Struct TurnTracker 

pub struct TurnTracker {
    pub turns: Vec<Turn>,
}

Tracks turn boundaries over a Vec<Message>.

This is a lightweight index — it doesn’t own the messages, just tracks where each turn starts and how many messages it contains.

Fields

turns: Vec<Turn>

Implementations

impl TurnTracker

pub fn new() -> Self

pub fn rebuild(messages: &[Message]) -> Self

Rebuild the turn index from an existing message list. Used when loading conversation history from disk.

pub fn on_user_message(&mut self, msg_idx: usize)

Notify that a new user message was added at msg_idx. Closes the previous turn and opens a new Active turn.

── SAFETY INVARIANT ── This method assumes msg_idx >= prev.start_idx (always true when messages are added sequentially). However, after compression, this invariant could be violated if Turn indices are corrupted. We now defend against this by clamping the result.

pub fn on_message_added(&mut self, msg_idx: usize)

Notify that a message was appended (assistant text, tool call, tool result). Extends the current active turn’s msg_count.

pub fn complete_current(&mut self)

Mark the current (last) turn as completed.

pub fn active_turn(&self) -> Option<&Turn>

Get the current (last) active turn, if any.

pub fn completed_count(&self) -> usize

Number of completed turns (available for summarization).

Trait Implementations

impl Clone for TurnTracker

fn clone(&self) -> TurnTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TurnTracker

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

Formats the value using the given formatter.

impl Default for TurnTracker

fn default() -> TurnTracker

Returns the “default value” for a type.