nixpkgs/pkgs/development/ocaml-modules/zarith/default.nix

{ lib, stdenv, fetchFromGitHub
, ocaml, findlib, pkg-config
, gmp
, version ? if lib.versionAtLeast ocaml.version "4.08" then "1.14" else "1.13"
}:

if lib.versionOlder ocaml.version "4.04"
then throw "zarith is not available for OCaml ${ocaml.version}"
else

stdenv.mkDerivation (finalAttrs: {
  pname = "ocaml${ocaml.version}-zarith";
  inherit version;
  src = fetchFromGitHub {
    owner = "ocaml";
    repo = "Zarith";
    rev = "release-${version}";
    hash = {
      "1.13" = "sha256-CNVKoJeO3fsmWaV/dwnUA8lgI4ZlxR/LKCXpCXUrpSg=";
      "1.14" = "sha256-xUrBDr+M8uW2KOy7DZieO/vDgsSOnyBnpOzQDlXJ0oE=";
    }."${finalAttrs.version}";
  };

  nativeBuildInputs = [ pkg-config ocaml findlib ];
  propagatedBuildInputs = [ gmp ];
  strictDeps = true;

  dontAddPrefix = true;
  dontAddStaticConfigureFlags = true;
  configurePlatforms = [];
  configureFlags = [ "-installdir ${placeholder "out"}/lib/ocaml/${ocaml.version}/site-lib" ];

  preInstall = "mkdir -p $out/lib/ocaml/${ocaml.version}/site-lib/stublibs";

  meta = with lib; {
    description = "Fast, arbitrary precision OCaml integers";
    homepage    = "https://github.com/ocaml/Zarith";
    changelog   = "https://github.com/ocaml/Zarith/raw/${finalAttrs.src.rev}/Changes";
    license     = licenses.lgpl2;
    inherit (ocaml.meta) platforms;
    maintainers = with maintainers; [ thoughtpolice vbgl ];
  };
})