How to display all the possible permutations of a string in Go?

permutations.go

func printAllPermutations(s string) {
	permute(s, 0, len(s)-1)
}

func permute(s string, left, right int) {
	if left == right {
		fmt.Printf("%s\n", s)
	}

	for i := left; i <= right; i++ {
		s = swap(s, left, i)
		permute(s, left+1, right)
		s = swap(s, left, i)
	}
}

func swap(s string, i1, i2 int) string {
	r := []rune(s)
	tmp := r[i1]
	r[i1] = r[i2]
	r[i2] = tmp
	return string(r)
}