From: Simon Strandgaard <neoneye@...>
Date: 2004-05-07T01:11:44+09:00
Subject: Re: [ann] iterator-0.7

Michael Neumann <mneumann@ntecs.de> wrote:
> On Thu, May 06, 2004 at 07:07:09PM +0900, Simon Strandgaard wrote:
> > homepage:
> > http://raa.ruby-lang.org/list.rhtml?name=iterator
> > 
> > download:
> > http://rubyforge.org/frs/?group_id=18&release_id=467
> > 
> > 
> > External iterators with some STL inspiration.
> 
> BTW, enumerator and generator both serve similar puposes and ship with
> Ruby by default.
[snip] 
> I am not sure where the differences are. And I don't say that iterator
> is not useful ;-)
 

Yes they can do somewhat the same, I just needed some iterators customized
for my regexp engine. In paticular I needed to be able to reverse the
direction of an iterator, so that I could do lookbehind.. for instance:

irb(main):001:0> require 'iterator'
=> true
irb(main):002:0> i = %w(a b c d e).create_iterator_end.reverse
=> #<Iterator::Reverse:0x8196d3c @i=#<Iterator::Collection:0x8196df0 @data=["a", "b", "c", "d", "e"], @position=5>>
irb(main):003:0> i.to_a
=> ["e", "d", "c", "b", "a"]
irb(main):004:0>

There are probably other differences.

--
Simon Strandgaard