From: Austin Ziegler <austin@...>
Date: 2003-08-30T02:07:22+09:00
Subject: Re: #collect with block modifying receiver

On Fri, 29 Aug 2003 22:02:01 +0900, Dan North wrote:
> So it's undefined behaviour, but "Don't modify the receiver while you are
> iterating over it." :)
> 
> Can I suggest the solution that Java uses, which is to fail fast in that
> situation (ConcurrentModificationException). You would not believe how
> much debugging time that one tiny feature has saved me!

I wouldn't like that, personally. I don't remember exactly where, but I 
believe that I have a piece of code taking advantage of the fact that a 
receiver *can* be modified during iteration. I don't modify during a 
#collect, but during an #each. One of the things you can do is:

  arr.each { |e| arr << f.flatten if f.kind_of?(Array) }

-austin
--
austin ziegler    * austin@halostatue.ca * Toronto, ON, Canada
software designer * pragmatic programmer * 2003.08.29
                                         * 13.04.26