Perhaps in the future, deterministic parsers when added to the framework, will perform no backtracking and will need just a single token lookahead, hence will require input iterators only.

• 也许在将来，确定性的分析器被增加到本框架中时，将不再执行回溯，只需要前瞻一个记号，这时只需要输入迭代器即可。