in src/prettify/parser/CombinePrefixPattern.java [103:111]
protected static String encodeEscape(int charCode) {
if (charCode < 0x20) {
return (charCode < 0x10 ? "\\x0" : "\\x") + Integer.toString(charCode, 16);
}
String ch = new String(Character.toChars(charCode));
return (charCode == '\\' || charCode == '-' || charCode == ']' || charCode == '^')
? "\\" + ch : ch;
}