%
\begin{code}
+-- |
+-- #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; abstact
- NameSpace, tcName, clsName, tcClsName, dataName, varName,
+ -- * The 'NameSpace' type
+ NameSpace, -- Abstract
+
+ -- ** Construction
+ -- $real_vs_source_data_constructors
+ tcName, clsName, tcClsName, dataName, varName,
tvName, srcDataName,
- -- ** Printing
+ -- ** Pretty Printing
pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief,
- -- * The OccName type
+ -- * The 'OccName' type
OccName, -- Abstract, instance of Outputable
pprOccName,
-- ** Construction
mkOccName, mkOccNameFS,
mkVarOcc, mkVarOccFS,
- mkTyVarOcc,
+ mkDataOcc, mkDataOccFS,
+ mkTyVarOcc, mkTyVarOccFS,
+ mkTcOcc, mkTcOccFS,
+ mkClsOcc, mkClsOccFS,
mkDFunOcc,
mkTupleOcc,
setOccNameSpace,
- -- ** Derived OccNames
+ -- ** Derived 'OccName's
+ isDerivedOccName,
mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc,
- mkDerivedTyConOcc, mkNewTyCoOcc,
+ mkDerivedTyConOcc, mkNewTyCoOcc, mkClassOpAuxOcc,
+ mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc,
mkSuperDictSelOcc, mkLocalOcc, mkMethodOcc, mkInstTyTcOcc,
mkInstTyCoOcc, mkEqPredCoOcc,
mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
- mkPArrayTyConOcc, mkPArrayDataConOcc,
- mkPReprTyConOcc,
+ mkPDataTyConOcc, mkPDataDataConOcc,
+ mkPReprTyConOcc,
mkPADFunOcc,
-- ** Deconstruction
occNameFS, occNameString, occNameSpace,
isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,
- parenSymOcc, reportIfUnused, isTcClsName, isVarName,
+ parenSymOcc, startsWithUnderscore,
+
+ isTcClsNameSpace, isTvNameSpace, isDataConNameSpace, isVarNameSpace, isValNameSpace,
isTupleOcc_maybe,
- -- The OccEnv type
+ -- * The 'OccEnv' type
OccEnv, emptyOccEnv, unitOccEnv, extendOccEnv, mapOccEnv,
lookupOccEnv, mkOccEnv, mkOccEnv_C, extendOccEnvList, elemOccEnv,
occEnvElts, foldOccEnv, plusOccEnv, plusOccEnv_C, extendOccEnv_C,
- filterOccEnv, delListFromOccEnv, delFromOccEnv,
+ extendOccEnv_Acc, filterOccEnv, delListFromOccEnv, delFromOccEnv,
- -- The OccSet type
+ -- * The 'OccSet' type
OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet,
extendOccSetList,
unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts,
foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet,
- -- Tidying up
+ -- * Tidying up
TidyOccEnv, emptyTidyOccEnv, tidyOccName, initTidyOccEnv,
- -- The basic form of names
+ -- * Lexical characteristics of Haskell names
isLexCon, isLexVar, isLexId, isLexSym,
isLexConId, isLexConSym, isLexVarId, isLexVarSym,
startsVarSym, startsVarId, startsConSym, startsConId
import Util
import Unique
import BasicTypes
-import StaticFlags
import UniqFM
import UniqSet
import FastString
-import FastTypes
import Outputable
import Binary
-
-import GHC.Exts
import Data.Char
+\end{code}
+\begin{code}
-- Unicode TODO: put isSymbol in libcompat
#if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
#else
-- Note [Data Constructors]
-- see also: Note [Data Constructor Naming] in DataCon.lhs
---
--- "Source" data constructors are the data constructors mentioned
--- in Haskell source code
--
--- "Real" data constructors are the data constructors of the
--- representation type, which may not be the same as the source
--- type
-
--- Example:
--- data T = T !(Int,Int)
+-- $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@
--
--- 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
tvName = TvName
varName = VarName
-isTcClsName :: NameSpace -> Bool
-isTcClsName TcClsName = True
-isTcClsName _ = False
+isDataConNameSpace :: NameSpace -> Bool
+isDataConNameSpace DataName = True
+isDataConNameSpace _ = False
+
+isTcClsNameSpace :: NameSpace -> Bool
+isTcClsNameSpace TcClsName = True
+isTcClsNameSpace _ = False
+
+isTvNameSpace :: NameSpace -> Bool
+isTvNameSpace TvName = True
+isTvNameSpace _ = False
-isVarName :: NameSpace -> Bool -- Variables or type variables, but not constructors
-isVarName TvName = True
-isVarName VarName = True
-isVarName _ = 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")
mkVarOccFS :: FastString -> OccName
mkVarOccFS fs = mkOccNameFS varName fs
-mkTyVarOcc :: FastString -> OccName
-mkTyVarOcc fs = mkOccNameFS tvName 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
\end{code}
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, so we can make a Unique using
+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 reprsenting the name space. This in turn makes it
easy to build an OccEnv.
