; http://cap-lore.com/code/Scheme/try.html
(lambda (pb pe) (call/cc (lambda (p) (pb (lambda (ev) (p (pe ev)))))))

; perhaps:
(lambda (pb pe) (let* ((a #t) (rv
  (call/cc (lambda (p) (if a (pb (lambda (ev) (p (pe ev)))) (car "GoToHell"))))))
   (set! a #f) rv))