getf

(getf plist indicator &optional default)

Returns the value following indicator in a property list (a flat list of alternating indicators and values). If the indicator is absent, default is returned -- nil when it is omitted. getf is a function, so default is evaluated whether or not the indicator is found. An indicator that IS present but whose value is nil yields nil, not the default. It is the partner of remf. (setf (getf ...) value) is not supported; use remf to delete a property.