chickadee » srfi-209 » enum-set-projection

If enum-type-or-set is an enum set, its enum type is extracted and used; otherwise, the enum type is used directly. Returns an enum set containing the enums belonging to the enum type that have the same names as the members of enum-set, whose enum type need not be not the same as the enum-type. It is an error if enum-set contains an enum that does not correspond by name to an enum in enum-type-or-set.

(enum-set-projection us-traffic-light
                     (enum-set color color-red color-green color-blue))
 = (enum-set us-traffic-light
             us-traffic-light-red us-traffic-light-green)