// Chapter 29 example: an interface lets one slice hold different types.
// Run with: go run exercises/29/03-interface.go

package main

import "fmt"

type describer interface {
	describe()
}

type animal struct {
	name string
}

func (a animal) describe() {
	fmt.Printf("%s is an animal.\n", a.name)
}

type dog struct {
	animal
}

func (d dog) describe() {
	fmt.Printf("%s is a dog.\n", d.name)
}

type cat struct {
	animal
}

func (c cat) describe() {
	fmt.Printf("%s is a cat.\n", c.name)
}

type parrot struct {
	animal
}

func introduce(d describer) {
	fmt.Print("Meet this one: ")
	d.describe()
}

func main() {
	rex := dog{animal: animal{name: "Rex"}}
	tom := cat{animal: animal{name: "Tom"}}
	polly := parrot{animal: animal{name: "Polly"}}

	introduce(rex)

	creatures := []describer{rex, tom, polly, animal{name: "Bug"}}
	for _, c := range creatures {
		c.describe()
	}
}