Golang Value.Int方法代码示例

// convert to float64
func ToFloat(input reflect.Value) (output float64, err error) {
	//defer checkError(err)
	if !input.IsValid() {
		return 0, newTypeErr(methodName(), "input is invalid", input)
	}

	input = Underlying(input)
	k := input.Kind()
	switch {
	case IsBool(k):
		if input.Bool() {
			return 1, nil
		}
		return 0, nil
	case IsInt(k):
		return float64(input.Int()), nil
	case IsUint(k):
		return float64(input.Uint()), nil
	case IsFloat(k):
		return input.Float(), nil
	case IsString(k):
		return strconv.ParseFloat(input.String(), 32)
	default:
	}
	return 0, newTypeErr(methodName(), "input can not convert to float", input)
}

func convertAssignInt(d reflect.Value, s int64) (err error) {
	switch d.Type().Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		d.SetInt(s)
		if d.Int() != s {
			err = strconv.ErrRange
			d.SetInt(0)
		}
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		if s < 0 {
			err = strconv.ErrRange
		} else {
			x := uint64(s)
			d.SetUint(x)
			if d.Uint() != x {
				err = strconv.ErrRange
				d.SetUint(0)
			}
		}
	case reflect.Bool:
		d.SetBool(s != 0)
	default:
		err = cannotConvert(d, s)
	}
	return
}

func ReturnWhenSet(a, k interface{}) interface{} {
	av, isNil := indirect(reflect.ValueOf(a))
	if isNil {
		return ""
	}

	var avv reflect.Value
	switch av.Kind() {
	case reflect.Array, reflect.Slice:
		index, ok := k.(int)
		if ok && av.Len() > index {
			avv = av.Index(index)
		}
	case reflect.Map:
		kv := reflect.ValueOf(k)
		if kv.Type().AssignableTo(av.Type().Key()) {
			avv = av.MapIndex(kv)
		}
	}

	if avv.IsValid() {
		switch avv.Kind() {
		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
			return avv.Int()
		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
			return avv.Uint()
		case reflect.Float32, reflect.Float64:
			return avv.Float()
		case reflect.String:
			return avv.String()
		}
	}

	return ""
}

func convertToFloat64(depth int, v reflect.Value) (float64, bool) {
	if v.Kind() == reflect.Interface {
		v = v.Elem()
	}
	switch v.Kind() {
	case reflect.Float32, reflect.Float64:
		return v.Float(), true
	case reflect.Int16, reflect.Int8, reflect.Int, reflect.Int32, reflect.Int64:
		return float64(v.Int()), true
	case reflect.String:
		s := v.String()
		var f float64
		var err error
		if strings.HasPrefix(s, "0x") {
			f, err = strconv.ParseFloat(s, 64)
		} else {
			f, err = strconv.ParseFloat(s, 64)
		}
		if err == nil {
			return float64(f), true
		}
		if depth == 0 {
			s = intStrReplacer.Replace(s)
			rv := reflect.ValueOf(s)
			return convertToFloat64(1, rv)
		}
	case reflect.Slice:
		// Should we grab first one?  Or Error?
		//u.Warnf("ToFloat() but is slice?: %T first=%v", v, v.Index(0))
		return convertToFloat64(0, v.Index(0))
	default:
		//u.Warnf("Cannot convert type?  %v", v.Kind())
	}
	return math.NaN(), false
}

// isTrue reports whether the value is 'true', in the sense of not the zero of its type,
// and whether the value has a meaningful truth value.
func isTrue(val reflect.Value) (truth, ok bool) {
	if !val.IsValid() {
		// Something like var x interface{}, never set. It's a form of nil.
		return false, true
	}
	switch val.Kind() {
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
		truth = val.Len() > 0
	case reflect.Bool:
		truth = val.Bool()
	case reflect.Complex64, reflect.Complex128:
		truth = val.Complex() != 0
	case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface:
		truth = !val.IsNil()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		truth = val.Int() != 0
	case reflect.Float32, reflect.Float64:
		truth = val.Float() != 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		truth = val.Uint() != 0
	case reflect.Struct:
		truth = true // Struct values are always true.
	default:
		return
	}
	return truth, true
}

func formatValue(value reflect.Value, indentation uint) string {
	if indentation > MaxDepth {
		return "..."
	}

	if isNilValue(value) {
		return "nil"
	}

	if UseStringerRepresentation {
		if value.CanInterface() {
			obj := value.Interface()
			switch x := obj.(type) {
			case fmt.GoStringer:
				return x.GoString()
			case fmt.Stringer:
				return x.String()
			}
		}
	}

