anchor.diff:    (check-type direction (member :input :output :io :probe))
     (check-type if-exists (member :error :new-version :rename :rename-and-delete :overwrite :append :supersede nil))
     (check-type if-does-not-exist (member :error :create nil))
  -  (let* ((path (merge-pathnames filespec))
  +  (let* ((path (translate-logical-pathname (merge-pathnames filespec)))
            (host (pathname-host path)))
       (when (wild-pathname-p path)
         (error 'simple-file-error
  
positive.code: (defgeneric file-write-date-using-host (host path))
  
  (defun file-write-date (pathspec)
    (let ((path (merge-pathnames pathspec)))
      (assert (not (wild-pathname-p path)))
      (file-write-date-using-host (pathname-host path) path)))
  
  (defgeneric delete-file-using-host (host path &key))
  
  (defun delete-file (filespec &rest args &key &allow-other-keys)
    (let ((path (merge-pathnames filespec)))
      (assert (not (wild-pathname-p path)))
      (apply #'delete-file-using-host (pathname-host path) path args)))
  
  (defgeneric expunge-directory-using-host (host path &key))
  
  (defun expunge-directory (filespec &rest args &key &allow-other-keys)
    (let ((path (merge-pathnames filespec)))
      (assert (not (wild-pathname-p path)))
      (apply #'expunge-directory-using-host (pathname-host path) path args)))
  
  
negative.code: (defgeneric host-name (host))
  (defgeneric host-default-device (host))
  
  (defgeneric host-pathname-class (host)
    (:method (host) (find-class 'pathname)))
  
  (defvar *host-alist* '())
  
  (define-condition unknown-host (error)
  