package main

import “fmt”

// fibonacci is a function that returns // a function that returns an int.

func fibonacci() func(x int) int {

a, b := 0, 1 
return func(x int) int {
    if x == 0 { return a }       
	a, b = b, a+b
	return a
} }

func main() {

f := fibonacci()
for i := 0; i < 10; i++ {
    fmt.Println(f(i))
} }