Document OccName and expand it's API

diff --git a/compiler/basicTypes/OccName.lhs b/compiler/basicTypes/OccName.lhs
index debaa28..1868c3f 100644 (file)
--- a/compiler/basicTypes/OccName.lhs
+++ b/compiler/basicTypes/OccName.lhs
@@ -4,28 +4,49 @@
 %
 
 \begin{code}
 %
 
 \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 (
 module OccName (

-        mk_deriv,
-       -- * 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,
 
        tvName, srcDataName,
 

-       -- ** Printing
+       -- ** Pretty Printing

        pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief,
 
        pprNameSpace, pprNonVarNameSpace, pprNameSpaceBrief,
 

-       -- * The OccName type
+       -- * The 'OccName' type

        OccName,        -- Abstract, instance of Outputable
        pprOccName, 
 
        -- ** Construction      
        mkOccName, mkOccNameFS, 
        mkVarOcc, mkVarOccFS,
        OccName,        -- Abstract, instance of Outputable
        pprOccName, 
 
        -- ** Construction      
        mkOccName, mkOccNameFS, 
        mkVarOcc, mkVarOccFS,

-       mkTyVarOcc,
+       mkDataOcc, mkDataOccFS,
+       mkTyVarOcc, mkTyVarOccFS,
+       mkTcOcc, mkTcOccFS,
+       mkClsOcc, mkClsOccFS,

        mkDFunOcc,
        mkTupleOcc, 
        setOccNameSpace,
 
        mkDFunOcc,
        mkTupleOcc, 
        setOccNameSpace,
 

-       -- ** Derived OccNames
+       -- ** Derived 'OccName's

         isDerivedOccName,
        mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc,
        mkDerivedTyConOcc, mkNewTyCoOcc, 
         isDerivedOccName,
        mkDataConWrapperOcc, mkWorkerOcc, mkDefaultMethodOcc,
        mkDerivedTyConOcc, mkNewTyCoOcc, 

@@ -44,26 +65,28 @@ module OccName (
        occNameFS, occNameString, occNameSpace, 
 
        isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,
        occNameFS, occNameString, occNameSpace, 
 
        isVarOcc, isTvOcc, isTcOcc, isDataOcc, isDataSymOcc, isSymOcc, isValOcc,

-       parenSymOcc, reportIfUnused, isTcClsName, isVarName,
+       parenSymOcc, reportIfUnused, 
+       
+       isTcClsNameSpace, isTvNameSpace, isDataConNameSpace, isVarNameSpace, isValNameSpace,

 
        isTupleOcc_maybe,
 
 
        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,
 
        OccEnv, emptyOccEnv, unitOccEnv, extendOccEnv, mapOccEnv,
        lookupOccEnv, mkOccEnv, mkOccEnv_C, extendOccEnvList, elemOccEnv,
        occEnvElts, foldOccEnv, plusOccEnv, plusOccEnv_C, extendOccEnv_C,
         filterOccEnv, delListFromOccEnv, delFromOccEnv,
 

-       -- The OccSet type
+       -- * The 'OccSet' type

        OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet, 
        extendOccSetList,
        unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts, 
        foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet,
                   
        OccSet, emptyOccSet, unitOccSet, mkOccSet, extendOccSet, 
        extendOccSetList,
        unionOccSets, unionManyOccSets, minusOccSet, elemOccSet, occSetElts, 
        foldOccSet, isEmptyOccSet, intersectOccSet, intersectsOccSet,
                   

-       -- Tidying up
+       -- * Tidying up

        TidyOccEnv, emptyTidyOccEnv, tidyOccName, initTidyOccEnv,
 
        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
        isLexCon, isLexVar, isLexId, isLexSym,
        isLexConId, isLexConSym, isLexVarId, isLexVarSym,
        startsVarSym, startsVarId, startsConSym, startsConId

@@ -82,7 +105,9 @@ import Binary
 
 import GHC.Exts
 import Data.Char
 
 import GHC.Exts
 import Data.Char

+\end{code}

 
 

+\begin{code}

 -- Unicode TODO: put isSymbol in libcompat
 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
 #else
 -- Unicode TODO: put isSymbol in libcompat
 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ > 604
 #else

