Enum DropBehavior 

pub enum DropBehavior {
    Restrict,
    Cascade,
}

Behavior of a DROP NODE TYPE / DROP EDGE TYPE statement when the type still has surviving instances or inbound type dependencies.

Restrict (the default when no behavior keyword is written) is the Seam-B fix from the deletion-reclamation audit (Item 3): dropping a type whose instances still exist would otherwise leave orphan instances whose declared type no longer exists (a silent graph-type-consistency violation on a closed GG02 graph). Restrict makes that rejection explicit and early. Cascade (selene-db IM_DROP_CASCADE vendor extension) truncates the instances first, then drops the type, atomically in one transaction.

Variants

Restrict

Reject the drop when instances or inbound type dependencies remain; the type is not dropped and no Change is recorded (no partial state).

Cascade

Truncate every instance of the type first (reusing the Mutator::truncate_* funnel), then drop the type — both in one transaction.

Trait Implementations

impl Clone for DropBehavior

fn clone(&self) -> DropBehavior

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for DropBehavior

impl Debug for DropBehavior

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

Formats the value using the given formatter.

impl Default for DropBehavior

fn default() -> DropBehavior

Returns the “default value” for a type.

impl Eq for DropBehavior

impl Hash for DropBehavior

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DropBehavior

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