package main

// github.com/psilva261/timsort

type iter struct {
   a []int
   index int
}

func (it *iter) Next() int {
   it.index ++
   return it.a[it.index]
}

func newIter(a []int) *iter {
   return &iter{a:a, index: -1}
}

func (it *iter) Has() bool {
   return it.index < len(it.a) - 1
}

func main() {
	it := newIter([]int{1, 2, 3})
	for it.Has() {
	   println(it.Next())
	}
}