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] {

var notletterTest = []rune{
	0x20,
	0x35,
	0x375,
	0x619,
	0x700,
	0x1885,
	0xfffe,
	0x1ffff,
	0x10ffff,
}

// Contains all the special cased Latin-1 chars.
var spaceTest = []rune{
	0x09,
	0x0a,
	0x0b,
	0x0c,
	0x0d,
	0x20,
	0x85,
	0xA0,
	0x2000,
	0x3000,
}

type caseT struct {
	cas     int
	in, out rune
}

var caseTest = []caseT{
	// errors

}

var sinkInt int

func BenchmarkRuneCount(b *testing.B) {
	// Each sub-benchmark counts the runes in a string in a different way.
	b.Run("lenruneslice", func(b *testing.B) {
		for _, sd := range stringdata {
			b.Run(sd.name, func(b *testing.B) {
				for i := 0; i < b.N; i++ {
					sinkInt += len([]rune(sd.data))
				}
			})
		}
	})
	b.Run("rangeloop", func(b *testing.B) {

			ss = 0
			continue
		}
		info := f.info(src, i)
		if info.size == 0 {
			if atEOF {
				// include incomplete runes
				return n, true
			}
			return lastSegStart, true
		}
		// This block needs to be before the next, because it is possible to
		// have an overflow for runes that are starters (e.g. with U+FF9E).
		switch ss.next(info) {
		case ssStarter:
			lastSegStart = i
		case ssOverflow:

			ss = 0
			continue
		}
		info := f.info(src, i)
		if info.size == 0 {
			if atEOF {
				// include incomplete runes
				return n, true
			}
			return lastSegStart, true
		}
		// This block needs to be before the next, because it is possible to
		// have an overflow for runes that are starters (e.g. with U+FF9E).
		switch ss.next(info) {
		case ssStarter:
			lastSegStart = i
		case ssOverflow:

// A mapFunc takes a context set to the current rune and writes the mapped
// version to the same context. It may advance the context to the next rune. It
// returns whether a checkpoint is possible: whether the pDst bytes written to
// dst so far won't need changing as we see more source bytes.
type mapFunc func(*context) bool

// A spanFunc takes a context set to the current rune and returns whether this

			}
			continue // All other multibyte runes are correctly encoded and assumed printable.
		}
		if r == utf8.RuneError {
			return false
		}
		if (r < ' ' && r != '\t') || r == '`' || r == '\u007F' {
			return false
		}
	}
	return true
}

func unhex(b byte) (v rune, ok bool) {
	c := rune(b)
	switch {
	case '0' <= c && c <= '9':
		return c - '0', true

		sep := ""
		for i := 0; i < len(re.Rune); i += 2 {
			b.WriteString(sep)
			sep = " "
			lo, hi := re.Rune[i], re.Rune[i+1]
			if lo == hi {
				fmt.Fprintf(b, "%#x", lo)
			} else {
				fmt.Fprintf(b, "%#x-%#x", lo, hi)
			}
		}
	}
	b.WriteByte('}')
}

func mkCharClass(f func(rune) bool) string {
	re := &Regexp{Op: OpCharClass}
	lo := rune(-1)
	for i := rune(0); i <= unicode.MaxRune; i++ {

that is, runes. (This differs from C's printf where the
units are always measured in bytes.) Either or both of the flags
may be replaced with the character '*', causing their values to be
obtained from the next operand (preceding the one to format),
which must be of type int.

For most values, width is the minimum number of runes to output,
padding the formatted form with spaces if necessary.

package norm

import (
	"fmt"
	"unicode/utf8"
)

// MaxSegmentSize is the maximum size of a byte buffer needed to consider any
// sequence of starter and non-starter runes for the purpose of normalization.
const MaxSegmentSize = maxByteBufferSize

// An Iter iterates over a string or byte slice, while normalizing it
// to a given Form.
type Iter struct {
	rb     reorderBuffer