Enum OutcomeError 

pub enum OutcomeError {
    Arguments(String),
    Answer(String),
    NotAnObject(JsonObjectError),
    NotLowerable(LowerError),
}

Why a generated handler could not produce an answer.

Variants

Arguments(String)

The peer’s arguments object did not deserialise into the handler’s argument struct.

Carries the deserialiser’s own message. A second, shorter vocabulary for “that is not the right shape” would lose the one field a caller can act on, which is which field and why.

Answer(String)

The handler’s return value could not be serialised.

A Serialize impl that fails is a bug in the handler’s types — a non-string map key, a NaN — not a bad request, and the message says so rather than blaming the peer.

NotAnObject(JsonObjectError)

The assembled document was not a JSON object.

Cannot happen for a value this function builds, and propagated rather than swallowed so that a future member with a different shape fails loudly instead of producing an empty result.

NotLowerable(LowerError)

A handler answered with a ToolResult the negotiated revision cannot express.

Reached only from codec::result::verbatim, which is the path a #[tool] takes when its return type is a ToolResult. Carries the codec’s own error rather than a paraphrase of it: the revision, the feature, and whether a policy named a rule for it are three different fixes and the caller cannot pick between them without all three.

Trait Implementations

impl Clone for OutcomeError

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 OutcomeError

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

Formats the value using the given formatter.

impl Display for OutcomeError

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

Formats the value using the given formatter.

impl Eq for OutcomeError

impl Error for OutcomeError

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 From<OutcomeError> for DispatchError

fn from(error: OutcomeError) -> Self

A reader or getter that could not produce a document failed.

Every variant becomes DispatchError::HandlerFailed carrying the outcome’s own message. None of them is a bad request — the peer named a resource or a prompt that exists and sent well-formed params — so reporting any of them as InvalidParams would send a client looking in its own request for something it got right.

impl PartialEq for OutcomeError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for OutcomeError