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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- A D A . S T R I N G S . U N B O U N D E D . 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.Unbounded.Hash
(Key : Unbounded_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 1 .. Key.Last loop
Tmp := Rotate_Left (Tmp, 3) + Character'Pos (Key.Reference (J));
end loop;
return Tmp;
end Ada.Strings.Unbounded.Hash;
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