class RubyLex

def indent_difference(lines, line_results, line_index)
  loop do
    _tokens, prev_opens, _next_opens, min_depth = line_results[line_index]
    open_token = prev_opens.last
    if !open_token || (open_token.event != :on_heredoc_beg && !free_indent_token?(open_token))
      # If the leading whitespace is an indent, return the difference
      indent_level = calc_indent_level(prev_opens.take(min_depth))
      calculated_indent = 2 * indent_level
      actual_indent = lines[line_index][/^ */].size
      return actual_indent - calculated_indent
    elsif open_token.event == :on_heredoc_beg && open_token.tok.match?(/^<<[^-~]/)
      return 0
    end
    # If the leading whitespace is not an indent but part of a multiline token
    # Calculate base_indent of the multiline token's beginning line
    line_index = open_token.pos[0] - 1
  end
end