1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
------------------------------------------------------------------------------
-- G N A T C O L L --
-- --
-- Copyright (C) 2009-2017, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY 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 program allows a user to determine whether a given (big) integer is a
-- prime number. It is based directly on the example provided by the
-- underlying C implementation of the GMP. Note that the input can be
-- expressed in bases other than base 10, if desired, by using C prefixes such
-- as "0x" and so forth.
--
-- This program also illustrates use of an underlying C library routine that
-- does not have a corresponding Ada binding already defined elsewhere.
with Ada.Text_IO; use Ada.Text_IO;
with GNATCOLL.GMP.Integers; use GNATCOLL.GMP.Integers;
with GNATCOLL.GMP.Integers.IO; use GNATCOLL.GMP.Integers.IO;
with Interfaces.C; use Interfaces.C;
with GNATCOLL.GMP.Lib; use GNATCOLL.GMP.Lib;
procedure IsPrime is
N : Big_Integer;
Result : int;
function mpz_probab_prime_p (this : access constant mpz_t; x : int)
return int;
pragma Import (C, mpz_probab_prime_p, "__gmpz_probab_prime_p");
begin
loop
Put ("Enter candidate number (return to quit): ");
declare
Input : constant String := Get_Line;
begin
if Input'Length = 0 then
return;
else
Set (N, Input, 0); -- base 0 allows the input to define the base
end if;
end;
Result := mpz_probab_prime_p (As_mpz_t (N), 5);
Put (N);
case Result is
when 0 =>
Put_Line (" is not a prime");
when 1 =>
Put_Line (" is a probable prime");
when 2 =>
Put_Line (" is a prime");
when others =>
Put_Line ("Unexpected result from mpz_probab_prime_p:" &
Result'Img);
return;
end case;
end loop;
end IsPrime;
|
