docs: public boolean alphaNum(TextProvider textProvider)
          
      {
          clearLastToken(textProvider);
          clearLeadingSpaces(textProvider);
          mark(textProvider);
          if (m_debug)
  			debug("testing",textProvider);
          StringBuilder sb = new StringBuilder();
          while (true)
          {
              char c = getNextChar(textProvider);
  
              if (!Character.isLetterOrDigit(c)) break;
              remark(textProvider);
              sb.append(c);
          }
          reset(textProvider); // removes last char
          if (sb.toString().length() == 0) return false;
          textProvider.setLastToken(sb.toString());
          debug(textProvider);
          return true;
      }