From: GOTO Kentaro <gotoken@...>
Date: 2002-09-24T05:00:39+09:00
Subject: Re: Speed up suggestions

At Tue, 24 Sep 2002 03:58:45 +0900,
Kent Dahl wrote:
> I am confused. Ruby '\n' is not equivalent with Ruby "\n", so a
> difference would not be unexpected. (The size of the difference perhaps)

As you said '\n' != "\n" and '\n' == "\\n" indeed.  And also 

  p Regexp.new("\n")  == eval("/\n/")   #=> true
  p Regexp.new("\\n") == eval("/\\n/")  #=> true

Try below if you are confused:
  p "/\n/"
  p "/\\n/"


By the way, in 1.7.x, String#split behavior was changed about a month ago:

  % ruby17 -e 'p "a\nb".split("\\n")'  
  -e:1: warning: string pattern instead of regexp; metacharacters no longer effective
  ["a\nb"]
  % ruby17 -e 'p "a\\nb".split("\\n")' 
  -e:1: warning: string pattern instead of regexp; metacharacters no longer effective
  ["a", "b"]

In current version 1.7.3, split(sep) does like as follows:

  def split(sep)
    case sep
    when String
      sep = if sep.size > 1
              Regexp.new(Regexp.escape(sep))
            else
              Regexp.new(sep)
            end
    when Regexp
    else
      raise TypeError, "wrong argument type #{sep.type} (expected Regexp)"
    end

    And do real split action with sep
  end

-- Gotoken