Range over element of interface implementation - go

Question

Let's supposed I've got the following interface and two structs that implement it:
type Tmp interface {
MyTmp() string
}
type MyStructA struct {
ArrayOfItems []int
}
func (a MyStructA) MyTmp() string {
return "Hello World"
}
type MyStructB struct {
ArrayOfItems []int
}
func (a MyStructB) MyTmp() string {
return "Hello World B"
}
As you notice both MyStructA and MyStructB implement Tmp and both have a property named ArrayOfItems. Using the interface signature, how could I iterate over that property which both have? Something similar to:
func (c ADifferentStruct) iterate(myTmp Tmp) {
for _, number := range myTmp.ArrayOfItems {
fmt.Println(number)
}
}
NOTE: I don't want to add another method to the interface (ie getter/setters) to process or to define ArrayOfItems
is this possible?

Answer 1

You need a method to return those items...
see this:
https://play.golang.org/p/rnH0riWKqRY
package main
import "fmt"
type Tmp interface {
MyTmp() string
Items() []int
}
type MyStructA struct {
ArrayOfItems []int
}
func (a MyStructA) MyTmp() string {
return "Hello World"
}
func (a MyStructA) Items() []int {
return a.ArrayOfItems
}
type MyStructB struct {
ArrayOfItems []int
}
func (a MyStructB) MyTmp() string {
return "Hello World B"
}
func (a MyStructB) Items() []int {
return a.ArrayOfItems
}
func iterate(tmp Tmp) {
for _, val := range tmp.Items() {
fmt.Println(val)
}
}
func main() {
a := MyStructA{[]int{1, 2, 3}}
b := MyStructA{[]int{-1, -2, -3}}
iterate(a)
iterate(b)
}