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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- A D A . C O N T A I N E R S . --
-- G E N E R I C _ C O N S T R A I N E D _ A R R A Y _ S O R T --
-- --
-- B o d y --
-- --
-- Copyright (C) 2004-2006, 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- --
-- 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. --
-- --
-- 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. --
-- --
-- This unit has originally being developed by Matthew J Heaney. --
------------------------------------------------------------------------------
-- This algorithm was adapted from GNAT.Heap_Sort_G (see g-hesorg.ad[sb])
with System;
procedure Ada.Containers.Generic_Constrained_Array_Sort
(Container : in out Array_Type)
is
type T is range System.Min_Int .. System.Max_Int;
function To_Index (J : T) return Index_Type;
pragma Inline (To_Index);
procedure Sift (S : T);
A : Array_Type renames Container;
--------------
-- To_Index --
--------------
function To_Index (J : T) return Index_Type is
K : constant T'Base := Index_Type'Pos (A'First) + J - T'(1);
begin
return Index_Type'Val (K);
end To_Index;
Max : T := A'Length;
Temp : Element_Type;
----------
-- Sift --
----------
procedure Sift (S : T) is
C : T := S;
Son : T;
begin
loop
Son := 2 * C;
exit when Son > Max;
declare
Son_Index : Index_Type := To_Index (Son);
begin
if Son < Max then
if A (Son_Index) < A (Index_Type'Succ (Son_Index)) then
Son := Son + 1;
Son_Index := Index_Type'Succ (Son_Index);
end if;
end if;
A (To_Index (C)) := A (Son_Index); -- Move (Son, C);
end;
C := Son;
end loop;
while C /= S loop
declare
Father : constant T := C / 2;
Father_Elem : Element_Type renames A (To_Index (Father));
begin
if Father_Elem < Temp then -- Lt (Father, 0)
A (To_Index (C)) := Father_Elem; -- Move (Father, C)
C := Father;
else
exit;
end if;
end;
end loop;
A (To_Index (C)) := Temp; -- Move (0, C);
end Sift;
-- Start of processing for Generic_Constrained_Array_Sort
begin
for J in reverse 1 .. Max / 2 loop
Temp := Container (To_Index (J)); -- Move (J, 0);
Sift (J);
end loop;
while Max > 1 loop
declare
Max_Elem : Element_Type renames A (To_Index (Max));
begin
Temp := Max_Elem; -- Move (Max, 0);
Max_Elem := A (A'First); -- Move (1, Max);
end;
Max := Max - 1;
Sift (1);
end loop;
end Ada.Containers.Generic_Constrained_Array_Sort;
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