Golang State.Precision方法代码示例

func (m Mass) Format(fs fmt.State, c rune) {
	switch c {
	case 'v':
		if fs.Flag('#') {
			fmt.Fprintf(fs, "%T(%v)", m, float64(m))
			return
		}
		fallthrough
	case 'e', 'E', 'f', 'F', 'g', 'G':
		p, pOk := fs.Precision()
		w, wOk := fs.Width()
		switch {
		case pOk && wOk:
			fmt.Fprintf(fs, "%*.*"+string(c), w, p, float64(m))
		case pOk:
			fmt.Fprintf(fs, "%.*"+string(c), p, float64(m))
		case wOk:
			fmt.Fprintf(fs, "%*"+string(c), w, float64(m))
		default:
			fmt.Fprintf(fs, "%"+string(c), float64(m))
		}
		fmt.Fprint(fs, " kg")
	default:
		fmt.Fprintf(fs, "%%!%c(%T=%g kg)", c, m, float64(m))
		return
	}
}

// TODO: Implement left/right align
func (b ByteSize) Format(f fmt.State, c rune) {
	var decimal bool
	switch c {
	case 'd':
		decimal = true
	case 'b':
		decimal = false
	case 'v':
		fmt.Fprintf(f, "%s", b.String())
		return
	default:
		fmt.Fprintf(f, "%%!%c(ByteSize=%s)", c, b.String())
		return
	}

	unit, divisor := b.UnitDivisor(decimal)
	fmtstring := "%"

	if w, ok := f.Width(); ok {
		fmtstring += fmt.Sprintf("%d", w-len(unit)-1)
	}
	if p, ok := f.Precision(); ok {
		fmtstring += fmt.Sprintf(".%d", p)
	}
	fmtstring += "f %s"

	fmt.Fprintf(f, fmtstring, float64(b)/float64(divisor), unit)
}

// Format makes Unit satisfy the fmt.Formatter interface. The unit is formatted
// with dimensions appended. If the power if the dimension is not zero or one,
// symbol^power is appended, if the power is one, just the symbol is appended
// and if the power is zero, nothing is appended. Dimensions are appended
// in order by symbol name with positive powers ahead of negative powers.
func (u *Unit) Format(fs fmt.State, c rune) {
	if u == nil {
		fmt.Fprint(fs, "<nil>")
	}
	switch c {
	case 'v':
		if fs.Flag('#') {
			fmt.Fprintf(fs, "&%#v", *u)
			return
		}
		fallthrough
	case 'e', 'E', 'f', 'F', 'g', 'G':
		p, pOk := fs.Precision()
		w, wOk := fs.Width()
		switch {
		case pOk && wOk:
			fmt.Fprintf(fs, "%*.*"+string(c), w, p, u.value)
		case pOk:
			fmt.Fprintf(fs, "%.*"+string(c), p, u.value)
		case wOk:
			fmt.Fprintf(fs, "%*"+string(c), w, u.value)
		default:
			fmt.Fprintf(fs, "%"+string(c), u.value)
		}
	default:
		fmt.Fprintf(fs, "%%!%c(*Unit=%g)", c, u)
		return
	}
	if u.formatted == "" && len(u.dimensions) > 0 {
		u.formatted = u.dimensions.String()
	}
	fmt.Fprintf(fs, " %s", u.formatted)
}

// Format implements fmt.Formatter. It accepts format.State for
// language-specific rendering.
func (v Value) Format(s fmt.State, verb rune) {
	var lang int
	if state, ok := s.(format.State); ok {
		lang, _ = language.CompactIndex(state.Language())
	}

	// Get the options. Use DefaultFormat if not present.
	opt := v.format
	if opt == nil {
		opt = defaultFormat
	}
	cur := v.currency
	if cur.index == 0 {
		cur = opt.currency
	}

	// TODO: use pattern.
	io.WriteString(s, opt.symbol(lang, cur))
	if v.amount != nil {
		s.Write(space)

