signal (to destination)? throw catch-name catch-parameter* signal (to destination)? rethrow
signal action is used to send a signal to a destination.
The destination, if specified, must be a reference to a
source. If no destination is specified, the signal will be sent to
signal throw action behaves as the action
throw, except the throw happens in
destination instead of in the current scope. The
signal rethrow variant can be used within a
catch clause to resend the caught exception to another destination.
If destination is a coroutine that cannot catch the exception, the exception propagates to the
coroutine's parent. If none of the destination coroutine's ancestors can catch the exception, the
signal action raises a