Struct EditorSnapshot 

pub struct EditorSnapshot {
    pub text: Text,
    pub cursor: (usize, usize),
    pub content_revision: NonZeroU64,
}

Atomic view of the editor’s (lines, cursor, content_revision) tuple at a single point in time. Producers (today TextEditorComponent::view_snapshot) own the construction-time invariant: the cursor’s row is in-bounds for lines. Consumers (view.rs, click_to_logical_u16, the autocomplete host, etc.) take a &EditorSnapshot and skip the per-leaf .get() guards that previously defended against drift between cursor and lines.

The Cow lets the Textarea backend borrow its lines directly (zero clone) while the Nvim backend clones out from behind its Mutex (the lines must outlive the MutexGuard, which is dropped before the snapshot is returned).

Fields

text: Text

The text itself. Cloning one is O(1) — the rope shares its structure — so a snapshot is the buffer’s text rather than a copy of it, and the cursor below cannot drift away from what it was read with.

cursor: (usize, usize)

(row, col), clamped at construction when the producer’s source was stale. A text always has at least one row, so there is no empty-buffer case to special-case.

content_revision: NonZeroU64

Content identity at construction. Stable across cursor moves; bumps on real text changes only (see [[decouple-text-revision]]).

Implementations

impl EditorSnapshot

pub fn borrowed( lines: &[String], cursor: (usize, usize), content_revision: NonZeroU64, ) -> Self

Build one from rows, for the nvim backend and for tests.

pub fn of_buffer( text: Text, cursor: (usize, usize), content_revision: NonZeroU64, ) -> Self

The hot path: the buffer already holds the text, so nothing is rebuilt.

pub fn owned( lines: Vec<String>, cursor: (usize, usize), content_revision: NonZeroU64, ) -> EditorSnapshot

Owned-mode constructor for the Nvim backend (lines cloned out from behind the Mutex) and for tests that don’t have a long-lived borrow.

pub fn cursor_in_bounds(&self) -> bool

true when the cursor’s row exists. A text always has at least one row, so this is false only for a cursor past the end.

pub fn cursor_row_clamped(&self) -> usize

Cursor row, guaranteed to exist.

pub fn cursor_line(&self) -> Cow<'_, str>

The cursor row’s text.

pub fn cursor_byte_offset(&self) -> usize

The cursor’s byte offset into the whole buffer.

Was a row walk summing lengths; the text addresses it directly. The row is clamped and an unrepresentable column falls back to the end of the buffer — the return type leaves no way to refuse, and the callers (the autocomplete controller) treat the offset as a trigger point rather than an edit site.