char attr = readChar(ch);
char attr = readCodePoint((int)ch);
  public static int digit(char ch, int radix)  {    if (radix < MIN_RADIX || radix > MAX_RADIX)      return -1;    char attr = readChar(ch);    if (((1 << (attr & TYPE_MASK))         & ((1 << UPPERCASE_LETTER)            | (1 << LOWERCASE_LETTER)            | (1 << DECIMAL_DIGIT_NUMBER))) != 0)      {        // Signedness doesn't matter; 0xffff vs. -1 are both rejected.        int digit = numValue[attr >> 7];        return (digit < radix) ? digit : -1;      }    return -1;  }