From: Robert Klemme <bob.news@...>
Date: 2005-09-14T22:21:34+09:00
Subject: Re: Surprising Regexp Behavior

James Edward Gray II wrote:
> On Sep 14, 2005, at 6:26 AM, Robert Klemme wrote:
> 
>> James Edward Gray II wrote:
>> 
>>> I keep running into some surprising points with Ruby's Regexp engine
>>> today and this first one just looks plain wrong to me:
>>> 
>>> irb(main):001:0> html = "<p>one</p>\n\n<p>two</p>"
>>> => "<p>one</p>\n\n<p>two</p>"
>>> irb(main):002:0> html.sub!(/<p>(.*?)<\/p>(.*)/) { $1.strip }
>>> => "one\n\n<p>two</p>"
>>> irb(main):003:0> $2
>>> => ""
>>> 
>> 
>> Maybe I overlooked something but I didn't see anybody mention it: the
>> trailing (.*) seems quite superfluous to me.  Why did you put it
>> there?
> 
> So I could check to see if there was more content after the first
> paragraph that I trimmed.  The code goes on to replace it with an
> ellipses if there was.

Ah!  In that case I'd something like:

html.sub!(/(<p>)(.*?)(<\/p>)(.*)/) { $1 << $2.strip << $3 }
html.sub!(/<p>(.*?)<\/p>(.*)/) { "<p>#{$1.strip}</p>" }

Kind regards

    robert