// 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. // +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] }