Bagaimana Menghuraikan Medan YAML secara Dinamik ke dalam Set Struktur Terhad dalam Go?

<code class="go">type yamlNode struct {
    unmarshal func(interface{}) error
}

func (n *yamlNode) UnmarshalYAML(unmarshal func(interface{}) error) error {
    n.unmarshal = unmarshal
    return nil
}

type Spec struct {
    Kind string      `yaml:"kind"`
    Spec interface{} `yaml:"-"
}</code>

<code class="go">func (s *Spec) UnmarshalYAML(unmarshal func(interface{}) error) error {
    type S Spec
    type T struct {
        S `yaml:",inline"`
        Spec yamlNode `yaml:"spec"`
    }

    obj := &T{}
    if err := unmarshal(obj); err != nil {
        return err
    }
    *s = Spec(obj.S)

    switch s.Kind {
    case "foo":
        s.Spec = new(Foo)
    case "bar":
        s.Spec = new(Bar)
    default:
        panic("kind unknown")
    }
    return obj.Spec.unmarshal(s.Spec)
}</code>

<code class="go">type Spec struct {
    Kind string      `yaml:"kind"`
    Spec interface{} `yaml:"-"
}</code>

<code class="go">func (s *Spec) UnmarshalYAML(n *yaml.Node) error {
    type S Spec
    type T struct {
        *S `yaml:",inline"`
        Spec yaml.Node `yaml:"spec"`
    }

    obj := &T{S: (*S)(s)}
    if err := n.Decode(obj); err != nil {
        return err
    }

    switch s.Kind {
    case "foo":
        s.Spec = new(Foo)
    case "bar":
        s.Spec = new(Bar)
    default:
        panic("kind unknown")
    }
    return obj.Spec.Decode(s.Spec)
}</code>