Struct Cursor 

pub struct Cursor {
    pub position: usize,
    pub anchor: Option<usize>,
    pub sticky_column: usize,
    pub selection_mode: SelectionMode,
    pub block_anchor: Option<Position2D>,
    pub deselect_on_move: bool,
}

A cursor in the buffer with optional selection

Fields

position: usize

Primary position (where edits happen) - byte offset

anchor: Option<usize>

Selection anchor (if any) for visual selection - byte offset

sticky_column: usize

Desired column for vertical navigation When moving up/down, try to stay in this column

selection_mode: SelectionMode

Selection mode (normal or block)

block_anchor: Option<Position2D>

Block selection anchor position (line, column) for rectangular selections Only used when selection_mode is Block

deselect_on_move: bool

Whether regular movement should clear the selection (default: true) When false (e.g., after set_mark in Emacs mode), movement preserves the anchor

Implementations

impl Cursor

pub fn new(position: usize) -> Self

Create a new cursor at a position

pub fn with_selection(start: usize, end: usize) -> Self

Create a cursor with a selection

pub fn collapsed(&self) -> bool

Is the cursor collapsed (no selection)?

pub fn selection_range(&self) -> Option<Range<usize>>

Get the selection range, if any (for normal selection)

pub fn has_block_selection(&self) -> bool

Check if this cursor has a block selection

pub fn block_selection_bounds(&self) -> Option<(usize, usize, usize, usize)>

Get the block selection bounds (start_line, start_col, end_line, end_col) Returns None if not in block selection mode

pub fn selection_start(&self) -> usize

Get the start of the selection (min of position and anchor)

pub fn selection_end(&self) -> usize

Get the end of the selection (max of position and anchor)

pub fn clear_selection(&mut self)

Clear the selection, keeping only the position

pub fn set_anchor(&mut self, anchor: usize)

Set the selection anchor

pub fn start_block_selection(&mut self, line: usize, column: usize)

Start a block selection at the given 2D position

pub fn clear_block_selection(&mut self)

Clear block selection and return to normal mode

pub fn move_to(&mut self, position: usize, extend_selection: bool)

Move to a position, optionally extending selection

pub fn adjust_for_edit( &mut self, edit_pos: usize, old_len: usize, new_len: usize, )

Adjust cursor position after an edit If an edit happens before the cursor, adjust position accordingly

Trait Implementations

impl Clone for Cursor

fn clone(&self) -> Cursor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Cursor

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

Formats the value using the given formatter.

impl PartialEq for Cursor

fn eq(&self, other: &Cursor) -> 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 Copy for Cursor

impl Eq for Cursor

impl StructuralPartialEq for Cursor