From: Josh Cheek <josh.cheek@...>
Date: 2011-08-29T10:43:07+09:00
Subject: Re: String#split resets regex captures variables (Ruby 1.8.7)

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On Sun, Aug 28, 2011 at 7:54 PM, Olivier Lance <bestiol@gmail.com> wrote:

> Hi,
>
> I've just spent some time on this problem until I found the solution,
> and I wanted to share it/ask for opinions on this:
>
> I've got a string on which I try to match a regexp. If it matches, I
> split the string with one of the captured groups, zip the resulting
> array with an array of symbols and merge with a last symbol/string array
> pair representing the captured separator.
>
> Here's some code to give you an idea:
>
> n = "a:c"
> if n =~ /([a-z])([.:])([a-z])/
>  p [:first, :second].zip(n.split($2)) | [[:separator, $2]]
> end
>
> (see pastie here: http://pastie.org/2445983)
>
>
> The problem is, the resulting array will contain "nil" for :separator.
> Apparently, String#split will reset all regexp-related variables... I
> guess it uses regexp internally, but I haven't seen anything documenting
> this behavior, and I honestly believed this code would work...
>
> So what's your take on this? Does it feel natural/logical to you?
> Should I file a bug to enhance Ruby's documentation?
>
> --
> Posted via http://www.ruby-forum.com/.
>
>

It worked for me, you probably are using an old version of Ruby.

RUBY_VERSION # => "1.9.2"

n = "a:c"
if n =~ /([a-z])([.:])([a-z])/
  p [:first, :second].zip(n.split($2)) | [[:separator, $2]]
end
# >> [[:first, "a"], [:second, "c"], [:separator, ":"]]



Anyway, why not just do [[:first, $1], [:second, $3], [:separator, $2]]

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