Enum InstanceError 

pub enum InstanceError {
    NotFound {
        class: Name,
    },
    Ambiguous {
        class: Name,
        candidates: Vec<Name>,
    },
    MaxDepthExceeded {
        depth: usize,
    },
    CircularDependency {
        chain: Vec<Name>,
    },
    UnresolvableSubgoal {
        instance: Name,
        subgoal: Name,
    },
}

Error type for instance resolution failures.

Variants

NotFound

No matching instance.

Fields

class: Name

The class that had no matching instance.

Ambiguous

Multiple equally-prioritised instances.

Fields

class: Name

The class with multiple instances.

candidates: Vec<Name>

Candidate instance names.

MaxDepthExceeded

Recursive search went too deep.

Fields

depth: usize

The depth at which the search was aborted.

CircularDependency

Circular dependency between instances.

Fields

chain: Vec<Name>

The dependency chain forming the cycle.

UnresolvableSubgoal

Instance has unresolvable sub-goals.

Fields

instance: Name

The instance with the unresolvable sub-goal.

subgoal: Name

The sub-goal that could not be resolved.

Trait Implementations

impl Clone for InstanceError

fn clone(&self) -> InstanceError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for InstanceError

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

Formats the value using the given formatter.

impl Display for InstanceError

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

Formats the value using the given formatter.

impl PartialEq for InstanceError

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