home *** CD-ROM | disk | FTP | other *** search
- ------------------------------------------------------------------------------
- -- --
- -- GNAT RUNTIME COMPONENTS --
- -- --
- -- G N A T . B U B B L E _ S O R T _ A --
- -- --
- -- S p e c --
- -- --
- -- $Revision: 1.4 $ --
- -- --
- -- Copyright (c) 1994,1995 NYU, All Rights Reserved --
- -- --
- -- The GNAT library is free software; you can redistribute it and/or modify --
- -- it under terms of the GNU Library General Public License as published by --
- -- the Free Software Foundation; either version 2, or (at your option) any --
- -- later version. The GNAT library is distributed in the hope that it will --
- -- be useful, but WITHOUT ANY WARRANTY; without even the implied warranty --
- -- of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU --
- -- Library General Public License for more details. You should have --
- -- received a copy of the GNU Library General Public License along with --
- -- the GNAT library; see the file COPYING.LIB. If not, write to the Free --
- -- Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. --
- -- --
- ------------------------------------------------------------------------------
-
- -- This package provides a bubblesort routine that works with access to
- -- subprogram parameters, so that it can be used with different types with
- -- shared sorting code. See also GNAT.Bubble_Sort_G, the generic version
- -- which is a little more efficient, but does not allow code sharing.
-
- package GNAT.Bubble_Sort_A is
- pragma Preelaborate (Bubble_Sort_A);
-
- -- The data to be sorted is assumed to be indexed by integer values from
- -- 1 to N, where N is the number of items to be sorted. In addition, the
- -- index value zero is used for a temporary location used during the sort.
-
- type Move_Procedure is access procedure (From : Natural; To : Natural);
- -- A pointer to a procedure that moves the data item with index From to
- -- the data item with index To. An index value of zero is used for moves
- -- from and to the single temporary location used by the sort.
-
- type Lt_Function is access function (Op1, Op2 : Natural) return Boolean;
- -- A pointer to a function that compares two items and returns True if
- -- the item with index Op1 is less than the item with index Op2, and False
- -- if the Op2 item is greater than or equal to the Op1 item.
-
- procedure Sort (N : Positive; Move : Move_Procedure; Lt : Lt_Function);
- -- This procedures sorts items indexed from 1 to N into ascending order
- -- making calls to Lt to do required comparisons, and Move to move items
- -- around. Note that, as described above, both Move and Lt use a single
- -- temporary location with index value zero. This sort is not stable,
- -- i.e. the order of equal elements in the input is not preserved.
-
- end GNAT.Bubble_Sort_A;
-