go tour exercise (moretypes/26)

exercise-fibonacci-closure.go

package main

import "fmt"

func fibonacci() func() int {
	x1 := 0
	x2 := 1
	res := 0
	return func() int {
		res, x1, x2 = x1, x2, x1 + x2
		return res
	}
}

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