From: Daniel DeLorme <dan-ml@...42.com>
Date: 2007-02-28T20:57:22+09:00
Subject: Re: How can I monitor a Regexp?

Jan Friedrich wrote:
> ruby -v
> # ==> ruby 1.8.4 (2005-12-24) [i486-linux]
> 
> class String; def =~(o); raise "S"; end; end
> class Regexp; def =~(o); raise "R"; end; end
> 
> r = /x/
> r =~ 'a'
> # ==> RuntimeError: R
>         from (irb):2:in `=~'
>         from (irb):4
> 'a' =~ r
> # ==> RuntimeError: S
>         from (irb):1:in `=~'
>         from (irb):5

Very interesting. If you assign the regexp to a variable you get
the overridden methods. I guess there's some voodoo optimization
at work when you use =~ on a regexp literal?

Daniel