Page Comparison

parse_expr[int p]
   :   primary
       (   {prec[input.LA(1)]>=p}?=>     bop r= parse_expr[nextp(p)]
           {
           switch ( $bop.start.getType() ) {
               case '+' :
               case '-' :
                  action-for-this-alt
                  break;
               ...
               case '=' :
                  action-for-this-alt
                  break;
               default : // no action
           }
           }
       |   {postprec[input.LA(1)]>=p}?=> suffix[$e.tree]
       )*
   ;

suffix[CommonTree lhs]
   :   t='[' expre ']'                -> ^(INDEX[$t] {$lhs} expre)
   |   t='(' (expre (',' expre)*)? ')' -> ^(CALL[$t] {$lhs} expre*)
   |   t='++'                        -> ^(POSTINC[$t] {$lhs})
   ;