1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--                   G N A T . B U B B L E _ S O R T _ G                    --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--                     Copyright (C) 1995-2010, AdaCore                     --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  Bubblesort generic package using formal procedures
33
34--  This package provides a generic bubble sort routine that can be used with
35--  different types of data.
36
37--  See also GNAT.Bubble_Sort, a version that works with subprogram access
38--  parameters, allowing code sharing. The generic version is slightly more
39--  efficient but does not allow code sharing and has an interface that is
40--  more awkward to use.
41
42--  There is also GNAT.Bubble_Sort_A, which is now considered obsolete, but
43--  was an older version working with subprogram parameters. This version
44--  is retained for backwards compatibility with old versions of GNAT.
45
46generic
47   --  The data to be sorted is assumed to be indexed by integer values from
48   --  1 to N, where N is the number of items to be sorted. In addition, the
49   --  index value zero is used for a temporary location used during the sort.
50
51   with procedure Move (From : Natural; To : Natural);
52   --  A procedure that moves the data item with index value From to the data
53   --  item with index value To (the old value in To being lost). An index
54   --  value of zero is used for moves from and to a single temporary location
55   --  used by the sort.
56
57   with function Lt (Op1, Op2 : Natural) return Boolean;
58   --  A function that compares two items and returns True if the item with
59   --  index Op1 is less than the item with Index Op2, and False if the Op2
60   --  item is greater than or equal to the Op1 item.
61
62package GNAT.Bubble_Sort_G is
63   pragma Pure;
64
65   procedure Sort (N : Natural);
66   --  This procedures sorts items in the range from 1 to N into ascending
67   --  order making calls to Lt to do required comparisons, and Move to move
68   --  items around. Note that, as described above, both Move and Lt use a
69   --  single temporary location with index value zero. This sort is stable,
70   --  that is the order of equal elements in the input is preserved.
71
72end GNAT.Bubble_Sort_G;
73