How to stable reverse sort a slice in Go?

Question

I do have

4, 5', 6, 5''

and want to reverse stable sort as

6, 5', 5'', 4

but not

6, 5'', 5', 4

This (invalid) code would not work

keys := []int{4, 5', 6, 5''}
sort.Stable(sort.Reverse(sort.Ints(keys)))

it would produce:

6, 5'', 5', 4

---

Here the problem is shown as simplified as a slice of integers, but In reality I need to use it applied to a slice of structs

type myStruct struct {
    t time.Time
    d time.Duration
}

and reverse stable sort based in the t field.

---

Edit: After few comments I made explicit that the integer one is a non working example to simplify the problem.

Answer 1

Implement the sort.Interface interface on your custom struct.

type myStruct struct{
    t time.Time
    d time.Duration
}

type Slice []myStruct

func (s Slice) Len() int {  return len(s) }

func (s Slice) Less(i, j int) bool {
    return (s[i].t).After(s[j].t)
}

func (s Slice) Swap(i, j int) {
    s[i], s[j] = s[j], s[i]
}

In your case, following function will sort in reverse order based on t

func (s Slice) Less(i, j int) bool {
    return (s[i].t).After(s[j].t)
}

(s[i].t).After(s[j].t) reports whether s[i].t is after s[j].t.

If you want only sort, use following one

func (s Slice) Less(i, j int) bool {
    return (s[i].t).Before(s[j].t)
}

Hope this will help.