The named construct
establishes a name for an implicit block surrounding the
entire loop so that the return-from special operator can be used to return
values from or to exit loop.
Only one name per loop form can be assigned.
If used, the named construct must be the first clause in the loop expression.
The return construct takes one form.
Any values returned by the form
are immediately returned by the loop form.
This construct is similar to the return-from special operator and the return macro.
The return construct does not execute any finally clause that the loop form is given.