package checked_oint

checked_oint

checked_oint is an OCaml library for checked integer arithmetic. We support the full set of signed and unsigned integers of bitnesses 8, 16, 32, 64, and 128.

Installation

$ opam install checked_oint

Usage

open Checked_oint

let () =
  let x = U8.of_int_exn 50 in
  let y = U8.of_int_exn 70 in
  assert (U8.equal (U8.add_exn x y) (U8.of_int_exn 120));
  assert (Option.is_none (U8.mul x y))

You can find the API documentation here.

Implementation

• u8, u16, i8, and i16 are represented as int internally.
• u32 and i32 (resp. u64 and i64) are represented as int32 (resp. int64) internally.
• u128 and i128 are represented as { high : int64; low : int64 } internally.
• Operations on integers of 8, 16, 32, and 64 bits are implemented primarily in OCaml, save a small amount of C stub functions.

• Operations on 128-bit integers are implemented solely in C.

  • We heavily rely on the __int128 extension by GCC and Clang.

Release procedure

1. Update the version field in dune-project.
2. Type dune build to generate checked_oint.opam.
3. Update CHANGELOG.md.

4. Release the project in GitHub Releases.

   1. Generate a source code archive and include it in the release:
      git archive HEAD -o checked_oint-<major>.<minor>.<patch>.tar.gz

5. Type git pull && opam publish.

   1. Specify the correct archive URL and checksums (by running md5sum and sha512sum on the archive).