[project @ 1999-06-28 15:42:33 by simonmar]

[ghc-hetmet.git] / ghc / compiler / parser / Parser.y

diff --git a/ghc/compiler/parser/Parser.y b/ghc/compiler/parser/Parser.y
index 4c29906..f97ff96 100644 (file)
--- a/ghc/compiler/parser/Parser.y
+++ b/ghc/compiler/parser/Parser.y
@@ -1,6 +1,6 @@
 {-
 -----------------------------------------------------------------------------
-$Id: Parser.y,v 1.4 1999/06/02 16:05:56 simonmar Exp $
+$Id: Parser.y,v 1.8 1999/06/28 15:42:33 simonmar Exp $
 
 Haskell grammar.
 
@@ -61,7 +61,6 @@ Conflicts: 14 shift/reduce
 
 %token
  '_'            { ITunderscore }               -- Haskell keywords
- 'as'          { ITas }
  'case'        { ITcase }      
  'class'       { ITclass } 
  'data'        { ITdata } 
@@ -69,7 +68,6 @@ Conflicts: 14 shift/reduce
  'deriving'    { ITderiving }
  'do'          { ITdo }
  'else'        { ITelse }
- 'hiding'      { IThiding }
  'if'          { ITif }
  'import'      { ITimport }
  'in'          { ITin }
@@ -81,7 +79,6 @@ Conflicts: 14 shift/reduce
  'module'      { ITmodule }
  'newtype'     { ITnewtype }
  'of'          { ITof }
- 'qualified'   { ITqualified }
  'then'        { ITthen }
  'type'        { ITtype }
  'where'       { ITwhere }
@@ -501,12 +498,10 @@ inst_type :: { RdrNameHsType }
        : ctype                         {% checkInstType $1 }
 
 ctype  :: { RdrNameHsType }
-       : 'forall' tyvars '.' btype '=>' type
-                                       {% checkContext $4 `thenP` \c ->
-                                          returnP (HsForAllTy (Just $2) c $6) }
+       : 'forall' tyvars '.' context type
+                                       { HsForAllTy (Just $2) $4 $5 }
        | 'forall' tyvars '.' type      { HsForAllTy (Just $2) [] $4 }
-       | btype '=>' type               {% checkContext $1 `thenP` \c ->
-                                          returnP (HsForAllTy Nothing c $3) }
+       | context type                  { HsForAllTy Nothing   $1 $2 }
        | type                          { $1 }
 
 types0  :: { [RdrNameHsType] }
@@ -531,15 +526,23 @@ constrs :: { [RdrNameConDecl] }
        : constrs '|' constr            { $3 : $1 }
        | constr                        { [$1] }
 
-{- ToDo: existential stuff -}
-
 constr :: { RdrNameConDecl }
-       : srcloc scontype   
-               { ConDecl (fst $2) [] [] (VanillaCon (snd $2)) $1 }
-       | srcloc sbtype conop sbtype    
-               { ConDecl $3 [] [] (InfixCon $2 $4) $1 }
-       | srcloc con '{' fielddecls '}' 
-               { ConDecl $2 [] [] (RecCon (reverse $4)) $1 }
+       : srcloc forall context constr_stuff
+               { ConDecl (fst $4) $2 $3 (snd $4) $1 }
+       | srcloc forall constr_stuff
+               { ConDecl (fst $3) $2 [] (snd $3) $1 }
+
+forall :: { [RdrNameHsTyVar] }
+       : 'forall' tyvars '.'           { $2 }
+       | {- empty -}                   { [] }
+
+context :: { RdrNameContext }
+       : btype '=>'                    {% checkContext $1 }
+
+constr_stuff :: { (RdrName, RdrNameConDetails) }
+       : scontype                      { (fst $1, VanillaCon (snd $1)) }
+       | sbtype conop sbtype           { ($2, InfixCon $1 $3) }
+       | con '{' fielddecls '}'        { ($1, RecCon (reverse $3)) }
 
 newconstr :: { RdrNameConDecl }
        : srcloc conid atype    { ConDecl $2 [] [] (NewCon $3 Nothing) $1 }
@@ -633,7 +636,7 @@ exp10 :: { RdrNameHsExpr }
 
         | '_scc_' STRING exp                   { if opt_SccProfilingOn
                                                        then HsSCC $2 $3
-                                                       else $3 }
+                                                       else HsPar $3 }
 
        | fexp                                  { $1 }
 
@@ -758,10 +761,13 @@ stmtlist :: { [RdrNameStmt] }
        |     layout_on  stmts close    { reverse $2 }
 
 stmts :: { [RdrNameStmt] }
-       : stmts ';' stmt                { $3 : $1 }
-       | stmts ';'                     { $1 }
+       : ';' stmts1                    { $2 }
+       | stmts1                        { $1 }
+
+stmts1 :: { [RdrNameStmt] }
+       : stmts1 ';' stmt               { $3 : $1 }
+       | stmts1 ';'                    { $1 }
        | stmt                          { [$1] }
-       | {- empty -}                   { [] }
 
 stmt  :: { RdrNameStmt }
        : srcloc infixexp '<-' exp      {% checkPattern $2 `thenP` \p ->
@@ -851,9 +857,6 @@ 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 }
@@ -862,14 +865,16 @@ 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
 
@@ -961,9 +966,6 @@ 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 }