From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-06-29T03:53:23+09:00
Subject: Re: Regex.escape bug

Tasos Laskos wrote:
> Hi guys,
> 
> I'm using "ruby 1.9.1p378 (2010-01-10 revision 26273) [x86_64-linux]"
> and just noticed a possible bug in Regex.escape() while using it with
> gsub()
> 
> 
> This:
> --------
> pp Regexp.escape( '.rb' )
> --------
> 
> yields:
> --------
> "\\.rb"
> --------
> 
> while it should be "\.rb".
> 
> Regexp.new( '.rb' ) or Regexp.new( '\.rb' ) work though, they replaces
> the ".rb" string as expected.
> Yes I know that "Regexp.new( '.rb' )" works incidentally but I'm just
> mentioning it. :)

It is correct, because it lets you do this:

 >> dot_rb = Regexp.escape( '.rb' )
=> "\\.rb"
 >> /file#{dot_rb}/ =~ "file.rb"
=> 0
 >> /file#{dot_rb}/ =~ "fileQrb"
=> nil

Note that "\\.rb" is the same string as '\.rb'.