(cmark >= 1.0.0)
CommonMark\Interfaces\IVisitor::enter — Visitation
$visitable): int|IVisitable|nullvisitableThe current CommonMark\Interfaces\IVisitable being entered
Returning CommonMark\Interfaces\IVisitor::Done will cause the backing iterator to exit.
Returning CommonMark\Interfaces\IVisitor::Enter will reset the backing iterator at entering the current IVisitable
Returning CommonMark\Interfaces\IVisitor::Leave will reset the backing iterator at exiting the current IVisitable
Returning an IVisitable will reset the backing iterator at entering the given IVisitable
Returning nothing will allow the backing iterator to continue