my first generator in Go - fibonacci sequence

fib_gen.go

package main

import "fmt"

func fibgen() func() {
    a, b := 0, 1
    return func() {
	sum := a + b
	fmt.Println(sum)
	a, b = b, sum
    }
}

func main() {
    gen := fibgen()
    for i := 0; i < 10; i++ {
	gen()
    }
}