how to parse class in class

Hello,

I would like to parse a CLASS in CLASS dynamically.
How can I do it?

qi::rule<Iterator, Skipper> symbol_def_class;

symbol_class    = "CLASS"
symbol_of       = "OF"
symbol_endclass = "ENDCLASS"

symbol_alpha = +[a-zA-Z] *[a-zA-Z0-9_]


              symbol_def_class =
                  (symbol_class >> symbol_alpha >> symbol_of >> 
symbol_alpha >>
                   symbol_endclass >> (qi::eoi | qi::eol))
                  |
                  (symbol_class >> symbol_alpha >> symbol_of >> 
symbol_alpha >>
                  (symbol_def_class_inner) >>
                   symbol_endclass >> (qi::eoi | qi::eol))
                  ;

              symbol_def_class_inner =
                  *( symbol_class >> symbol_alpha >> symbol_of  >> 
symbol_alpha
                  >  symbol_endclass)
                  |
                  *( symbol_class >> symbol_alpha >> symbol_of  >> 
symbol_alpha
                  >> *(symbol_def_class_inner) > symbol_endclass)
                  ;

As Result:

CLASS
...
     CLASS
     ...
     ENDCLASS
....
ENDCLASS

TIA
Jens


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