class RubyLex

def configure_io(io)
  @io = io
  if @io.respond_to?(:check_termination)
    @io.check_termination do |code|
      if Reline::IOGate.in_pasting?
        rest = check_termination_in_prev_line(code)
        if rest
          Reline.delete_text
          rest.bytes.reverse_each do |c|
            Reline.ungetc(c)
          end
          true
        else
          false
        end
      else
        # Accept any single-line input for symbol aliases or commands that transform args
        next true if single_line_command?(code)
        _tokens, _opens, terminated = check_code_state(code)
        terminated
      end
    end
  end
  if @io.respond_to?(:dynamic_prompt)
    @io.dynamic_prompt do |lines|
      lines << '' if lines.empty?
      tokens = self.class.ripper_lex_without_warning(lines.map{ |l| l + "\n" }.join, context: @context)
      line_results = IRB::NestingParser.parse_by_line(tokens)
      tokens_until_line = []
      line_results.map.with_index do |(line_tokens, _prev_opens, next_opens, _min_depth), line_num_offset|
        line_tokens.each do |token, _s|
          # Avoid appending duplicated token. Tokens that include "\n" like multiline tstring_content can exist in multiple lines.
          tokens_until_line << token if token != tokens_until_line.last
        end
        continue = should_continue?(tokens_until_line)
        prompt(next_opens, continue, line_num_offset)
      end
    end
  end
  if @io.respond_to?(:auto_indent) and @context.auto_indent_mode
    @io.auto_indent do |lines, line_index, byte_pointer, is_newline|
      next nil if lines == [nil] # Workaround for exit IRB with CTRL+d
      next nil if !is_newline && lines[line_index]&.byteslice(0, byte_pointer)&.match?(/\A\s*\z/)
      code = lines[0..line_index].map { |l| "#{l}\n" }.join
      tokens = self.class.ripper_lex_without_warning(code, context: @context)
      process_indent_level(tokens, lines, line_index, is_newline)
    end
  end
end