I am thinking what is the next step. Probably looks like:

!FILENAME sql/parser.rs

    fn parse(&self) {
        let mut iter = self.tokens.iter();
        let category = iter.next().unwrap().token;

        match category {
            Token::CreateDatabase => {}
            Token::CreateTable => {}
            // ...
            // ...
            _ => {}
        }
    }

!FILENAME sql/create.rs

struct CreateDatabase {
    // ...
}

struct CreateTable {
    // ...
}