class Nokogiri::CSS::GeneratedTokenizer

def scan_evaluate( str )
  scan_setup
  @rex_tokens = []
  @lineno  =  1
  ss = StringScanner.new(str)
  state = nil
  until ss.eos?
    text = ss.peek(1)
    @lineno  +=  1  if text == "\n"
    case state
    when nil
      case
      when (text = ss.scan(/[-@]?([_A-Za-z]|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])([_A-Za-z0-9-]|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])*\(\s*/))
         @rex_tokens.push action { [:FUNCTION, text] }
      when (text = ss.scan(/[-@]?([_A-Za-z]|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])([_A-Za-z0-9-]|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])*/))
         @rex_tokens.push action { [:IDENT, text] }
      when (text = ss.scan(/\#([_A-Za-z0-9-]|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])+/))
         @rex_tokens.push action { [:HASH, text] }
      when (text = ss.scan(/[\s\r\n\f]*~=[\s\r\n\f]*/))
         @rex_tokens.push action { [:INCLUDES, text] }
      when (text = ss.scan(/[\s\r\n\f]*\|=[\s\r\n\f]*/))
         @rex_tokens.push action { [:DASHMATCH, text] }
      when (text = ss.scan(/[\s\r\n\f]*\^=[\s\r\n\f]*/))
         @rex_tokens.push action { [:PREFIXMATCH, text] }
      when (text = ss.scan(/[\s\r\n\f]*\$=[\s\r\n\f]*/))
         @rex_tokens.push action { [:SUFFIXMATCH, text] }
      when (text = ss.scan(/[\s\r\n\f]*\*=[\s\r\n\f]*/))
         @rex_tokens.push action { [:SUBSTRINGMATCH, text] }
      when (text = ss.scan(/[\s\r\n\f]*!=[\s\r\n\f]*/))
         @rex_tokens.push action { [:NOT_EQUAL, text] }
      when (text = ss.scan(/[\s\r\n\f]*=[\s\r\n\f]*/))
         @rex_tokens.push action { [:EQUAL, text] }
      when (text = ss.scan(/[\s\r\n\f]*\)/))
         @rex_tokens.push action { [:RPAREN, text] }
      when (text = ss.scan(/[\s\r\n\f]*\[[\s\r\n\f]*/))
         @rex_tokens.push action { [:LSQUARE, text] }
      when (text = ss.scan(/[\s\r\n\f]*\]/))
         @rex_tokens.push action { [:RSQUARE, text] }
      when (text = ss.scan(/[\s\r\n\f]*\+[\s\r\n\f]*/))
         @rex_tokens.push action { [:PLUS, text] }
      when (text = ss.scan(/[\s\r\n\f]*>[\s\r\n\f]*/))
         @rex_tokens.push action { [:GREATER, text] }
      when (text = ss.scan(/[\s\r\n\f]*,[\s\r\n\f]*/))
         @rex_tokens.push action { [:COMMA, text] }
      when (text = ss.scan(/[\s\r\n\f]*~[\s\r\n\f]*/))
         @rex_tokens.push action { [:TILDE, text] }
      when (text = ss.scan(/\:not\([\s\r\n\f]*/))
         @rex_tokens.push action { [:NOT, text] }
      when (text = ss.scan(/-?([0-9]+|[0-9]*\.[0-9]+)/))
         @rex_tokens.push action { [:NUMBER, text] }
      when (text = ss.scan(/[\s\r\n\f]*\/\/[\s\r\n\f]*/))
         @rex_tokens.push action { [:DOUBLESLASH, text] }
      when (text = ss.scan(/[\s\r\n\f]*\/[\s\r\n\f]*/))
         @rex_tokens.push action { [:SLASH, text] }
      when (text = ss.scan(/U\+[0-9a-f?]{1,6}(-[0-9a-f]{1,6})?/))
         @rex_tokens.push action {[:UNICODE_RANGE, text] }
      when (text = ss.scan(/[\s\t\r\n\f]+/))
         @rex_tokens.push action { [:S, text] }
      when (text = ss.scan(/"([^\n\r\f"]|\\n|\r\n|\r|\f|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])*"|'([^\n\r\f']|\\n|\r\n|\r|\f|[^\0-\177]|\\[0-9A-Fa-f]{1,6}(\r\n|[\s\n\r\t\f])?|\\[^\n\r\f0-9A-Fa-f])*'/))
         @rex_tokens.push action { [:STRING, text] }
      when (text = ss.scan(/./))
         @rex_tokens.push action { [text, text] }
      else
        text = ss.string[ss.pos .. -1]
        raise  ScanError, "can not match: '" + text + "'"
      end  # if
    else
      raise  ScanError, "undefined state: '" + state.to_s + "'"
    end  # case state
  end  # until ss
end  # def scan_evaluate