revisit

.gitignore

@@ -1,3 +1,5 @@
 dist/**
 dist-newstyle/
 .*.swp
+.direnv/
+.envrc

shell.nix

@@ -1,33 +1,7 @@
-{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:
+{ pkgs ? import <nixpkgs> {}}:
 
 let
-
+  raycharles = pkgs.haskellPackages.callCabal2nix "raycharles" (gitignore ./.) {};
-  inherit (nixpkgs) pkgs;
+  gitignore = dir: pkgs.nix-gitignore.gitignoreSource [] dir;
-
-  f = { mkDerivation, base, deepseq, linear, matrix, monad-loops
-      , parallel, stdenv, suspend, vector, vty
-      }:
-      mkDerivation {
-        pname = "raycharles";
-        version = "0.0.0.0";
-        src = ./.;
-        isLibrary = false;
-        isExecutable = true;
-        executableHaskellDepends = [
-          base deepseq linear matrix monad-loops parallel suspend vector vty
-        ];
-        description = "A simple raytracer on the Console";
-        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
-
+  raycharles.env
-  if pkgs.lib.inNixShell then drv.env else drv