implements_protocol(Object, Protocol) implements_protocol(Category, Protocol) implements_protocol(Object, Protocol, Scope) implements_protocol(Category, Protocol, Scope)
Enumerates, by backtracking, all pairs of entities such that an object or a category implements a protocol. The relation scope is represented by the atoms public, protected, and private.
implements_protocol(?object_identifier, ?protocol_identifier) implements_protocol(?category_identifier, ?protocol_identifier) implements_protocol(?object_identifier, ?protocol_identifier, ?scope) implements_protocol(?category_identifier, ?protocol_identifier, ?scope)
type_error(object_identifier, Object)type_error(category_identifier, Category)type_error(protocol_identifier, Protocol)type_error(scope, Scope)| ?- implements_protocol(List, listp). | ?- implements_protocol(List, listp, public).