}
	}
}

func TestAppendRune(t *testing.T) {
	for _, tt := range encodeTests {
		var out []uint16
		for _, u := range tt.in {
			out = AppendRune(out, u)
		}
		if !reflect.DeepEqual(out, tt.out) {
			t.Errorf("AppendRune(%x) = %x; want %x", tt.in, out, tt.out)
		}
	}
}

func TestEncodeRune(t *testing.T) {
	for i, tt := range encodeTests {
		j := 0
		for _, r := range tt.in {

			i++
		default:
			// WTF-8 fallback.
			// This only handles the 3-byte case of utf8.AppendRune,
			// as surrogates always fall in that case.
			ar = rune(r)
			if ar > utf8.MaxRune {
				ar = utf8.RuneError
			}
			buf = append(buf, t3|byte(ar>>12), tx|byte(ar>>6)&maskx, tx|byte(ar)&maskx)
			continue
		}
		buf = utf8.AppendRune(buf, ar)
	}
	return buf

func (rb *reorderBuffer) decomposeHangul(r rune) {
	r -= hangulBase
	x := r % jamoTCount
	r /= jamoTCount
	rb.appendRune(jamoLBase + r/jamoVCount)
	rb.appendRune(jamoVBase + r%jamoVCount)
	if x != 0 {
		rb.appendRune(jamoTBase + x)
	}
}

// combineHangul algorithmically combines Jamo character components into Hangul.

func (rb *reorderBuffer) decomposeHangul(r rune) {
	r -= hangulBase
	x := r % jamoTCount
	r /= jamoTCount
	rb.appendRune(jamoLBase + r/jamoVCount)
	rb.appendRune(jamoVBase + r%jamoVCount)
	if x != 0 {
		rb.appendRune(jamoTBase + x)
	}
}

// combineHangul algorithmically combines Jamo character components into Hangul.

	fmt.Println(utf8.ValidString(valid))
	fmt.Println(utf8.ValidString(invalid))
	// Output:
	// true
	// false
}

func ExampleAppendRune() {
	buf1 := utf8.AppendRune(nil, 0x10000)
	buf2 := utf8.AppendRune([]byte("init"), 0x10000)
	fmt.Println(string(buf1))
	fmt.Println(string(buf2))
	// Output:
	// 𐀀
	// init𐀀

		}
	}
}

func TestAppendRune(t *testing.T) {
	for _, m := range utf8map {
		if buf := AppendRune(nil, m.r); string(buf) != m.str {
			t.Errorf("AppendRune(nil, %#04x) = %s, want %s", m.r, buf, m.str)
		}
		if buf := AppendRune([]byte("init"), m.r); string(buf) != "init"+m.str {
			t.Errorf("AppendRune(init, %#04x) = %s, want %s", m.r, buf, "init"+m.str)
		}
	}
}

func TestDecodeRune(t *testing.T) {

			if 'a' <= c && c <= 'z' {
				c -= 'a' - 'A'
			}
			out = append(out, c)
			i++
			continue
		}
		// Handle multi-byte Unicode.
		r, n := utf8.DecodeRune(in[i:])
		out = utf8.AppendRune(out, foldRune(r))
		i += n
	}
	return out
}

// foldRune is returns the smallest rune for all runes in the same fold set.
func foldRune(r rune) rune {
	for {
		r2 := unicode.SimpleFold(r)
		if r2 <= r {

			n += 2
		default:
			a[n] = uint16(replacementChar)
			n++
		}
	}
	return a[:n]
}

// AppendRune appends the UTF-16 encoding of the Unicode code point r
// to the end of p and returns the extended buffer. If the rune is not
// a valid Unicode code point, it appends the encoding of U+FFFD.
func AppendRune(a []uint16, r rune) []uint16 {
	// This function is inlineable for fast handling of ASCII.
	switch {

		}
		length += len(s) + 1
	}
	length += 1

	b := make([]uint16, 0, length)
	for _, s := range envv {
		for _, c := range s {
			b = utf16.AppendRune(b, c)
		}
		b = utf16.AppendRune(b, 0)
	}
	b = utf16.AppendRune(b, 0)
	return b, nil
}

func CloseOnExec(fd Handle) {
	SetHandleInformation(Handle(fd), HANDLE_FLAG_INHERIT, 0)
}

// WriteRune appends the UTF-8 encoding of Unicode code point r to b's buffer.
// It returns the length of r and a nil error.
func (b *Builder) WriteRune(r rune) (int, error) {
	b.copyCheck()
	n := len(b.buf)
	b.buf = utf8.AppendRune(b.buf, r)
	return len(b.buf) - n, nil
}

// WriteString appends the contents of s to b's buffer.
// It returns the length of s and a nil error.
func (b *Builder) WriteString(s string) (int, error) {