Re: What about big integers in Ada 2005?

[<adaworks@sbcglobal.net>]

"Martin Krischik" <krischik@users.sourceforge.net> wrote in message
news:1581461.uQ1jN63t33@linux1.krischik.com...
> jtg wrote:
>
> > When I started to learn Ada, one of the most interesting features for me
> > was the possibility to declare integer type of the specified range.
> > I imagined that the integer type may be of any size.
> > However, several years later I needed big integers and I was
> > disappointed - Ada95 does not support integers of ANY size,
> > it can support only those integers that are supported
> > by the processor, or smaller.
>
> You are mistaken here. i.E GNAT supports 64 integers for 32 bit CPUs. It's
> all up to the particular compiler. In theory you could create an Ada
> compiler which supports intergers up to the memory limit - it would still
> conform to the standart.
>
I interepreted this question to refer to integers of arbitrary size such as
those in Smalltalk.   In Ada compilers, as with other language with
implementations tied to the underlying platrform, numbers are related
to the word size of the targeted machine.    For example, I cannot define,
on any Ada compiler that I know of, an Integer such as,

       type Number is range 0..2**78;

since this would overflow contemporary (not future) architectures.  In
Smalltalk,
and many other languages, we can do arithmetic on numbers such as,

        34567345754784567745464478456345356675
and
        99874257918340987932560129346591237523

Of course, this is not an inherent limitation of Ada.  One can create a package
to do this kind of arithmetic, but it is not all that easy to do so.

Richard Riehle