Re: Constraint error overflow

[Simon Wright <simon@pushface.org>]

Richard Iswara <haujekchifan@gmail.com> writes:

> So the compiler is restricted to 32 bit integer value. I had hoped for
> 64 bit to get 18 digits.

GNAT comes with Long_Integer (64 bits).

Or yu could go with the Ada202x Big_Integers package
(http://www.ada-auth.org/standards/2xrm/html/RM-A-5-6.html),

pragma Ada_2020;

with Ada.Text_IO;
with Ada.Numerics.Big_Numbers.Big_Integers;

procedure Iswara is

   use Ada.Numerics.Big_Numbers.Big_Integers;

   Sum : Big_Natural := 0;
   Mul : Big_Natural := 1;

begin
   Ada.Text_IO.Put ( "Sum of the first 100 integers is :" );
   Ada.Text_IO.New_Line;
   Summing:
   for I in 1 .. 100 loop
      Sum := Sum + To_Big_Integer (I);
   end loop Summing;
   Ada.Text_IO.Put ( Sum'Image );
   Ada.Text_IO.New_Line;

   Ada.Text_IO.Put ( "Multiple of the first 100 integers is :" );
   Ada.Text_IO.New_Line;
   Multiplying:
   for J in 1 .. 100 loop
      Mul := Mul * To_Big_Integer (J);
   end loop Multiplying;
   Ada.Text_IO.Put ( Mul'Image );
   Ada.Text_IO.New_Line;
end Iswara;

which compiles fine with GNAT CE 2020 & FSF GCC 11.0.1; result

$ ./iswara 
Sum of the first 100 integers is :
 5050
Multiple of the first 100 integers is :
 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000