String (RegExpSimpleClass simpleClass) { return switch (simpleClass.getKind()) { case DIGIT -> "\\D"; case NON_DIGIT -> "\\d"; case WORD -> "\\W"; case NON_WORD -> "\\w"; case SPACE -> "\\S"; case NON_SPACE -> "\\s"; case HORIZONTAL_SPACE -> "\\H"; case NON_HORIZONTAL_SPACE -> "\\h"; case VERTICAL_SPACE -> "\\V"; case NON_VERTICAL_SPACE -> "\\v"; case XML_NAME_START -> "\\I"; case NON_XML_NAME_START -> "\\i"; case XML_NAME_PART -> "\\C"; case NON_XML_NAME_PART -> "\\c"; default -> null; }; }