From: matz@... (Yukihiro Matsumoto)
Date: 2001-05-30T00:06:50+09:00
Subject: [ruby-talk:15932] Re: Regexp (a\1)

Hi,

In message "[ruby-talk:15924] Re: Regexp (a\1)"
    on 01/05/29, ts <decoux@moulon.inra.fr> writes:

|Y>   * backreferences corresponding to unclosed/unmatched parentheses
|Y>     should fail always.
|
| This is not what do perl, and this will be a difference from perl/ruby.
|
| For perl a reference exist only *after* it has found the close ')'
|     ruby    ....                *when*    ......         open  '('

Hmm, I don't get the point.

| This mean that perl can re-use a previous backreference, for example this
| is valid in perl
|
|  "aaaaaa" =~  /^(a\1?)(a\1?)(a\2?)(a\3?)$/
|
| and it must give the result $1 = "a", $2 = "aa", $3 = "a", $4 = "aa" (this
| is extract from the tests of perl).

Ruby gives same result (before and after the modification).
Probably I'm missing something.

							matz.