------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- ADA.CONTAINERS.GENERIC_ANONYMOUS_ARRAY_SORT -- -- -- -- B o d y -- -- -- -- 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 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. -- -- -- -- 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. -- -- -- -- 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 -- -- . -- -- -- -- 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 type T is range System.Min_Int .. System.Max_Int; function To_Index (J : T) return Index_Type; pragma Inline (To_Index); function Lt (J, K : T) return Boolean; pragma Inline (Lt); procedure Xchg (J, K : T); pragma Inline (Xchg); procedure Sift (S : T); -------------- -- To_Index -- -------------- 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; -------- -- Lt -- -------- function Lt (J, K : T) return Boolean is begin return Less (To_Index (J), To_Index (K)); end Lt; ---------- -- Xchg -- ---------- 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 Son := C + C; if Son < Max then if Lt (Son, Son + 1) then Son := Son + 1; end if; elsif Son > Max then exit; end if; Xchg (Son, C); C := Son; end loop; while C /= S loop Father := C / 2; if Lt (Father, C) then Xchg (Father, C); C := Father; else exit; end if; end loop; end Sift; -- 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;