From: dblack@...
Date: 2002-12-06T10:52:33+09:00
Subject: Re: Regexp imxo - does 'x' work?

Hi --

On Fri, 6 Dec 2002, ahoward wrote:

>
> should this not work ?
>
>   irb(main):001:0> %r{
>   irb(main):002:0/ foo
>   irb(main):003:0/ #foo
>   irb(main):004:0/ bar
>   irb(main):005:0/ #bar
>   irb(main):006:0/ }
>   /\nfoo\n#foo\nbar\n#bar\n/

That's working, isn't it?

> or this?
>
>   irb(main):007:0> %r{foo bar}x
>   /foo bar/x
>
> what DOES 'x' do?

It's an eXtended regex, which means that literal spaces and
newlines are ignored.

>   perl -e 'print "foobar" =~ /foo bar/x'      >> 1

Yikes, I can't even remember what Perl returns for these
cases....

>   ruby -e 'print "foobar" =~ /foo bar/x'      >> 0

The 0 is the index into the string of where the match
starts -- and there was indeed a match.

Here are some more examples:

  irb(main):017:0> /foo bar/.match("foobar")
  nil

  irb(main):018:0> /foo bar/x.match("foobar")
  #<MatchData:0x401a3814>

  # Throwing in a newline:
  irb(main):019:0> /foo
  irb(main):020:0/ b a r/x.match("foobar")
  #<MatchData:0x401a0a88>


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav