Struct ChatState 

pub struct ChatState { /* private fields */ }

The transcript reducer.

This is plain data: construct it in a host or wrap it in an entity. The rules are deliberately small:

• only MessageState::Streaming messages accept append;
• finish only moves a streaming message to complete;
• stop keeps the partial body;
• fail keeps the partial body and records the reason.

Implementations

impl ChatState

pub fn messages(&self) -> &[ChatMessage]

All messages in display order.

pub fn len(&self) -> usize

Number of messages.

pub fn is_empty(&self) -> bool

Returns whether the transcript is empty.

pub fn get(&self, id: MessageId) -> Option<&ChatMessage>

Look up a message by identity.

pub fn last(&self) -> Option<&ChatMessage>

The most recent message.

pub fn last_assistant(&self) -> Option<&ChatMessage>

The most recent assistant message.

pub fn streaming_id(&self) -> Option<MessageId>

The message currently streaming, if any.

pub fn is_streaming(&self) -> bool

Returns whether any message is still streaming.

pub fn push(&mut self, message: NewMessage) -> MessageId

Append a message and assign it a fresh identity.

pub fn insert_before( &mut self, before: MessageId, message: NewMessage, ) -> Option<MessageId>

Insert a message immediately before before.

Returns None when before is unknown; the transcript is unchanged in that case.

pub fn push_user(&mut self, text: impl Into<String>) -> MessageId

Append a complete user message.

pub fn push_system(&mut self, text: impl Into<String>) -> MessageId

Append a complete system notice.

pub fn begin_assistant(&mut self) -> MessageId

Append an empty streaming assistant message.

pub fn append(&mut self, id: MessageId, delta: &str) -> bool

Append delta to a streaming message.

Returns false for unknown messages and for messages that are no longer streaming, so late tokens can be dropped safely.

pub fn finish(&mut self, id: MessageId) -> bool

Mark a streaming message as complete.

pub fn stop(&mut self, id: MessageId) -> bool

Mark a streaming message as stopped by the user.

pub fn fail(&mut self, id: MessageId, error: impl Into<String>) -> bool

Mark a message as failed, keeping any partial body.

pub fn set_meta(&mut self, id: MessageId, meta: MessageMeta) -> bool

Replace a message’s footer metadata.

pub fn add_source(&mut self, id: MessageId, source: SourceRef) -> bool

Add one source to a message’s footer, deduplicating by source id.

Returns whether the source was added.

pub fn clear(&mut self)

Remove every message. Identities continue from the previous run.

pub fn remove(&mut self, id: MessageId) -> bool

Remove one message, keeping the relative order of the rest.

Returns whether the message existed.

pub fn replace( &mut self, messages: impl IntoIterator<Item = NewMessage>, ) -> Vec<MessageId>

Replace the transcript, assigning fresh identities.

Trait Implementations

impl Debug for ChatState

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

Formats the value using the given formatter.

impl Default for ChatState

fn default() -> Self

Returns the “default value” for a type.