Enum HexeractError 

#[non_exhaustive]
pub enum HexeractError {
    #[non_exhaustive]
    HandlerNotFound {
        message_type: &'static str,
    },
    #[non_exhaustive]
    HandlerFailed {
        source: Box<dyn Error + Send + Sync>,
    },
    #[non_exhaustive]
    Timeout {
        type_name: &'static str,
        duration: Duration,
    },
    #[non_exhaustive]
    DowncastFailed {
        expected: &'static str,
    },
    #[non_exhaustive]
    InputDowncastFailed {
        expected: &'static str,
    },
    #[non_exhaustive]
    Cancelled {
        type_name: &'static str,
    },
    #[non_exhaustive]
    PublishFailed {
        notification_type: &'static str,
        total: usize,
        failures: Vec<NotificationFailure>,
    },
    Dispatch(String),
}

Top-level error type for the Hexeract framework.

This enum is marked #[non_exhaustive] so that new variants can be added in minor versions without breaking downstream match arms.

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.

#[non_exhaustive]

HandlerNotFound

No handler was registered for the given message type.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

message_type: &'static str

The fully-qualified type name of the unregistered command, query or notification.

#[non_exhaustive]

HandlerFailed

A handler returned an error. The original error is preserved as source.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

source: Box<dyn Error + Send + Sync>

The original error returned by the handler.

#[non_exhaustive]

Timeout

A dispatch exceeded its configured deadline.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

type_name: &'static str

Fully-qualified type name of the message being dispatched.

duration: Duration

Configured timeout that was exceeded.

#[non_exhaustive]

DowncastFailed

A dispatch produced a value that could not be downcast to the expected output type.

This indicates a short-circuiting Middleware boxed a value whose type is not the message’s Output. A correct short-circuit must box exactly the dispatched message’s output type.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

expected: &'static str

Fully-qualified name of the output type the dispatch expected.

#[non_exhaustive]

InputDowncastFailed

The boxed input passed to an erased handler could not be downcast to the concrete message type the handler was registered for.

Under normal operation this variant is unreachable: the mediator only boxes a value of type C, Q, or Arc<N> immediately before calling the matching typed adapter, so the downcast always succeeds. A mismatch would indicate an internal invariant violation in the dispatch plumbing.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

expected: &'static str

Fully-qualified name of the message type the adapter expected.

#[non_exhaustive]

Cancelled

A dispatch was cancelled before the handler produced a result because its HandlerContext cancellation token fired.

The dispatch pipeline observes the token before each middleware and before the terminal handler, so a middleware that cancels the token short-circuits the rest of the chain. Handlers and middlewares may also raise this variant themselves via HexeractError::cancelled.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

type_name: &'static str

Fully-qualified type name of the message whose dispatch was cancelled.

#[non_exhaustive]

PublishFailed

One or more notification handlers failed during a publish fan-out.

Every handler runs regardless of its siblings; the failures are collected here in registration order, each retaining the handler’s typed error and its source chain. Prefer matching this variant and inspecting NotificationFailure over parsing the message when a caller needs to recover an individual handler’s error.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

notification_type: &'static str

Fully-qualified type name of the published notification.

total: usize

Total number of handlers the notification fanned out to.

failures: Vec<NotificationFailure>

Per-handler failures, in registration order.

Dispatch(String)

A generic dispatch-level error with a human-readable message.

Reserved as a last resort for cases that have no dedicated structured variant, such as aggregating several notification handler failures into one message, or reporting a framework invariant violation. Prefer a specific variant (HandlerNotFound, DowncastFailed, Cancelled, …) whenever one applies.

Implementations

impl HexeractError

pub fn handler_not_found(message_type: &'static str) -> Self

Builds a HexeractError::HandlerNotFound from the fully-qualified type name of the unregistered message. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

pub fn handler_failed(source: impl Error + Send + Sync + 'static) -> Self

Wraps any Send + Sync error as a HexeractError::HandlerFailed.

pub fn timeout(type_name: &'static str, duration: Duration) -> Self

Builds a HexeractError::Timeout from the dispatched message type name and the timeout that was exceeded. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

pub fn downcast_failed(expected: &'static str) -> Self

Builds a HexeractError::DowncastFailed from the fully-qualified name of the output type the dispatch expected. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

pub fn input_downcast_failed(expected: &'static str) -> Self

Builds a HexeractError::InputDowncastFailed from the fully-qualified name of the message type the erased adapter expected. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

pub fn cancelled(type_name: &'static str) -> Self

Builds a HexeractError::Cancelled from the fully-qualified name of the message whose dispatch was cancelled. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

pub fn publish_failed( notification_type: &'static str, total: usize, failures: Vec<NotificationFailure>, ) -> Self

Builds a HexeractError::PublishFailed from the published notification’s type name, the total number of handlers it fanned out to, and the per-handler failures collected in registration order. This is the only way to construct the variant from outside this crate, since it is marked #[non_exhaustive].

Trait Implementations

impl Debug for HexeractError

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

Formats the value using the given formatter.

impl Display for HexeractError

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

Formats the value using the given formatter.

impl Error for HexeractError

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.