| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- A D A . C O N T A I N E R S . P R I M E _ N U M B E R S -- |
| -- -- |
| -- 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. -- |
| ------------------------------------------------------------------------------ |
| |
| package body Ada.Containers.Prime_Numbers is |
| |
| -------------- |
| -- To_Prime -- |
| -------------- |
| |
| function To_Prime (Length : Count_Type) return Hash_Type is |
| I, J, K : Integer'Base; |
| Index : Integer'Base; |
| |
| begin |
| I := Primes'Last - Primes'First; |
| Index := Primes'First; |
| while I > 0 loop |
| J := I / 2; |
| K := Index + J; |
| |
| if Primes (K) < Hash_Type (Length) then |
| Index := K + 1; |
| I := I - J - 1; |
| else |
| I := J; |
| end if; |
| end loop; |
| |
| return Primes (Index); |
| end To_Prime; |
| |
| end Ada.Containers.Prime_Numbers; |