@@ -109,19 +134,21 @@ data NameSpace = VarName  -- Variables, including "real" data constructors
 
 -- Note [Data Constructors]  
 -- see also: Note [Data Constructor Naming] in DataCon.lhs
 
 -- 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
 -- GHC chooses a representation based on the strictness etc.
 
 tcName, clsName, tcClsName :: NameSpace

@@ -141,14 +168,27 @@ srcDataName = DataName    -- Haskell-source data constructors should be
 tvName      = TvName
 varName     = VarName
 
 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")
 
 pprNameSpace :: NameSpace -> SDoc
 pprNameSpace DataName  = ptext (sLit "data constructor")

@@ -233,8 +273,29 @@ mkVarOcc s = mkOccName varName s
 mkVarOccFS :: FastString -> OccName
 mkVarOccFS fs = mkOccNameFS varName fs
 
 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}
 
 
 \end{code}
 
 

@@ -351,7 +412,7 @@ occNameString (OccName _ s) = unpackFS s
 setOccNameSpace :: NameSpace -> OccName -> OccName
 setOccNameSpace sp (OccName _ occ) = OccName sp occ
 
 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
 
 isVarOcc (OccName VarName _) = True
 isVarOcc _                   = False

@@ -362,33 +423,40 @@ isTvOcc _                  = False
 isTcOcc (OccName TcClsName _) = True
 isTcOcc _                     = 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
 
 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
 
 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!
 -- 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
 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
 
 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}
 parenSymOcc occ doc | isSymOcc occ = parens doc
                    | otherwise    = doc
 \end{code}

@@ -396,8 +464,9 @@ parenSymOcc occ doc | isSymOcc occ = parens doc
 
 \begin{code}
 reportIfUnused :: OccName -> Bool
 
 \begin{code}
 reportIfUnused :: OccName -> Bool

-  -- Haskell 98 encourages compilers to suppress warnings about
-  -- unused names in a pattern if they start with "_".
+-- ^ Haskell 98 encourages compilers to suppress warnings about
+-- unused names in a pattern if they start with @_@: this implements
+-- that test

 reportIfUnused occ = case occNameString occ of
                        ('_' : _) -> False
                        _other    -> True
 reportIfUnused occ = case occNameString occ of
                        ('_' : _) -> False
                        _other    -> True

@@ -415,14 +484,14 @@ 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)
 

-       $f...           dict-fun identifiers (from inst decls)
-       $dm...          default methods
-       $p...           superclass selectors
-       $w...           workers
+       \$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
        :T...           compiler-generated tycons for dictionaries
        :D...           ...ditto data cons
         :Co...          ...ditto coercions

-       $sf..           specialised version of f
+       \$sf..          specialised version of f

 
        in encoded form these appear as Zdfxxx etc
 
 
        in encoded form these appear as Zdfxxx etc
 

@@ -512,38 +581,37 @@ mkDataConWorkerOcc datacon_occ = setOccNameSpace varName datacon_occ
 \end{code}
 
 \begin{code}
 \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)
 
 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}
 
 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}
 \begin{code}

-mkInstTyTcOcc :: Int                   -- Index
-             -> OccName                -- Family name (e.g. "Map")
-             -> OccName                -- Nice unique version (":R23Map")
+-- | Derive a name for the representation type constructor of a @data@/@newtype@
+-- instance.
+mkInstTyTcOcc :: Int                   -- ^ DFun Index
+             -> OccName                -- ^ Family name, e.g. @Map@
+             -> OccName                -- ^ Nice unique version, e.g. @:R23Map@

 mkInstTyTcOcc index occ
    = mk_deriv tcName (":R" ++ show index) (occNameString occ)
 \end{code}
 
 \begin{code}
 mkInstTyTcOcc index occ
    = mk_deriv tcName (":R" ++ show index) (occNameString occ)
 \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
                                -- Only used in debug mode, for extra clarity

-         -> Bool               -- True <=> hs-boot instance dfun
-         -> Int                -- Unique index
-         -> OccName            -- "$f3OrdMaybe"
+         -> Bool               -- ^ Is this a hs-boot instance DFun?
+         -> Int                -- ^ Unique index
+         -> OccName            -- ^ E.g. @$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
 
 -- 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