A Tour of Go - Fibonacci Closure

fibonacci.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	now := 0
	next := 1
	return func() int {
		result := now
		temp := next
		next = next + now
		now = temp
		return result
	}
}

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

Back in my school days this solution would have me totally perplexed on how this actually worked. C++ back then had no support for Lambdas or Closures. Only when I learnt JavaScript did I learn the magic of Closures and now can understand the beauty of this solution.