From: Simon Strandgaard <neoneye@...>
Date: 2004-05-01T21:17:28+09:00
Subject: Re: def [](v) xx; return yy; end # returned value is ignored !?

Jean-Hugues ROBERT <jean_hugues_robert@yahoo.com> wrote:
> Ruby is cool, a lvalue can be a *method call*.
> So when I say "lvalue" I mean Ruby's ones, not the subset that some
> other languages provide.
> 
> I believe my version of Pointer works with any Ruby valid lvalue:
>    a = [1,2,3]
>    ptr = Pointer.new{ "a[2]"}
>    ptr[] = 4
>    p a # => [1,2,4]
> See it at end of page http://www.c2.com/cgi/wiki?SinisterSchemeSampleInRuby
> 

I have made iterator package, which does the same,
plus a few other goodies (continuation-iterator), see
http://raa.ruby-lang.org/list.rhtml?name=iterator

Only difference I see, is that you use a String, where I use a reference.
Any advantages in using a String over a reference ?


irb(main):001:0> require 'iterator'
=> true
irb(main):002:0> a = [1,2,3]
=> [1, 2, 3]
irb(main):003:0> ptr = a.create_iterator
=> #<Iterator::Collection:0x8190324 @position=0, @data=[1, 2, 3]>
irb(main):004:0> ptr.next(2)
=> #<Iterator::Collection:0x8190324 @position=2, @data=[1, 2, 3]>
irb(main):005:0> ptr.current = 4
=> 4
irb(main):006:0> p a
[1, 2, 4]
=> nil

--
Simon Strandgaard