fmt.Printf("%s\n", bytes.ReplaceAll([]byte("oink oink oink"), []byte("oink"), []byte("moo")))
	// Output:
	// moo moo moo
}

func ExampleRunes() {
	rs := bytes.Runes([]byte("go gopher"))
	for _, r := range rs {
		fmt.Printf("%#U\n", r)
	}
	// Output:
	// U+0067 'g'
	// U+006F 'o'
	// U+0020 ' '
	// U+0067 'g'
	// U+006F 'o'
	// U+0070 'p'
	// U+0068 'h'
	// U+0065 'e'
	// U+0072 'r'
}

	// TODO(quasilyte): improve error message (#21860).
	V4FMADDPS (AX), [Z4-Z0], K1, Z7  // ERROR "invalid instruction"
	V4FMADDPS (AX), [Z1-Z0], K1, Z7  // ERROR "invalid instruction"
	// Mismatching registers in a range.
	// TODO(quasilyte): improve error message (#21860).
	V4FMADDPS (AX), [AX-Z3], K1, Z7  // ERROR "invalid instruction"
	V4FMADDPS (AX), [Z0-AX], K1, Z7  // ERROR "invalid instruction"

	for _, w := range walkers {
		for _, name := range w.stdPackages {
			pkg, err := w.import_(name)
			if _, nogo := err.(*build.NoGoError); nogo {
				continue
			}
			if err != nil {
				log.Fatalf("Import(%q): %v", name, err)
			}
			w.export(pkg)
		}

		ctxName := contextName(w.context)
		for _, f := range w.Features() {
			if featureCtx[f] == nil {

	VDUP	V8.B[17], V3.B8                                  // ERROR "register element index out of range 0 to 15"
	VDUP	V8.H[9], V3.H4                                   // ERROR "register element index out of range 0 to 7"
	VDUP	V8.H[9], V3.H8                                   // ERROR "register element index out of range 0 to 7"
	VDUP	V8.S[4], V3.S2                                   // ERROR "register element index out of range 0 to 3"

		if codeHex == "" {
			codeHex = "empty"
		}
		ok := false
		for _, hex := range strings.Split(hexes, " or ") {
			if codeHex == hex {
				ok = true
				break
			}
		}
		if !ok {
			t.Errorf("%s: have encoding %s, want %s", p, codeHex, hexes)
		}
	}

	if len(hexByLine) > 0 {
		var missing []string
		for key := range hexByLine {
			missing = append(missing, key)
		}
		sort.Strings(missing)

// Test that the rune splitter returns same sequence of runes (not bytes) as for range string.
func TestScanRune(t *testing.T) {
	for n, test := range scanTests {
		buf := strings.NewReader(test)
		s := NewScanner(buf)
		s.Split(ScanRunes)
		var i, runeCount int
		var expect rune
		// Use a string range loop to validate the sequence of runes.
		for i, expect = range test {
			if !s.Scan() {
				break
			}
			runeCount++

	out, err := cmd.Output()
	if err != nil {
		return "", fmt.Errorf("ideviceinfo: %v", err)
	}
	var iosVer, buildVer string
	lines := bytes.Split(out, []byte("\n"))
	for _, line := range lines {
		key, val, ok := strings.Cut(string(line), ": ")
		if !ok {
			continue
		}
		switch key {
		case "ProductVersion":
			iosVer = val
		case "BuildVersion":
			buildVer = val
		}
	}

		}},
	}}

	b.Run("Writer", func(b *testing.B) {
		for _, v := range vectors {
			b.Run(v.label, func(b *testing.B) {
				b.ReportAllocs()
				for i := 0; i < b.N; i++ {
					// Writing to io.Discard because we want to
					// test purely the writer code and not bring in disk performance into this.
					tw := NewWriter(io.Discard)
					for _, file := range v.files {
						if err := tw.WriteHeader(file.hdr); err != nil {

	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling licence.\nWrite more examples."},
	}
	for _, file := range files {
		f, err := w.Create(file.Name)
		if err != nil {
			log.Fatal(err)
		}
		_, err = f.Write([]byte(file.Body))
		if err != nil {
			log.Fatal(err)
		}
	}

		if ok1 || ok2 {
			return ok1 && ok2
		}
		return x == y
	}
	for _, v := range vectors {
		t.Run(path.Base(v.file), func(t *testing.T) {
			const maxSize = 10 << 10 // 10KiB
			buf := new(bytes.Buffer)
			tw := NewWriter(iotest.TruncateWriter(buf, maxSize))

			for i, tf := range v.tests {
				switch tf := tf.(type) {
				case testHeader:
					err := tw.WriteHeader(&tf.hdr)