From: William James <w_a_x_man@...>
Date: 2007-08-29T10:15:17+09:00
Subject: Re: gsub help

On Aug 28, 5:11 pm, hurcan solter <hsol...@gmail.com> wrote:
>   Hi there;
>   this is more of a regexp question but I'de be happy if you help me
> since i am doing it in ruby.
>   i want to beautify some line by inserting or removing some space
> around the operators like = or ==
>  so i came up with an expression like;
>
>   line.gsub!(/\s*([=]+)\s*/ ,' \1 ')
>
> But it applies every = on the line ofc, but I want to exclude
> expressions between quotation marks ("sth=sth") or regexp (/sth=sth/).
> I've tried negated character classes and such to no avail.How can I do
> this?
>  Any help would be greatly appreciated...
>  Hurcan

If " and / are the only wrappers you have to worry
about, this may work.

DATA.each{|line|
  line.chomp!

  array = line.scan(
    %r{
      \G
      (?:
        [^"/]+
        |
        "
          (?> \\. | [^"] ) *
        "
        |
        /
          (?> \\. | [^/] ) *
        /
      )
    }xm
  ).map{|s|
    if s =~ %r{^[^"/]}
      s.gsub!( /\s*(=+)\s*/, ' \1 ' )
    end
    s
  }
  puts array.join

}

__END__
/x==9/ { print "x==9 and AWK is everywhere!"; x=9 }
/\/x==9/ { print "x==\"9"; x==9 }