Golang reflect.Type類代碼示例

func finishNewTable(b *tablebase, ty reflect.Type) Table {
	id := C.newTable()
	t := &table{
		scroller:  newScroller(id, true), // border on Table
		tablebase: b,
		selected:  newEvent(),
	}
	t.fpreferredSize = t.xpreferredSize
	// also sets the delegate
	C.tableMakeDataSource(t.id, unsafe.Pointer(t))
	for i := 0; i < ty.NumField(); i++ {
		colname := ty.Field(i).Tag.Get("uicolumn")
		if colname == "" {
			colname = ty.Field(i).Name
		}
		cname := C.CString(colname)
		coltype := C.colTypeText
		editable := false
		switch {
		case ty.Field(i).Type == reflect.TypeOf((*image.RGBA)(nil)):
			coltype = C.colTypeImage
		case ty.Field(i).Type.Kind() == reflect.Bool:
			coltype = C.colTypeCheckbox
			editable = true
		}
		C.tableAppendColumn(t.id, C.intptr_t(i), cname, C.int(coltype), toBOOL(editable))
		C.free(unsafe.Pointer(cname)) // free now (not deferred) to conserve memory
	}
	return t
}

// Add imports for each of the methods of the interface, but not the interface
// itself.
func addImportsForInterfaceMethods(imports importMap, it reflect.Type) {
	// Handle each method.
	for i := 0; i < it.NumMethod(); i++ {
		m := it.Method(i)
		addImportsForType(imports, m.Type)
	}
}

func sampleFormat(b reflect.Type) (f C.PaSampleFormat) {
	if b.Kind() != reflect.Slice {
		return 0
	}
	b = b.Elem()
	if b.Kind() == reflect.Slice {
		f = C.paNonInterleaved
		b = b.Elem()
	}
	switch b.Kind() {
	case reflect.Float32:
		f |= C.paFloat32
	case reflect.Int32:
		f |= C.paInt32
	default:
		if b == reflect.TypeOf(Int24{}) {
			f |= C.paInt24
		} else {
			return 0
		}
	case reflect.Int16:
		f |= C.paInt16
	case reflect.Int8:
		f |= C.paInt8
	case reflect.Uint8:
		f |= C.paUInt8
	}
	return f
}

// Copy matching Lua table entries to a struct, given the struct type
// and the index on the Lua stack.
func CopyTableToStruct(L *lua.State, t reflect.Type, idx int) interface{} {
	was_ptr := t.Kind() == reflect.Ptr
	if was_ptr {
		t = t.Elem()
	}
	s := reflect.New(t) // T -> *T
	ref := s.Elem()
	L.PushNil()
	if idx < 0 {
		idx--
	}
	for L.Next(idx) != 0 {
		key := L.ToString(-2)
		f := ref.FieldByName(strings.Title(key))
		if f.IsValid() {
			val := luaToGoValue(L, f.Type(), -1)
			f.Set(val)
		}
		L.Pop(1)
	}
	if was_ptr {
		return s.Interface()
	}
	return s.Elem().Interface()
}

// lessFunc returns a function that implements the "<" operator
// for the given type, or nil if the type doesn't support "<" .
func lessFunc(t reflect.Type) func(v1, v2 interface{}) bool {
	switch t.Kind() {
	case reflect.String:
		return func(v1, v2 interface{}) bool { return v1.(string) < v2.(string) }
	case reflect.Int:
		return func(v1, v2 interface{}) bool { return v1.(int) < v2.(int) }
	case reflect.Int8:
		return func(v1, v2 interface{}) bool { return v1.(int8) < v2.(int8) }
	case reflect.Int16:
		return func(v1, v2 interface{}) bool { return v1.(int16) < v2.(int16) }
	case reflect.Int32:
		return func(v1, v2 interface{}) bool { return v1.(int32) < v2.(int32) }
	case reflect.Int64:
		return func(v1, v2 interface{}) bool { return v1.(int64) < v2.(int64) }
	case reflect.Uint:
		return func(v1, v2 interface{}) bool { return v1.(uint) < v2.(uint) }
	case reflect.Uint8:
		return func(v1, v2 interface{}) bool { return v1.(uint8) < v2.(uint8) }
	case reflect.Uint16:
		return func(v1, v2 interface{}) bool { return v1.(uint16) < v2.(uint16) }
	case reflect.Uint32:
		return func(v1, v2 interface{}) bool { return v1.(uint32) < v2.(uint32) }
	case reflect.Uint64:
		return func(v1, v2 interface{}) bool { return v1.(uint64) < v2.(uint64) }
	case reflect.Float32:
		return func(v1, v2 interface{}) bool { return v1.(float32) < v2.(float32) }
	case reflect.Float64:
		return func(v1, v2 interface{}) bool { return v1.(float64) < v2.(float64) }
	default:
		return nil
	}
}

