From: "NARUSE, Yui" <naruse@...>
Date: 2008-03-05T02:37:42+09:00
Subject: Re: Named captures and regular captures

Dave Thomas wrote:
> It seems that once you have a named capture in a regular expression, you 
> can no longer use numeric captures.
> 
>          m = /(.)(.)(?<digit_prefix>\d+)(\d)/.match("THX1138.")
>          m.begin(:digit_prefix)
>          m.begin(2)    #=> index 2 out of matches
> 
>         $1 #=>  113
>         $2 #=> nil
> 
>         m.to_a  #=> => ["HX1138", "113"]
> 
> 
> Is this expected?

Yes, expected.
http://www.geocities.jp/kosako3/oniguruma/doc/RE.txt
In Ruby ONIG_OPTION_DONT_CAPTURE_GROUP is on.

This is because there are few cases when both named capture and number capture are required.

-- 
NARUSE, Yui  <naruse@airemix.com>
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