Golang State.Flag方法代碼示例

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
	}
}

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 (v value) Format(f fmt.State, c rune) {
	if debug || f.Flag('#') {
		fmt.Fprintf(f, "%s["+v.format+"]", typeName(v.v), v.v)
	} else {
		fmt.Fprintf(f, v.format, v.v)
	}
}

// Format formats the frame according to the fmt.Formatter interface.
//
//    %s    source file
//    %d    source line
//    %n    function name
//    %v    equivalent to %s:%d
//
// Format accepts flags that alter the printing of some verbs, as follows:
//
//    %+s   path of source file relative to the compile time GOPATH
//    %+v   equivalent to %+s:%d
func (f Frame) Format(s fmt.State, verb rune) {
	switch verb {
	case 's':
		switch {
		case s.Flag('+'):
			pc := f.pc()
			fn := runtime.FuncForPC(pc)
			if fn == nil {
				io.WriteString(s, "unknown")
			} else {
				file, _ := fn.FileLine(pc)
				fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
			}
		default:
			io.WriteString(s, path.Base(f.file()))
		}
	case 'd':
		fmt.Fprintf(s, "%d", f.line())
	case 'n':
		name := runtime.FuncForPC(f.pc()).Name()
		io.WriteString(s, funcname(name))
	case 'v':
		f.Format(s, 's')
		io.WriteString(s, ":")
		f.Format(s, 'd')
	}
}

// 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 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)
}

// 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 satisfies the fmt.Formatter interface.
func (f formatter) Format(fs fmt.State, c rune) {
	if c == 'v' && fs.Flag('#') {
		fmt.Fprintf(fs, "%#v", f.matrix)
		return
	}
	format(f.matrix, f.prefix, f.margin, f.dot, f.squeeze, fs, c)
}

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)
}

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 (m fm) Format(fs fmt.State, c rune) {
	if c == 'v' && fs.Flag('#') {
		fmt.Fprintf(fs, "%#v", m.Matrix)
		return
	}
	Format(m.Matrix, m.margin, '.', fs, c)
}

func (fo formatter) Format(f fmt.State, c rune) {
	if c == 'v' && f.Flag('#') && f.Flag(' ') {
		fo.format(f)
		return
	}
	fo.passThrough(f, c)
}

// Format is a support routine for fmt.Formatter. It accepts
// the formats 'b' (binary), 'o' (octal), 'd' (decimal), 'x'
// (lowercase hexadecimal), and 'X' (uppercase hexadecimal).
//
func (x *Int) Format(s fmt.State, ch int) {
	cs := charset(ch)

	// special cases
	switch {
	case cs == "":
		// unknown format
		fmt.Fprintf(s, "%%!%c(big.Int=%s)", ch, x.String())
		return
	case x == nil:
		fmt.Fprint(s, "<nil>")
		return
	}

	// determine format
	format := "%s"
	if s.Flag('#') {
		switch ch {
		case 'o':
			format = "0%s"
		case 'x':
			format = "0x%s"
		case 'X':
			format = "0X%s"
		}
	}
	if x.neg {
		format = "-" + format
	}

	fmt.Fprintf(s, format, x.abs.string(cs))
}

func format(b Bed, fs fmt.State, c rune) {
	bv := reflect.ValueOf(b)
	if bv.IsNil() {
		fmt.Fprint(fs, "<nil>")
		return
	}
	bv = bv.Elem()
	switch c {
	case 'v':
		if fs.Flag('#') {
			fmt.Fprintf(fs, "&%#v", bv.Interface())
			return
		}
		fallthrough
	case 's':
		width, _ := fs.Width()
		if !b.canBed(width) {
			fmt.Fprintf(fs, "%%!(BADWIDTH)%T", b)
			return
		}
		if width == 0 {
			width = bv.NumField()
		}
		for i := 0; i < width; i++ {
			f := bv.Field(i).Interface()
			if i >= rgbField {
				switch i {
				case rgbField:
					rv := reflect.ValueOf(f)
					if reflect.DeepEqual(rv.Interface(), color.RGBA{}) {
						fs.Write([]byte{'0'})
					} else {
						fmt.Fprintf(fs, "%d,%d,%d",
							rv.Field(0).Interface(), rv.Field(1).Interface(), rv.Field(2).Interface())
					}
				case blockCountField:
					fmt.Fprint(fs, f)
				case blockSizesField, blockStartsField:
					av := reflect.ValueOf(f)
					l := av.Len()
					for j := 0; j < l; j++ {
						fmt.Fprint(fs, av.Index(j).Interface())
						if j < l-1 {
							fs.Write([]byte{','})
						}
					}
				}
			} else {
				fmt.Fprint(fs, f)
			}
			if i < width-1 {
				fs.Write([]byte{'\t'})
			}
		}
	default:
		fmt.Fprintf(fs, "%%!%c(%T=%3s)", c, b, b)
	}
}

// Format implements the fmt.Formatter interface.
func (v val) Format(s fmt.State, c rune) {
	if c == 'v' || c == 's' {
		fprint(s, reflect.ValueOf(v.v), state{
			defaults: s.Flag('+') || s.Flag('#'),
		})
	} else {
		fmt.Fprintf(s, "%%!%c(pretty.Val)", c)
	}
}