Golang Value.SetFloat方法代碼示例

func (db *DataBinder) submitProperty(prop Property, field reflect.Value) error {
	value := prop.Get()
	if value == nil {
		// This happens e.g. if CurrentIndex() of a ComboBox returns -1.
		// FIXME: Should we handle this differently?
		return nil
	}
	if err, ok := value.(error); ok {
		return err
	}

	if f64, ok := value.(float64); ok {
		switch field.Kind() {
		case reflect.Float32, reflect.Float64:
			field.SetFloat(f64)

		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
			field.SetInt(int64(f64))

		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
			field.SetUint(uint64(f64))

		default:
			return newError(fmt.Sprintf("Field '%s': Can't convert float64 to %s.", prop.Source().(string), field.Type().Name()))
		}

		return nil
	}

	field.Set(reflect.ValueOf(value))

	return nil
}

func (tbl *Table) setVal(field *reflect.Value, val interface{}) {
	str, ok := val.(string)
	log.Println("trying to set")
	if ok {
		log.Println("setting string")
		field.SetString(str)
		return
	}
	i, ok := val.(int64)
	if ok {
		field.SetInt(i)
		return
	}
	ui, ok := val.(uint64)
	if ok {
		field.SetUint(ui)
		return
	}
	b, ok := val.(bool)
	if ok {
		field.SetBool(b)
		return
	}
	f, ok := val.(float64)
	if ok {
		field.SetFloat(f)
		return
	}
	t, ok := val.(time.Time)
	if ok {
		field.Set(reflect.ValueOf(t))
		return
	}

}

func setFieldDefaults(v reflect.Value, sf reflect.StructField, s reflect.Value) {
	if v.CanInterface() && reflect.DeepEqual(
		v.Interface(), reflect.Zero(v.Type()).Interface()) {
		tag := sf.Tag.Get("ebmldef")
		if tag != "" {
			switch v.Kind() {
			case reflect.Int, reflect.Int64:
				u, _ := strconv.ParseInt(tag, 10, 0)
				v.SetInt(int64(u))
			case reflect.Uint, reflect.Uint64:
				u, _ := strconv.ParseUint(tag, 10, 0)
				v.SetUint(u)
			case reflect.Float32, reflect.Float64:
				f, _ := strconv.ParseFloat(tag, 64)
				v.SetFloat(f)
			case reflect.String:
				v.SetString(tag)
			default:
				log.Panic("Unsupported default value")
			}
		}
		ltag := sf.Tag.Get("ebmldeflink")
		if ltag != "" {
			v.Set(s.FieldByName(ltag))
		}
	}
}

func (e *Element) readField(v reflect.Value) (err error) {
	switch v.Kind() {
	case reflect.Struct:
		err = e.readStruct(v)
	case reflect.Slice:
		err = e.readSlice(v)
	case reflect.Array:
		for i, l := 0, v.Len(); i < l && err == nil; i++ {
			err = e.readStruct(v.Index(i))
		}
	case reflect.String:
		var s string
		s, err = e.readString()
		v.SetString(s)
	case reflect.Int, reflect.Int64:
		var u uint64
		u, err = e.readUint64()
		v.SetInt(int64(u))
	case reflect.Uint, reflect.Uint64:
		var u uint64
		u, err = e.readUint64()
		v.SetUint(u)
	case reflect.Float32, reflect.Float64:
		var f float64
		f, err = e.readFloat()
		v.SetFloat(f)
	default:
		err = errors.New("Unknown type: " + v.String())
	}
	return
}

// setValue updates the field value in fv to the data extracted from config
// with key.
func setValue(fv *reflect.Value, c *Config, key string) error {
	// Update the value with the correct type
	switch fv.Kind() {
	case reflect.Int:
		val, err := c.GetInt(key)
		if err != nil {
			return err
		}
		fv.SetInt(int64(val))
	case reflect.Float64:
		val, err := c.GetFloat(key)
		if err != nil {
			return err
		}
		fv.SetFloat(val)
	case reflect.Bool:
		val, err := c.GetBool(key)
		if err != nil {
			return err
		}
		fv.SetBool(val)
	case reflect.String:
		val, err := c.GetString(key)
		if err != nil {
			return err
		}
		fv.SetString(val)
	}

