These are types from system libraries that are complex or
system-dependent. They are implemented as
#<window> type is an opaque type that contains information
about the characters and renditions for a given window. It is created
by the function
newwin and is used and most curses functions.
#<screen> type is an opaque types that contain information
about the physical terminal. Variables of type
created with the function
newterm and used by the function
This type is usually only found in programs that use multiple terminals.
#<item> type is an opaque type that represents one menu
item in a menu. It is created with
new-item. It is part of
the menu library.
#<menu> type is an opaque type that represents a menu.
It is created with
new-menu from a list of
#<field> type is an opaque type that represents one text
box or entry on a form.
This represents a form, created using
new-form from a list of
elements of type