// The text itself is stored in a separate buffer; cell only describes the
// segment's size in bytes, its width in runes, and whether it's an htab
// ('\t') terminated cell.
type cell struct {
	size  int  // cell size in bytes
	width int  // cell width in runes
	htab  bool // true if the cell is terminated by an htab ('\t')
}

// A Writer is a filter that inserts padding around tab-delimited

// TODO(rfindley): this should not be necessary.
func sanitizeObjectString(s string) string {
	var runes []rune
	for _, r := range s {
		if '₀' <= r && r < '₀'+10 {
			continue // trim type parameter subscripts
		}
		runes = append(runes, r)
	}
	return string(runes)
}

func checkFile(t *testing.T, filename string, src []byte) *types.Package {
	fset := token.NewFileSet()

	buf.WriteString(s.Name)
	return InternString(buf.Bytes())
}

func sconv2(b *bytes.Buffer, s *Sym, verb rune, mode fmtMode) {
	if verb == 'L' {
		panic("linksymfmt")
	}
	if s == nil {
		b.WriteString("<S>")
		return
	}

	symfmt(b, s, verb, mode)
}

func symfmt(b *bytes.Buffer, s *Sym, verb rune, mode fmtMode) {
	name := s.Name
	if q := pkgqual(s.Pkg, verb, mode); q != "" {
		b.WriteString(q)

	}
	copy(b, s)
	return b
}

func stringtoslicerune(buf *[tmpStringBufSize]rune, s string) []rune {
	// two passes.
	// unlike slicerunetostring, no race because strings are immutable.
	n := 0
	for range s {
		n++
	}

	var a []rune
	if buf != nil && n <= len(buf) {
		*buf = [tmpStringBufSize]rune{}
		a = buf[:n]
	} else {
		a = rawruneslice(n)
	}

	n = 0

	Flag(c int) bool
}

// Formatter is implemented by any value that has a Format method.
// The implementation controls how [State] and rune are interpreted,
// and may call [Sprint] or [Fprint](f) etc. to generate its output.
type Formatter interface {
	Format(f State, verb rune)
}

// Stringer is implemented by any value that has a String method,
// which defines the “native” format for that value.

// But there are at least two subtle considerations.
//
// First, note that not all case-fold equivalent distinct runes
// form an upper/lower pair.
// For example, U+004B ('K'), U+006B ('k'), and U+212A ('K' for Kelvin)
// are three distinct runes that case-fold to each other.
// When we do add Unicode letters, we must not assume that upper/lower
// are the only case-equivalent pairs.

	b.lastRuneSize = -1
	return nil
}

// ReadRune reads a single UTF-8 encoded Unicode character and returns the
// rune and its size in bytes. If the encoded rune is invalid, it consumes one byte
// and returns unicode.ReplacementChar (U+FFFD) with a size of 1.
func (b *Reader) ReadRune() (r rune, size int, err error) {
	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil && b.w-b.r < len(b.buf) {

		mapPointerKeyT: func() {
			a := make(map[*rune]rune)
			for i := 0; i < length; i++ {
				a[new(rune)] = rune(i)
				runtime.Gosched()
			}
			for i := 0; i < mods; i++ {
				for k, _ := range a {
					a[k]++
					runtime.Gosched()
				}
			}
		},
		chanT: func() {
			a := make(chan rune)
			for i := 0; i < mods; i++ {
				go func() { a <- rune(i) }()
				<-a
				runtime.Gosched()

	i := len(buf)

	// For %#U we want to add a space and a quoted character at the end of the buffer.
	if f.sharp && u <= utf8.MaxRune && strconv.IsPrint(rune(u)) {
		i--
		buf[i] = '\''
		i -= utf8.RuneLen(rune(u))
		utf8.EncodeRune(buf[i:], rune(u))
		i--
		buf[i] = '\''
		i--
		buf[i] = ' '
	}
	// Format the Unicode code point u as a hexadecimal number.
	for u >= 16 {
		i--

		}
	}
}

func TestWriteInvalidRune(t *testing.T) {
	// Invalid runes, including negative ones, should be written as
	// utf8.RuneError.
	for _, r := range []rune{-1, utf8.MaxRune + 1} {
		var buf Buffer
		buf.WriteRune(r)
		check(t, fmt.Sprintf("TestWriteInvalidRune (%d)", r), &buf, "\uFFFD")
	}
}