func labelType(t reflect.Type) bool {
	switch t.Kind() {
	case reflect.Interface, reflect.Struct:
		return true
	}
	return false
}

// Recursively check composite literals, where a child composite lit's type depends the
// parent's type For example, the expression [][]int{{1,2},{3,4}} contains two
// slice lits, {1,2} and {3,4}, but their types are inferenced from the parent [][]int{}.
func checkCompositeLitR(lit *ast.CompositeLit, t reflect.Type, env Env) (*CompositeLit, []error) {
	alit := &CompositeLit{CompositeLit: lit}

	// We won't generate any errors here if the given type does not match lit.Type.
	// The caller will need to detect the type incompatibility.
	if lit.Type != nil {
		var errs []error
		lit.Type, t, _, errs = checkType(lit.Type, env)
		if errs != nil {
			return alit, errs
		}
	} else if t == nil {
		return alit, []error{ErrMissingCompositeLitType{alit}}
	}

	alit.knownType = knownType{t}
	if alit.CompositeLit.Elts != nil {
		alit.Elts = make([]Expr, len(alit.CompositeLit.Elts))
	}

	switch t.Kind() {
	case reflect.Map:
		return checkCompositeLitMap(alit, t, env)
	case reflect.Array, reflect.Slice:
		return checkCompositeLitArrayOrSlice(alit, t, env)
	case reflect.Struct:
		return checkCompositeLitStruct(alit, t, env)
	default:
		panic("eval: unimplemented composite lit " + t.Kind().String())
	}
}

func readStructColumns(t reflect.Type) (cols []*ColumnMap, version *ColumnMap) {
	n := t.NumField()
	for i := 0; i < n; i++ {
		f := t.Field(i)
		if f.Anonymous && f.Type.Kind() == reflect.Struct {
			// Recursively add nested fields in embedded structs.
			subcols, subversion := readStructColumns(f.Type)
			cols = append(cols, subcols...)
			if subversion != nil {
				version = subversion
			}
		} else {
			columnName := f.Tag.Get("db")
			if columnName == "" {
				columnName = f.Name
			}
			cm := &ColumnMap{
				ColumnName: columnName,
				Transient:  columnName == "-",
				fieldName:  f.Name,
				gotype:     f.Type,
			}
			cols = append(cols, cm)
			if cm.fieldName == "Version" {
				version = cm
			}
		}
	}
	return
}

func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) (string, []byte, error) {
	switch val.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return strconv.FormatInt(val.Int(), 10), nil, nil
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return strconv.FormatUint(val.Uint(), 10), nil, nil
	case reflect.Float32, reflect.Float64:
		return strconv.FormatFloat(val.Float(), 'g', -1, val.Type().Bits()), nil, nil
	case reflect.String:
		return val.String(), nil, nil
	case reflect.Bool:
		return strconv.FormatBool(val.Bool()), nil, nil
	case reflect.Array:
		if typ.Elem().Kind() != reflect.Uint8 {
			break
		}
		// [...]byte
		var bytes []byte
		if val.CanAddr() {
			bytes = val.Slice(0, val.Len()).Bytes()
		} else {
			bytes = make([]byte, val.Len())
			reflect.Copy(reflect.ValueOf(bytes), val)
		}
		return "", bytes, nil
	case reflect.Slice:
		if typ.Elem().Kind() != reflect.Uint8 {
			break
		}
		// []byte
		return "", val.Bytes(), nil
	}
	return "", nil, &UnsupportedTypeError{typ}
}

