Support template file

[Kazuki Shimizu]

In current version, template file(vm file) does not support.

For example:

• CityMapper-findByState.vm

select
  id, name, state, country
from
  city
where
  state = @{state}

• Mapper

@Select("#parse('/mappers/CityMapper-findByState.vm')")
City findByState(@Param("state") String state);

In above case, @{state} cannot translate to JDBC bind variable (?).

We will consider to support a template file(.vm) like as mybatis-freemarker and mybatis-thymeleaf.