The non-local flow of control caused by continuations might sometimes
not be wanted. You can use
with-continuation-barrier etc to
errect fences that continuations can not pass.
Call proc and return its result. Do not allow the invocation of continuations that would leave or enter the dynamic extent of the call to
with-continuation-barrier. Such an attempt causes an error to be signaled.
Throws (such as errors) that are not caught from within proc are caught by
with-continuation-barrier. In that case, a short message is printed to the current error port and
with-continuation-barrierreturns exactly once.