# Pastebin OcXvg9c7
```
{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc822", doBenchmark ? false }:

let

  inherit (nixpkgs) pkgs;

f = { mkDerivation, base, inline-r, R, random, stdenv
    , template-haskell}:
      mkDerivation {
        pname = "mrp";
        version = "1.0.0";
        src = ./.;
        isLibrary = false;
        isExecutable = true;
        executableHaskellDepends = [ base inline-r random template-haskell ];
        executableSystemDepends = [ R ];
        license = stdenv.lib.licenses.bsd3;
      };

  haskellPackages = if compiler == "default"
                       then pkgs.haskellPackages
                       else pkgs.haskell.packages.${compiler};

  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;

  drv = variant (haskellPackages.callPackage f {});

in

  if pkgs.lib.inNixShell then drv.env else drv
```