+-- | Applying 'block' to a computation will
+-- execute that computation with asynchronous exceptions
+-- /blocked/. That is, any thread which
+-- attempts to raise an exception in the current thread will be
+-- blocked until asynchronous exceptions are enabled again. There\'s
+-- no need to worry about re-enabling asynchronous exceptions; that is
+-- done automatically on exiting the scope of
+-- 'block'.