Enum MetropolisMoveApplicationFailure 

#[non_exhaustive]
pub enum MetropolisMoveApplicationFailure {
    BackendMutation {
        operation: BackendMutationOperation,
        target: String,
        detail: String,
    },
    BackendRollback {
        operation: BackendMutationOperation,
        target: String,
        detail: String,
        rollback_errors: String,
    },
    DelaunayValidation {
        level: DelaunayValidationLevel,
        detail: String,
    },
    Validation {
        check: CdtValidationCheck,
        failure: CdtValidationFailure,
    },
    TopologyMismatch {
        topology: CdtTopology,
        euler_characteristic: i128,
        expected_euler_characteristics: Vec<i128>,
        vertices: usize,
        edges: usize,
        faces: usize,
    },
    Foliation(FoliationError),
    CausalityViolation {
        time_0: u32,
        time_1: u32,
        step_distance: u32,
    },
    Unexpected {
        detail: String,
    },
}

Lower-level source for a Metropolis-accepted move that could not be applied.

CdtError::MetropolisMoveApplicationFailed uses this enum to preserve the category and structured context of a hard failure after Metropolis has accepted a move type. It is intentionally smaller than recursively storing a full CdtError while still giving callers typed branches for backend, validation, topology, foliation, and causality failures.

Examples

use causal_triangulations::prelude::errors::{
    BackendMutationOperation, MetropolisMoveApplicationFailure,
};

let failure = MetropolisMoveApplicationFailure::BackendMutation {
    operation: BackendMutationOperation::RemoveVertex,
    target: "vertex VertexKey(7v1)".to_string(),
    detail: "backend reported invalid vertex key".to_string(),
};

assert!(format!("{failure}").contains("remove_vertex"));

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.

BackendMutation

A backend payload or topology edit failed while applying the accepted move.

Fields

operation: BackendMutationOperation

Mutation operation being attempted.

target: String

Human-readable target handle.

detail: String

Additional failure detail.

BackendRollback

A backend mutation failed, then rollback of staged payloads also failed.

Fields

operation: BackendMutationOperation

Mutation operation being attempted when the first failure occurred.

target: String

Human-readable target handle for the first failure.

detail: String

Primary mutation failure detail.

rollback_errors: String

Rollback failure details for one or more payloads.

DelaunayValidation

Upstream Delaunay validation rejected the evolved geometry.

Fields

level: DelaunayValidationLevel

Cumulative upstream validation level being enforced.

detail: String

Upstream validation diagnostic.

Validation

CDT validation rejected the evolved triangulation.

Fields

check: CdtValidationCheck

Validation check that failed.

failure: CdtValidationFailure

Structured validation failure detail.

TopologyMismatch

Topology metadata did not match the evolved backend Euler characteristic.

Fields

topology: CdtTopology

Topology requested by CDT metadata.

euler_characteristic: i128

Observed Euler characteristic from the backend.

expected_euler_characteristics: Vec<i128>

Accepted Euler characteristics for the requested topology.

vertices: usize

Backend vertex count at validation time.

edges: usize

Backend edge count at validation time.

faces: usize

Backend face count at validation time.

Foliation(FoliationError)

Foliation bookkeeping or validation failed.

CausalityViolation

A post-mutation edge violated CDT causality.

Fields

time_0: u32

Time label of the first endpoint.

time_1: u32

Time label of the second endpoint.

step_distance: u32

Topology-aware temporal step distance between the two labels.

Unexpected

A hard failure reached the Metropolis boundary through an unexpected error category.

Fields

detail: String

Lower-level error text retained for diagnostics.

Trait Implementations

impl Clone for MetropolisMoveApplicationFailure

fn clone(&self) -> MetropolisMoveApplicationFailure

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetropolisMoveApplicationFailure

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

Formats the value using the given formatter.

impl Display for MetropolisMoveApplicationFailure

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

Formats the value using the given formatter.

impl Error for MetropolisMoveApplicationFailure

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<CdtError> for MetropolisMoveApplicationFailure

fn from(error: CdtError) -> Self

Converts to this type from the input type.

impl PartialEq for MetropolisMoveApplicationFailure

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for MetropolisMoveApplicationFailure