Enum DagError 

pub enum DagError {
    SupersessionCycle {
        from: SymbolId,
        to: SymbolId,
        kind: EdgeKind,
    },
    SelfEdge {
        memory: SymbolId,
        kind: EdgeKind,
    },
}

Errors produced by SupersessionDag mutations.

Variants

SupersessionCycle

The edge would close a cycle in the DAG. Per temporal-model.md § 6.2 invariant #1, cycles are forbidden.

Fields

from: SymbolId

Source of the rejected edge.

to: SymbolId

Target of the rejected edge.

kind: EdgeKind

Kind of the rejected edge.

SelfEdge

The edge’s endpoints are identical (from == to). Supersession of a memory by itself has no meaningful semantics.

Fields

memory: SymbolId

The memory that appeared on both sides.

kind: EdgeKind

Edge kind.

Trait Implementations

impl Clone for DagError

fn clone(&self) -> DagError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DagError

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

Formats the value using the given formatter.

impl Display for DagError

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

Formats the value using the given formatter.

impl Error for DagError

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<DagError> for EmitError

fn from(source: DagError) -> Self

Converts to this type from the input type.

impl From<DagError> for StoreError

fn from(source: DagError) -> Self

Converts to this type from the input type.

impl PartialEq for DagError

fn eq(&self, other: &DagError) -> 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 Eq for DagError

impl StructuralPartialEq for DagError