-- --
-- GNAT LIBRARY COMPONENTS --
-- --
--- A D A . C O N T A I N E R S . --
--- G E N E R I C _ A N O N Y M O U S _ A R R A Y _ S O R T --
+-- ADA.CONTAINERS.GENERIC_ANONYMOUS_ARRAY_SORT --
-- --
-- B o d y --
-- --
--- Copyright (C) 2004-2005, Free Software Foundation, Inc. --
--- --
--- This specification is derived from the Ada Reference Manual for use with --
--- GNAT. The copyright notice above, and the license provisions that follow --
--- apply solely to the contents of the part following the private keyword. --
+-- Copyright (C) 2004-2009, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
+-- --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
-- --
-- This unit was originally developed by Matthew J Heaney. --
------------------------------------------------------------------------------
+-- This algorithm was adapted from GNAT.Heap_Sort (see g-heasor.ad[sb])
+
+with System;
+
procedure Ada.Containers.Generic_Anonymous_Array_Sort
(First, Last : Index_Type'Base)
is
- Pivot, Lo, Mid, Hi : Index_Type;
+ type T is range System.Min_Int .. System.Max_Int;
-begin
- if Last <= First then
- return;
- end if;
-
- Lo := First;
- Hi := Last;
-
- if Last = Index_Type'Succ (First) then
- if not Less (Lo, Hi) then
- Swap (Lo, Hi);
- end if;
-
- return;
- end if;
-
- Mid := Index_Type'Val
- (Index_Type'Pos (Lo) +
- (Index_Type'Pos (Hi) - Index_Type'Pos (Lo)) / 2);
-
- -- We need to figure out which case we have:
- -- x < y < z
- -- x < z < y
- -- z < x < y
- -- y < x < z
- -- y < z < x
- -- z < y < x
-
- if Less (Lo, Mid) then
- if Less (Lo, Hi) then
- if Less (Mid, Hi) then
- Swap (Lo, Mid);
+ function To_Index (J : T) return Index_Type;
+ pragma Inline (To_Index);
- else
- Swap (Lo, Hi);
+ function Lt (J, K : T) return Boolean;
+ pragma Inline (Lt);
- end if;
+ procedure Xchg (J, K : T);
+ pragma Inline (Xchg);
+
+ procedure Sift (S : T);
+
+ --------------
+ -- To_Index --
+ --------------
- else
- null; -- lo is median
- end if;
+ function To_Index (J : T) return Index_Type is
+ K : constant T'Base := Index_Type'Pos (First) + J - T'(1);
+ begin
+ return Index_Type'Val (K);
+ end To_Index;
- elsif Less (Lo, Hi) then
- null; -- lo is median
+ --------
+ -- Lt --
+ --------
- elsif Less (Mid, Hi) then
- Swap (Lo, Hi);
+ function Lt (J, K : T) return Boolean is
+ begin
+ return Less (To_Index (J), To_Index (K));
+ end Lt;
- else
- Swap (Lo, Mid);
- end if;
+ ----------
+ -- Xchg --
+ ----------
- Pivot := Lo;
- Outer : loop
+ procedure Xchg (J, K : T) is
+ begin
+ Swap (To_Index (J), To_Index (K));
+ end Xchg;
+
+ Max : T := Index_Type'Pos (Last) - Index_Type'Pos (First) + T'(1);
+
+ ----------
+ -- Sift --
+ ----------
+
+ procedure Sift (S : T) is
+ C : T := S;
+ Son : T;
+ Father : T;
+
+ begin
loop
- exit Outer when not (Pivot < Hi);
+ Son := C + C;
- if Less (Hi, Pivot) then
- Swap (Hi, Pivot);
- Pivot := Hi;
- Lo := Index_Type'Succ (Lo);
+ if Son < Max then
+ if Lt (Son, Son + 1) then
+ Son := Son + 1;
+ end if;
+ elsif Son > Max then
exit;
- else
- Hi := Index_Type'Pred (Hi);
end if;
+
+ Xchg (Son, C);
+ C := Son;
end loop;
- loop
- exit Outer when not (Lo < Pivot);
+ while C /= S loop
+ Father := C / 2;
- if Less (Lo, Pivot) then
- Lo := Index_Type'Succ (Lo);
+ if Lt (Father, C) then
+ Xchg (Father, C);
+ C := Father;
else
- Swap (Lo, Pivot);
- Pivot := Lo;
- Hi := Index_Type'Pred (Hi);
exit;
end if;
end loop;
- end loop Outer;
+ end Sift;
- Generic_Anonymous_Array_Sort (First, Index_Type'Pred (Pivot));
- Generic_Anonymous_Array_Sort (Index_Type'Succ (Pivot), Last);
+-- Start of processing for Generic_Anonymous_Array_Sort
+begin
+ for J in reverse 1 .. Max / 2 loop
+ Sift (J);
+ end loop;
+
+ while Max > 1 loop
+ Xchg (1, Max);
+ Max := Max - 1;
+ Sift (1);
+ end loop;
end Ada.Containers.Generic_Anonymous_Array_Sort;
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