[Caml-list] Arbitrary precision unsigned integers

[Caml-list] Arbitrary precision unsigned integers

[Thomas Braibant]

Hi list,

I wonder if there is a publicly available library that implements
arbitrary precision (un)signed integers. I could not find anything
relevant with Google, nor on Opam.

By arbitrary, I mean that I want to implement e.g., 43 bits unsigned
arithmetic, and have the right overflow behaviors. I know of zarith
which seems to implement arbitrary precision in the sense that the
precision of the numbers grows as needed.

Best,
Thomas

Re: [Caml-list] Arbitrary precision unsigned integers

[Xavier Leroy]

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Hi Thomas,

In a pinch, you can use Zarith and follow each arithmetic operation by a
Z.extract or Z.signed_extract operation to normalize the result to the
desired range (N-bit unsigned or N-bit signed).  It's not as fast as it
could be, but should be reasonably efficient.

- Xavier Leroy



2014-05-20 17:18 GMT+02:00 Thomas Braibant <thomas.braibant@gmail.com>:

> Hi list,
>
> I wonder if there is a publicly available library that implements
> arbitrary precision (un)signed integers. I could not find anything
> relevant with Google, nor on Opam.
>
> By arbitrary, I mean that I want to implement e.g., 43 bits unsigned
> arithmetic, and have the right overflow behaviors. I know of zarith
> which seems to implement arbitrary precision in the sense that the
> precision of the numbers grows as needed.
>
> Best,
> Thomas
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs
>
>

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Re: [Caml-list] Arbitrary precision unsigned integers

[Thomas Braibant]

Thanks for the quick reply. I guess I will do exactly that and release
the wrapper library.


On Tue, May 20, 2014 at 4:29 PM, Xavier Leroy <Xavier.Leroy@inria.fr> wrote:
> Hi Thomas,
>
> In a pinch, you can use Zarith and follow each arithmetic operation by a
> Z.extract or Z.signed_extract operation to normalize the result to the
> desired range (N-bit unsigned or N-bit signed).  It's not as fast as it
> could be, but should be reasonably efficient.
>
> - Xavier Leroy
>
>
>
> 2014-05-20 17:18 GMT+02:00 Thomas Braibant <thomas.braibant@gmail.com>:
>>
>> Hi list,
>>
>>
>> I wonder if there is a publicly available library that implements
>> arbitrary precision (un)signed integers. I could not find anything
>> relevant with Google, nor on Opam.
>>
>> By arbitrary, I mean that I want to implement e.g., 43 bits unsigned
>> arithmetic, and have the right overflow behaviors. I know of zarith
>> which seems to implement arbitrary precision in the sense that the
>> precision of the numbers grows as needed.
>>
>> Best,
>> Thomas
>>
>> --
>> Caml-list mailing list.  Subscription management and archives:
>> https://sympa.inria.fr/sympa/arc/caml-list
>> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
>> Bug reports: http://caml.inria.fr/bin/caml-bugs
>>
>