// the Unicode replacement code point U+FFFD.
func DecodeRune(r1, r2 rune) rune {
	if surr1 <= r1 && r1 < surr2 && surr2 <= r2 && r2 < surr3 {
		return (r1-surr1)<<10 | (r2 - surr2) + surrSelf
	}
	return replacementChar
}

// EncodeRune returns the UTF-16 surrogate pair r1, r2 for the given rune.
// If the rune is not a valid Unicode code point or does not need encoding,
// EncodeRune returns U+FFFD, U+FFFD.

func decodeWTF16(s []uint16, buf []byte) []byte {
	for i := 0; i < len(s); i++ {
		var ar rune
		switch r := s[i]; {
		case r < surr1, surr3 <= r:
			// normal rune
			ar = rune(r)
		case surr1 <= r && r < surr2 && i+1 < len(s) &&
			surr2 <= s[i+1] && s[i+1] < surr3:
			// valid surrogate sequence
			ar = utf16.DecodeRune(rune(r), rune(s[i+1]))
			i++
		default:
			// WTF-8 fallback.

	{'\U0010FFFD', false}, // PRIVATE USE CHARACTER-10FFFD (last Unicode code point)

	{rune(0xd7ff), false}, // surr1-1
	{rune(0xd800), true},  // surr1
	{rune(0xdc00), true},  // surr2
	{rune(0xe000), false}, // surr3
	{rune(0xdfff), true},  // surr3-1
}

func TestIsSurrogate(t *testing.T) {
	for i, tt := range surrogateTests {
		got := IsSurrogate(tt.r)
		if got != tt.want {

)

// writeConsole writes bufLen bytes from buf to the console File.
// It returns the number of bytes written.
func writeConsole(handle uintptr, buf unsafe.Pointer, bufLen int32) int {
	const surr2 = (surrogateMin + surrogateMax + 1) / 2

	// Do not use defer for unlock. May cause issues when printing a panic.
	lock(&utf16ConsoleBackLock)

	b := (*[1 << 30]byte)(buf)[:bufLen]

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package utf16

// Extra names for constants so we can validate them during testing.
const (
	Surr1           = surr1
	Surr3           = surr3
	SurrSelf        = surrSelf
	MaxRune         = maxRune
	ReplacementChar = replacementChar

Richtsfeld, Rodrigo Silveira, Ruizhi, Santosh Kumar, Seb Bro, Sergei Lebedev,
sfujiwara, Shaba Abhiram, Shashi, SneakyFish5, Soila Kavulya, Stefan Dyulgerov,
Steven Winston, Sunitha Kambhampati, Surry Shome, Taehoon Lee, Thor Johnsen,
Tristan Rice, TShapinsky, tucan, tucan9389, Vicente Reyes, Vilmar-Hillow, Vitaly
Lavrukhin, wangershi, weidan.kong, weidankong, Wen-Heng (Jack) Chung, William D.