anchor.diff:  ;;;
   ;;; Parser
   
  -(define-parser simple-type-spec
  +(define-parser simple-type-spec-parser
     (lambda (tokens)
       (if (and (not (null tokens))
   	     (member (car tokens) '(fixnum float t nil)))
  
positive.code: 		(cdr tokens))
  	(values nil nil tokens))))
  
  (define-parser destructured-type-spec
    (consecutive (lambda (of-type tree)
  		 (declare (ignore of-type))
  		 (make-instance 'destructured-type-spec
  
negative.code: 	       (keyword-parser 'of-type)
  	       (singleton #'identity (constantly t))))
  
  (define-parser type-spec-parser
    (alternative 'simple-type-spec 'destructured-type-spec))
  