Enum MessageResult 

#[non_exhaustive]
pub enum MessageResult {
    Delivered {
        response: String,
    },
    Failed(ServerError),
    Refused(ServerError),
    NotSent {
        reason: String,
    },
}

What became of a message you sent.

A message can fail in three different places and this crate keeps them apart, because the right response differs: a message that never left this client can be retried immediately, one the server refused will be refused again, and one the Metadata Adapter rejected is an application-level answer.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Delivered

The Metadata Adapter processed the message without raising [docs/spec/04-notifications.md §4.1].

Fields

response: String

The adapter’s own response text, empty when it supplied none. Its meaning is entirely the application’s.

Failed(ServerError)

The message reached the server but was not delivered, or the Metadata Adapter failed while processing it [docs/spec/04-notifications.md §4.2].

Appendix B codes 32, 33, 38 and 39 concern the sequence numbering specifically — a progressive already used, or one skipped because the server stopped waiting for it [docs/spec/05-error-codes.md §2].

Refused(ServerError)

The server refused the request outright, so no delivery outcome will ever follow [docs/spec/03-requests.md §13.2].

NotSent

The message never reached the server.

Messages are not buffered and not resent. A subscription is a statement of desired state and is safely re-created on whatever session comes next; a message is a one-shot side effect whose ordering and deduplication the server tracks per session. Replaying one across a session replacement would restart the numbering the server deduplicates against, so this crate fails the send rather than promise an ordering it cannot keep. Whether to retry is yours to decide, because you are the only one who can decide it correctly.

Fields

reason: String

What stopped it. Never contains a credential.

Trait Implementations

impl Clone for MessageResult

fn clone(&self) -> MessageResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MessageResult

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

Formats the value using the given formatter.

impl Eq for MessageResult

impl PartialEq for MessageResult

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MessageResult