simplifying nix shell

shell.nix

@@ -1,20 +1,20 @@
-{ nixpkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs-channels/archive/1fe82110feb.tar.gz") {} }:
 let
- inherit (nixpkgs) pkgs;
+ pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs-channels/archive/1fe82110feb.tar.gz") {};
  inherit (pkgs) haskellPackages;
+ drv = haskellPackages.callCabal2nix "shopping-cart" ./. {};
 
- project = import ./release.nix;
 in
-pkgs.stdenv.mkDerivation {
- name = "shell";
- buildInputs = project.env.nativeBuildInputs ++ [
- haskellPackages.cabal-install
- haskellPackages.hlint
- ];
- shellHook = ''
- export NIX_GHC="$(which ghc)"
- export NIX_GHCPKG="$(which ghc-pkg)"
- export NIX_GHC_DOCDIR="$NIX_GHC/../../share/doc/ghc/html"
- export NIX_GHC_LIBDIR="$(ghc --print-libdir)"
- '';
-}
+ {
+ my_project = drv;
+ shell = haskellPackages.shellFor {
+ withHoogle = true;
+ packages = p: [drv];
+ buildInputs = with haskellPackages; [ hlint cabal-install ];
+ shellHook = ''
+ export NIX_GHC="$(which ghc)"
+ export NIX_GHCPKG="$(which ghc-pkg)"
+ export NIX_GHC_DOCDIR="$NIX_GHC/../../share/doc/ghc/html"
+ export NIX_GHC_LIBDIR="$(ghc --print-libdir)"
+ '';
+ };
+ }.shell