> <quote> > my_program ( 0, 1) ( 1, 3) (( 0, 1), 15 ), (( 0,1), (7.8) ) > This is input of 2 points circle and line. > </quote> > > This isn't a simple parsing task anymore. > > Regards Hartmut
Depends. Imagine we have defined input operators for Shape classes istream& operator>>( istream&, Point& ); // accept format (x,y); in other case throw an exception istream& operator>>( istream&, Circle& ); // accept format ((x,y), r); in other case throw an exception istream& operator>>( istream&, Line& ); // accept format ((x1,y1), (x2,y2)) in other case throw an exception They could even exist by itself without CLA processing needs. Each one of them is easily implemented (with tokenizer for example). Now In combination with chain_lookup_policy we could have a cla::parser that accept above syntax with arbitrary order of elements. The idea is originated by the article "Industrial strength Pluggable Factories" that could be found online. Gennadiy. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