\begin{code}
instance Uniquable OccName where
- getUnique (OccName ns fs)
- = mkUnique char (iBox (uniqueOfFS fs))
- where -- See notes above about this getUnique function
- char = case ns of
- VarName -> 'i'
- DataName -> 'd'
- TvName -> 'v'
- TcClsName -> 't'
+ -- 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)
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
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
setOccNameSpace :: NameSpace -> OccName -> OccName
setOccNameSpace sp (OccName _ occ) = OccName sp occ
-isVarOcc, isTvOcc, isDataSymOcc, isSymOcc, isTcOcc, isValOcc, isDataOcc :: OccName -> Bool
+isVarOcc, isTvOcc, isTcOcc, isDataOcc :: OccName -> Bool
isVarOcc (OccName VarName _) = True
isVarOcc _ = 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
--- Data constructor operator (starts with ':', or '[]')
--- Pretty inefficient!
-isDataSymOcc (OccName DataName s) = isLexConSym s
-isDataSymOcc (OccName VarName s)
- | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
- -- Jan06: I don't think this should happen
-isDataSymOcc _ = False
-
isDataOcc (OccName DataName _) = True
isDataOcc (OccName VarName s)
| isLexCon s = pprPanic "isDataOcc: check me" (ppr s)
-- Jan06: I don't think this should happen
isDataOcc _ = False
--- Any operator (data constructor or variable)
+-- | 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 (OccName VarName s)
+ | isLexConSym s = pprPanic "isDataSymOcc: check me" (ppr s)
+ -- Jan06: I don't think this should happen
+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) = isLexConSym s
isSymOcc (OccName VarName s) = isLexSym s
isSymOcc (OccName TvName s) = isLexSym s
+-- Pretty inefficient!
parenSymOcc :: OccName -> SDoc -> SDoc
--- Wrap parens around an operator
+-- ^ Wrap parens around an operator
parenSymOcc occ doc | isSymOcc occ = parens doc
| otherwise = doc
\end{code}
\begin{code}
-reportIfUnused :: OccName -> Bool
- -- Haskell 98 encourages compilers to suppress warnings about
- -- unused names in a pattern if they start with "_".
-reportIfUnused occ = case occNameString occ of
- ('_' : _) -> False
- _other -> True
+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
\end{code}
Here's our convention for splitting up the interface file name space:
- d... dictionary identifiers
- (local variables, so no name-clash worries)
+ 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)
- $dm... default methods
- $p... superclass selectors
- $w... workers
- :T... compiler-generated tycons for dictionaries
- :D... ...ditto data cons
- :Co... ...ditto coercions
- $sf.. specialised version of f
+ $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'
+ $sf.. Specialised version of f
+ T:C Tycon for dictionary for class C
+ D:C Data constructor for dictionary for class C
+ NTCo:T Coercion connecting newtype T with its representation type
+ TFCo:R Coercion connecting a data family to its respresentation type R
- in encoded form these appear as Zdfxxx etc
+In encoded form these appear as Zdfxxx etc
:... keywords (export:, letrec: etc.)
--- I THINK THIS IS WRONG!
This knowledge is encoded in the following functions.
-
@mk_deriv@ generates an @OccName@ from the prefix and a string.
NB: The string must already be encoded!
-> OccName
mk_deriv occ_sp sys_prefix str = mkOccName occ_sp (sys_prefix ++ str)
+
+isDerivedOccName :: OccName -> Bool
+isDerivedOccName occ =
+ case occNameString occ of
+ '$':c:_ | isAlphaNum c -> True
+ ':':c:_ | isAlphaNum c -> True
+ _other -> False
\end{code}
\begin{code}
mkClassTyConOcc, mkClassDataConOcc, mkDictOcc, mkIPOcc,
mkSpecOcc, mkForeignExportOcc, mkGenOcc1, mkGenOcc2,
mkDataTOcc, mkDataCOcc, mkDataConWorkerOcc, mkNewTyCoOcc,
- mkInstTyCoOcc, mkEqPredCoOcc,
+ mkInstTyCoOcc, mkEqPredCoOcc, mkClassOpAuxOcc,
+ mkCon2TagOcc, mkTag2ConOcc, mkMaxTagOcc,
mkVectOcc, mkVectTyConOcc, mkVectDataConOcc, mkVectIsoOcc,
- mkPArrayTyConOcc, mkPArrayDataConOcc, mkPReprTyConOcc, mkPADFunOcc
+ mkPDataTyConOcc, mkPDataDataConOcc, mkPReprTyConOcc, mkPADFunOcc