	switch value.Kind() {
	case reflect.Bool:
		return fmt.Sprintf("%v", value.Bool())
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return fmt.Sprintf("%v", value.Int())
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		return fmt.Sprintf("%v", value.Uint())
	case reflect.Uintptr:
		return fmt.Sprintf("0x%x", value.Uint())
	case reflect.Float32, reflect.Float64:
		return fmt.Sprintf("%v", value.Float())
	case reflect.Complex64, reflect.Complex128:
		return fmt.Sprintf("%v", value.Complex())
	case reflect.Chan:
		return fmt.Sprintf("0x%x", value.Pointer())
	case reflect.Func:
		return fmt.Sprintf("0x%x", value.Pointer())
	case reflect.Ptr:
		return formatValue(value.Elem(), indentation)
	case reflect.Slice:
		return formatSlice(value, indentation)
	case reflect.String:
		return formatString(value.String(), indentation)
	case reflect.Array:
		return formatSlice(value, indentation)
	case reflect.Map:
		return formatMap(value, indentation)
	case reflect.Struct:
		return formatStruct(value, indentation)
	case reflect.Interface:
		return formatValue(value.Elem(), indentation)
	default:
		if value.CanInterface() {
			return fmt.Sprintf("%#v", value.Interface())
		} else {
			return fmt.Sprintf("%#v", value)
		}
	}
}

func plain_extract_value(name string, field reflect.Value) url.Values {
	values := make(url.Values)
	switch field.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		values.Add(name, strconv.FormatInt(field.Int(), 10))
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		values.Add(name, strconv.FormatUint(field.Uint(), 10))
	case reflect.Bool:
		values.Add(name, strconv.FormatBool(field.Bool()))
	case reflect.Struct:
		values = merge(values, plain_extract_struct(field))
	case reflect.Slice:
		for i := 0; i < field.Len(); i++ {
			sv := field.Index(i)
			values = merge(values, plain_extract_value(name, sv))
		}
	case reflect.String:
		values.Add(name, field.String())
	case reflect.Float32, reflect.Float64:
		values.Add(name, strconv.FormatFloat(field.Float(), 'f', -1, 64))
	case reflect.Ptr, reflect.Interface:
		values = merge(values, plain_extract_pointer(field))
	}
	return values
}

func indexBytes(typ reflect.Type, value reflect.Value) (b []byte, err error) {
	switch typ.Kind() {
	case reflect.String:
		b = []byte(value.String())
	case reflect.Int:
		buf := new(bytes.Buffer)
		if err = binary.Write(buf, binary.BigEndian, value.Int()); err != nil {
			return
		}
		b = buf.Bytes()
	case reflect.Slice:
		switch typ.Elem().Kind() {
		case reflect.Uint8:
			b = value.Bytes()
		default:
			err = fmt.Errorf("%v is not an indexable type", typ)
		}
	case reflect.Bool:
		if value.Bool() {
			b = []byte{1}
		} else {
			b = []byte{0}
		}
	default:
		err = fmt.Errorf("%v is not an indexable type", typ)
		return
	}
	if len(b) == 0 {
		b = []byte{0}
	}
	return
}

func (encoder *Encoder) encode(v reflect.Value) error {

	switch v.Kind() {
	case reflect.Map:
		return encoder.encodeMap(v)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		return encoder.encodeUint(v.Uint())
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return encoder.encodeInt(v.Int())
	case reflect.String:
		return encoder.encodeString(v.String())
	case reflect.Array:
		v = v.Slice(0, v.Len())
		return encoder.encodeSlice(v)
	case reflect.Slice:
		return encoder.encodeSlice(v)
	case reflect.Float64, reflect.Float32:
		return encoder.encodeFloat(v.Float())
	case reflect.Interface:
		v = reflect.ValueOf(v.Interface())
		return encoder.encode(v)
	case reflect.Ptr:
		if v.IsNil() {
			return encoder.encodeNull()
		}
		vv := reflect.Indirect(v)
		if vv.Kind() == reflect.Struct {
			return encoder.encodeStruct(v)
		}
		return encoder.encode(vv)
	}

	return errors.New("unsupported type:" + v.Type().String())
}

func (me *Record) PutValue(key string, value reflect.Value) {

	monolog.Debug("PutValue: %s %v", key, value)

	stringer, ok := value.Interface().(fmt.Stringer)
	if ok {
		me.Put(key, stringer.String())
		return
	}

	switch value.Kind() {
	case reflect.Int, reflect.Int32, reflect.Int64:
		me.Putf(key, "%d", value.Int())
	case reflect.Uint, reflect.Uint32, reflect.Uint64:
		me.Putf(key, "%d", value.Uint())
	case reflect.Float32, reflect.Float64:
		me.Putf(key, "%f", value.Float())
	case reflect.String:
		me.Putf(key, "%s", value.String())
	case reflect.Struct:
		me.PutStruct(key+".", value.Interface())
	default:
		me.Put(key, "???")
	}

	monolog.Debug("Put: key %s value %s, result %v", key, value, me)

