anchor.diff:              (progn
                 (ensure-directories-exist ,new)
                 (uiop:chdir ,new)
  -              (let ((*default-pathname-defaults* ,new))
  -                ,@body))
  +              ,@body)
            (uiop:chdir ,old)))))
   
   (defun minimal-shell-namestring (pathname)
  
positive.code:         (:flag
           `((T)))
          (:bool
           `((T ,(format NIL "~a~a" prefix name)))))))
  
  (defgeneric location (thing)
    (:method ((pathname pathname))
  
negative.code:           ,@(loop for arg in req unless (front-arg-p arg) collect (parse-rargdef arg))
            ,@(loop for arg in opt unless (front-arg-p arg) collect (parse-oargdef arg)))))))
  
  (defmacro %opt (options &rest forms)
    `(let ((args (or ,@(loop for option in (if (listp options) options (list options))
                             collect `(assoc ,option options)))))
       (when args
         ,@forms)))
  
  