* Add comment field for schema.

* Replace wait by try.

* Move out the comment from space option.

* Change parameter order.

* Format feature file.

* Fix the memory leak. And try the std::vairant instead of boost::variant.

* Throw the semantic error when exceed comment length limit.

* Rename the nullable getter.

* Check the comment length in parser.

* Add chinese comment.

* Ignore the can't check file.

* Format.

Co-authored-by: Yee <2520865+yixinglu@users.noreply.github.com>