In article <AD4480A509455343AEFACCC231BA850F17C434 / ukexchange>,
  Elliott Hughes <ehughes / bluearc.com> writes:

>   def uri.progress_Bar( percent_done )
>     puts "Yeah, we're at " + percent_done + "% now!"
>   end
>
> instead of
>
>   def uri.progress_bar( percent_done )
>     puts "Yeah, we're at " + percent_done + "% now!"
>   end
>
> the only indication i'll have of this is that my program will silently do
> the wrong thing at run-time. [this problem occurs with overriding of
> non-abstract methods in most languages, too.]

I think more essential problem with URI's singleton method is redirection.

When redirection is occur, single open call may access two or more URIs.

Since singleton method is bound for single URI object, it is not
suitable to use with other URI object created by redirection.  So it
is not suitable to control behavior over open call.
-- 
Tanaka Akira