Logtalk reference manual
Built-in predicate: extends_category/2-3

extends_category/2-3

Description

extends_category(Category1, Category2)
extends_category(Category1, Category2, Scope)

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

Template and modes

extends_category(?category_identifier, ?category_identifier)
extends_category(?category_identifier, ?category_identifier, ?scope)

Errors

Category1 is neither a variable nor a valid protocol identifier:
type_error(category_identifier, Category1)
Category2 is neither a variable nor a valid protocol identifier:
type_error(category_identifier, Category2)
Scope is neither a variable nor an atom:
type_error(atom, Scope)
Scope is not a valid entity scope:
domain_error(scope, Scope)

Examples

| ?- extends_category(basic, Category).

| ?- extends_category(Category, extended, private).

See also

current_category/1, complements_object/2, imports_category/2-3