The Golang's range operator is limited to a few times, this example allows you to iterate over custom collections

Iter.go

package main

import "fmt"

type Container struct {
	values []int
}

func (this *Container) Iter() <- chan int {
	ch := make(chan int)
	
	go func() {
		for _, el := range this.values {
			ch <- el
		}
		close(ch)
	}()
	
	return ch
}
func main() {
	fmt.Println("Hello, playground")
	
	a := &Container{
		values: []int{1, 2, 3, 9, 8, 7, 6, 5, 4},
	}
	
	for el := range a.Iter() {
		fmt.Println(el)
	}	
}