interfaces and references example

interfaces and references

package main

import "log"

type A interface {
	SetId(string)
}

type B struct{
	Afield A
}
func (b B)SetA(a A) {
	b.Afield=a
}

// A interface implementation
type Atype struct{
	id string
}
func (a Atype) SetId(s string){
	a.id=s
}

// constructor for Atype
func NewA() *Atype{
	ret:=new(Atype)
	ret.SetId("qwe")
	return ret
}

func main(){

	b:=new(B)

	a:=NewA()
	log.Printf("NewA: %+v",a)
	a.SetId("asd")
	log.Printf("Update A: %+v",a)

	b.SetA(a)
	log.Printf("B: %+v",b)	
}