Go tour "Fibonacci closure factory" method: http://tour.golang.org

Closure Go Tour Exercise

package main

import "fmt"

// Fibonacci closure factory
func fibonacci() func() int {
	previous := 0
	current  := 1
    
	return func() int {
		result  := previous
		previous = current
		current  = result + current
		
		return result
	}
}

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