Struct TreeCursorMut

pub struct TreeCursorMut<'n: 'f, 'f, N: 'n> { /* private fields */ }

A cursor that holds a mutable reference to its tree.

Implementations

impl<'n, N: 'n> TreeCursorMut<'n, 'n, N>

pub fn new(root: &'n mut N) -> Self

Creates a new TreeCursorMut starting at root.

impl<'n: 'f, 'f, N: 'n> TreeCursorMut<'n, 'f, N>

pub fn down_map<F>(&mut self, f: F) -> bool

where F: Fn(&'n mut N, usize) -> Option<&'n mut N>,

Passes f the active node and the current value of the “next child” counter. If f returns a node, it’s set as the active node, the old active node’s “next child” counter is incremented, and this method returns true. Otherwise, this method returns false.

pub fn down_map_new<'s, F>( &'s mut self, f: F, ) -> Option<TreeCursorMut<'n, 's, N>>

where F: Fn(&'n mut N, usize) -> Option<&'n mut N>,

Like down_new, except that it takes a closure like down_map.

pub fn zero(&mut self)

Resets the active node’s “next child” counter to 0.

pub fn up(&mut self) -> bool

Moves the cursor up one node. Returns true if there was a node to move to, and false otherwise. In both cases, the old active node’s “next child” counter is reset, as if zero had been called.

pub fn take<'s>(&'s mut self) -> Option<TreeCursorMut<'n, 's, N>>

Takes the active node from this TreeCursorMut and returns a new TreeCursorMut at that position. self is frozen until the new cursor goes out of scope.

pub fn get(&self) -> &N

Returns a shared reference to the active node.

pub fn get_mut(&mut self) -> &mut N

Returns a mutable reference to the active node.

pub fn as_cursor<'s>(&'s self) -> TreeCursor<'n, 's, N>

impl<'n: 'f, 'f, N: 'n + DownMut> TreeCursorMut<'n, 'f, N>

pub fn pos(&self) -> TreeCursorPos

Returns an opaque object that stores the current position of the cursor. Pass it to set_pos to restore that position.

pub fn set_pos(&mut self, pos: &TreeCursorPos)

Moves the cursor to the given position, as long as tree mutation hasn’t invalidated the position since it was retrieved.

Panics

If the tree has changed such that the position is no longer valid, this method panics. However, since the position is stored using “next child” indices (not pointers), it remains valid as long as the tree has a node in that position, even if the node’s value changes or it’s replaced with another node. If this is a problem, you should track the position’s validity yourself.

pub fn down(&mut self) -> bool

Moves the cursor down one node. The node to move to is determined by calling DownMut::down_mut on the active node and passing it the “next child” counter. Returns true and increments the old active node’s “next child” counter if there was a node to move to, and returns false otherwise.

pub fn down_new<'s>(&'s mut self) -> Option<TreeCursorMut<'n, 's, N>>

Like down, except instead of moving the position of self, it returns a new TreeCursorMut whose root is the new position. self is frozen until the new cursor goes out of scope.

Trait Implementations

impl<'n: 'f, 'f, N: Debug + 'n> Debug for TreeCursorMut<'n, 'f, N>

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

Formats the value using the given formatter.

impl<'n: 'f, 'f, N: 'n> From<TreeCursorMut<'n, 'f, N>> for TreeCursor<'n, 'f, N>

fn from(cm: TreeCursorMut<'n, 'f, N>) -> Self

Converts to this type from the input type.

impl<'n: 'f, 'f, N: Hash + 'n> Hash for TreeCursorMut<'n, 'f, N>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'n: 'f, 'f, N: PartialEq + 'n> PartialEq for TreeCursorMut<'n, 'f, N>

fn eq(&self, other: &TreeCursorMut<'n, 'f, N>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'n: 'f, 'f, N: Eq + 'n> Eq for TreeCursorMut<'n, 'f, N>

impl<'n: 'f, 'f, N: 'n> StructuralPartialEq for TreeCursorMut<'n, 'f, N>