	return nil
}

// setWithProperType sets proper value to field based on its type,
// but it does not return error for failing parsing,
// because we want to use default value that is already assigned to strcut.
func setWithProperType(t reflect.Type, key *Key, field reflect.Value, delim string) error {
	switch t.Kind() {
	case reflect.String:
		if len(key.String()) == 0 {
			return nil
		}
		field.SetString(key.String())
	case reflect.Bool:
		boolVal, err := key.Bool()
		if err != nil {
			return nil
		}
		field.SetBool(boolVal)
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		durationVal, err := key.Duration()
		// Skip zero value
		if err == nil && int(durationVal) > 0 {
			field.Set(reflect.ValueOf(durationVal))
			return nil
		}

		intVal, err := key.Int64()
		if err != nil || intVal == 0 {
			return nil
		}
		field.SetInt(intVal)
	//	byte is an alias for uint8, so supporting uint8 breaks support for byte
	case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		durationVal, err := key.Duration()
		// Skip zero value
		if err == nil && int(durationVal) > 0 {
			field.Set(reflect.ValueOf(durationVal))
			return nil
		}

		uintVal, err := key.Uint64()
		if err != nil {
			return nil
		}
		field.SetUint(uintVal)

	case reflect.Float64:
		floatVal, err := key.Float64()
		if err != nil {
			return nil
		}
		field.SetFloat(floatVal)
	case reflectTime:
		timeVal, err := key.Time()
		if err != nil {
			return nil
		}
		field.Set(reflect.ValueOf(timeVal))
	case reflect.Slice:
		return setSliceWithProperType(key, field, delim)
	default:
		return fmt.Errorf("unsupported type '%s'", t)
	}
	return nil
}

func setConfigVal(str string, field reflect.Value) error {
	t := field.Kind()
	switch {
	case t == reflect.String:
		field.SetString(str)
	case t >= reflect.Int && t <= reflect.Int64:
		if x, err := strconv.ParseInt(str, 10, 64); err != nil {
			return err
		} else {
			field.SetInt(x)
		}
	case t >= reflect.Uint && t <= reflect.Uint64:
		if x, err := strconv.ParseUint(str, 10, 64); err != nil {
			return err
		} else {
			field.SetUint(x)
		}
	case t >= reflect.Float32 && t <= reflect.Float64:
		if x, err := strconv.ParseFloat(str, 64); err != nil {
			return err
		} else {
			field.SetFloat(x)
		}
	case t == reflect.Bool:
		if x, err := strconv.ParseBool(str); err != nil {
			return err
		} else {
			field.SetBool(x)
		}
	default:
		return nil
	}
	return nil
}

func (d *Decoder) decodeField(v reflect.Value, val string) error {
	switch v.Type() {
	case reflect.TypeOf(time.Duration(0)):
		a, err := time.ParseDuration(val)
		if err != nil {
			return err
		}
		v.SetInt(int64(a))
	default:
		switch v.Kind() {
		case reflect.String:
			v.SetString(val)
		case reflect.Int, reflect.Int32, reflect.Int64:
			v.Type()
			nv, err := strconv.ParseInt(val, 10, 64)
			if err != nil {
				return err
			}
			v.SetInt(nv)
		case reflect.Bool:
			b, err := strconv.ParseBool(val)
			if err != nil {
				return err
			}
			v.SetBool(b)
		case reflect.Float32, reflect.Float64:
			f, err := strconv.ParseFloat(val, 64)
			if err != nil {
				return err
			}
			v.SetFloat(f)
		}
	}
	return nil
}

func (decoder *Decoder) readFloat(value reflect.Value) error {
	bytes, err := decoder.readBytes(8)
	if err != nil {
		return err
	}

	n := uint64(0)
	for _, b := range bytes {
		n <<= 8
		n |= uint64(b)
	}

	v := math.Float64frombits(n)

	switch value.Kind() {
	case reflect.Float32, reflect.Float64:
		value.SetFloat(v)
	case reflect.Int32, reflect.Int, reflect.Int64:
		value.SetInt(int64(v))
	case reflect.Uint32, reflect.Uint, reflect.Uint64:
		value.SetUint(uint64(v))
	case reflect.Interface:
		value.Set(reflect.ValueOf(v))
	default:
		return errors.New("invalid type:" + value.Type().String() + " for double")
	}

