learning go

fibonacci-closure.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	prev := [2]int{0, 1}
	return func() int {
		n := prev[0]
		next := prev[0] + prev[1]
		prev = [2]int{prev[1], next}
		return n
	}
}

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

Why the memory/syntactic overhead of a list for prev? Why not two variables?