Struct Selection 

pub struct Selection {
    pub anchor: Position,
    pub head: Position,
    pub visual: Option<VisualMode>,
}

One cursor or visual extent in a buffer.

anchor and head are not ordered: moving backwards in Visual mode puts head before anchor, and consumers normalise (min/max) when they need a span. With visual set, the extent follows vim’s inclusive convention — Charwise covers the character at head too (a renderer converts to a half-open Range by extending end one character), Linewise covers whole lines regardless of the byte columns, and Blockwise covers the rectangle the two corners span.

Examples

use lattice_protocol::{Position, Selection, VisualMode};

let caret = Selection::cursor(Position::new(4, 2));
assert!(caret.is_cursor());

// A backwards charwise selection: head precedes anchor.
let backwards = Selection {
    anchor: Position::new(0, 8),
    head: Position::new(0, 3),
    visual: Some(VisualMode::Charwise),
};
assert!(!backwards.is_cursor());
assert!(backwards.head < backwards.anchor);

Fields

anchor: Position

The fixed end — where Visual mode was entered. Equals head for a plain cursor.

head: Position

The moving end: the cursor the user sees and motions move.

visual: Option<VisualMode>

The visual-mode shape of the extent, or None outside Visual mode.

Implementations

impl Selection

pub const fn cursor(at: Position) -> Self

A plain cursor at at: anchor == head, no visual extent.

pub fn is_cursor(&self) -> bool

true for a plain cursor: collapsed and not in Visual mode. A one-character visual selection (anchor == head, visual set) is not a cursor — it selects that character.

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 Copy for Selection

impl Debug for Selection

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Selection

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Selection

impl PartialEq for Selection

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Selection

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Selection