Enum ExistenceError 

#[non_exhaustive]
pub enum ExistenceError {
    EdgeMissing {
        src: String,
        tgt: String,
        kind: String,
    },
    KindInconsistency {
        kind: String,
        targets: Vec<String>,
    },
    LabelInconsistency {
        label: String,
        targets: Vec<String>,
    },
    RequiredFieldMissing {
        vertex: String,
        field: String,
    },
    ConstraintTightened {
        vertex: String,
        sort: String,
        src_val: String,
        tgt_val: String,
    },
    ResolverInvalid {
        pair: (String, String),
    },
    WellFormedness {
        message: String,
    },
    SignatureCoherence {
        hyper_edge: String,
        label: String,
    },
    Simultaneity {
        hyper_edge: String,
        missing_label: String,
    },
    ReachabilityRisk {
        vertex: String,
        reason: String,
    },
    NotAMorphism {
        detail: String,
    },
}

A structured existence error detected by check_existence.

These conditions are theory-derived: the set of applicable checks depends on the sorts present in the protocol’s schema and instance theories.

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.

EdgeMissing

An edge required by the target schema has no preimage in the migration.

Fields

src: String

Source vertex ID.

tgt: String

Target vertex ID.

kind: String

Edge kind.

KindInconsistency

A vertex is mapped to targets with inconsistent kinds.

Fields

kind: String

The vertex kind that is inconsistent.

targets: Vec<String>

The set of target kinds observed.

LabelInconsistency

A label is mapped to targets with inconsistent names.

Fields

label: String

The label that is inconsistent.

targets: Vec<String>

The set of target labels observed.

RequiredFieldMissing

A required field in the target has no source.

Fields

vertex: String

The target vertex ID.

field: String

The missing field (edge name).

ConstraintTightened

A constraint was tightened (target is more restrictive than source).

Fields

vertex: String

The vertex ID.

sort: String

The constraint sort (e.g., "maxLength").

src_val: String

Source constraint value.

tgt_val: String

Target constraint value.

ResolverInvalid

A resolver entry references an invalid vertex pair.

Fields

pair: (String, String)

The invalid (src, tgt) pair.

WellFormedness

A general well-formedness violation.

Fields

message: String

Description of the violation.

SignatureCoherence

A hyper-edge signature is incoherent after mapping.

Fields

hyper_edge: String

The hyper-edge ID.

label: String

The problematic label.

Simultaneity

A hyper-edge requires simultaneous presence of labels that the migration drops.

Fields

hyper_edge: String

The hyper-edge ID.

missing_label: String

The label that would be missing.

ReachabilityRisk

A vertex risks becoming unreachable after migration.

Fields

vertex: String

The vertex at risk.

reason: String

Why it risks becoming unreachable.

NotAMorphism

The migration’s mapped fragment is not a structure-preserving theory morphism: a mapped edge does not connect the images of its own endpoints, or a mapped vertex is absent from the target.

Fields

detail: String

The underlying structural violation, as reported by check_morphism.

Trait Implementations

impl Clone for ExistenceError

fn clone(&self) -> ExistenceError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExistenceError

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ExistenceError

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for ExistenceError

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

Formats the value using the given formatter.

impl Error for ExistenceError

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<ExistenceError> for MigError

fn from(source: ExistenceError) -> Self

Converts to this type from the input type.

impl Serialize for ExistenceError

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.