		// TODO: apply currency-specific rounding
		scale, _ := opt.kind.Rounding(cur)
		if _, ok := s.Precision(); !ok {
			fmt.Fprintf(s, "%.*f", scale, v.amount)
		} else {
			fmt.Fprint(s, v.amount)
		}
	}
}

func (af *ansiFormatter) Format(f fmt.State, c rune) {
	// reconstruct the format string in bf
	bf := new(bytes.Buffer)
	bf.WriteByte('%')
	for _, x := range []byte{'-', '+', '#', ' ', '0'} {
		if f.Flag(int(x)) {
			bf.WriteByte(x)
		}
	}
	if w, ok := f.Width(); ok {
		fmt.Fprint(bf, w)
	}
	if p, ok := f.Precision(); ok {
		fmt.Fprintf(bf, ".%d", p)
	}
	bf.WriteRune(c)
	format := bf.String()

	if len(af.codes) == 0 {
		fmt.Fprintf(f, format, af.value)
		return
	}

	fmt.Fprintf(f, "\x1b[%d", af.codes[0])
	for _, code := range af.codes[1:] {
		fmt.Fprintf(f, ";%d", code)
	}
	f.Write([]byte{'m'})
	fmt.Fprintf(f, format, af.value)
	fmt.Fprint(f, "\x1b[0m")
}

func (st *stacktrace) Format(f fmt.State, c rune) {
	var text string
	if f.Flag('+') && !f.Flag('#') && c == 's' { // "%+s"
		text = formatFull(st)
	} else if f.Flag('#') && !f.Flag('+') && c == 's' { // "%#s"
		text = formatBrief(st)
	} else {
		text = map[Format]func(*stacktrace) string{
			FormatFull:  formatFull,
			FormatBrief: formatBrief,
		}[DefaultFormat](st)
	}

	formatString := "%"
	// keep the flags recognized by fmt package
	for _, flag := range "-+# 0" {
		if f.Flag(int(flag)) {
			formatString += string(flag)
		}
	}
	if width, has := f.Width(); has {
		formatString += fmt.Sprint(width)
	}
	if precision, has := f.Precision(); has {
		formatString += "."
		formatString += fmt.Sprint(precision)
	}
	formatString += string(c)
	fmt.Fprintf(f, formatString, text)
}

// fmtFlag computes the (internal) FmtFlag
// value given the fmt.State and format verb.
func fmtFlag(s fmt.State, verb rune) FmtFlag {
	var flag FmtFlag
	if s.Flag('-') {
		flag |= FmtLeft
	}
	if s.Flag('#') {
		flag |= FmtSharp
	}
	if s.Flag('+') {
		flag |= FmtSign
	}
	if s.Flag(' ') {
		flag |= FmtUnsigned
	}
	if _, ok := s.Precision(); ok {
		flag |= FmtComma
	}
	if s.Flag('0') {
		flag |= FmtByte
	}
	switch verb {
	case 'S':
		flag |= FmtShort
	case 'L':
		flag |= FmtLong
	}
	return flag
}

// Format may call Sprint(f) or Fprint(f) etc. to generate its output.
func (e *goof) Format(f fmt.State, c rune) {
	s := e.getMessage(e.includeFieldsInFormat)
	fs := &bytes.Buffer{}
	fs.WriteRune('%')
	if f.Flag('+') {
		fs.WriteRune('+')
	}
	if f.Flag('-') {
		fs.WriteRune('-')
	}
	if f.Flag('#') {
		fs.WriteRune('#')
	}
	if f.Flag(' ') {
		fs.WriteRune(' ')
	}
	if f.Flag('0') {
		fs.WriteRune('0')
	}
	if w, ok := f.Width(); ok {
		fs.WriteString(fmt.Sprintf("%d", w))
	}
	if p, ok := f.Precision(); ok {
		fs.WriteString(fmt.Sprintf("%d", p))
	}
	fs.WriteRune(c)
	fmt.Fprintf(f, fs.String(), s)
}

func (e escapable) Format(f fmt.State, c rune) {
	s := "%"
	for i := 0; i < 128; i++ {
		if f.Flag(i) {
			s += string(i)
		}
	}
	if w, ok := f.Width(); ok {
		s += fmt.Sprintf("%d", w)
	}
	if p, ok := f.Precision(); ok {
		s += fmt.Sprintf(".%d", p)
	}
	// If we have an uppercase format char and a slice, format each slice
	// element
	if unicode.IsUpper(c) && reflect.TypeOf(e.x).Kind() == reflect.Slice {
		s += strings.ToLower(string(c))
		v := reflect.ValueOf(e.x)
		for i := 0; i < v.Len(); i++ {
			formatted := fmt.Sprintf(s, v.Index(i))
			io.WriteString(f, ReadableEscapeArg(formatted))
			if i+1 != v.Len() {
				io.WriteString(f, " ")
			}
		}
		return
	}
	s += string(c)
	formatted := fmt.Sprintf(s, e.x)
	io.WriteString(f, ReadableEscapeArg(formatted))
}

