From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2007-10-27T06:43:45+09:00
Subject: Re: Newlines included in bracket negation

On 10/26/07, Chris Morris <the.chrismo@gmail.com> wrote:
> Adding \n inside the brackets fixes it, I just wouldn't expect to have to do
> this since I didn't add the multiline mode option.
>
> require 'test/unit'
>
> class TestRE < Test::Unit::TestCase
>   def test_newlines
>     src = "happy\n\nbirthday"
>     assert_equal("hday", src.scan(/h[^x\n]*?day/).to_s)
>   end
> end

There's also something I don't understand, similar to the above.
I always thought that in a non-multiline regexp, the dot didn't match
newlines (\n), so I don't understand this:

irb(main):036:0> re = /(h)(.*)(day)/
=> /(h)(.*)(day)/
irb(main):037:0> "happy\n\nbirthday".match(re).captures
=> ["h", "", "day"]
irb(main):038:0> re = /(h)(.*)(day)/m
=> /(h)(.*)(day)/m
irb(main):039:0> "happy\n\nbirthday".match(re).captures
=> ["h", "appy\n\nbirth", "day"]

I thought the first case wouldn't match.
Can anyone shed some light?

Jesus.