[project @ 1999-06-28 16:42:22 by simonmar]

Back out changes for "specialid"s.  It didn't work this way: there was
a conflict in the grammar.

diff --git a/ghc/compiler/parser/Lex.lhs b/ghc/compiler/parser/Lex.lhs
index 727039c..d705043 100644 (file)
--- a/ghc/compiler/parser/Lex.lhs
+++ b/ghc/compiler/parser/Lex.lhs
@@ -96,13 +96,15 @@ Laziness, you know it makes sense :-)
 
 \begin{code}
 data Token
-  = ITcase                     -- Haskell keywords
+  = ITas                       -- Haskell keywords
+  | ITcase
   | ITclass
   | ITdata
   | ITdefault
   | ITderiving
   | ITdo
   | ITelse
+  | IThiding
   | ITif
   | ITimport
   | ITin
@@ -114,6 +116,7 @@ data Token
   | ITmodule
   | ITnewtype
   | ITof
+  | ITqualified
   | ITthen
   | ITtype
   | ITwhere
@@ -242,6 +245,7 @@ pragmaKeywordsFM = listToUFM $
 haskellKeywordsFM = listToUFM $
       map (\ (x,y) -> (_PK_ x,y))
        [( "_",         ITunderscore ),
+       ( "as",         ITas ),
        ( "case",       ITcase ),     
        ( "class",      ITclass ),    
        ( "data",       ITdata ),     
@@ -249,6 +253,7 @@ haskellKeywordsFM = listToUFM $
        ( "deriving",   ITderiving ), 
        ( "do",         ITdo ),       
        ( "else",       ITelse ),     
+       ( "hiding",     IThiding ),
        ( "if",         ITif ),       
        ( "import",     ITimport ),   
        ( "in",         ITin ),       
@@ -260,6 +265,7 @@ haskellKeywordsFM = listToUFM $
        ( "module",     ITmodule ),   
        ( "newtype",    ITnewtype ),  
        ( "of",         ITof ),       
+       ( "qualified",  ITqualified ),
        ( "then",       ITthen ),     
        ( "type",       ITtype ),     
        ( "where",      ITwhere ),
@@ -335,10 +341,6 @@ haskellKeySymsFM = listToUFM $
        ,("!",          ITbang)
        ,(".",          ITdot)          -- sadly, for 'forall a . t'
        ]
-
-not_special_op ITminus = False
-not_special_op ITbang  = False
-not_special_op _ = True
 \end{code}
 
 -----------------------------------------------------------------------------
@@ -977,11 +979,9 @@ lex_id3 cont glaexts mod buf just_a_conid
        -- real lexeme is M.<sym>
        new_buf = mergeLexemes buf buf'
      in
-     case lookupUFM haskellKeySymsFM lexeme of {
-       Just kwd_token | not_special_op kwd_token
-                       -> just_a_conid;        -- avoid M.::, but not M.!
-       other -> cont (mk_qvar_token mod lexeme) new_buf
-     }}
+     cont (mk_qvar_token mod lexeme) new_buf
+       -- wrong, but arguably morally right: M... is now a qvarsym
+     }
 
   | otherwise   =
      let 
@@ -1002,6 +1002,8 @@ lex_id3 cont glaexts mod buf just_a_conid
      case _scc_ "Lex.haskellKeyword" lookupUFM haskellKeywordsFM lexeme of {
            Just kwd_token -> just_a_conid; -- avoid M.where etc.
            Nothing        -> is_a_qvarid
+       -- TODO: special ids (as, qualified, hiding) shouldn't be
+       -- recognised as keywords here.  ie.  M.as is a qualified varid.
      }}}
 
 

diff --git a/ghc/compiler/parser/ParseUtil.lhs b/ghc/compiler/parser/ParseUtil.lhs
index 2be5030..ce4f71b 100644 (file)
--- a/ghc/compiler/parser/ParseUtil.lhs
+++ b/ghc/compiler/parser/ParseUtil.lhs
@@ -14,10 +14,6 @@ module ParseUtil (
        , mkRecConstrOrUpdate   -- HsExp -> [HsFieldUpdate] -> P HsExp
        , groupBindings
 
