flake.nix

   1 {
   2 inputs.nixpkgs.url = "flake:nixpkgs"; # Reuse any local nixpkgs, at cost of reproductibility
   3 inputs.flake-utils.url = "github:numtide/flake-utils";
   4 outputs = inputs: inputs.flake-utils.lib.eachDefaultSystem (system: let
   5   pkgs = inputs.nixpkgs.legacyPackages.${system};
   6   ghc = null; # Use default ghc, but could have been ghc901
   7   haskellPackages =
   8     if ghc == null
   9     then pkgs.haskellPackages
  10     else pkgs.haskell.packages.${ghc};
  11   hs = haskellPackages.extend (with pkgs.haskell.lib; hfinal: hprev: {
  12     "AoC202004" = hfinal.callCabal2nix "AoC2020" ./Day04 {};
  13   });
  14   in rec {
  15     devShell = hs.shellFor {
  16       packages = p: [ p."AoC202004" ];
  17       withHoogle = false;
  18       nativeBuildInputs = [
  19         hs.cabal-install
  20         hs.haskell-language-server
  21         #hs.hpc
  22       ];
  23       buildInputs = [
  24         #hs.ghcid
  25         #hs.ormolu
  26         #hs.hlint
  27         #pkgs.nixpkgs-fmt
  28       ];
  29     };
  30     packages = {
  31       "Day04" = hs."AoC202004";
  32     };
  33     apps = pkgs.lib.genAttrs [
  34         "Day04"
  35       ] (day: {
  36         type = "app";
  37         program = "${packages.Day04}/bin/Day";
  38       }
  39     );
  40   }
  41 );
  42 }