From: Bertram Scharpf <lists@...>
Date: 2007-07-06T17:13:57+09:00
Subject: Re: Regex: What does the ^ do? What is it called?

Hi,

Am Freitag, 06. Jul 2007, 14:33:12 +0900 schrieb Thomas Wieczorek:
> >/^abc/ =~ "!abc"
> >returns nil
> >"You can use an anchor to match the beginning of a string"
> 
> Just like the definition says ^ is used to mark the beginning of a string:
> /^abc/ =~ "abc!"

Another time:

  ^  and $   match the beginning/end of a ___line___
  \A and \z  match the beginning/end of a ___string___

This makes a difference when you string contains newline
characters.

  "abc\nde\nfgh\n".scan /^./       # => ["a", "d", "f"]
  "abc\nde\nfgh\n" =~ /.$/         # => 2
  $&                               # => "c"

I would have guessed that /\z/ is faster than /$/ but /$/ is
approximately 10 times faster here. Does anybody know why?

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de