[project @ 1998-06-08 11:45:09 by simonpj]

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

diff --git a/ghc/compiler/parser/hsparser.y b/ghc/compiler/parser/hsparser.y
index 05441f9..ab59ce6 100644 (file)
--- a/ghc/compiler/parser/hsparser.y
+++ b/ghc/compiler/parser/hsparser.y
@@ -504,10 +504,14 @@ deriving: /* empty */                             { $$ = mknothing(); }
         | DERIVING dtyclses                     { $$ = mkjust($2); }
        ;
 
-classd :  classkey simple_context DARROW simple_con_app1 cbody
-               { $$ = mkcbind($2,$4,$5,startlineno); }
-       |  classkey simple_con_app1 cbody                       
-               { $$ = mkcbind(Lnil,$2,$3,startlineno); }
+classd :  classkey btype DARROW simple_con_app1 cbody
+               /* Context can now be more than simple_context */
+               { $$ = mkcbind(type2context($2),$4,$5,startlineno); }
+       |  classkey btype cbody
+               /* We have to say btype rather than simple_con_app1, else
+                  we get reduce/reduce errs */
+               { check_class_decl_head($3);
+                 $$ = mkcbind(Lnil,$2,$3,startlineno); }
        ;
 
 cbody  :  /* empty */                          { $$ = mknullbind(); }
@@ -521,7 +525,7 @@ instd       :  instkey inst_type rinst              { $$ = mkibind($2,$3,startlineno); }
 /* Compare ctype */
 inst_type : type DARROW type                   { is_context_format( $3, 0 );   /* Check the instance head */
                                                  $$ = mkcontext(type2context($1),$3); }
-         | type                                { is_context_format( $1, 0 );   /* Check the instance head */
+         | btype                               { is_context_format( $1, 0 );   /* Check the instance head */
                                                  $$ = $1; }
          ;
 
@@ -649,7 +653,7 @@ type_and_maybe_id :
 /* A sigtype is a rank 2 type; it can have for-alls as function args:
        f :: All a => (All b => ...) -> Int
 */
-sigtype        : type DARROW sigarrowtype              { $$ = mkcontext(type2context($1),$3); }
+sigtype        : btype DARROW sigarrowtype             { $$ = mkcontext(type2context($1),$3); }
        | sigarrowtype 
        ;
 
@@ -659,11 +663,11 @@ sigarrowtype : bigatype RARROW sigarrowtype       { $$ = mktfun($1,$3); }
             ;
 
 /* A "big" atype can be a forall-type in brackets.  */
-bigatype: OPAREN type DARROW type CPAREN       { $$ = mkcontext(type2context($2),$4); }
+bigatype: OPAREN btype DARROW type CPAREN      { $$ = mkcontext(type2context($2),$4); }
        ;
 
        /* 1 S/R conflict at DARROW -> shift */
-ctype   : type DARROW type                     { $$ = mkcontext(type2context($1),$3); }
+ctype   : btype DARROW type                    { $$ = mkcontext(type2context($1),$3); }
        | type
        ;
 
@@ -733,7 +737,7 @@ constrs     :  constr                               { $$ = lsing($1); }
        ;
 
 constr :  constr_after_context
-       |  type DARROW constr_after_context     { $$ = mkconstrcxt ( type2context($1), $3 ); }
+       |  btype DARROW constr_after_context    { $$ = mkconstrcxt ( type2context($1), $3 ); }
        ;
 
 constr_after_context :