Enum Address 

pub enum Address {
    Direct {
        participant: ParticipantId,
    },
    Session {
        participant: ParticipantId,
        session: SessionId,
    },
    Room {
        room: RoomId,
    },
}

Where a message goes, or who it is from: one account directly, one of that account’s live sessions, or a room the mailbox tracks membership for. Serde-tagged on kind ("direct" / "session" / "room").

Replaces the source’s HarnessMailAddressV1::Session/Task: a room is a named group of participants the mailbox itself tracks, with no relationship to any task system – unlike Task, which addressed every grant able to read a given task_id in a foreign task kernel this crate must never learn about. Self::Session is this crate’s own addition (mailbox-service-extraction-and-signed-session-identity-2026-09-16.md §5e): a session is a participant, not a new concept beside one, so it is a third shape of the same address type rather than a parallel id.

Variants

Direct

Fields

participant: ParticipantId

Session

Fields

participant: ParticipantId

session: SessionId

Room

Fields

room: RoomId

Implementations

impl Address

pub fn validate(&self) -> Result<(), MailError>

pub fn account(&self) -> Option<&ParticipantId>

The account this address ultimately names: itself for Self::Direct, the owning account for Self::Session, None for Self::Room (a room has no owning account).

Trait Implementations

impl Clone for Address

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Address

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Address

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Address

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

The shape a human or a tool argument writes – claude for the account, claude/s-7f3a... for one of its sessions, #room-1 for a room – not the wire shape. The wire shape stays the tagged JSON object Serialize/Deserialize above produce; this is a second, display-only encoding, chosen to match mailbox-service-extraction-and-signed-session-identity-2026-09-16.md §5e’s own example.

impl Eq for Address

impl FromStr for Address

fn from_str(value: &str) -> Result<Self, Self::Err>

Parses the same shape [Display] writes: a leading # names a room; one / splits an account from one of its sessions; anything else is the account address directly. A room id and a participant id share the same charset (see their own new methods), so the leading # is what disambiguates a room from an account whose name happens to look the same – neither charset permits # or /, so there is nothing for either component to accidentally supply.

type Err = MailError

The associated error which can be returned from parsing.

impl Hash for Address

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Address

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Address

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Address