	return nil
}

// This sets the value in a struct of an indeterminate type to the
// matching value from the request (via Form middleware) in the
// same type, so that not all deserialized values have to be strings.
// Supported types are string, int, float, and bool.
func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value, nameInTag string, errors Errors) {
	if scan, ok := structField.Addr().Interface().(sql.Scanner); ok {
		scan.Scan(val)
		return
	}
	switch valueKind {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		if val == "" {
			val = "0"
		}
		intVal, err := strconv.ParseInt(val, 10, 64)
		if err != nil {
			errors.Add([]string{nameInTag}, TypeError, "Value could not be parsed as integer")
		} else {
			structField.SetInt(intVal)
		}
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		if val == "" {
			val = "0"
		}
		uintVal, err := strconv.ParseUint(val, 10, 64)
		if err != nil {
			errors.Add([]string{nameInTag}, TypeError, "Value could not be parsed as unsigned integer")
		} else {
			structField.SetUint(uintVal)
		}
	case reflect.Bool:
		if val == "" {
			val = "false"
		}
		boolVal, err := strconv.ParseBool(val)
		if err != nil {
			errors.Add([]string{nameInTag}, TypeError, "Value could not be parsed as boolean")
		} else {
			structField.SetBool(boolVal)
		}
	case reflect.Float32:
		if val == "" {
			val = "0.0"
		}
		floatVal, err := strconv.ParseFloat(val, 32)
		if err != nil {
			errors.Add([]string{nameInTag}, TypeError, "Value could not be parsed as 32-bit float")
		} else {
			structField.SetFloat(floatVal)
		}
	case reflect.Float64:
		if val == "" {
			val = "0.0"
		}
		floatVal, err := strconv.ParseFloat(val, 64)
		if err != nil {
			errors.Add([]string{nameInTag}, TypeError, "Value could not be parsed as 64-bit float")
		} else {
			structField.SetFloat(floatVal)
		}
	case reflect.String:
		structField.SetString(val)
	}
}

// setFieldVal first converts v to the type of structField, then uses reflection
// to set the field to the converted value.
func setFieldVal(structField reflect.Value, name string, v string) error {
	switch structField.Kind() {
	case reflect.String:
		structField.SetString(v)
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		vInt, err := strconv.Atoi(v)
		if err != nil {
			return fmt.Errorf("envvar: Error parsing environment variable %s: %s\n%s", name, v, err.Error())
		}
		structField.SetInt(int64(vInt))
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		vUint, err := strconv.ParseUint(v, 10, 64)
		if err != nil {
			return fmt.Errorf("envvar: Error parsing environment variable %s: %s\n%s", name, v, err.Error())
		}
		structField.SetUint(uint64(vUint))
	case reflect.Float32, reflect.Float64:
		vFloat, err := strconv.ParseFloat(v, 64)
		if err != nil {
			return fmt.Errorf("envvar: Error parsing environment variable %s: %s\n%s", name, v, err.Error())
		}
		structField.SetFloat(vFloat)
	case reflect.Bool:
		vBool, err := strconv.ParseBool(v)
		if err != nil {
			return fmt.Errorf("envvar: Error parsing environment variable %s: %s\n%s", name, v, err.Error())
		}
		structField.SetBool(vBool)
	default:
		return fmt.Errorf("envvar: Unsupported struct field type: %s", structField.Type().String())
	}
	return nil
}

func processField(value string, field reflect.Value) error {
	typ := field.Type()

	decoder := decoderFrom(field)
	if decoder != nil {
		return decoder.Decode(value)
	}

	switch typ.Kind() {
	case reflect.String:
		field.SetString(value)
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		var (
			val int64
			err error
		)
		if field.Kind() == reflect.Int64 && typ.PkgPath() == "time" && typ.Name() == "Duration" {
			var d time.Duration
			d, err = time.ParseDuration(value)
			val = int64(d)
		} else {
			val, err = strconv.ParseInt(value, 0, typ.Bits())
		}
		if err != nil {
			return err
		}

