From: Warren Brown <wkb@...>
Date: 2003-04-17T00:05:40+09:00
Subject: Re: case insensitive match with regexp object

Gavin,

> So you can do
>
>   def insensitive(regex)
>     Regexp.new(regex, Regexp::IGNORE_CASE)
>   end
>
> However, ri tells me that when a regex is given to
> Regexp.new, *its options are not propagated* !!
>
> Therefore, the definition of #insensitive above is
> incorrect for inputs that have Regexp::EXTENDED or
> Regexp::POSIX_LINE enabled, and I can't see any way
> to define it correctly.

    It looks like this oversight has been fixed in 1.8:

%ruby -v -e "x = /x/imx; puts x.options"
ruby 1.8.0 (2003-04-04) [i386-freebsd4.7]
135

    So your function could be:

def insensitive(regex)
  Regexp.new(regex, regex.options | Regexp::IGNORECASE)
end

    Or even:

def insensitive(regex)
  if regex.options & Regexp::IGNORECASE
    regex
  else
    Regexp.new(regex, regex.options | Regexp::IGNORECASE)
  end
end

    - Warren Brown