anchor.diff:  		 str)))
   
   (defparameter string.prototype
  -  (make-instance 'native-hash :value ""))
  +  (js::!new js::string.ctor ("")))
   
   (setf (prop string.ctor 'js-user::prototype) string.prototype)
   (setf (prop *global* 'js-user::String) string.ctor)
  
positive.code: print(s2.substr("1",8))
  print(s2.substring (0, 100))
  .
  
negative.code: 	 (action (gethash key sealed)))
      (if action
  	(funcall action str)
  	(prop string.prototype key default))))
  
  (defmethod value ((str string)) str)
  
  