From: GOTO Kentaro <gotoken@...>
Date: 2002-05-09T02:48:53+09:00
Subject: Re: RegExp: using $& in 2nd gsub argument

At Thu, 9 May 2002 02:23:57 +0900,
Morris, Chris <chris.morris@snelling.com> wrote:

> i want to do the following:
> 
>   "test\n (he\nllo) \nhey".gsub(/\((.*\n.*)\)/, $&.gsub("\n", ''))

Move the second argument to inside of block, i.e., 
  "test\n (he\nllo) \nhey".gsub(/\((.*\n.*)\)/m){
    $&.gsub("\n", '')
  }

A method is evaluated after all arguments are evaluated.  
So, any pattern matching isn't done when $& is evaluated. 
On the other hand, block is evaluated every pattern matching. 

See also:
  http://www.rubycentral.com/book/ref_c_string.html#String.gsub

Hope this helps, 

-- Gotoken