Struct NavCursor 

pub struct NavCursor<'a, K, V, S> { /* private fields */ }

A graph-navigational cursor that sits directly on a tree node, exposing raw topography traversal and augmented subtree metrics.

Unlike a standard, linear cursor that tracks abstract gaps between elements, the NavCursor provides power-users with low-level access to the tree’s actual graph edges (left, right, and parent) along with the node’s sorted sequence links (next, prev).

The State Model: Advance-and-Yield

All mutation methods (next, prev, left, right, parent) follow a look-before-you-leap sequence:

1. They move the internal cursor pointer to the target destination node first.
2. If the destination exists, they update the state and yield its data.
3. If the edge points to an empty child or terminal bound, the internal state becomes None, and the method yields None.

⚠️ Crucial Warning: Because movement methods advance the cursor before reading, calling a movement method immediately after initialization will skip the data of the node you started on. Always check .get() first if you need to process the initial search node.

Implementations

impl<'a, K, V, S> NavCursor<'a, K, V, S>

pub fn get(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the current node’s key, value, and stats.

pub fn peek_next(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the next node’s key, value, and stats without moving the cursor.

pub fn peek_prev(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the previous node’s key, value, and stats without moving the cursor.

pub fn peek_parent(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the parent node’s key, value, and stats without moving the cursor.

pub fn peek_left(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the left child node’s key, value, and stats without moving the cursor.

pub fn peek_right(&self) -> Option<(&'a K, &'a V, &'a S)>

Returns a reference to the right child node’s key, value, and stats without moving the cursor.

pub fn next(&mut self) -> Option<(&'a K, &'a V, &'a S)>

Moves the cursor to the next node in sorted order and returns its key, value, and stats.

pub fn prev(&mut self) -> Option<(&'a K, &'a V, &'a S)>

Moves the cursor to the previous node in sorted order and returns its key, value, and stats.

pub fn parent(&mut self) -> Option<(&'a K, &'a V, &'a S)>

Moves the cursor to the parent node and returns its key, value, and stats.

pub fn left(&mut self) -> Option<(&'a K, &'a V, &'a S)>

Moves the cursor to the left child node and returns its key, value, and stats.

pub fn right(&mut self) -> Option<(&'a K, &'a V, &'a S)>

Moves the cursor to the right child node and returns its key, value, and stats.

Trait Implementations

impl<K, V, S> Clone for NavCursor<'_, K, V, S>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a, K: Copy, V: Copy, S: Copy> Copy for NavCursor<'a, K, V, S>

impl<'a, K: Debug, V: Debug, S: Debug> Debug for NavCursor<'a, K, V, S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.