gcc/ada/g-busorg.ads

   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
  46 generic
  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
  62 package 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
  72 end GNAT.Bubble_Sort_G;