built-in predicate

instantiates_class/2-3

Description

instantiates_class(Instance, Class)
instantiates_class(Instance, Class, Scope)

Enumerates, by backtracking, all pairs of objects such that the first one instantiates the second. The relation scope is represented by the atoms public, protected, and private.

Modes and number of proofs

instantiates_class(?object_identifier, ?object_identifier) - zero_or_more
instantiates_class(?object_identifier, ?object_identifier, ?scope) - zero_or_more

Errors

Instance is neither a variable nor a valid object identifier:

type_error(object_identifier, Instance)

Class is neither a variable nor a valid object identifier:

type_error(object_identifier, Class)

Scope is neither a variable nor an atom:

type_error(atom, Scope)

Scope is an atom but an invalid entity scope:

domain_error(scope, Scope)

Examples

% check that the water_jug is an instante of state_space:
| ?- instantiates_class(water_jug, state_space).

% enumerate the state_space instances where the
% instantiation relation is public:
| ?- instantiates_class(Space, state_space, public).

See also

current_object/1, extends_object/2-3, specializes_class/2-3