} else {
			curDir = RightToLeft
		}
		if curDir != prevDir {
			if i > 0 {
				o.runes = append(o.runes, runes[prevI:i])
				o.directions = append(o.directions, prevDir)
				o.startpos = append(o.startpos, prevI)
			}
			prevI = i
			prevDir = curDir
		}
	}
	o.runes = append(o.runes, runes[prevI:])
	o.directions = append(o.directions, prevDir)
	o.startpos = append(o.startpos, prevI)
	return o

		partLen = c.Rand.Intn(63) + 1 // len is [1, 63]
	}

	runes := make([]rune, partLen)
	if partLen == 0 {
		return string(runes)
	}

	runes[0] = validStartEnd[c.Rand.Intn(len(validStartEnd))].choose(c.Rand)
	for i := range runes[1:] {
		runes[i+1] = validMiddle[c.Rand.Intn(len(validMiddle))].choose(c.Rand)
	}
	runes[len(runes)-1] = validStartEnd[c.Rand.Intn(len(validStartEnd))].choose(c.Rand)

			if syntax.Flags(inst.Arg)&syntax.FoldCase != 0 {
				r0 := inst.Rune[0]
				runes = append(runes, r0, r0)
				for r1 := unicode.SimpleFold(r0); r1 != r0; r1 = unicode.SimpleFold(r1) {
					runes = append(runes, r1, r1)
				}
				slices.Sort(runes)
			} else {
				runes = append(runes, inst.Rune[0], inst.Rune[0])
			}
			onePassRunes[pc] = runes
			inst.Next = make([]uint32, len(onePassRunes[pc])/2+1)
			for i := range inst.Next {

	buf := []byte("Hello, 世界")
	fmt.Println("bytes =", len(buf))
	fmt.Println("runes =", utf8.RuneCount(buf))
	// Output:
	// bytes = 13
	// runes = 9
}

func ExampleRuneCountInString() {
	str := "Hello, 世界"
	fmt.Println("bytes =", len(str))
	fmt.Println("runes =", utf8.RuneCountInString(str))
	// Output:
	// bytes = 13
	// runes = 9
}

func ExampleRuneLen() {
	fmt.Println(utf8.RuneLen('a'))

	_ = myString([]myByte{'\xf0', '\x9f', '\x8c', '\x8d'}) // "🌍

	// 3
	_ = string([]rune{0x767d, 0x9d6c, 0x7fd4}) // "\u767d\u9d6c\u7fd4" == "白鵬翔"
	_ = string([]rune{})                       // ""
	_ = string([]rune(nil))                    // ""

	type runes []rune
	_ = string(runes{0x767d, 0x9d6c, 0x7fd4}) // "\u767d\u9d6c\u7fd4" == "白鵬翔"

	type myRune rune
	_ = string([]myRune{0x266b, 0x266c}) // "\u266b\u266c" == "♫♬"

	// Treated as a quoting character by IE.
	'`': "`",
}

// htmlReplacer returns s with runes replaced according to replacementTable
// and when badRunes is true, certain bad runes are allowed through unescaped.
func htmlReplacer(s string, replacementTable []string, badRunes bool) string {
	written, b := 0, new(strings.Builder)
	r, w := rune(0), 0
	for i := 0; i < len(s); i += w {

//
// For our approximation, we group the Word Break types into the following
// categories, with associated rules:
//
// 1) Letter:
//    ALetter, Hebrew_Letter, Numeric, ExtendNumLet, Extend, Format_FE, ZWJ.
//    Rule: Never break between consecutive runes of this category.
//
// 2) Mid:
//    MidLetter, MidNumLet, Single_Quote.
//    (Cf. case-ignorable: MidLetter, MidNumLet, Single_Quote or cat is Mn,

//	2..0  case mode
//
// For the non-exceptional cases, a rune must be either uncased, lowercase or
// uppercase. If the rune is cased, the XOR pattern maps either a lowercase
// rune to uppercase or an uppercase rune to lowercase (applied to the 10
// least-significant bits of the rune).
//
// See the definitions below for a more detailed description of the various
// bits.
type info uint16

		if n := runtimeRuneCount(ts); n != count {
			t.Errorf("%q: len([]rune()) counted %d runes; got %d from RuneCountInString", ts, n, count)
			break
		}

		runes := []rune(ts)
		if n := len(runes); n != count {
			t.Errorf("%q: []rune() has length %d; got %d from RuneCountInString", ts, n, count)
			break
		}
		i := 0
		for _, r := range ts {
			if r != runes[i] {

		}
		t.historyIndex++
		runes := []rune(entry)
		t.setLine(runes, len(runes))
	case keyDown:
		switch t.historyIndex {
		case -1:
			return
		case 0:
			runes := []rune(t.historyPending)
			t.setLine(runes, len(runes))
			t.historyIndex--
		default:
			entry, ok := t.history.NthPreviousEntry(t.historyIndex - 1)
			if ok {
				t.historyIndex--
				runes := []rune(entry)