[plt-scheme] abstract methods/classes

At Fri, 21 Mar 2003 23:30:53 -0500, "Neil W. Van Dyke" wrote:
> Is there a way to do abstract methods in with the class.ss object
> system?
> 
> I suppose one way would be to let class impose an interface constraint
> upon *sub*classes that is enforced at instantiation time.

Interesting idea. What if you added something like

 (unless (this . is-a? . <some-interface>)
   (error "didn't implement required methods"))

to the body of your class?

Matthew