From: Dominik Bathon <dbatml@...>
Date: 2006-04-06T09:45:18+09:00
Subject: Re: compare to strings

Hi,

On Thu, 06 Apr 2006 01:23:31 +0200, Clint Pidlubny  
<clint.pidlubny@gmail.com> wrote:

> Excellent info Zach. Very relevant for me. I'll have thousands of
> links to do this with.

$ cat str_inc_bench.rb
require 'benchmark'

url = "http://www.url.com/"
url2 = "http://www.url.com/page"
urlrx = /#{url}/

Benchmark.bm{ |x|
x.report{ 100000.times { url2.include?( url ) } }
x.report{ 100000.times { url2 =~ urlrx } }
x.report{ 100000.times { url2 =~ /#{url}/ } }
}
$ ruby -v str_inc_bench.rb
ruby 1.8.4 (2005-12-24) [i686-linux]
       user     system      total        real
   0.070000   0.000000   0.070000 (  0.071435)
   0.130000   0.000000   0.130000 (  0.130016)
   1.130000   0.020000   1.150000 (  1.182629)

So, regular expression matching itself is not that much slower than  
String#include?.
What makes "url2 =~ /#{url}/" slow is the creation of so many Regexp  
objects.

I just wanted to point that out.

Dominik