Struct Message 

pub struct Message {
    pub role: Role,
    pub content: String,
}

A single message in the conversation history.

Fields

role: Role

The role of the speaker who produced this message.

content: String

The textual content of the message.

Implementations

impl Message

pub fn new(role: Role, content: impl Into<String>) -> Self

Create a new Message with the given role and content.

Panics

This function does not panic.

pub fn user(content: impl Into<String>) -> Self

Create a User role message.

pub fn assistant(content: impl Into<String>) -> Self

Create an Assistant role message.

pub fn system(content: impl Into<String>) -> Self

Create a System role message.

pub fn role(&self) -> &Role

Return a reference to the message role.

pub fn content(&self) -> &str

Return the message content as a &str.

pub fn is_user(&self) -> bool

Return true if this is a User role message.

pub fn is_assistant(&self) -> bool

Return true if this is an Assistant role message.

pub fn is_system(&self) -> bool

Return true if this is a System role message.

pub fn is_tool(&self) -> bool

Return true if this is a Tool role message.

pub fn is_empty(&self) -> bool

Return true if the message content is empty.

pub fn word_count(&self) -> usize

Return the approximate number of whitespace-separated words in the content.

pub fn byte_len(&self) -> usize

Return the byte length of the content string.

For ASCII-only content this equals the character count; for multi-byte UTF-8 sequences it will be larger. Useful for rough token estimation.

pub fn content_starts_with(&self, prefix: &str) -> bool

Return true if the content string starts with prefix.

The check is byte-exact (case-sensitive). Returns true for an empty prefix regardless of content.

Trait Implementations

impl Clone for Message

fn clone(&self) -> Message

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Message

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Message

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Message

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

Render as "{role}: {content}".

Useful for logging and quick inspection of conversation history.

impl From<(Role, &str)> for Message

fn from((role, content): (Role, &str)) -> Self

Construct a Message from a (Role, &str) tuple.

impl From<(Role, String)> for Message

fn from((role, content): (Role, String)) -> Self

Construct a Message from a (Role, String) tuple.

impl Serialize for Message

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

where __S: Serializer,

Serialize this value into the given Serde serializer.