From: Ryan Davis <ryand-ruby@...>
Date: 2008-05-24T04:57:49+09:00
Subject: Re: Ruby observer module


On May 23, 2008, at 11:49 , S2 wrote:

>  for i in @observer_peers.dup
>    i.update(*arg)
>  end
>
> Why is there a "dup" on the array? Is that really necessary? Isn't  
> this a
> waste of memory? I am sure there is a really good explanation, but I  
> don't
> grasp it.

(waste of memory? one array? ... who cares?)

what if one of the members of @observer_peers' update method removes  
everything from @observer_peers? How will the rest of the members get  
their update? What if they needed to do stuff to properly clean up too?