Sort a slice or whatever with ability to provide sorting order (ascending/descending etc)

sort.go

package main

import (
	"fmt"
	"sort"
)

/*
  Use sort.Sort(data Interface).
  Data is an object that is not necessarily a slice.
  Data need to implement following functions.
  http://golang-examples.tumblr.com/post/66101563407/sort-a-slice
*/

type Interface interface {
	Len() int
	Less(i, j int) bool
	Swap(i, j int)
}

// If you want to sort []int, define a type intArray
type intArray []int

func (s intArray) Len() int           { return len(s) }
func (s intArray) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
func (s intArray) Less(i, j int) bool { return s[i] > s[j] }

func main() {
	// and cast []int to intArray
	a := []int{1, 43, 5, 10, 4}
	sort.Sort(intArray(a))
	fmt.Println(a)
}