import "fmt" type Sorter interface {   Len() int   Less(i, j int) bool   Swap(i, j int) } type Xi []int type Xs []string func (p Xi) Len() int { return len(p) } func (p Xi) Less(i int, j int) bool { return p[j] < p[i] } func (p Xi) Swap(i int, j int) { p[i], p[j] = p[j], p[i] } func (p Xs) Len() int { return len(p) } func (p Xs) Less(i int, j int) bool { return p[j] < p[i] } func (p Xs) Swap(i int, j int) { p[i], p[j] = p[j], p[i] } func Sort(x Sorter) {   for i := 0; i < x.Len() - 1; i++ {     for j := i + 1; j < x.Len(); j++ {       if x.Less(i, j) {         x.Swap(i, j)       }     }   } } func main() {   ints := Xi{44, 67, 3, 17, 89, 10, 73, 9, 14, 8}   strings := Xs{"nut", "ape", "elephant", "zoo", "go"}   Sort(ints)   fmt.Printf("%v\n", ints)   Sort(strings)   fmt.Printf("%v\n", strings) }