}
	if x >= 0x100 {
		b = append(b, digits[x>>8&0xf])
	}
	if x >= 0x10 {
		b = append(b, digits[x>>4&0xf])
	}
	return append(b, digits[x&0xf])
}

// appendHexPad appends the fully padded hex string representation of x to b.
func appendHexPad(b []byte, x uint16) []byte {
	return append(b, digits[x>>12], digits[x>>8&0xf], digits[x>>4&0xf], digits[x&0xf])
}

func (ip Addr) string4() string {

        builder.append('%');
        builder.append(Character.toUpperCase(Character.forDigit(ch >> 4 & 0xFF, 16)));
        builder.append(Character.toUpperCase(Character.forDigit(ch & 0xF, 16)));
    }

    private String join(boolean leadingSlash, boolean trailingSlash, List<String> parts) {
        if (parts.isEmpty() && leadingSlash) {
            return "/";
        }

	PTRACE_GETFPREGS                 = 0xe
	PTRACE_GETFPXREGS                = 0x12
	PTRACE_GET_THREAD_AREA           = 0x19
	PTRACE_OLDSETOPTIONS             = 0x15
	PTRACE_SETFPREGS                 = 0xf
	PTRACE_SETFPXREGS                = 0x13
	PTRACE_SET_THREAD_AREA           = 0x1a
	PTRACE_SINGLEBLOCK               = 0x21
	PTRACE_SYSEMU                    = 0x1f
	PTRACE_SYSEMU_SINGLESTEP         = 0x20

	PTRACE_GETWMMXREGS               = 0x12
	PTRACE_GET_THREAD_AREA           = 0x16
	PTRACE_OLDSETOPTIONS             = 0x15
	PTRACE_SETCRUNCHREGS             = 0x1a
	PTRACE_SETFPREGS                 = 0xf
	PTRACE_SETHBPREGS                = 0x1e
	PTRACE_SETVFPREGS                = 0x1c
	PTRACE_SETWMMXREGS               = 0x13
	PTRACE_SET_SYSCALL               = 0x17
	PT_DATA_ADDR                     = 0x10004

    if (n > MAX_FACTORIAL) {
      return Double.POSITIVE_INFINITY;
    } else {
      // Multiplying the last (n & 0xf) values into their own accumulator gives a more accurate
      // result than multiplying by everySixteenthFactorial[n >> 4] directly.
      double accum = 1.0;
      for (int i = 1 + (n & ~0xf); i <= n; i++) {
        accum *= i;
      }
      return accum * everySixteenthFactorial[n >> 4];
    }
  }

    if (n > MAX_FACTORIAL) {
      return Double.POSITIVE_INFINITY;
    } else {
      // Multiplying the last (n & 0xf) values into their own accumulator gives a more accurate
      // result than multiplying by everySixteenthFactorial[n >> 4] directly.
      double accum = 1.0;
      for (int i = 1 + (n & ~0xf); i <= n; i++) {
        accum *= i;
      }
      return accum * everySixteenthFactorial[n >> 4];
    }
  }

	PTRACE_GETFPREGS                 = 0xe
	PTRACE_GETFPXREGS                = 0x12
	PTRACE_GET_THREAD_AREA           = 0x19
	PTRACE_OLDSETOPTIONS             = 0x15
	PTRACE_SETFPREGS                 = 0xf
	PTRACE_SETFPXREGS                = 0x13
	PTRACE_SET_THREAD_AREA           = 0x1a
	PTRACE_SINGLEBLOCK               = 0x21
	PTRACE_SYSEMU                    = 0x1f
	PTRACE_SYSEMU_SINGLESTEP         = 0x20

		if got8 != x8 {
			t.Fatalf("RotateLeft8(%#02x, -%d) == %#02x; want %#02x", want8, k, got8, x8)
		}

		x16 := uint16(m)
		got16 := RotateLeft16(x16, int(k))
		want16 := x16<<(k&0xf) | x16>>(16-k&0xf)
		if got16 != want16 {
			t.Fatalf("RotateLeft16(%#04x, %d) == %#04x; want %#04x", x16, k, got16, want16)
		}
		got16 = RotateLeft16(want16, -int(k))
		if got16 != x16 {

      encodings[ 0x7] = encoding // Bell
      encodings['\b'.code] = encoding // Backspace
      encodings[ 0xb] = encoding // Vertical Tab
      encodings[ 0xe] = encoding // Shift Out
      encodings[ 0xf] = encoding // Shift In
      encodings[ 0x10] = encoding // Data Link Escape
      encodings[ 0x11] = encoding // Device Control 1 (oft. XON)
      encodings[ 0x12] = encoding // Device Control 2

                    case '\r':
                        out.write('\\');
                        out.write('r');
                        break;
                    default:
                        if (ch > 0xf) {
                            out.write("\\u00" + hex(ch));
                        } else {
                            out.write("\\u000" + hex(ch));
                        }
                        break;