From: Philipp Huber <huber.philipp@...>
Date: 2005-09-01T17:09:08+09:00
Subject: Re: implementing the "each" method for own classes

thanks a lot, works exactly as i wanted :)

On 9/1/05, Brian Schr�der <ruby.brian@gmail.com> wrote:
> On 01/09/05, Philipp Huber <huber.philipp@gmail.com> wrote:
> > hello!
> >
> > first of all, i'm new to ruby and this list.
> >
> > my question is, i have a class "Queue" which implements a queue as
> > linked list of "Item" objects. i'd like to implement an each method,
> > so i can do something like
> >
> > queue.each do |item|
> >    item.do_somethng
> > end
> >
> > any help would be appreciated!
> > thanks,
> > philipp
> >
> >
> 
> It is a bit hard to help you, if we don't know your classes. But lets
> say you have a class
> class QueueNode
>   attr_accessor :next
>   ...
> end
> 
> and a class Queue with a variable @root holding the first entry of the
> queue you could implement each as
> 
> class Queue
>   ...
> 
>   def each(&block)
>     node = @root
>     begin
>       block[node]
>     end while node = node.next
>   end
> end
> 
> or you could use yield
> 
> class Queue
>   ...
> 
>   def each
>     node = @root
>     begin
>       yield node
>     end while node = node.next
>   end
> end
> 
> that depends on personal preference.
> 
> hope to help,
> 
> Brian
> --
> http://ruby.brian-schroeder.de/
> 
> Stringed instrument chords: http://chordlist.brian-schroeder.de/
> 
>