From: "Hal E. Fulton" <hal9000@...>
Date: 2003-03-25T16:22:29+09:00
Subject: Re: Iterate over two lists in parallel

----- Original Message ----- 
From: "Jim Weirich" <jweirich@one.net>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Tuesday, March 25, 2003 12:57 AM
Subject: Re: Iterate over two lists in parallel


> I don't know what you have in Gen, but I would expect it to work
> something like this ...
> 
>    x = [5,6,7,8,9]
>    it = x.iterator
>    loop do
>      a = it.get
>      break if a.nil?
>      p a
>    end
> 
> A generator is really just a fancy external iterator.  So you need an
> operation to create it (hence the iterator call).  You then use the
> iterator to, ummm, iterator; not the array itself.
> 
> The iterator method will probably look something like this ....
> 
>   def iterator
>     Generator.new { |g| each { |it| g.generate(it) } }
>   end
> 
> That's the only thing you would need to mixin.  Generator can still
> stand alone.
> 
> Does that help?

Yes... I was mistaken in that I was initializing the
generator all right, but then was calling a method
of Array... and wondering why I got Continuations out. :D

I'd really rather use the object itself to 
iterate, even if I must initialize it.

Something like:

  x = [5,6,7,8,9]
  x.reset
  loop do
    a = x.get
    # ...
  end

C'est possible?

Hal