%semantic token 'c' 
%tree
%{
use Data::Dumper;
$Data::Dumper::Indent = 1;
%}
%%
S:      'c'+  'd'+ 
           { 
              print Dumper($_[1]);
              print Dumper($_[2]);
           } 
;

%%

# eyapp -C  List3_tree.yp
# ./List3_tree.pm -c 'ccdd'