The cross referencing problems may be solved by some kind of forward declaration, or, if this does not work, by introducing some dummy template argument to the non-templated grammars.

• 交叉引用的问题可以通过一些前向声明来解决，或者，如果这样不行的话，也可以通过向非模板语法引入一些伪模板参数来解决。