-       , checkAs
-       , checkHiding
-       , checkQualified
-
        , checkPrec             -- String -> P String
        , checkCallConv         -- FAST_STRING -> P CallConv
        , checkContext          -- HsType -> P HsContext
@@ -37,9 +33,10 @@ module ParseUtil (
        , funTyCon_RDR
 
        -- pseudo-keywords, in var and tyvar forms (all :: RdrName)
-       , forall_var_RDR
+       , as_var_RDR, hiding_var_RDR, qualified_var_RDR, forall_var_RDR
        , export_var_RDR, label_var_RDR, dynamic_var_RDR, unsafe_var_RDR
 
+       , as_tyvar_RDR, hiding_tyvar_RDR, qualified_tyvar_RDR
        , export_tyvar_RDR, label_tyvar_RDR, dynamic_tyvar_RDR
        , unsafe_tyvar_RDR
 
@@ -72,9 +69,6 @@ parseError s =
   getSrcLocP `thenP` \ loc ->
   failMsgP (hcat [ppr loc, text ": ", text s])
 
-parseErrorOnInput :: P a
-parseErrorOnInput buf PState{ loc = loc } = PFailed (srcParseErr buf loc)
-
 srcParseErr :: StringBuffer -> SrcLoc -> Message
 srcParseErr s l
   = hcat [ppr l, ptext SLIT(": parse error on input "),
@@ -83,18 +77,6 @@ srcParseErr s l
 cbot = panic "CCall:result_ty"
 
 -----------------------------------------------------------------------------
--- Special Ids
-
-checkAs, checkQualified, checkHiding :: FAST_STRING -> P ()
-
-checkAs s       | s == SLIT("as")        = returnP ()
-                | otherwise              = parseErrorOnInput
-checkQualified s | s == SLIT("qualified") = returnP ()
-                | otherwise              = parseErrorOnInput
-checkHiding s           | s == SLIT("hiding")    = returnP ()
-                | otherwise              = parseErrorOnInput
-
------------------------------------------------------------------------------
 -- splitForConApp
 
 -- When parsing data declarations, we sometimes inadvertently parse
@@ -446,18 +428,27 @@ unitName = SLIT("()")
 funName  = SLIT("(->)")
 listName = SLIT("[]")
 
+asName              = SLIT("as")
+hidingName          = SLIT("hiding")
+qualifiedName       = SLIT("qualified")
 forallName          = SLIT("forall")
 exportName         = SLIT("export")
 labelName          = SLIT("label")
 dynamicName        = SLIT("dynamic")
 unsafeName          = SLIT("unsafe")
 
+as_var_RDR          = mkSrcUnqual varName asName
+hiding_var_RDR      = mkSrcUnqual varName hidingName
+qualified_var_RDR   = mkSrcUnqual varName qualifiedName
 forall_var_RDR      = mkSrcUnqual varName forallName
 export_var_RDR      = mkSrcUnqual varName exportName
 label_var_RDR       = mkSrcUnqual varName labelName
 dynamic_var_RDR     = mkSrcUnqual varName dynamicName
 unsafe_var_RDR      = mkSrcUnqual varName unsafeName
 
+as_tyvar_RDR        = mkSrcUnqual tvName asName
+hiding_tyvar_RDR    = mkSrcUnqual tvName hidingName
+qualified_tyvar_RDR = mkSrcUnqual tvName qualifiedName
 export_tyvar_RDR    = mkSrcUnqual tvName exportName
 label_tyvar_RDR     = mkSrcUnqual tvName labelName
 dynamic_tyvar_RDR   = mkSrcUnqual tvName dynamicName

diff --git a/ghc/compiler/parser/Parser.y b/ghc/compiler/parser/Parser.y
index f97ff96..3348da9 100644 (file)
--- a/ghc/compiler/parser/Parser.y
+++ b/ghc/compiler/parser/Parser.y
@@ -1,6 +1,6 @@
 {-
 -----------------------------------------------------------------------------
-$Id: Parser.y,v 1.8 1999/06/28 15:42:33 simonmar Exp $
+$Id: Parser.y,v 1.9 1999/06/28 16:42:23 simonmar Exp $
 
 Haskell grammar.
 
