Enum Selection 

pub enum Selection {
    Char {
        anchor: Position,
        head: Position,
    },
    Line {
        anchor_row: usize,
        head_row: usize,
    },
    Block {
        anchor: Position,
        head: Position,
    },
}

First-class vim selection. Each variant carries the kind directly rather than relying on a single char-range primitive with separate “treat as line / block” overlays — that’s the whole point of owning the buffer model. Anchor is where the user pressed v / V / Ctrl-V; head moves with the cursor and is updated via Selection::extend_to.

Variants

Char

v — character-wise. Covers anchor..=head inclusive, row-major. Empty rows in the middle of a multi-row span are treated as having one virtual cell so the highlight is visible (matches vim).

Fields

anchor: Position

head: Position

Line

V — line-wise. Both endpoints are pure row indices; column is irrelevant (the whole row is always covered).

Fields

anchor_row: usize

head_row: usize

Block

Ctrl-V — block-wise. Covers the inclusive rectangle whose corners are anchor and head. Row range is min..=max; column range is min..=max independently of the corner diagonals.

Fields

anchor: Position

head: Position

Implementations

impl Selection

pub fn head(self) -> Position

Where the cursor end of the selection lives. After Selection::extend_to this is the freshly-set value.

pub fn anchor(self) -> Position

The opposite end of the selection — fixed when the user entered visual mode.

pub fn extend_to(&mut self, pos: Position)

Move the cursor end of the selection to pos. Anchor stays put; for Line we drop the column since rows are all that matter.

pub fn row_span(self, row: usize) -> RowSpan

What columns of row the selection covers. Used by the render layer to paint the selection bg without having to know each variant’s quirks.

• Char on a single row: [min_col, max_col].
• Char spanning rows: from head/anchor.col on the start row to end-of-line, then full rows in between, then 0..=end.col on the last row.
• Line: (0, usize::MAX) for every row in range.
• Block: [min_col, max_col] regardless of which row.

pub fn row_bounds(self) -> (usize, usize)

Inclusive (top_row, bottom_row) covered by the selection.

Trait Implementations

impl Clone for Selection

fn clone(&self) -> Selection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Selection

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

Formats the value using the given formatter.

impl PartialEq for Selection

fn eq(&self, other: &Selection) -> 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 Selection

impl Eq for Selection

impl StructuralPartialEq for Selection