}

func isZero(v reflect.Value) bool {
	switch v.Kind() {
	case reflect.String:
		return len(v.String()) == 0
	case reflect.Ptr, reflect.Interface:
		return v.IsNil()
	case reflect.Slice:
		return v.Len() == 0
	case reflect.Map:
		return v.Len() == 0
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Bool:
		return !v.Bool()
	case reflect.Struct:
		vt := v.Type()
		if vt == typeTime {
			return v.Interface().(time.Time).IsZero()
		}
		for i := 0; i < v.NumField(); i++ {
			if vt.Field(i).PkgPath != "" && !vt.Field(i).Anonymous {
				continue // Private field
			}
			if !isZero(v.Field(i)) {
				return false
			}
		}
		return true
	}
	return false
}

// formatAtom formats a value without inspecting its internal structure.
// It is a copy of the the function in gopl.io/ch11/format.
func formatAtom(v reflect.Value) string {
	switch v.Kind() {
	case reflect.Invalid:
		return "invalid"
	case reflect.Int, reflect.Int8, reflect.Int16,
		reflect.Int32, reflect.Int64:
		return strconv.FormatInt(v.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16,
		reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return strconv.FormatUint(v.Uint(), 10)
	// ...floating-point and complex cases omitted for brevity...
	case reflect.Bool:
		if v.Bool() {
			return "true"
		}
		return "false"
	case reflect.String:
		return strconv.Quote(v.String())
	case reflect.Chan, reflect.Func, reflect.Ptr,
		reflect.Slice, reflect.Map:
		return v.Type().String() + " 0x" +
			strconv.FormatUint(uint64(v.Pointer()), 16)
	default: // reflect.Array, reflect.Struct, reflect.Interface
		return v.Type().String() + " value"
	}
}

func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) error {
	// Normally we don't see structs, but this can happen for an attribute.
	if val.Type() == timeType {
		p.WriteString(val.Interface().(time.Time).Format(time.RFC3339Nano))
		return nil
	}
	switch val.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		p.WriteString(strconv.FormatInt(val.Int(), 10))
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		p.WriteString(strconv.FormatUint(val.Uint(), 10))
	case reflect.Float32, reflect.Float64:
		p.WriteString(strconv.FormatFloat(val.Float(), 'g', -1, 64))
	case reflect.String:
		// TODO: Add EscapeString.
		Escape(p, []byte(val.String()))
	case reflect.Bool:
		p.WriteString(strconv.FormatBool(val.Bool()))
	case reflect.Array:
		// will be [...]byte
		bytes := make([]byte, val.Len())
		for i := range bytes {
			bytes[i] = val.Index(i).Interface().(byte)
		}
		Escape(p, bytes)
	case reflect.Slice:
		// will be []byte
		Escape(p, val.Bytes())
	default:
		return &UnsupportedTypeError{typ}
	}
	return p.cachedWriteError()
}

func encodeBasic(v reflect.Value) string {
	t := v.Type()
	switch k := t.Kind(); k {
	case reflect.Bool:
		return strconv.FormatBool(v.Bool())
	case reflect.Int,
		reflect.Int8,
		reflect.Int16,
		reflect.Int32,
		reflect.Int64:
		return strconv.FormatInt(v.Int(), 10)
	case reflect.Uint,
		reflect.Uint8,
		reflect.Uint16,
		reflect.Uint32,
		reflect.Uint64:
		return strconv.FormatUint(v.Uint(), 10)
	case reflect.Float32:
		return strconv.FormatFloat(v.Float(), 'g', -1, 32)
	case reflect.Float64:
		return strconv.FormatFloat(v.Float(), 'g', -1, 64)
	case reflect.Complex64, reflect.Complex128:
		s := fmt.Sprintf("%g", v.Complex())
		return strings.TrimSuffix(strings.TrimPrefix(s, "("), ")")
	case reflect.String:
		return v.String()
	}
	panic(t.String() + " has unsupported kind " + t.Kind().String())
}

// valueSortLess returns whether the first value should sort before the second
// value.  It is used by valueSorter.Less as part of the sort.Interface
// implementation.
func valueSortLess(a, b reflect.Value) bool {
	switch a.Kind() {
	case reflect.Bool:
		return !a.Bool() && b.Bool()
	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
		return a.Int() < b.Int()
	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
		return a.Uint() < b.Uint()
	case reflect.Float32, reflect.Float64:
		return a.Float() < b.Float()
	case reflect.String:
		return a.String() < b.String()
	case reflect.Uintptr:
		return a.Uint() < b.Uint()
	case reflect.Array:
		// Compare the contents of both arrays.
		l := a.Len()
		for i := 0; i < l; i++ {
			av := a.Index(i)
			bv := b.Index(i)
			if av.Interface() == bv.Interface() {
				continue
			}
			return valueSortLess(av, bv)
		}
	}
	return a.String() < b.String()
}