blob: c7435583b5f2d92788b5629172193da25f6ec6c3 [file] [log] [blame]
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !go1.2
// +build !go1.2
package language
import "sort"
func sortStable(s sort.Interface) {
ss := stableSort{
s: s,
pos: make([]int, s.Len()),
}
for i := range ss.pos {
ss.pos[i] = i
}
sort.Sort(&ss)
}
type stableSort struct {
s sort.Interface
pos []int
}
func (s *stableSort) Len() int {
return len(s.pos)
}
func (s *stableSort) Less(i, j int) bool {
return s.s.Less(i, j) || !s.s.Less(j, i) && s.pos[i] < s.pos[j]
}
func (s *stableSort) Swap(i, j int) {
s.s.Swap(i, j)
s.pos[i], s.pos[j] = s.pos[j], s.pos[i]
}