till we find a unique one. There's a wrinkle for operators. Consider '>>='. We can't use '>>=1' because that isn't a single lexeme. So we encode it to 'lle' and *then* tack on the '1', if necessary. Note [TidyOccEnv] ~~~~~~~~~~~~~~~~~ type TidyOccEnv = UniqFM Int * Domain = The OccName's FastString. These FastStrings are "taken"; make sure that we don't re-use * Int, n = A plausible starting point for new guesses There is no guarantee that "FSn" is available; you must look that up in the TidyOccEnv. But it's a good place to start looking. * When looking for a renaming for "foo2" we strip off the "2" and start with "foo". Otherwise if we tidy twice we get silly names like foo23. -} type TidyOccEnv = UniqFM Int -- The in-scope OccNames -- See Note [TidyOccEnv] emptyTidyOccEnv :: TidyOccEnv emptyTidyOccEnv = emptyUFM initTidyOccEnv :: [OccName] -> TidyOccEnv -- Initialise with names to avoid! initTidyOccEnv = foldl add emptyUFM where add env (OccName _ fs) = addToUFM env fs 1 tidyOccName :: TidyOccEnv -> OccName -> (TidyOccEnv, OccName) tidyOccName env occ@(OccName occ_sp fs) = case lookupUFM env fs of Just n -> find n Nothing -> (addToUFM env fs 1, occ) where base :: String -- Drop trailing digits (see Note [TidyOccEnv]) base = dropWhileEndLE isDigit (unpackFS fs) find n = case lookupUFM env new_fs of Just n' -> find (n1 `max` n') -- The max ensures that n increases, avoiding loops Nothing -> (addToUFM (addToUFM env fs n1) new_fs n1, OccName occ_sp new_fs) -- We update only the beginning and end of the -- chain that find explores; it's a little harder to -- update the middle and there's no real need. where n1 = n+1 new_fs = mkFastString (base ++ show n) {- ************************************************************************ * * Binary instance Here rather than BinIface because OccName is abstract * * ************************************************************************ -} instance Binary NameSpace where put_ bh VarName = do putByte bh 0 put_ bh DataName = do putByte bh 1 put_ bh TvName = do putByte bh 2 put_ bh TcClsName = do putByte bh 3 get bh = do h <- getByte bh case h of 0 -> do return VarName 1 -> do return DataName 2 -> do return TvName _ -> do return TcClsName instance Binary OccName where put_ bh (OccName aa ab) = do put_ bh aa put_ bh ab get bh = do aa <- get bh ab <- get bh return (OccName aa ab)