anchor.diff:        ((eql name :any) net.sockets:+ipv4-unspecified+)
         (t (nth-value 0 (net.sockets:convert-or-lookup-inet-address name))))))
   
  -(defun open-stream (peer-host peer-port 
  -                    &key (local-host :any) (local-port 0)
  +(defun open-stream (peer-host peer-port &key
  +                    (local-host :any) (local-port 0)
                       (external-format :default)
                       (element-type 'character)
                       (protocol :tcp))
  
positive.code: ;;;;
  
  (defmacro with-server ((name arguments) &body forms)
    `(let (,name)
       (unwind-protect 
            (progn
              (setf ,name (open-server ,@arguments))
              (locally
                  ,@forms))
         (when ,name (close-server ,name)))))
  
negative.code: (defun close-server (server)
    (close server))
  
  (defun accept-connection (socket &key
                            (external-format :default)
                            (element-type 'character))
    (declare (ignore element-type))       ; bivalent streams
  