docs: def gen_cmake_command(config):
      """
      Generate CMake command.
      """
      from autocmake.extract import extract_list
  
      s = []
      s.append("\n\ndef gen_cmake_command(options, arguments):")
      s.append('    """')
      s.append("    Generate CMake command based on options and arguments.")
      s.append('    """')
      s.append("    command = []")
  
      for env in config['export']:
          s.append('    command.append({0})'.format(env))
  
      s.append("    command.append(arguments['--cmake-executable'])")
  
      for definition in config['define']:
          s.append('    command.append({0})'.format(definition))
  
      s.append("    command.append('-DCMAKE_BUILD_TYPE={0}'.format(arguments['--type']))")
      s.append("    command.append('-G\"{0}\"'.format(arguments['--generator']))")
      s.append("    if arguments['--cmake-options'] != \"''\":")
      s.append("        command.append(arguments['--cmake-options'])")
      s.append("    if arguments['--prefix']:")
      s.append("        command.append('-DCMAKE_INSTALL_PREFIX=\"{0}\"'.format(arguments['--prefix']))")
  
      s.append("\n    return ' '.join(command)")
  
      return '\n'.join(s)