:: 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"
mkDefaultMethodOcc = mk_simple_deriv varName "$dm"
+mkClassOpAuxOcc = mk_simple_deriv varName "$c"
mkDerivedTyConOcc = mk_simple_deriv tcName ":" -- The : prefix makes sure it classifies
-mkClassTyConOcc = mk_simple_deriv tcName ":T" -- as a tycon/datacon
-mkClassDataConOcc = mk_simple_deriv dataName ":D" -- We go straight to the "real" data con
+mkClassTyConOcc = mk_simple_deriv tcName "T:" -- 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"
-mkNewTyCoOcc = mk_simple_deriv tcName ":Co"
-mkInstTyCoOcc = mk_simple_deriv tcName ":CoF" -- derived from rep ty
-mkEqPredCoOcc = mk_simple_deriv tcName "$co"
+mkNewTyCoOcc = mk_simple_deriv tcName "NTCo:" -- Coercion for newtypes
+mkInstTyCoOcc = mk_simple_deriv tcName "TFCo:" -- Coercion for type functions
+mkEqPredCoOcc = mk_simple_deriv tcName "$co"
+
+-- used in derived instances
+mkCon2TagOcc = mk_simple_deriv varName "$con2tag_"
+mkTag2ConOcc = mk_simple_deriv varName "$tag2con_"
+mkMaxTagOcc = mk_simple_deriv varName "$maxtag_"
-- Generic derivable classes
mkGenOcc1 = mk_simple_deriv varName "$gfrom"
mkVectTyConOcc = mk_simple_deriv tcName ":V_"
mkVectDataConOcc = mk_simple_deriv dataName ":VD_"
mkVectIsoOcc = mk_simple_deriv varName "$VI_"
-mkPArrayTyConOcc = mk_simple_deriv tcName ":VP_"
-mkPArrayDataConOcc = mk_simple_deriv dataName ":VPD_"
+mkPDataTyConOcc = mk_simple_deriv tcName ":VP_"
+mkPDataDataConOcc = mk_simple_deriv dataName ":VPD_"
mkPReprTyConOcc = mk_simple_deriv tcName ":VR_"
mkPADFunOcc = mk_simple_deriv varName "$PA_"
\end{code}
\begin{code}
-mkSuperDictSelOcc :: Int -- Index of superclass, eg 3
- -> OccName -- Class, eg "Ord"
- -> OccName -- eg "$p3Ord"
+mkSuperDictSelOcc :: Int -- ^ Index of superclass, e.g. 3
+ -> OccName -- ^ Class, e.g. @Ord@
+ -> OccName -- ^ Derived 'Occname', e.g. @$p3Ord@
mkSuperDictSelOcc index cls_occ
= mk_deriv varName "$p" (show index ++ occNameString cls_occ)
-mkLocalOcc :: Unique -- Unique
- -> OccName -- Local name (e.g. "sat")
- -> OccName -- Nice unique version ("$L23sat")
+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'!)
\end{code}
-Derive a name for the representation type constructor of a data/newtype
-instance.
-
\begin{code}
-mkInstTyTcOcc :: Int -- Index
- -> OccName -- Family name (e.g. "Map")
- -> OccName -- Nice unique version (":R23Map")
-mkInstTyTcOcc index occ
- = mk_deriv tcName (":R" ++ show index) (occNameString occ)
+-- | 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
\end{code}
\begin{code}
-mkDFunOcc :: String -- Typically the class and type glommed together e.g. "OrdMaybe"
+mkDFunOcc :: String -- ^ Typically the class and type glommed together e.g. @OrdMaybe@.
-- Only used in debug mode, for extra clarity
- -> Bool -- True <=> hs-boot instance dfun
- -> Int -- Unique index
- -> OccName -- "$f3OrdMaybe"
+ -> Bool -- ^ Is this a hs-boot instance DFun?
+ -> OccSet -- ^ avoid these Occs
+ -> OccName -- ^ E.g. @$f3OrdMaybe@
-- In hs-boot files we make dict funs like $fx7ClsTy, which get bound to the real
-- thing when we compile the mother module. Reason: we don't know exactly
-- what the mother module will call it.
-mkDFunOcc info_str is_boot index
- = mk_deriv VarName prefix string
+mkDFunOcc info_str is_boot set
+ = chooseUniqueOcc VarName (prefix ++ info_str) set
where
prefix | is_boot = "$fx"
| otherwise = "$f"
- string | opt_PprStyle_Debug = show index ++ info_str
- | otherwise = show index
+\end{code}
+
+Sometimes we need to pick an OccName that has not already been used,
+given a set of in-use OccNames.
+
+\begin{code}
+chooseUniqueOcc :: NameSpace -> String -> OccSet -> OccName
+chooseUniqueOcc ns str set = loop (mkOccName ns str) (0::Int)
+ where
+ loop occ n
+ | occ `elemOccSet` set = loop (mkOccName ns (str ++ show n)) (n+1)
+ | otherwise = occ
\end{code}
We used to add a '$m' to indicate a method, but that gives rise to bad
projects / ghc-hetmet.git / blobdiff