A Tour of GO - Exercise: Fibonacci closure

Exercise: Fibonacci closure

Let's have some fun with functions.
Implement a fibonacci function that returns a function (a closure) that returns successive fibonacci numbers (0, 1, 1, 2, 3, 5, ...).

package main
import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
 a := 0
 b := 1
 return func() int {
  a, b = b, a+b
  return b - a
 }
}

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