func (fo formatter) passThrough(f fmt.State, c rune) {
	s := "%"
	for i := 0; i < 128; i++ {
		if f.Flag(i) {
			s += string(i)
		}
	}
	if w, ok := f.Width(); ok {
		s += fmt.Sprintf("%d", w)
	}
	if p, ok := f.Precision(); ok {
		s += fmt.Sprintf(".%d", p)
	}
	s += string(c)
	fmt.Fprintf(f, s, fo.x)
}

func (e escapable) Format(f fmt.State, c rune) {
	s := "%"
	for i := 0; i < 128; i++ {
		if f.Flag(i) {
			s += string(i)
		}
	}
	if w, ok := f.Width(); ok {
		s += fmt.Sprintf("%d", w)
	}
	if p, ok := f.Precision(); ok {
		s += fmt.Sprintf(".%d", p)
	}
	s += string(c)
	formatted := fmt.Sprintf(s, e.x)
	io.WriteString(f, ReadableEscapeArg(formatted))
}

func defaultFormat(v interface{}, f fmt.State, c rune) {
	buf := make([]string, 0, 10)
	buf = append(buf, "%")
	for i := 0; i < 128; i++ {
		if f.Flag(i) {
			buf = append(buf, string(i))
		}
	}

	if w, ok := f.Width(); ok {
		buf = append(buf, strconv.Itoa(w))
	}
	if p, ok := f.Precision(); ok {
		buf = append(buf, "."+strconv.Itoa(p))
	}
	buf = append(buf, string(c))
	format := strings.Join(buf, "")
	fmt.Fprintf(f, format, v)
}

func formatString(fs fmt.State, c rune) string {
	w, wOk := fs.Width()
	p, pOk := fs.Precision()
	var b bytes.Buffer
	b.WriteByte('%')
	for _, f := range "+-# 0" {
		if fs.Flag(int(f)) {
			b.WriteRune(f)
		}
	}
	if wOk {
		fmt.Fprint(&b, w)
	}
	if pOk {
		b.WriteByte('.')
		fmt.Fprint(&b, p)
	}
	b.WriteRune(c)
	return b.String()
}

func (x *M_Cmd) Format(f fmt.State, c int) {
	if c == 'v' && f.Flag('#') && x != nil {
		fmt.Fprintf(f, "M_%s", M_Cmd_name[int32(*x)])
		return
	}

	s := "%"
	for i := 0; i < 128; i++ {
		if f.Flag(i) {
			s += string(i)
		}
	}
	if w, ok := f.Width(); ok {
		s += fmt.Sprintf("%d", w)
	}
	if p, ok := f.Precision(); ok {
		s += fmt.Sprintf(".%d", p)
	}
	s += string(c)
	fmt.Fprintf(f, s, (*int32)(x))
}

// Format allows text to satisfy the fmt.Formatter interface. The format
// behaviour is the same as for fmt.Print.
func (t text) Format(fs fmt.State, c rune) {
	if t.Mode&activeBits != 0 {
		t.Mode.set(fs)
	}

	w, wOk := fs.Width()
	p, pOk := fs.Precision()
	var (
		b          bytes.Buffer
		prevString bool
	)
	b.WriteByte('%')
	for _, f := range "+-# 0" {
		if fs.Flag(int(f)) {
			b.WriteRune(f)
		}
	}
	if wOk {
		fmt.Fprint(&b, w)
	}
	if pOk {
		b.WriteByte('.')
		fmt.Fprint(&b, p)
	}
	b.WriteRune(c)
	format := b.String()

	for _, v := range t.v {
		isString := v != nil && doesString(v)
		if isString && prevString {
			fs.Write([]byte{' '})
		}
		prevString = isString
		fmt.Fprintf(fs, format, v)
	}

	if t.Mode&activeBits != 0 && t.Mode&activeBits != Reset && t.Mode&NoResetAfter == 0 {
		t.reset(fs)
	}
}