		field.SetInt(val)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		val, err := strconv.ParseUint(value, 0, typ.Bits())
		if err != nil {
			return err
		}
		field.SetUint(val)
	case reflect.Bool:
		val, err := strconv.ParseBool(value)
		if err != nil {
			return err
		}
		field.SetBool(val)
	case reflect.Float32, reflect.Float64:
		val, err := strconv.ParseFloat(value, typ.Bits())
		if err != nil {
			return err
		}
		field.SetFloat(val)
	case reflect.Slice:
		vals := strings.Split(value, ",")
		sl := reflect.MakeSlice(typ, len(vals), len(vals))
		for i, val := range vals {
			err := processField(val, sl.Index(i))
			if err != nil {
				return err
			}
		}
		field.Set(sl)
	}

	return nil
}

// setWithProperType sets proper value to field based on its type,
// but it does not return error for failing parsing,
// because we want to use default value that is already assigned to strcut.
func setWithProperType(kind reflect.Kind, key *Key, field reflect.Value, delim string) error {
	switch kind {
	case reflect.String:
		if len(key.String()) == 0 {
			return nil
		}
		field.SetString(key.String())
	case reflect.Bool:
		boolVal, err := key.Bool()
		if err != nil {
			return nil
		}
		field.SetBool(boolVal)
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		intVal, err := key.Int64()
		if err != nil {
			return nil
		}
		field.SetInt(intVal)
	case reflect.Float64:
		floatVal, err := key.Float64()
		if err != nil {
			return nil
		}
		field.SetFloat(floatVal)
	case reflectTime:
		timeVal, err := key.Time()
		if err != nil {
			return nil
		}
		field.Set(reflect.ValueOf(timeVal))
	case reflect.Slice:
		vals := key.Strings(delim)
		numVals := len(vals)
		if numVals == 0 {
			return nil
		}

		sliceOf := field.Type().Elem().Kind()

		var times []time.Time
		if sliceOf == reflectTime {
			times = key.Times(delim)
		}

		slice := reflect.MakeSlice(field.Type(), numVals, numVals)
		for i := 0; i < numVals; i++ {
			switch sliceOf {
			case reflectTime:
				slice.Index(i).Set(reflect.ValueOf(times[i]))
			default:
				slice.Index(i).Set(reflect.ValueOf(vals[i]))
			}
		}
		field.Set(slice)
	default:
		return fmt.Errorf("unsupported type '%s'", kind)
	}
	return nil
}

func numberDecoder(node RMNode, data interface{}, v reflect.Value) {
	val, err := redis.String(data, nil)
	if err != nil {
		panic(err)
	}

	switch v.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		n, err := strconv.ParseInt(val, 10, 64)
		if err != nil || v.OverflowInt(n) {
			panic(fmt.Sprintf("Unable to convert int: %s \n", val))
		}
		v.SetInt(n)

	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		n, err := strconv.ParseUint(val, 10, 64)
		if err != nil || v.OverflowUint(n) {
			panic(fmt.Sprintf("Unable to convert uint: %s \n", val))
		}
		v.SetUint(n)

	case reflect.Float32, reflect.Float64:
		n, err := strconv.ParseFloat(val, v.Type().Bits())
		if err != nil || v.OverflowFloat(n) {
			panic(fmt.Sprintf("Unable to convert float: %s \n", val))
		}
		v.SetFloat(n)

	default:
		panic(fmt.Sprintf("Unsupported number convertion for type[%v] with value[%v]", v.Type(), data))
	}
}

// type(1) | name length(1) | raw name bytes | 0x00 | value bytes(8)
func (d *decodeState) double(v reflect.Value) {
	d.off += 1 // type

	klen := int(Int8(d.data[d.off:]))
	d.off += 1 // name length

	if klen > 0 {
		key := d.data[d.off : d.off+klen-1]
		d.off += klen
		v = fieldByTag(v, key)
		u, pv := d.indirect(v, false)
		if u != nil {
			d.off -= 1 + 1 + klen
			if err := u.UnmarshalMCPACK(d.next()); err != nil {
				d.error(err)
			}
			return
		}
		v = pv
	}

	val := Float64(d.data[d.off:])
	d.off += 8

	if !v.IsValid() {
		return
	}
	v.SetFloat(val)
}