Closure

/*Go functions may be closures. A closure is a function value that references variables from outside its body.
The function may access and assign to the referenced variables; in this sense the function is "bound" to the variables.

Implement a fibonacci function that returns a function (a closure) that returns successive fibonacci numbers.*/

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	fib := 0
	prev := 0
	auxFib := 0
	return func() int{
		if fib == 0{
			fib = 1
		}else{
			auxFib = fib
			fib += prev
			prev = auxFib
		}
		return fib
	}
}

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


/*output
1
1
2
3
5
8
13
21
34
55
*/