class
	DIRECTORY_NAME

General
	cluster: base.kernel
	description: "Directory name abstraction"
	create: make_from_string, make

Ancestors
	PATH_NAME

Queries
	is_directory_name_valid (dir_name: STRING): BOOLEAN
	is_empty: BOOLEAN
	is_equal (other: [like Current] DIRECTORY_NAME): BOOLEAN
	is_valid: BOOLEAN
	is_volume_name_valid (vol_name: STRING): BOOLEAN
	to_c: ANY

Commands
	extend (directory_name: STRING)
	extend_from_array (directories: ARRAY [STRING])
	make
	make_from_string (p: STRING)
	set_directory (directory_name: STRING)
	set_subdirectory (directory_name: STRING)
	set_volume (volume_name: STRING)
	wipe_out