Enum GraphError 

pub enum GraphError {
    NodeNotFound(NodeId),
    EdgeAlreadyExists(NodeId, NodeId),
    SelfLoop(NodeId),
    NegativeCycle,
    NotConnected,
    InvalidOperation(&'static str),
}

Errors that can arise from graph operations.

Methods that mutate or query a graph return Result<T, GraphError> whenever the operation could meaningfully fail (e.g. referencing a node that does not exist).

Examples

use graph_core::{GraphError, NodeId};

let err = GraphError::NodeNotFound(NodeId::new(99));
assert!(matches!(err, GraphError::NodeNotFound(_)));

Variants

NodeNotFound(NodeId)

The referenced node does not exist in the graph.

EdgeAlreadyExists(NodeId, NodeId)

An edge between these two nodes already exists.

SelfLoop(NodeId)

The operation would create a self-loop, which is disallowed.

NegativeCycle

A negative-weight cycle was detected (Bellman-Ford / Floyd-Warshall).

NotConnected

The graph is not connected where connectivity is required (e.g. MST).

InvalidOperation(&'static str)

A catch-all for operations that are invalid in the current context.

Trait Implementations

impl Clone for GraphError

fn clone(&self) -> GraphError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GraphError

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

Formats the value using the given formatter.

impl Display for GraphError

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

Formats the value using the given formatter.

impl Error for GraphError

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 GraphError

fn eq(&self, other: &GraphError) -> 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 GraphError