On Nov 25, 2008, at 12:44 PM, Yukihiro Matsumoto wrote:

> Even though it's syntactically allowed, we have never made it
> "official".  The current behavior is useless.  It's not a bug either.
> It's undocumented and should not be used nor touched.  I'd like to
> spare this syntax for the future.

I don't think it's useless: it's a great way of having a method  
redefine itself after the first call.

def something
    def something
      @result
    end

    @result = really_expensive_calculation
end

(OK, maybe not the best example, but I have used this capability a few  
times in real code)



Dave