case.lisp

(defmacro case+ (form test &body clauses)
  (let ((gtest (gensym))
	(gform (gensym)))
    (labels
	((clause->or (clause)
	   (if (listp (car clause))
	       `((or
		  ,@(mapcar
		     #'(lambda (x)
			 `(funcall ,gtest ,gform ,x))
		     (car clause)))
		 ,@(cdr clause))
	       (cond
		 ((eq (car clause) cl:T)
		  `(cl:T ,@(cdr clause)))
		 ((and (symbolp (car clause))
		       (string-equal (symbol-name (car clause)) "otherwise"))
		  `(cl:T ,@(cdr clause)))
		 (T `((funcall ,gtest ,gform ,(car clause))
		      ,@(cdr clause)))))))
      `(let ((,gform ,form)
	     (,gtest ,test))
	 (cond
	   ,@(mapcar #'clause->or clauses))))))