Messing around with Go fibonacci example. Making the function successive forwards and backwards. #golang

fib-example.go

package main

import "fmt"

// fib returns a function that returns
// successive Fibonacci numbers.
func fib() func(int) int {
	a, b := 0, 1
	i := 0
	return func(x int) int {
		if x == i {
			return a
		} else if x < i {
			for ; x < i; i-- {
				a, b = b-a, a
			}
		} else {
			for ; x > i; i++ {
				a, b = b, a+b
			}
		}
		return a
	}
}

func main() {
	f := fib()
	// Function calls are evaluated left-to-right.
	fmt.Println(f(1), f(2), f(3), f(4), f(5), f(4), f(3), f(2), f(1), f(6), f(7), f(4))
}