implements_protocol/2-3

Description

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.

Template and modes

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)

Errors

Object is neither a variable nor a valid object identifier:

type_error(object_identifier, Object)

Category is neither a variable nor a valid category identifier:

type_error(category_identifier, Category)

Protocol is neither a variable nor a valid protocol identifier:

type_error(protocol_identifier, Protocol)

Scope is neither a variable nor a valid entity scope:

type_error(scope, Scope)

Examples

| ?- implements_protocol(List, listp).

| ?- implements_protocol(List, listp, public).