------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- ADA.CONTAINERS.GENERIC_ANONYMOUS_ARRAY_SORT -- -- -- -- B o d y -- -- -- -- Copyright (C) 2004 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, 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 was originally developed by Matthew J Heaney. -- ------------------------------------------------------------------------------ procedure Ada.Containers.Generic_Anonymous_Array_Sort (First, Last : Index_Type'Base) is Pivot, Lo, Mid, Hi : Index_Type; 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); else Swap (Lo, Hi); end if; else null; -- lo is median end if; elsif Less (Lo, Hi) then null; -- lo is median elsif Less (Mid, Hi) then Swap (Lo, Hi); else Swap (Lo, Mid); end if; Pivot := Lo; Outer : loop loop exit Outer when not (Pivot < Hi); if Less (Hi, Pivot) then Swap (Hi, Pivot); Pivot := Hi; Lo := Index_Type'Succ (Lo); exit; else Hi := Index_Type'Pred (Hi); end if; end loop; loop exit Outer when not (Lo < Pivot); if Less (Lo, Pivot) then Lo := Index_Type'Succ (Lo); else Swap (Lo, Pivot); Pivot := Lo; Hi := Index_Type'Pred (Hi); exit; end if; end loop; end loop Outer; Generic_Anonymous_Array_Sort (First, Index_Type'Pred (Pivot)); Generic_Anonymous_Array_Sort (Index_Type'Succ (Pivot), Last); end Ada.Containers.Generic_Anonymous_Array_Sort;