ai.grakn.concept

Interface Relation

All Superinterfaces:

Comparable<Concept>, Concept, Instance

public interface Relation
extends Instance

A Relation represents an instance of a Relation Type, which is a concept that represents how different entities relate to one another. Relations are used to model n-ary relationships between instances.

Method Summary

Modifier and Type	Method and Description
Relation	deleteScope(Instance scope) Delete the scope specified.
Relation	putRolePlayer(RoleType roleType, Instance instance) Expands this Relation to include a new role player which is playing a specific role.
Map<RoleType,Instance>	rolePlayers() Retrieve a list of all Instances involved in the Relation, and the Role Types they play.
Relation	scope(Instance instance) Sets the Instance that can scope this Relation to a specific domain.
Collection<Instance>	scopes() Retrieve a list of the Instances that scope this Relation.
RelationType	type() Retrieve the associated Relation Type for this Relation.

Methods inherited from interface ai.grakn.concept.Instance

hasResource, playsRoles, relations, resources

Methods inherited from interface ai.grakn.concept.Concept

asEntity, asEntityType, asInstance, asRelation, asRelationType, asResource, asResourceType, asRoleType, asRule, asRuleType, asType, delete, getId, isEntity, isEntityType, isInstance, isRelation, isRelationType, isResource, isResourceType, isRoleType, isRule, isRuleType, isType

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

scope

Relation scope(Instance instance)

Sets the Instance that can scope this Relation to a specific domain. For example, if a relation is only valid for a particular language you can scope the relation to an Instance representing that language.

Parameters:

instance - A new instance which scopes this Relation

Returns:

The Relation itself

type

RelationType type()

Retrieve the associated Relation Type for this Relation.

Specified by:

type in interface Concept

Returns:

The associated Relation Type for this Relation.

See Also:

RelationType

rolePlayers

Map<RoleType,Instance> rolePlayers()

Retrieve a list of all Instances involved in the Relation, and the Role Types they play.

Returns:

A list of all the Instances and their Role Types.

See Also:

RoleType

scopes

Collection<Instance> scopes()

Retrieve a list of the Instances that scope this Relation.

Returns:

A list of the Instances that scope this Relation.

putRolePlayer

Relation putRolePlayer(RoleType roleType,
                       Instance instance)

Expands this Relation to include a new role player which is playing a specific role.

Parameters:

roleType - The Role Type of the new role player.

instance - The new role player.

Returns:

The Relation itself.

deleteScope

Relation deleteScope(Instance scope)
              throws ConceptException

Delete the scope specified.

Parameters:

scope - The Instances that is currently scoping this Relation.

Returns:

The Relation itself

Throws:

ConceptException