reflect-path.go

func Path(v interface{}, ks ...interface{}) (reflect.Value, error) {
	val := reflect.ValueOf(v)
	for i, k := range ks {
		switch key := k.(type) {
		case string: // struct field
			if val.Kind() != reflect.Struct {
				return reflect.ValueOf(nil), fmt.Errorf("Error at %v[%d]: must be struct", ks, i)
			}
			val = val.FieldByName(key)
		case reflect.Kind: // type
			if val.Kind() != key {
				return reflect.ValueOf(nil), fmt.Errorf("Error at %v[%d]: must be %s", ks, i, key)
			}
			switch key {
			case reflect.Array, reflect.Slice, reflect.Chan, reflect.Ptr:
				val = val.Elem()
			default:
				return reflect.ValueOf(nil), fmt.Errorf("Error at %v[%d]: must be %s", ks, i, key)
			}
		default:
			return reflect.ValueOf(nil), fmt.Errorf("Error at %v[%d]: must be %s", ks, i, key)
		}
		if i == len(ks)-1 {
			break
		}
	}
	return val, nil
}