Enum ProtocolError 

pub enum ProtocolError {
    PayloadMismatch {
        expected: Payload,
        got: Payload,
    },
    UnexpectedFrame {
        cursor_kind: &'static str,
        frame_kind: &'static str,
    },
    UnknownLabel {
        label: String,
        expected: Vec<String>,
    },
    CreditExhausted {
        payload: Payload,
        budget: u64,
    },
    AlreadyComplete {
        frame_kind: &'static str,
    },
    MalformedFrame(String),
    Transport(String),
    NoInterruptArmed,
    SignalMismatch {
        expected: Payload,
        got: Payload,
    },
    WatchdogBreach {
        bound: u32,
        actual: u32,
    },
    DoubleResume,
}

Runtime protocol violation — the peer’s next frame is inconsistent with the session-type cursor or with the credit window.

Variants

PayloadMismatch

The cursor expected a send/recv of payload expected but the peer’s frame announced payload got. The static type discipline is violated — at runtime this means the peer is not running the dual of our declared role.

Fields

expected: Payload

got: Payload

UnexpectedFrame

The cursor expected an operation of one kind (e.g. recv) but the peer’s frame announced another (e.g. select). The connection state machine has no transition rule for the observed input.

Fields

cursor_kind: &'static str

frame_kind: &'static str

UnknownLabel

The cursor is at an internal/external choice and the peer’s label is not in the type’s arm set. Lists the declared labels so the peer can recover.

Fields

label: String

expected: Vec<String>

CreditExhausted

A send was attempted at zero available credit — the §Fase 41.c “no rule at n = 0” axiom (paper §4.2) projected onto the runtime. Static analysis (credit_analyse) catches this at compile time when the declared protocol demands more than k sends in a burst; at runtime it is the dynamic-safety net for an off-spec peer.

Fields

payload: Payload

budget: u64

AlreadyComplete

The cursor has reached end but the peer sent more data, or the peer requested an action while we already closed our half.

Fields

frame_kind: &'static str

MalformedFrame(String)

The frame did not parse as a well-formed AXON session-typed envelope (malformed JSON, unknown kind, missing required field). Carries the raw payload for diagnostics.

Transport(String)

The transport (WebSocket) returned an I/O error or was closed abruptly mid-dialogue.

NoInterruptArmed

§Fase 79.d — a signal fired but no interruptible region is armed (the cursor is not inside an interrupt { … } body).

SignalMismatch

§Fase 79.d — the fired signal’s cause does not match the armed region’s declared on <Signal>.

Fields

expected: Payload

got: Payload

WatchdogBreach

§Fase 79.d — the fail-closed WCET watchdog (D79.5): the reaction path (signal → cancellation-acknowledged) took more transitions than the statically-declared bound. A breach never silently degrades — it trips this fault, which the carrier audits.

Fields

bound: u32

actual: u32

DoubleResume

§Fase 79.d — resume invoked on an already-consumed (or never captured) one-shot continuation — the linear-type violation of D79.1, caught at runtime even if it somehow slipped the static check.

Implementations

impl ProtocolError

pub fn code(&self) -> &'static str

A compact identifier suitable for the WebSocket close-frame reason payload (RFC 6455 §5.5.1 caps the reason at 123 bytes UTF-8 — keep these stable, short and machine-readable).

Trait Implementations

impl Clone for ProtocolError

fn clone(&self) -> ProtocolError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ProtocolError

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

Formats the value using the given formatter.

impl Display for ProtocolError

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

Formats the value using the given formatter.

impl Eq for ProtocolError

impl Error for ProtocolError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for ProtocolError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ProtocolError