Struct RoleType

pub struct RoleType {
    pub label: ScopedLabel,
    pub is_root: bool,
    pub is_abstract: bool,
}

Roles are special internal types used by relations. We can not create an instance of a role in a database. But we can set an instance of another type (role player) to play a role in a particular instance of a relation type.

Roles allow a schema to enforce logical constraints on types of role players.

Fields

label: ScopedLabel

is_root: bool

is_abstract: bool

Trait Implementations

impl Clone for RoleType

fn clone(&self) -> RoleType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RoleType

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

Formats the value using the given formatter.

impl PartialEq for RoleType

fn eq(&self, other: &RoleType) -> 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 RoleTypeAPI for RoleType

fn is_abstract(&self) -> bool

Checks if the type is prevented from having data instances (i.e., abstract).

fn get_relation_type<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> BoxPromise<'tx, Result<Option<RelationType>>>

Retrieves the RelationType that this role is directly related to.

fn is_deleted<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> BoxPromise<'tx, Result<bool>>

Checks if this type is deleted.

fn delete<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> BoxPromise<'tx, Result>

Deletes this type from the database.

fn set_label<'tx>( &self, transaction: &'tx Transaction<'_>, new_label: String, ) -> BoxPromise<'tx, Result>

Renames the label of the type. The new label must remain unique.

fn get_supertype<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> BoxPromise<'tx, Result<Option<RoleType>>>

Retrieves the most immediate supertype of the RoleType.

fn get_supertypes<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> Result<BoxStream<'tx, Result<RoleType>>>

Retrieves all supertypes of the RoleType.

fn get_subtypes<'tx>( &self, transaction: &'tx Transaction<'_>, transitivity: Transitivity, ) -> Result<BoxStream<'tx, Result<RoleType>>>

Retrieves all direct and indirect (or direct only) subtypes of the RoleType.

fn get_relation_types<'tx>( &self, transaction: &'tx Transaction<'_>, ) -> Result<BoxStream<'tx, Result<RelationType>>>

Retrieves RelationTypes that this role is related to (directly or indirectly).

fn get_player_types<'tx>( &self, transaction: &'tx Transaction<'_>, transitivity: Transitivity, ) -> Result<BoxStream<'tx, Result<ThingType>>>

Retrieves the ThingTypes whose instances play this role.

fn get_relation_instances<'tx>( &self, transaction: &'tx Transaction<'_>, transitivity: Transitivity, ) -> Result<BoxStream<'tx, Result<Relation>>>

Retrieves the Relation instances that this role is related to.

fn get_player_instances<'tx>( &self, transaction: &'tx Transaction<'_>, transitivity: Transitivity, ) -> Result<BoxStream<'tx, Result<Thing>>>

Retrieves the Thing instances that play this role.

impl Eq for RoleType

impl StructuralPartialEq for RoleType