From: "Mark J. Reed" <markjreed@...>
Date: 2004-02-09T10:10:43+09:00
Subject: Re: gsub with match replacement

On Wed, Feb 04, 2004 at 02:05:44AM +0900, James R. Leu wrote:
> I'm trying to convert
> 
> "12&#58;34" => "12:34"
> 
> (I know there is a CGI module with unescapeHTML(), I'm working in a
> ruby environment that does not allow for additions of modules)
> 
> I'm trying:
> 
>     "12&#58;34".gsub(/&#(\d+);/,'\1'.to_i.chr)
> 
> But I get "1234"
> 
> Can anyone explain what I'm doing wrong?

That doesn't work because to_i is being called on the literal string '\1' - 
before gsub ever sees it and replaces '\1' with the matching portion of the
string.  

> BTW I know I can do:
> 
>     "12&#58;34".gsub(/&#(\d+);/) do
> 	Integer($1).chr
>     end
> 
> but for some reason in the ruby environment I'm working in
> I get 'Undefined method Integer for main:Object'

What version of Ruby?  (You can look at the constant RUBY_VERSION).
But this should work:

        "12&#58;34".gsub(/&#(\d+);/) { $1.to_i.chr }

-Mark