func getFields(typ reflect.Type) *fields {
	numField := typ.NumField()
	fs := newFields(numField)

	for i := 0; i < numField; i++ {
		f := typ.Field(i)
		if f.PkgPath != "" && !f.Anonymous {
			continue
		}

		name, opts := parseTag(f.Tag.Get("msgpack"))
		if name == "-" {
			continue
		}

		if opts.Contains("inline") {
			inlineFields(fs, f)
			continue
		}

		if name == "" {
			name = f.Name
		}
		field := field{
			name:      name,
			index:     f.Index,
			omitEmpty: opts.Contains("omitempty"),
			encoder:   getEncoder(f.Type),
			decoder:   getDecoder(f.Type),
		}
		fs.Add(&field)
	}
	return fs
}

func fixupArgs(t reflect.Type, v ...interface{}) []reflect.Value {
	res := make([]reflect.Value, len(v))
	for ix, vv := range v {
		res[ix] = fixupArg(t.In(ix), vv)
	}
	return res
}

// Returns the type of the elements of N slice(s). If the type is different,
// another slice or undefined, returns an error.
func sliceElementType(slices ...[]interface{}) (reflect.Type, error) {
	var prevType reflect.Type
	for _, s := range slices {
		// Go through elements of all given slices and make sure they are all the same type.
		for _, v := range s {
			currentType := reflect.TypeOf(v)
			if prevType == nil {
				prevType = currentType
				// We don't support lists of lists yet.
				if prevType.Kind() == reflect.Slice {
					return nil, errNoListOfLists
				}
			} else {
				if prevType != currentType {
					return nil, fmt.Errorf("list element types are not identical: %v", fmt.Sprint(slices))
				}
				prevType = currentType
			}
		}
	}

	if prevType == nil {
		return nil, fmt.Errorf("no elements in any of the given slices")
	}

	return prevType, nil
}

func getParams(elem reflect.Type) []Parameter {
	parameters := []Parameter{}

	l := elem.NumField()

	for i := 0; i < l; i++ {
		f := elem.Field(i)

		jsonName := f.Tag.Get("json")

		if f.Anonymous {
			parameters = append(parameters, getParams(f.Type)...)
		} else if jsonName != "" {
			p := Parameter{}

			p.Name = jsonName
			p.Type = f.Type.String()
			p.Description = f.Tag.Get("description")
			enum := f.Tag.Get("enum")
			if enum != "" {
				p.EnumValues = strings.Split(enum, ",")
				p.Type = "enum"
			} else {
				p.EnumValues = []string{}
			}

			parameters = append(parameters, p)
		}
	}

	return parameters
}

func fixArgs(args []reflect.Value, lastParamType reflect.Type, context Context) []reflect.Value {
	if lastParamType.String() == "interface {}" ||
		lastParamType.String() == "hprose.Context" {
		args = append(args, reflect.ValueOf(context))
	}
	return args
}

// Convert a string into the specified type. Return the type's zero value
// if we receive an empty string
func convert(t reflect.Type, value string) (reflect.Value, error) {
	if value == "" {
		return reflect.ValueOf(nil), nil
	}

	var d time.Duration

	switch t {
	case reflect.TypeOf(d):
		result, err := time.ParseDuration(value)
		return reflect.ValueOf(result), err
	default:
	}

	switch t.Kind() {
	case reflect.String:
		return reflect.ValueOf(value), nil
	case reflect.Int:
		return parseInt(value)
	case reflect.Bool:
		return parseBool(value)
	}

	return reflect.ValueOf(nil), conversionError(value, `unsupported `+t.Kind().String())
}