Exercise: Fibonacci closure

fibonacci_closure.go

package main

import "fmt"

func fibonacci() func() int {
    x, y := 0, 1
    return func () int {
        x, y = x + y, x
        return x
    } 
}

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