| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- A D A . S T R I N G S . W I D E _ W I D E _ H A S H -- |
| -- -- |
| -- 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 -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- This unit was originally developed by Matthew J Heaney. -- |
| ------------------------------------------------------------------------------ |
| |
| -- Note: source of this algorithm: GNAT.HTable.Hash (g-htable.adb) |
| |
| function Ada.Strings.Wide_Wide_Hash |
| (Key : Wide_Wide_String) return Containers.Hash_Type |
| is |
| use Ada.Containers; |
| |
| function Rotate_Left |
| (Value : Hash_Type; |
| Amount : Natural) return Hash_Type; |
| pragma Import (Intrinsic, Rotate_Left); |
| |
| Tmp : Hash_Type; |
| |
| begin |
| Tmp := 0; |
| for J in Key'Range loop |
| Tmp := Rotate_Left (Tmp, 3) + Wide_Wide_Character'Pos (Key (J)); |
| end loop; |
| |
| return Tmp; |
| end Ada.Strings.Wide_Wide_Hash; |
