From: Ryan Leavengood <leavengood@...>
Date: 2005-12-21T06:58:50+09:00
Subject: Re: iterate chars in a string

"Wrong" is a strong word, but I'd say this isn't ideal Ruby for two reasons:

1. Generally in Ruby internal iterators (i.e. each, each_byte, etc.)
are preferred over external iterators like what you have here (and for
and while loops.)
2. Your code isn't as efficient, though it wasn't as bad as I thought:

-------------------------------------------------------------------------
|                      QuickBench Session Started                       |
|                            300 Iterations                             |
-------------------------------------------------------------------------
                                  user     system      total        real
1. s.each_byte{|b| b.chr ...  2.656000   0.000000   2.656000 (  2.669000)
2. 0.upto(s.length-1) { |...  2.859000   0.000000   2.859000 (  2.887000)
3. s.split(//).each { |ch...  3.297000   0.000000   3.297000 (  3.290000)
4. s.scan(/./m) { |charac...  7.594000   0.156000   7.750000 (  7.776000)
-------------------------------------------------------------------------
|              Fastest was <1. s.each_byte{|b| b.chr ...>               |
-------------------------------------------------------------------------

The string s above was 4000 x characters.

I was quite surprised the scan was so much slower, especially compared
to split, which creates an array every time.

Ryan

On 12/20/05, Dirk Meijer <hawkman.gelooft@gmail.com> wrote:
> i've always used this:
>
> 0.upto(string.length-1) do |n|
>     p string[n,1]
> end
>
> anything wrong with this?
> greetings, Dirk.