}
	wn, err = sw.WriteString(s[i:])
	n += wn
	return
}

// byteReplacer is the implementation that's used when all the "old"
// and "new" values are single ASCII bytes.
// The array contains replacement bytes indexed by old byte.
type byteReplacer [256]byte

func (r *byteReplacer) Replace(s string) string {
	var buf []byte // lazily allocated
	for i := 0; i < len(s); i++ {
		b := s[i]

				i, tc.in, n, len(tc.out), tc.out)
		}
	}
}

var algorithmTestCases = []struct {
	r    *Replacer
	want string
}{
	{capitalLetters, "*strings.byteReplacer"},
	{htmlEscaper, "*strings.byteStringReplacer"},
	{NewReplacer("12", "123"), "*strings.singleStringReplacer"},
	{NewReplacer("1", "12"), "*strings.byteStringReplacer"},
	{NewReplacer("", "X"), "*strings.genericReplacer"},