@@ -61,6 +61,7 @@ Conflicts: 14 shift/reduce
 
 %token
  '_'            { ITunderscore }               -- Haskell keywords
+ 'as'          { ITas }
  'case'        { ITcase }      
  'class'       { ITclass } 
  'data'        { ITdata } 
@@ -68,6 +69,7 @@ Conflicts: 14 shift/reduce
  'deriving'    { ITderiving }
  'do'          { ITdo }
  'else'        { ITelse }
+ 'hiding'      { IThiding }
  'if'          { ITif }
  'import'      { ITimport }
  'in'          { ITin }
@@ -79,6 +81,7 @@ Conflicts: 14 shift/reduce
  'module'      { ITmodule }
  'newtype'     { ITnewtype }
  'of'          { ITof }
+ 'qualified'   { ITqualified }
  'then'        { ITthen }
  'type'        { ITtype }
  'where'       { ITwhere }
@@ -857,6 +860,9 @@ qvarid :: { RdrName }
 
 varid :: { RdrName }
        : VARID                 { mkSrcUnqual varName $1 }
+       | 'as'                  { as_var_RDR }
+       | 'qualified'           { qualified_var_RDR }
+       | 'hiding'              { hiding_var_RDR }
        | 'forall'              { forall_var_RDR }
        | 'export'              { export_var_RDR }
        | 'label'               { label_var_RDR }
@@ -865,16 +871,14 @@ varid :: { RdrName }
 
 varid_no_unsafe :: { RdrName }
        : VARID                 { mkSrcUnqual varName $1 }
+       | 'as'                  { as_var_RDR }
+       | 'qualified'           { qualified_var_RDR }
+       | 'hiding'              { hiding_var_RDR }
        | 'forall'              { forall_var_RDR }
        | 'export'              { export_var_RDR }
        | 'label'               { label_var_RDR }
        | 'dynamic'             { dynamic_var_RDR }
 
--- ``special'' Ids
-'as'       :: { () } : VARID   {% checkAs $1 }
-'qualified' :: { () } : VARID  {% checkQualified $1 }
-'hiding'    :: { () } : VARID  {% checkHiding $1 }
-
 -----------------------------------------------------------------------------
 -- ConIds
 
@@ -966,6 +970,9 @@ qtycls      :: { RdrName }
 
 tyvar  :: { RdrName }
        : VARID                 { mkSrcUnqual tvName $1 }
+       | 'as'                  { as_tyvar_RDR }
+       | 'qualified'           { qualified_tyvar_RDR }
+       | 'hiding'              { hiding_tyvar_RDR }
        | 'export'              { export_var_RDR }
        | 'label'               { label_var_RDR }
        | 'dynamic'             { dynamic_var_RDR }

diff --git a/ghc/compiler/rename/ParseIface.y b/ghc/compiler/rename/ParseIface.y
index 419fa11..5d58b40 100644 (file)
--- a/ghc/compiler/rename/ParseIface.y
+++ b/ghc/compiler/rename/ParseIface.y
@@ -69,6 +69,9 @@ import Ratio ( (%) )
  'then'        { ITthen }
  'type'        { ITtype }
  'where'       { ITwhere }
+ 'as'          { ITas }
+ 'qualified'   { ITqualified }
+ 'hiding'      { IThiding }
 
  'forall'      { ITforall }                    -- GHC extension keywords
  'foreign'     { ITforeign }
@@ -456,6 +459,9 @@ var_fs              :: { EncodedFS }
                : VARID                 { $1 }
                | VARSYM                { $1 }
                | '!'                   { SLIT("!") }
+               | 'as'                  { SLIT("as") }
+               | 'qualified'           { SLIT("qualified") }
+               | 'hiding'              { SLIT("hiding") }
                | 'forall'              { SLIT("forall") }
                | 'foreign'             { SLIT("foreign") }
                | 'export'              { SLIT("export") }