From: Matt <mgregory22@...>
Date: 2008-05-18T16:55:07+09:00
Subject: Re: sub/gsub bug?

J. Cooper wrote:

> The gsub replacement string is a crazy thing when it comes to escaping,
> because remember you can put backreferences in it. Any double quoted
> string needs 2 backslashes to represent a literal backslash, but
> remember in this context, a literal backslash represents the
> backreference syntax, so you need to escape it with another "literal
> backslash" of 2 backslashes.
>
> At least, I think that's how I understand it :P

Yeah, I get all that, but I didn't think that \' was a backreference.
I thought it was limited to numbers and the ampersand.  But now that I
think about it, Perl has a $' variable that contains the portion of
the string after the match, so I guess that's where the idea came
from.  I've never seen that in backreference form before.

irb(main):005:0> "matt's test".gsub(/'/, "\\`")
=> "mattmatts test"
irb(main):006:0> "matt's test".gsub(/'/, "\\&")
=> "matt's test"
irb(main):007:0> "matt's test".gsub(/'/, "\\'")
=> "matts tests test"

Yay!
Matt