From: Kristof Bastiaensen <kristof@...>
Date: 2004-06-30T01:38:04+09:00
Subject: Re: String substitution bug

On Tue, 29 Jun 2004 14:16:09 +0200, Martin Schoettler wrote:

> (Ruby 1.8.1, Linux and Windows)
> 
>     puts "a\\b".sub( /\\/, "\\\\" )
> yields
>     a\b
> (I expected: a\\b)
> 
> But
>     puts "a\\b".sub( /\\/, "\\x\\" )
> yields
>     a\x\b
> (as I would expect.)
> 
> BTW: Mails to ruby-bugs@ruby-lang.org are rejected. Is there a new mail 
> adress for bugs?

Hi,

I don't know about bugs, but this however is not bug, 
but a feature :-)
When using a replacement string, gsub does another 
elimination step for backslashes, because "\1" and "\2"
have a special meaning.  So first "\\\\" will be translated
to "\\" for the quoted string, and the second time it will
be translated to "\" by gsub.  In the second case however gsub
will see "\x\", and since "\x" doesn't have a special meaning
it will be kept.  

Regards,
Kristof