From: Alexey Verkhovsky <alex@...>
Date: 2004-07-18T08:12:23+09:00
Subject: Re: [NUBY] Ruby Way code for shuffling an array doesn't behave as	expected

On Sun, 2004-07-18 at 01:43, Mark Sparshatt wrote:
> It's because the block passed to collect is changing the contents of a, 
> so it doesn't reach all the elements of a.

So, Ruby iterators operate on the original collection and let you modify
the collection in the process. Another fact useful to remember.

This is, by the way, one thing I like about Java iterators: they are
fail-safe in such scenarios. E.g.

List list = new ArrayList(2);
list.add(new Object());
list.add(new Object());
Iterator i = list.iterator();
i.next(); // this is OK
list.add(new Object()); // list gets changed
i.next(); // throws ConcurrentModificationException

IMHO, an exception here is The Right Thing (TM). At least, it saved me
from my own stupid mistakes more than once.

Best regards,
Alex