{ stdenv, fetchurl }:

assert stdenv.is64bit;
assert stdenv.isLinux || stdenv.isDarwin;

let
    osdir = if stdenv.isDarwin then "osx-64" else "linux-64";
    sha256 = if stdenv.isDarwin
             then "6757b2fcabed467c1ecda3f3b316a797c9ab320cd9d3b57c5de3263b4c27adad"
             else "54c44f891c05dd4df68be83f756d8317c903a9c67c19937bfb4d201119ba0f2c";
in stdenv.mkDerivation rec {
    name = "k";
    version = "2019.07.07-1207_ga0a263c";
    src = fetchurl {
        inherit sha256;
        url = "https://anaconda.org/shaktidb/shakti/${builtins.substring 0 10 version}/download/${osdir}/shakti-${version}.tar.bz2";
    };
    phases = [ "installPhase" ];
    installPhase = ''
        mkdir -p "$out"
        tar -xf "${src}" -C "$out" "bin/${name}"
        chmod +x "$out/bin/${name}"
    '';
    meta = with stdenv.lib; {
        description = "An interpreter for the k7 language.";
        license = {
            fullName = "Evaluation Agreement";
            url = https://shakti.com/license;
            free = false;
        };
        homepage = https://shakti.com/;
        platforms = with platforms; linux ++ darwin;
    };
}