anchor.diff:    (:report (lambda (c s)
                (format s "~&received ~A~%" (signal-name (signo c))))))
   
  -;; utility
  -(defun assocdr (item alist) (cdr (assoc item alist)))
   (cffi:defcallback call-signal-handler-in-lisp :void ((signo :int))
     #+debug
     (bt:with-lock-held (*print-lock*)
  
positive.code: (defvar *toplevel-signal-handlers* nil "Toplevel handler")
  (defvar *signal-handler-hierarchy* nil "Nested cons-tree of signal handlers")
  
  (defun canonical-signal-arg (signal)
    (if (integerp signal)
        signal
        (signal-number signal)))
  
  ;; you no longer able to explicitly access the current handlers.
  
  ;;;; cffi interfaces
  
  
negative.code:                 :callback)
    (:export :with-signal-handler
             :signal-handler-bind
             :signal-handler
  
             :unix-signal
             :signo
  