| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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. -- |
| -- -- |
| -- 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. -- |
| -- -- |
| -- 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; |
