Struct ActiveSnippet 

pub struct ActiveSnippet {
    pub origin_offset: usize,
    pub groups: Vec<TabstopGroup>,
    pub current: usize,
}

State of an in-flight snippet expansion.

Fields

origin_offset: usize

Where in the buffer this snippet began. The host uses this as the reference origin for offset arithmetic on the tabstop ranges.

groups: Vec<TabstopGroup>

Tabstop groups in display order ($1, $2, …, $0 last when present). Cycle order matches the LSP / TextMate convention: 1, 2, 3, …, then 0 to exit.

current: usize

Index into groups of the currently-focused group. groups.len() means “no focus yet” (just expanded; next <Tab> focuses index 0).

Implementations

impl ActiveSnippet

pub fn from_render(rendered: &RenderedSnippet, origin_offset: usize) -> Self

Build from a freshly-rendered snippet placed at the given byte offset in the buffer. Groups are built in $1 -> $2 -> ... -> $0 order so navigation matches the LSP convention.

pub fn has_tabstops(&self) -> bool

True when the snippet has at least one tabstop group to navigate. False when the body was pure literal text (in which case the host doesn’t need an ActiveSnippet at all).

pub fn focus_first(&mut self) -> Option<&TabstopGroup>

Focus the first tabstop group. Called by the host right after inserting the rendered text. Returns the group, or None when the snippet has no tabstops.

pub fn next(&mut self) -> Option<&TabstopGroup>

Step to the next tabstop group. Returns None when the snippet has been exited ($0 consumed or no further groups). The host drops the ActiveSnippet when this returns None.

pub fn prev(&mut self) -> Option<&TabstopGroup>

Step backward. Returns None when already at the first group.

pub fn current_group(&self) -> Option<&TabstopGroup>

Currently-focused group, when one is.

pub fn current_index(&self) -> Option<u32>

Currently-focused group’s index ($N).

pub fn shift_ranges_after(&mut self, at: usize, delta: isize)

Shift downstream ranges after a buffer edit at byte offset at. The host calls this AFTER manually expanding the active tabstop’s range to include the edit; this method only handles ranges strictly past the edit point. delta is signed: positive on insert, negative on delete.

The split (host expands active tabstop, this expands downstream) keeps the contract small. Snippet engines that ripple mirror edits typically own the per-mirror expansion logic; v1 does that host-side too. A future ripple_edit helper can encapsulate both halves once the host’s edit-pipeline integration lands.

Trait Implementations

impl Clone for ActiveSnippet

fn clone(&self) -> ActiveSnippet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ActiveSnippet

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

Formats the value using the given formatter.