Hello, How to parse lists?

Hello,

How to parse "parameter ccc , ccc, ggg, ddd" ? dynamical - not static!
I get success: "parameter ccc, vv vvv vvv",
and this is wrong.

TIA for help
Jens

This rule, I use, is wrong:

   symbol_def_parameter =
     (symbol_parameter >> symbol_alpha >> *(qi::char_(',') % symbol_alpha))
     ;

              symbol_alpha =
                   qi::char_("a-zA-Z_") >>
                  *qi::char_("a-zA-Z0-9_")
                  ;

symbol_parameter = no_case["parameter"];


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