在Go中实现Struct抽象的正确方法是什么？

Question

I'm having some issues understanding Go's struct inheritance. I'm trying to do somewhat of an abstraction for an object type. See the example code below:

package main

type Animal struct{}
type Dog struct {
    Animal
    Color string
}

type Person struct {
    Name string
    Age  int
    Pet  *Animal
}

func main() {
    dog := &Dog{Color: "brown"}
    tom := &Person{Name: "Tom", Age: 13, Pet: dog}
}

This is causing a compilation error:

cannot use dog (type *Dog) as type *Animal in field value

What is the correct way to go about doing an abstraction like this? Is it possible in Go?

End goal for the example would be to have different types of Pets - Dog, Cat, Hamser, etc. Then be able to store that into a struct expecting type Animal.

To visualize, something like:

type Person struct {
    Name string
    Age  int
    Pet  *Dog OR *Cat OR *Hamster
}

Go Playground Link

Answer 1

Two working samples:

1- Try this:

package main

import (
    "fmt"
)

type Animal interface {
    color() string
}
type Dog struct {
    Color string
}

func (d Dog) color() string {
    return d.Color
}

type Person struct {
    Name string
    Age  int
    Pet  Animal
}

func main() {
    dog := &Dog{Color: "brown"}
    tom := &Person{Name: "Tom", Age: 13, Pet: dog}
    fmt.Println(tom.Pet.color())
}

---

2- Try this:

package main

import (
    "fmt"
)

type Animal struct{}
type Dog struct {
    Animal
    Color string
}

type Person struct {
    Name string
    Age  int
    Pet  interface{}
}

func main() {
    dog := &Dog{Color: "brown"}
    tom := &Person{Name: "Tom", Age: 13, Pet: dog}
    fmt.Println(tom.Name)
}