The primary difference in tree-visitor is that the visit-node function returns several items: a new-node, a new-state, and a stop flag.

tree-visitor 中的主要差别在于，visit-node 函数返回多个项目：一个 new-node、一个 new-state 和一个 stop 标记。

youdao

Wigfall agreed. He told Anderson to lower his flag and the firing would stop.

VOA: special.2009.08.13

Tensions have been high since city council members there voted a month ago to stop flying the Union flag year-round, restricting it instead to certain days.

CNN: SHARE THIS

However Mr Aylward urged critics to stop focusing excessively on the flag issue.

BBC: MEPs split over EU's role in sport

Tensions have been high since City Council members there voted a month ago to stop flying the Union Jack flag year-round, restricting it instead to certain days.

CNN: STORY HIGHLIGHTS