class Sass::Engine

def split_lines
  @line = 0
  old_tabs = nil
  @template.each_with_index do |line, index|
    @line += 1
    tabs = count_tabs(line)
    if line[0] == COMMENT_CHAR && line[1] == SASS_COMMENT_CHAR && tabs == 0
      tabs = old_tabs
    end
    if tabs # if line isn't blank
      raise SyntaxError.new("Indenting at the beginning of the document is illegal.", @line) if old_tabs.nil? && tabs > 0
      if old_tabs && tabs - old_tabs > 1
        raise SyntaxError.new("#{tabs * 2} spaces were used for indentation. Sass must be indented using two spaces.", @line)
      end
      @lines << [line.strip, tabs]
      old_tabs = tabs
    else
      @lines << ['//', old_tabs || 0]
    end
  end
  @line = nil
end