From: Csaba Henk <csaba-ml@...>
Date: 2005-06-20T23:46:15+09:00
Subject: Re: Iterate with condition

On Mon, Jun 20, 2005 at 11:31:09PM +0900, G?bor SEBESTY?N wrote:
> 
> On 2005.06.20., at 14:10, Robert Klemme wrote:
> 
> >What exactly do you want to do with the collection?
> >
> I want to get the first N pieces of "valid" objects from a  
> collection. I would iterate in collection counting how many objects  
> were sucessfully accepted and would break the cycle if there are no  
> more objects or I already have my N objects. Here's my solution  
> (written for Rails and the collection consists of ActiveRecord objects):
> 
>         cl = CustomerQueue.find(:all, :conditions => cond, :order =>  
> "created_at ASC")
> 
>         i = 0
>         while i < cl.size and n > 0
>             c = _openChat(cl[i].customer_id, @session[:user].id)
>             unless c.nil?
>                 chats << c
>                 n = n - 1
>             end
>         end
> 
> I don't like referencing by index. That's why I asked you how to  
> implement this using iterator and not a simple while cycle with  
> indexing.

Maybe

 cl.each_with_index { |e,i|
   i < n or break
   c = _openChat(e.customer_id, @session[:user].id) and chats << c
 }

Csaba