check-keyword-arguments

[Dick Gabriel <RPG@SAIL.Stanford.EDU>]

I think Moon's suggestion for the name FUNCTION-KEYWORD is acceptable.
Here is the corrected code (Having Moon around to read code is
almost as good as having a computer. In fact, it's better because
sometimes he cracks a joke.):

(defmethod make-instance ((class standard-class) &rest initargs)
  (setq initargs (default-initargs class initargs))
  (let* ((proto (class-prototype class))
         (methods 
           (append
	     (compute-applicable-methods #'allocate-instance `(,class))
	     (compute-applicable-methods #'initialize-instance `(,proto))
	     (compute-applicable-methods #'shared-initialize `(,proto nil)))))
	(unless
	  (subsetp
	    (let ((keys '()))
	      (do ((plist initargs (cddr plist)))
		  ((null plist) keys)
		(push (car plist) keys)))
	    (union 
	      (class-slot-initargs class)
	      (reduce #'union (mapcar #'function-keywords methods))))
	  (error ...)))
  (let ((instance (apply #'allocate-instance class initargs)))
    (apply #'initialize-instance instance initargs)
    instance))