A Tour of Go 43: Exercise: Fibonacci closure

gistfile1.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	// we use seed values of F_−2 and F_−1
	// that way the first fibonacci number returned will be F_0
	a, b := -1, 1
	return func() int {
		next := a + b
		a, b = b, next
		return next
	}
}

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