Why use fold_with(x), while x has already implemented visit_mut

[JSerFeng]

From source, I found there is one line let module = module.fold_with(&mut resolver_with_mark(top_level_mark));, resolve_with_mark() returns value has already implemented VisitMut, and the doc says that VisitMut is better than fold, am I misunderstanding

[kdy1]

VisitMut is better, but it's the same for the caller if they call a visitor wrapped with as_folder

[JSerFeng]

Is calling module.visit_mut(&mut resolver_with_mark(top_level_mark)) directly has problems, thought it is more intuitive

[kdy1]

No it's actually better

[JSerFeng]

고맙습니다. 늦은 시간에 폐를 끼쳐서 죄송합니다. 안녕히 주무세요.