use git_object::bstr::BStr;use git_object::immutable; /// What to do after an entry was [recorded][Visit::visit_tree()].#[derive(Clone, Copy, PartialOrd, PartialEq, Ord, Eq, Hash)]pub enum Action {    /// Continue the traversal of entries.    Continue,    /// Stop the traversal of entries, making this te last call to [`visit_(tree|nontree)(…)`][Visit::visit_nontree()].    Cancel,    /// Don't dive into the entry, skipping children effectively. Only useful in [`visit_tree(…)`][Visit::visit_tree()].    Skip,} impl Action {    /// Returns true if this action means to stop the traversal.    pub fn cancelled(&self) -> bool {        matches!(self, Action::Cancel)    }} /// A trait to allow responding to a traversal designed to observe all entries in a tree, recursively while keeping track of/// paths if desired.pub trait Visit {    /// Sets the full path path in front of the queue so future calls to push and pop components affect it instead.    fn pop_front_tracked_path_and_set_current(&mut self);    /// Append a `component` to the end of a path, which may be empty.    fn push_back_tracked_path_component(&mut self, component: &BStr);    /// Append a `component` to the end of a path, which may be empty.    fn push_path_component(&mut self, component: &BStr);    /// Removes the last component from the path, which may leave it empty.    fn pop_path_component(&mut self);     /// Observe a tree entry that is a tree and return an instruction whether to continue or not.    /// [`Action::Skip`] can be used to prevent traversing it, for example if it's known to the caller already.    ///    /// The implementation may use the current path to learn where in the tree the change is located.    fn visit_tree(&mut self, entry: &immutable::tree::Entry<'_>) -> Action;     /// Observe a tree entry that is NO tree and return an instruction whether to continue or not.    /// [`Action::Skip`] has no effect here.    ///    /// The implementation may use the current path to learn where in the tree the change is located.    fn visit_nontree(&mut self, entry: &immutable::tree::Entry<'_>) -> Action;}