A role type can be used as the
argument to a
do or
dowhile loop. It can also be used as a
condition in
if statements. Please note
that it is not possible to navigate to an object, relationship or role from a
port instance. This is due to the fact that the same port instance is used in
each object instance, and thus it may be associated with several objects,
relationships or roles. There is no way to make a distinction between them from
within the generator, which only knows that it is ‘in’ a port in a
certain graph. Navigating to a port thus forms a dead end for further
navigation. Instead, navigate to the role, and from there query or generator the
information you need from the port, then navigate to the object.
