From: Dean Wampler <deanwampler@...>
Date: 2006-06-07T01:41:02+09:00
Subject: Re: Ruby and the Open-Closed Principle

Yes, you're exactly right! I forgot that the most precise and
"conservative" meaning of the OCP is that you don't modify the
original source code. That's more important than the broader
restriction that you shouldn't modify the class in any away, e.g., by
re-opening it the Ruby way. Certainly this should be done with great
"deliberation". For example, you risk breaking libraries when they are
changed in subsequent releases, as others have remarked. However, I
don't believe that re-opening classes violates the OCP, "a priori".

Note that byte-code modification frameworks have become very popular
in the Java world, where they are used to "modify classes", but in
very specific and controlled ways.

Thanks for the clarification on the OCP.

dean


On 6/6/06, Jim Weirich <jim@weirichhouse.org> wrote:
> [snip...]
>
> But isn't this the essence of OCP?  The ability to extend a class (open
> for extensions) without modifying the original code? (which remains
> closed).
>
> -- Jim Weirich
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


-- 
Dean Wampler
http://www.aspectassoc.com
http://www.aspectprogramming.com
http://www.contract4j.org